/* =========================================================
   EcE Hub — Professional Educational Design System
   ========================================================= */

:root {
  /* Typography scale */
  --font-body: clamp(14px, 0.9vw, 16px);
  --font-small: clamp(12px, 0.75vw, 14px);
  --font-label: clamp(13px, 0.8vw, 15px);
  --font-clock: clamp(48px, 3.2vw, 72px);
  --font-title: clamp(22px, 2vw, 32px);
  --font-heading: clamp(18px, 1.5vw, 24px);
  --font-subheading: clamp(15px, 1.1vw, 18px);
  --font-footer: clamp(11px, 0.55vw, 12px);
  --font-superheading: clamp(100px, 6vw, 180px);
  --font-nav: clamp(13px, 0.85vw, 15px);
  --font-button: clamp(13px, 0.85vw, 15px);

  /* Core palette — professional educational */
  --navy: #0f1c33;
  --navy-deep: #0a1424;
  --text: #1a2336;
  --muted: #5c6b82;
  --line: #e2e8f0;
  --bg: #f4f6fb;
  --card: #ffffff;
  --surface: #ffffff;
  --surface-2: #f1f4f9;

  /* Accents */
  --purple: #4f46e5;
  --purple-soft: #eef2ff;
  --purple-mid: #6366f1;
  --green: #059669;
  --green-soft: #ecfdf5;
  --blue: #0284c7;
  --blue-soft: #e0f2fe;
  --orange: #d97706;
  --orange-soft: #fffbeb;
  --danger: #dc2626;
  --danger-soft: #fef2f2;

  /* Elevation & effects */
  --shadow-sm: 0 1px 2px rgba(15, 28, 51, 0.04);
  --shadow: 0 4px 16px rgba(15, 28, 51, 0.06);
  --shadow-md: 0 8px 28px rgba(15, 28, 51, 0.08);
  --shadow-lg: 0 16px 48px rgba(15, 28, 51, 0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --radius-full: 999px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 0.18s;
}

/* Dark mode overrides */
.dark {
  --bg: #0b1220;
  --text: #e8eef8;
  --muted: #94a3b8;
  --line: #1e2a3f;
  --card: #111b2e;
  --surface: #111b2e;
  --surface-2: #162033;
  --purple-soft: #1e1b4b;
  --green-soft: #064e3b;
  --blue-soft: #0c4a6e;
  --orange-soft: #451a03;
  --danger-soft: #450a0a;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.4);
}

/* =========================================================
   Base & Reset
   ========================================================= */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: var(--font-body);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

p {
  font-size: var(--font-body);
  margin: 0 0 0.75em;
}

h1 {
  font-size: var(--font-title);
  font-weight: 750;
  letter-spacing: -0.025em;
  line-height: 1.2;
  margin: 0;
}

h2 {
  font-size: var(--font-heading);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin: 0;
}

h3 {
  font-size: var(--font-subheading);
  font-weight: 650;
  letter-spacing: -0.01em;
  margin: 0;
}

button {
  font-family: inherit;
  font-size: var(--font-button);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--muted);
  border-radius: var(--radius-full);
  opacity: 0.5;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text);
}

/* =========================================================
   Layout Shell
   ========================================================= */

.app-shell {
  min-height: 100vh;
  min-height: 100dvh;
}

.sidebar {
  position: fixed;
  z-index: 30;
  top: 0;
  left: 0;
  bottom: 0;
  width: 260px;
  height: 100vh;
  height: 100dvh;
  max-height: 100dvh;
  padding: 20px 14px;
  box-sizing: border-box;
  background: linear-gradient(180deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: #f1f5f9;
  display: block;
  overflow-x: hidden;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  touch-action: pan-y;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  margin: 0 6px 28px;
  padding: 4px 0;
}

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: linear-gradient(145deg, #818cf8, #4f46e5);
  font-size: var(--font-heading);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.35);
}

.brand-name {
  font-size: var(--font-heading);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand-subtitle {
  font-size: var(--font-small);
  color: #94a3b8;
  margin-top: 1px;
}

.nav-section {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #64748b;
  margin: 24px 8px 8px;
}

.nav-item {
  border: 0;
  background: transparent;
  color: #e2e8f0;
  border-radius: 10px;
  padding: 11px 12px;
  text-align: left;
  font-size: var(--font-nav);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  width: 100%;
  transition: background var(--duration) var(--ease), color var(--duration) var(--ease);
}

.nav-item:hover {
  background: rgba(255, 255, 255, 0.06);
}

.nav-item.active {
  background: linear-gradient(90deg, #4f46e5, #6366f1);
  color: #fff;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.35);
}

.nav-item span {
  width: 18px;
  text-align: center;
  opacity: 0.9;
}

.guest-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 0.5rem;
  margin: 24px 0 8px;
  border: 1px solid rgba(148, 163, 184, 0.18);
  background: rgba(255, 255, 255, 0.04);
  border-radius: 12px;
  padding: 16px 12px;
}

.guest-card > div {
  width: 100%;
  text-align: center;
  display: flex;
  justify-content: center;
  align-items: center;
}

.guest-card span {
  display: block;
  text-align: center;
}

.main {
  margin-left: 260px;
  min-height: 100vh;
  min-height: 100dvh;
  transition: margin-left 0.25s var(--ease);
}

.topbar {
  height: 72px;
  background: var(--card);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  padding: 0 28px;
  gap: 20px;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: var(--shadow-sm);
}

.menu-button,
.icon-button {
  border: 0;
  background: transparent;
  cursor: pointer;
  color: var(--text);
  transition: background var(--duration) var(--ease), border-color var(--duration) var(--ease);
}

.menu-button {
  font-size: var(--font-heading);
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border: 1px solid transparent;
}

.menu-button:hover {
  background: var(--surface-2);
  border-color: var(--line);
}

.dark .menu-button:hover {
  background: #1a2740;
  border-color: #34425c;
  color: #eef2fb;
}

.search {
  position: relative;
  height: 42px;
  max-width: 480px;
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
  color: var(--muted);
  background: var(--bg);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}

.search:focus-within {
  border-color: var(--purple);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
  background: var(--card);
}

.search-icon {
  flex: 0 0 auto;
  font-size: var(--font-subheading);
  opacity: 0.6;
}

.search input {
  border: 0;
  outline: 0;
  width: 100%;
  font-size: var(--font-subheading);
  background: transparent;
  color: inherit;
}

.search-clear {
  border: 0;
  background: var(--surface-2);
  color: var(--muted);
  width: 22px;
  height: 22px;
  border-radius: 50%;
  cursor: pointer;
  font-size: var(--font-subheading);
  line-height: 1;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  padding: 0;
  transition: background var(--duration) var(--ease);
}

.search-clear:hover {
  background: var(--line);
}

.search-results {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 8px);
  max-height: min(420px, 70vh);
  overflow-y: auto;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  z-index: 40;
  padding: 8px;
}

.search-group {
  padding: 8px 10px 4px;
  font-size: 11px;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.search-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  border: 0;
  background: transparent;
  text-align: left;
  padding: 10px;
  border-radius: 9px;
  cursor: pointer;
  color: var(--text);
  transition: background var(--duration) var(--ease);
}

.search-item:hover,
.search-item.active {
  background: var(--purple-soft);
}

.search-item .si-icon {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  display: grid;
  place-items: center;
  font-size: var(--font-body);
  flex: 0 0 auto;
  background: var(--purple-soft);
  color: var(--purple);
}

.search-item .si-icon.green { background: var(--green-soft); color: var(--green); }
.search-item .si-icon.blue { background: var(--blue-soft); color: var(--blue); }
.search-item .si-icon.orange { background: var(--orange-soft); color: var(--orange); }

.search-item .si-body { min-width: 0; flex: 1; }
.search-item .si-title {
  font-size: var(--font-body);
  font-weight: 650;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.search-item .si-sub {
  font-size: var(--font-small);
  color: var(--muted);
  margin-top: 2px;
}

.search-empty {
  padding: 20px 12px;
  text-align: center;
  color: var(--muted);
  font-size: var(--font-subheading);
}

.top-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 14px;
}

.icon-button {
  font-size: var(--font-subheading);
  width: 38px;
  height: 38px;
  border-radius: 10px;
  display: grid;
  place-items: center;
}

.icon-button:hover {
  background: var(--surface-2);
}

.profile-divider {
  height: 28px;
  width: 1px;
  background: var(--line);
  margin: 0 4px;
}

.profile {
  display: flex;
  align-items: center;
  gap: 12px;
}

.profile strong,
.profile span {
  display: block;
}

.profile strong {
  font-size: var(--font-subheading);
  font-weight: 650;
}

.profile span {
  font-size: var(--font-small);
  color: var(--muted);
  margin-top: 2px;
}

.avatar {
  position: relative;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: #334155;
  color: white;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 14px;
}

.avatar span {
  position: absolute;
  right: 0;
  bottom: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #22c55e;
  border: 2px solid var(--card);
}

.content {
  padding: 28px 32px 48px;
}

/* =========================================================
   Page headers & actions
   ========================================================= */

.page-title {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 24px;
}

.page-title h1 {
  font-size: var(--font-title);
  margin: 0 0 4px;
  letter-spacing: -0.03em;
}

.page-title p {
  margin: 0;
  color: var(--muted);
  font-size: var(--font-body);
}

.actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn {
  font-size: var(--font-small);
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--text);
  border-radius: 9px;
  padding: 9px 14px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: background var(--duration) var(--ease), border-color var(--duration) var(--ease),
    box-shadow var(--duration) var(--ease), transform 0.1s var(--ease);
}

.btn:hover {
  background: var(--surface-2);
  border-color: #cbd5e1;
}

.btn:active {
  transform: scale(0.98);
}

.btn.primary {
  background: var(--purple);
  border-color: var(--purple);
  color: #fff;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.25);
}

.btn.primary:hover {
  background: #4338ca;
  border-color: #4338ca;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.btn.danger {
  color: var(--danger);
  border-color: #fecaca;
  background: var(--card);
}

.btn.danger:hover {
  background: var(--danger-soft);
  border-color: #fca5a5;
}

/* =========================================================
   Cards & grids
   ========================================================= */

.grid {
  display: grid;
  gap: 16px;
}

.stats {
  grid-template-columns: repeat(4, 1fr);
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--duration) var(--ease), border-color var(--duration) var(--ease);
}

.card:hover {
  box-shadow: var(--shadow);
}

.stat {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 100px;
}

.round {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: var(--font-subheading);
  flex: 0 0 auto;
}

.round.purple { background: var(--purple-soft); color: var(--purple); }
.round.green { background: var(--green-soft); color: var(--green); }
.round.blue { background: var(--blue-soft); color: var(--blue); }
.round.orange { background: var(--orange-soft); color: var(--orange); }

.stat strong {
  font-size: var(--font-heading);
  display: block;
  font-weight: 750;
  letter-spacing: -0.02em;
}

.stat span {
  font-size: var(--font-subheading);
  display: block;
  margin-top: 2px;
  font-weight: 500;
}

.stat small {
  color: var(--muted);
  font-size: var(--font-small);
}

.home-grid {
  grid-template-columns: minmax(0, 1fr) 340px;
  margin-top: 20px;
}

.continue {
  height: 140px;
  background: linear-gradient(120deg, #f5f3ff 0%, #eef2ff 100%);
  border-color: #c7d2fe;
  display: flex;
  align-items: center;
  gap: 20px;
  position: relative;
  overflow: hidden;
}

.dark .continue {
  background: linear-gradient(120deg, #1e1b4b 0%, #172554 100%);
  border-color: #312e81;
}

.continue h2 {
  margin: 0 0 4px;
  font-size: var(--font-heading);
}

.continue p {
  margin: 0;
  color: var(--muted);
}

.continue-art {
  margin-left: auto;
  font-size: var(--font-title);
  opacity: 0.3;
}

.section {
  margin-top: 32px;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.section-head h2 {
  font-size: var(--font-subheading);
  margin: 0;
  font-weight: 700;
}

.class-grid {
  grid-template-columns: repeat(4, 1fr);
}

.class-card {
  position: relative;
}

.class-card h3 {
  margin: 14px 0 4px;
  font-size: var(--font-subheading);
}

.class-card p,
.class-card .meta {
  color: var(--muted);
  font-size: var(--font-small);
  margin: 0;
}

.class-card .meta {
  display: block;
  margin-top: 6px;
}

.progress {
  height: 6px;
  background: var(--surface-2);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: 14px;
}

.progress i {
  height: 100%;
  display: block;
  background: var(--green);
  border-radius: var(--radius-full);
  transition: width 0.4s var(--ease);
}

.class-card:nth-child(2) .progress i { background: #f59e0b; }
.class-card:nth-child(3) .progress i { background: var(--blue); }
.class-card:nth-child(4) .progress i { background: var(--purple); }

.progress-label {
  font-size: var(--font-small);
  float: right;
  margin-top: 4px;
  color: var(--muted);
}

.side-stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.activity-item {
  display: grid;
  grid-template-columns: 32px 1fr auto;
  gap: 10px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.activity-item:last-child {
  border: 0;
}

.activity-icon {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 13px;
}

.activity-item strong {
  font-size: var(--font-subheading);
  display: block;
  font-weight: 600;
}

.activity-item span {
  font-size: var(--font-small);
  color: var(--muted);
  display: block;
  margin-top: 2px;
}

.activity-item time {
  font-size: var(--font-small);
  color: var(--muted);
}

.goal-big {
  font-size: var(--font-heading);
  font-weight: 750;
  margin-top: 12px;
  letter-spacing: -0.02em;
}

.goal-big span {
  font-size: var(--font-subheading);
  color: var(--muted);
  font-weight: 500;
}

.goal-progress {
  height: 8px;
  background: var(--surface-2);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin: 14px 0;
}

.goal-progress i {
  height: 100%;
  display: block;
  background: var(--green);
  border-radius: var(--radius-full);
}

.empty {
  padding: 40px 24px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed #cbd5e1;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.table-card {
  overflow: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th,
.data-table td {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  font-size: var(--font-subheading);
}

.data-table th {
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.pill {
  display: inline-block;
  border-radius: var(--radius-full);
  padding: 3px 10px;
  font-size: var(--font-small);
  font-weight: 600;
  background: var(--purple-soft);
  color: var(--purple);
}

/* =========================================================
   Library, sets, notes, quizzes, tools
   ========================================================= */

.library-grid {
  grid-template-columns: repeat(3, 1fr);
}

.book-card {
  display: flex;
  flex-direction: column;
  min-height: 200px;
  width: 100%;
  max-width: 360px;
  padding: 16px;
}

.book-cover {
  width: 100%;
  height: 90px;
  overflow: hidden;
  border-radius: 10px;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #e0e7ff, #dbeafe);
  display: grid;
  place-items: center;
  font-size: var(--font-heading);
  color: var(--purple);
}

.book-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
}

.book-card h3 {
  font-size: var(--font-subheading);
  margin: 8px 0 4px;
  line-height: 1.3;
}

.book-card p {
  font-size: var(--font-small);
  color: var(--muted);
  margin: 0 0 12px;
}

.book-actions {
  margin-top: auto;
  padding-top: 12px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.book-actions .btn {
  font-size: var(--font-small);
  padding: 7px 10px;
}

.set-grid,
.note-grid {
  grid-template-columns: repeat(3, 1fr);
}

.set-card h3 {
  font-size: var(--font-subheading);
  margin: 0 0 4px;
}

.set-card p {
  font-size: var(--font-small);
  color: var(--muted);
  margin: 0;
}

.set-card .set-meta {
  margin-top: 14px;
  font-size: var(--font-small);
}

.note-card h3 {
  font-size: var(--font-subheading);
  margin: 0 0 8px;
}

.note-card p {
  font-size: var(--font-small);
  color: var(--muted);
  line-height: 1.55;
  white-space: pre-wrap;
  max-height: 90px;
  overflow: hidden;
}

.note-date {
  font-size: var(--font-small);
  color: var(--muted);
}

.quiz-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.quiz-card h3 {
  margin: 0 0 6px;
}

.quiz-card p {
  font-size: var(--font-small);
  color: var(--muted);
}

.quiz-card .quiz-meta {
  font-size: var(--font-small);
  margin: 12px 0;
}

.tool-grid {
  grid-template-columns: repeat(3, 1fr);
}

.timer {
  font-size: var(--font-clock);
  font-weight: 800;
  text-align: center;
  margin: 24px 0;
  letter-spacing: -0.03em;
  color: var(--text);
}

.timer-controls {
  display: flex;
  justify-content: center;
  gap: 8px;
}

/* =========================================================
   Modals & forms
   ========================================================= */

.modal-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(8, 18, 38, 0.55);
  z-index: 50;
  align-items: center;
  justify-content: center;
  padding: 18px;
  backdrop-filter: blur(4px);
}

.modal-backdrop.open {
  display: flex;
}

.modal {
  width: min(620px, 100%);
  max-height: 90vh;
  overflow: auto;
  background: var(--card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  border: 1px solid var(--line);
}

.modal h2 {
  margin: 0 0 18px;
}

.form-grid {
  display: grid;
  gap: 14px;
}

.form-grid.two {
  grid-template-columns: 1fr 1fr;
}

.field label {
  display: block;
  font-size: var(--font-small);
  font-weight: 650;
  margin-bottom: 6px;
  color: var(--muted);
}

.field input,
.field textarea,
.field select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 10px 12px;
  outline: 0;
  background: var(--card);
  color: var(--text);
  font-family: inherit;
  font-size: var(--font-body);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}

.field input:focus,
.field textarea:focus,
.field select:focus {
  border-color: var(--purple);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.field textarea {
  min-height: 110px;
  resize: vertical;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 20px;
}

/* =========================================================
   Flash study & quiz taking
   ========================================================= */

.flash-study {
  max-width: 760px;
  margin: auto;
  overflow-y: auto;
}

.flash-card {
  min-height: 320px;
  display: grid;
  place-items: center;
  text-align: center;
  cursor: pointer;
  padding: 40px;
  border-radius: var(--radius-lg);
  transition: transform 0.2s var(--ease);
}

.flash-card:hover {
  transform: translateY(-2px);
}

.flash-card .term {
  font-size: var(--font-heading);
  font-weight: 650;
}

.flash-card .hint {
  font-size: var(--font-subheading);
  color: var(--muted);
  margin-top: 12px;
}

.study-controls {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 16px;
}

.question {
  font-size: var(--font-subheading);
  font-weight: 650;
  margin: 10px 0 18px;
}

.option {
  display: block;
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 10px;
  margin: 8px 0;
  text-align: left;
  cursor: pointer;
  font-size: var(--font-body);
  transition: border-color var(--duration) var(--ease), background var(--duration) var(--ease);
}

.option:hover {
  border-color: #a5b4fc;
  background: var(--purple-soft);
}

.result {
  padding: 18px;
  color: var(--text);
  background: var(--bg);
  border-radius: 10px;
}

.toast {
  position: fixed;
  right: 24px;
  bottom: 24px;
  background: #0f172a;
  color: #f8fafc;
  padding: 12px 18px;
  border-radius: 10px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(10px);
  transition: 0.22s var(--ease);
  z-index: 100;
  font-size: var(--font-subheading);
  font-weight: 500;
}

.toast.show {
  opacity: 1;
  transform: none;
}

/* =========================================================
   Dark mode component overrides
   ========================================================= */

.dark .topbar,
.dark .card,
.dark .btn,
.dark .modal,
.dark .option,
.dark .book-card {
  background: var(--card);
  color: var(--text);
}

.dark .search {
  background: var(--surface-2);
  border-color: var(--line);
  color: var(--muted);
}

.dark .search input {
  color: var(--text);
}

.dark .search:focus-within {
  background: var(--card);
}

.dark .profile-divider {
  background: var(--line);
}

.dark .field input,
.dark .field textarea,
.dark .field select {
  background: var(--surface-2);
  color: var(--text);
  border-color: var(--line);
}

.dark .data-table td,
.dark .data-table th,
.dark .activity-item {
  border-color: var(--line);
}

.dark .search-results {
  background: var(--card);
  border-color: var(--line);
}

.dark .search-item:hover,
.dark .search-item.active {
  background: #1e293b;
}

.dark .search-clear {
  background: #1e293b;
  color: var(--muted);
}

/* =========================================================
   Quiz builder
   ========================================================= */

.modal.wide {
  width: min(720px, 100%);
}

.quiz-builder {
  margin-top: 20px;
  padding-top: 4px;
}

.quiz-builder-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.quiz-builder-head strong {
  font-size: var(--font-subheading);
  letter-spacing: -0.02em;
}

.quiz-builder-head .btn {
  background: linear-gradient(135deg, #6366f1, #4f46e5);
  border-color: transparent;
  color: #fff;
  font-size: var(--font-subheading);
  padding: 8px 14px;
}

.quiz-builder-head .btn:hover {
  filter: brightness(1.06);
}

.q-block {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 14px;
  background: var(--surface-2);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}

.q-block:focus-within {
  border-color: #a5b4fc;
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.q-block-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}

.q-num {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--font-small);
  font-weight: 750;
  color: var(--purple);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.q-num::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--purple);
  box-shadow: 0 0 0 4px var(--purple-soft);
}

.q-remove {
  padding: 6px 11px;
  font-size: var(--font-small);
  border-radius: 8px;
  border-color: #fecaca;
  background: var(--danger-soft);
  color: var(--danger);
}

.q-remove:hover {
  background: #fee2e2;
}

.q-block .field {
  margin-bottom: 4px;
}

.q-block .field label {
  font-size: var(--font-small);
  font-weight: 650;
  color: var(--muted);
  margin-bottom: 6px;
}

.q-block .q-text {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 13px;
  font-size: var(--font-subheading);
  font-weight: 600;
  background: var(--card);
  outline: 0;
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}

.q-block .q-text:focus {
  border-color: #818cf8;
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.q-block .q-text::placeholder {
  font-weight: 500;
  color: #94a3b8;
}

.q-options {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.q-option-row {
  display: grid;
  grid-template-columns: 20px 32px 1fr;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: var(--card);
  cursor: pointer;
  transition: background 0.12s var(--ease), border-color 0.12s var(--ease);
}

.q-option-row:hover {
  border-color: #c7d2fe;
  background: var(--purple-soft);
}

.q-option-row:has(input[type="radio"]:checked) {
  border-color: #a5b4fc;
  background: linear-gradient(90deg, #eef2ff, #f8fafc);
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.08);
}

.q-option-row input[type="radio"] {
  width: 17px;
  height: 17px;
  accent-color: var(--purple);
  cursor: pointer;
  margin: 0;
}

.opt-letter {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: var(--purple-soft);
  color: var(--purple);
  display: grid;
  place-items: center;
  font-size: var(--font-subheading);
  font-weight: 750;
  transition: background 0.12s, color 0.12s;
}

.q-option-row:has(input[type="radio"]:checked) .opt-letter {
  background: var(--purple);
  color: #fff;
}

.q-option-row .q-opt {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 11px;
  font-size: var(--font-subheading);
  outline: 0;
  background: var(--card);
  transition: border-color 0.15s;
}

.q-option-row .q-opt:focus {
  border-color: #818cf8;
}

.q-option-row .q-opt::placeholder {
  color: #94a3b8;
}

.q-hint {
  margin: 12px 0 0;
  padding: 8px 12px;
  font-size: var(--font-small);
  color: var(--muted);
  background: var(--surface-2);
  border-radius: 8px;
  border-left: 3px solid #a5b4fc;
}

.q-options-label {
  margin: 14px 0 8px;
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Dark quiz builder */
.dark .q-block {
  background: var(--surface-2);
  border-color: var(--line);
  box-shadow: none;
}

.dark .q-block:focus-within {
  border-color: #6366f1;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.dark .q-block .q-text,
.dark .q-option-row .q-opt {
  background: #0f172a;
  color: var(--text);
  border-color: var(--line);
}

.dark .q-option-row {
  background: #0f172a;
}

.dark .q-option-row:hover {
  background: #1e293b;
  border-color: #334155;
}

.dark .q-option-row:has(input[type="radio"]:checked) {
  background: linear-gradient(90deg, #1e1b4b, #1e293b);
  border-color: #6366f1;
}

.dark .opt-letter {
  background: #1e1b4b;
  color: #a5b4fc;
}

.dark .q-option-row:has(input[type="radio"]:checked) .opt-letter {
  background: var(--purple);
  color: #fff;
}

.dark .q-hint {
  background: #1e293b;
  color: var(--muted);
  border-left-color: #6366f1;
}

.dark .q-remove {
  background: #450a0a;
  border-color: #7f1d1d;
  color: #fca5a5;
}

.dark .quiz-builder-head {
  border-color: var(--line);
}

.dark .q-options-label {
  color: var(--muted);
}

/* =========================================================
   Sidebar collapse & overlay
   ========================================================= */

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 15;
  background: rgba(8, 18, 38, 0.45);
  opacity: 0;
  transition: opacity 0.2s;
  backdrop-filter: blur(2px);
}

.sidebar-overlay.show {
  display: block;
  opacity: 1;
}

body.nav-locked {
  overflow: hidden !important;
}

.app-shell.sidebar-collapsed .sidebar {
  transform: translateX(-100%);
  transition: transform 0.25s var(--ease);
}

.app-shell.sidebar-collapsed .main {
  margin-left: 0;
  transition: margin-left 0.25s var(--ease);
}

.sidebar,
.main {
  transition: transform 0.25s var(--ease), margin-left 0.25s var(--ease);
}

@media (max-width: 850px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.25s var(--ease);
    z-index: 25;
    box-shadow: 8px 0 32px rgba(0, 0, 0, 0.25);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main {
    margin-left: 0;
  }

  .app-shell.sidebar-collapsed .sidebar {
    transform: translateX(-100%);
  }

  .app-shell.sidebar-collapsed .sidebar.open {
    transform: translateX(0);
  }

  .app-shell.sidebar-collapsed .main {
    margin-left: 0;
  }
}

.sidebar-scroll {
  display: block;
}

.sidebar .nav-item {
  display: flex;
}

.sidebar.open {
  z-index: 30;
}

@media (max-width: 850px) {
  .sidebar {
    z-index: 30 !important;
    height: 100vh !important;
    height: 100dvh !important;
    max-height: 100dvh !important;
    overflow-y: scroll !important;
    overflow-x: hidden !important;
    -webkit-overflow-scrolling: touch !important;
    overscroll-behavior: contain;
    touch-action: pan-y !important;
  }

  .sidebar.open {
    transform: translateX(0) !important;
  }

  body.nav-locked {
    overflow: hidden !important;
  }

  body.nav-locked .sidebar {
    overflow-y: scroll !important;
    touch-action: pan-y !important;
  }
}

/* =========================================================
   Mobile search
   ========================================================= */

@media (max-width: 850px) {
  .topbar {
    padding: 0 12px !important;
    gap: 10px !important;
    height: auto !important;
    min-height: 64px;
    flex-wrap: wrap;
    padding-top: 10px !important;
    padding-bottom: 10px !important;
  }

  .search,
  #searchWrap {
    display: flex !important;
    visibility: visible !important;
    opacity: 1 !important;
    position: relative !important;
    flex: 1 1 auto !important;
    max-width: none !important;
    min-width: 0 !important;
    width: auto !important;
    order: 3;
  }

  .menu-button {
    order: 1;
  }

  .top-actions {
    order: 2;
    margin-left: auto;
  }

  .search-results,
  #searchResults {
    position: fixed !important;
    left: 10px !important;
    right: 10px !important;
    top: 72px !important;
    max-height: min(60vh, 420px) !important;
    z-index: 60 !important;
    display: block;
  }

  #searchResults[hidden] {
    display: none !important;
  }
}

@media (max-width: 600px) {
  .search,
  #searchWrap {
    height: 40px;
    display: flex !important;
    flex: 1 1 100% !important;
    width: 100% !important;
    order: 3;
  }

  .search input {
    font-size: var(--font-small) !important;
  }

  .topbar {
    flex-wrap: wrap;
    height: auto !important;
    min-height: 56px;
  }

  .icon-button {
    font-size: var(--font-small);
  }
}

#searchWrap[hidden] {
  display: none !important;
}

/* =========================================================
   Subject cards & delete
   ========================================================= */

.subject-card {
  position: relative;
}

.subject-delete {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 30px;
  height: 30px;
  padding: 0;
  display: grid;
  place-items: center;
  border-radius: 8px;
  z-index: 5;
  font-size: var(--font-heading);
  line-height: 1;
}

.subject-delete:hover {
  background: var(--danger-soft);
  border-color: #fca5a5;
  color: #b91c1c;
}

.delete-modal {
  text-align: center;
  padding: 8px 8px 2px;
}

.delete-modal-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--danger-soft);
  color: var(--danger);
  font-size: var(--font-heading);
  font-weight: 800;
}

.delete-modal h2 {
  margin: 0 0 8px;
  font-size: var(--font-subheading);
}

.delete-modal p {
  margin: 6px auto;
  color: var(--muted);
  font-size: var(--font-body);
  line-height: 1.5;
  max-width: 420px;
}

.delete-modal p strong {
  color: var(--text);
}

.delete-modal .delete-warning {
  font-size: var(--font-small);
  color: var(--danger);
}

.delete-modal .modal-actions {
  justify-content: center;
  margin-top: 24px;
}

.delete-confirm {
  background: var(--danger) !important;
  border-color: var(--danger) !important;
  color: #fff !important;
}

.delete-confirm:hover {
  background: #b91c1c !important;
  border-color: #b91c1c !important;
}

.dark .delete-modal-icon {
  background: #450a0a;
  color: #fca5a5;
}

.dark .delete-modal p strong {
  color: var(--text);
}

/* =========================================================
   Study Set Card Builder
   ========================================================= */

.set-builder {
  margin-top: 24px;
}

.set-builder-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.set-builder-head h3 {
  margin: 0;
  font-size: 16px;
}

.set-builder-head p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.set-card-editor {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 13px;
  padding: 16px;
  margin-bottom: 14px;
}

.set-card-editor:focus-within {
  border-color: #a5b4fc;
  box-shadow: 0 4px 16px rgba(79, 70, 229, 0.08);
}

.set-card-editor-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 15px;
}

.set-card-number {
  display: flex;
  align-items: center;
  gap: 9px;
}

.set-card-number span {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: var(--font-small);
  font-weight: 800;
}

.set-card-number strong {
  font-size: var(--font-body);
}

.set-card-remove {
  font-size: var(--font-small);
  padding: 6px 10px;
}

.set-card-fields {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 13px;
}

.set-card-fields .field {
  min-width: 0;
}

.set-card-fields label {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: var(--font-small);
  font-weight: 700;
  margin-bottom: 7px;
}

.field-number {
  width: 23px;
  height: 23px;
  border-radius: 6px;
  display: grid;
  place-items: center;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: var(--font-small);
  font-weight: 900;
}

.field-number.answer {
  background: var(--green-soft);
  color: var(--green);
}

.set-card-fields textarea {
  width: 100%;
  min-height: 105px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 11px;
  font-family: inherit;
  font-size: var(--font-body);
  line-height: 1.45;
  background: var(--card);
}

.set-card-fields textarea:focus {
  outline: none;
  border-color: #818cf8;
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.set-card-fields textarea::placeholder {
  color: #94a3b8;
}

.set-card-fields small {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: var(--font-small);
  line-height: 1.4;
}

.set-builder-empty {
  min-height: 130px;
  border: 1px dashed #cbd5e1;
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  color: var(--muted);
}

.set-empty-icon {
  font-size: var(--font-subheading);
  margin-bottom: 4px;
  color: var(--purple);
}

.set-builder-empty strong {
  color: var(--text);
  font-size: var(--font-body);
}

.set-builder-empty span {
  font-size: var(--font-small);
}

.dark .set-card-editor {
  background: var(--surface-2);
  border-color: var(--line);
}

.dark .set-card-fields textarea {
  background: #0f172a;
  color: var(--text);
  border-color: var(--line);
}

.dark .set-card-fields textarea::placeholder {
  color: #64748b;
}

.dark .set-card-number span {
  background: #1e1b4b;
}

.dark .field-number.answer {
  background: #064e3b;
}

.dark .set-builder-empty {
  border-color: var(--line);
}

@media (max-width: 650px) {
  .set-builder-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .set-card-fields {
    grid-template-columns: 1fr;
  }
}

.set-actions {
  flex-wrap: wrap;
}

.set-actions .danger {
  color: var(--danger);
  border-color: #fecaca;
  background: var(--card);
}

.set-actions .danger:hover {
  background: var(--danger-soft);
  border-color: #fca5a5;
}

.set-card-actions {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.set-card-actions .btn {
  flex: 1;
}

@media (max-width: 600px) {
  .set-card-actions {
    flex-direction: column;
  }

  .set-card-actions .btn {
    width: 100%;
  }
}

/* =========================================================
   Library folders
   ========================================================= */

.library-folders {
  margin-bottom: 32px;
}

.library-books {
  margin-top: 28px;
}

.library-section-heading {
  margin-bottom: 14px;
}

.library-section-heading h2 {
  margin: 0;
  font-size: var(--font-subheading);
}

.library-section-heading p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: var(--font-small);
}

.library-folder-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 14px;
}

.library-folder-card {
  display: flex;
  flex-direction: column;
  padding: 14px;
  min-width: 0;
  overflow: hidden;
}

.library-folder-cover {
  width: 100%;
  aspect-ratio: 3 / 4;
  border-radius: 10px;
  overflow: hidden;
  background: var(--surface-2);
  margin-bottom: 12px;
}

.library-folder-cover img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.library-folder-info {
  min-width: 0;
  flex: 1;
}

.library-folder-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--purple-soft);
  font-size: var(--font-subheading);
  flex: 0 0 auto;
}

.library-folder-info h3 {
  margin: 0;
  font-size: var(--font-body);
  line-height: 1.3;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  line-clamp: 2;
  -webkit-box-orient: vertical;
}

.library-folder-info p {
  margin: 5px 0 12px;
  font-size: var(--font-small);
  opacity: 0.7;
}

.library-folder-open {
  width: 100%;
  justify-content: center;
  margin-top: auto;
}

.library-empty {
  min-height: 130px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  text-align: center;
}

.library-empty-icon {
  font-size: var(--font-heading);
  margin-bottom: 4px;
}

.library-empty span {
  color: var(--muted);
  font-size: var(--font-small);
}

@media (max-width: 700px) {
  .library-folder-card {
    grid-template-columns: 100px 1fr;
  }

  .library-folder-grid,
  .library-grid {
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  }

  .library-folder-cover img,
  .book-cover img {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
  }

  .library-folder-open {
    grid-column: 2;
    justify-self: start;
  }

  .book-actions .btn {
    font-size: var(--font-footer);
    padding: 4px 6px;
    display: flex;
    justify-content: center;
  }
}

/* =========================================================
   Built-in Flashcards
   ========================================================= */

.builtin-flashcards-notice {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  margin-bottom: 20px;
  background: var(--purple-soft);
  border: 1px solid #c7d2fe;
  border-radius: 11px;
}

.builtin-notice-icon {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: #e0e7ff;
  color: var(--purple);
  font-size: var(--font-subheading);
}

.builtin-flashcards-notice strong {
  display: block;
  color: var(--text);
  font-size: var(--font-small);
}

.builtin-flashcards-notice p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: var(--font-small);
}

.builtin-flashcard-grid {
  grid-template-columns: repeat(3, 1fr);
}

.builtin-deck-card {
  display: flex;
  flex-direction: column;
  min-height: 280px;
}

.builtin-deck-icon {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: 23px;
}

.builtin-deck-content {
  flex: 1;
}

.builtin-badge {
  display: inline-block;
  margin-top: 14px;
  padding: 4px 8px;
  border-radius: var(--radius-full);
  background: var(--green-soft);
  color: var(--green);
  font-size: var(--font-footer);
  font-weight: 750;
  letter-spacing: 0.04em;
}

.builtin-deck-card h3 {
  margin: 9px 0 4px;
  font-size: var(--font-body);
  color: var(--text);
}

.builtin-subject {
  margin: 0;
  color: var(--purple);
  font-size: var(--font-small);
  font-weight: 650;
}

.builtin-description {
  margin: 10px 0;
  color: var(--muted);
  font-size: var(--font-small);
  line-height: 1.5;
}

.builtin-meta {
  color: var(--muted);
  font-size: var(--font-small);
}

.builtin-actions {
  display: flex;
  gap: 7px;
  margin-top: 16px;
}

.builtin-actions .btn {
  flex: 1;
}

.builtin-readonly-label {
  text-align: center;
  margin: -5px 0 12px;
  color: var(--muted);
  font-size: var(--font-small);
}

.builtin-flash-card {
  border: 2px solid #c7d2fe;
}

.dark .builtin-flashcards-notice {
  background: #1e1b4b;
  border-color: #312e81;
}

.dark .builtin-notice-icon {
  background: #312e81;
  color: #a5b4fc;
}

.dark .builtin-flashcards-notice strong {
  color: var(--text);
}

.dark .builtin-deck-icon {
  background: #312e81;
  color: #a5b4fc;
}

.dark .builtin-badge {
  background: #064e3b;
  color: #6ee7b7;
}

.dark .builtin-flash-card {
  border-color: #4338ca;
}

@media (max-width: 900px) {
  .builtin-flashcard-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .builtin-flashcard-grid {
    grid-template-columns: 1fr;
  }
}

/* =========================================================
   AI Flashcard Maker
   ========================================================= */

.ai-flashcard-maker {
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding-bottom: 40px;
}

.ai-flashcard-panel {
  position: relative;
  overflow: hidden;
  padding: 28px;
  border-radius: 18px;
}

.ai-flashcard-panel::before {
  content: "";
  display: block;
  height: 4px;
  width: 100%;
  position: absolute;
  top: 0;
  left: 0;
  background: var(--purple);
}

.ai-flashcard-field {
  display: flex;
  flex-direction: column;
  gap: 7px;
  margin-bottom: 20px;
}

.ai-flashcard-field label {
  font-size: var(--font-label);
  font-weight: 600;
}

.ai-flashcard-field input,
.ai-flashcard-field select,
.ai-flashcard-field textarea {
  width: 100%;
  box-sizing: border-box;
  font-family: inherit;
  font-size: var(--font-body);
}

.ai-flashcard-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.ai-flashcard-field textarea {
  resize: vertical;
  min-height: 110px;
}

.ai-flashcard-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.ai-flashcard-status {
  min-height: 22px;
  margin-top: 14px;
  text-align: right;
  font-size: var(--font-small);
  color: var(--muted);
}

.ai-flashcard-actions button:disabled {
  opacity: 0.65;
  cursor: wait;
}

.ai-flashcard-modal {
  position: fixed !important;
  inset: 0 !important;
  width: 100vw;
  height: 100vh;
  z-index: 999999 !important;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  box-sizing: border-box;
  background: rgba(15, 23, 42, 0.55);
  overflow: hidden;
  isolation: isolate;
}

.ai-flashcard-preview {
  position: relative;
  width: min(900px, 100%);
  max-height: min(850px, 90vh);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: 20px;
  background: var(--card);
  box-shadow: var(--shadow-lg);
  z-index: 1;
}

.ai-flashcard-preview .modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 24px 26px;
  border-bottom: 1px solid var(--line);
  flex-shrink: 0;
}

.ai-flashcard-preview .modal-header h2 {
  margin: 0;
  font-size: var(--font-heading);
}

.ai-flashcard-preview .modal-header p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: var(--font-small);
}

.ai-generated-count {
  margin: 16px 26px 4px;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--surface-2);
  font-size: var(--font-small);
  font-weight: 600;
  flex-shrink: 0;
}

.ai-preview-list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 16px 26px 22px;
  overscroll-behavior: contain;
}

.ai-preview-card {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 12px;
  padding: 14px;
  margin-bottom: 12px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--card);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.ai-preview-card:hover {
  border-color: var(--purple);
  box-shadow: var(--shadow-sm);
}

.ai-preview-number {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 9px;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: var(--font-small);
  font-weight: 700;
}

.ai-preview-content {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.ai-preview-question,
.ai-preview-answer {
  width: 100%;
  box-sizing: border-box;
  font-family: inherit;
  font-size: var(--font-body);
}

.ai-preview-question {
  font-weight: 600;
}

.ai-preview-answer {
  resize: vertical;
  min-height: 80px;
}

.ai-flashcard-preview .modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 18px 26px;
  border-top: 1px solid var(--line);
  background: var(--card);
  flex-shrink: 0;
}

@media (max-width: 700px) {
  .ai-flashcard-modal {
    padding: 10px;
  }

  .ai-flashcard-preview {
    width: 100%;
    max-height: 94vh;
    border-radius: 16px;
  }

  .ai-flashcard-preview .modal-header {
    padding: 18px;
  }

  .ai-generated-count {
    margin-left: 18px;
    margin-right: 18px;
  }

  .ai-preview-list {
    padding-left: 18px;
    padding-right: 18px;
  }

  .ai-flashcard-preview .modal-footer {
    padding: 14px 18px;
    flex-direction: column-reverse;
  }

  .ai-flashcard-preview .modal-footer .btn {
    width: 100%;
  }
}

/* =========================================================
   AI Unavailable Modal
   ========================================================= */

.ai-unavailable-modal {
  width: min(500px, calc(100vw - 32px));
  border-radius: 20px;
  overflow: hidden;
  position: relative;
  z-index: 10001;
}

.ai-unavailable-modal .modal-body {
  text-align: center;
  padding: 32px 28px;
}

.ai-unavailable-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: var(--purple-soft);
  font-size: 30px;
}

.ai-unavailable-modal .modal-body h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.ai-unavailable-modal .modal-body p {
  margin: 8px 0;
  line-height: 1.6;
  color: var(--muted);
}

.ai-unavailable-modal .modal-footer {
  display: flex;
  justify-content: flex-end;
  padding: 18px 24px;
  border-top: 1px solid var(--line);
}

#aiUnavailableModal {
  position: fixed;
  inset: 0;
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(0, 0, 0, 0.55);
}

@media (max-width: 600px) {
  .ai-unavailable-modal {
    padding: 12px;
  }

  .ai-unavailable-icon {
    width: 56px;
    height: 56px;
    margin-top: 22px;
  }

  .ai-unavailable-card .modal-footer .btn {
    width: 100%;
  }
}

/* =========================================================
   Profile
   ========================================================= */

.profile-card {
  width: 100%;
}

.profile-header {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 24px;
}

.profile-avatar {
  width: 76px;
  height: 76px;
  flex: 0 0 76px;
  border-radius: 50%;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--purple);
  color: #fff;
  font-size: 30px;
  font-weight: 700;
}

.profile-avatar-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.profile-heading {
  min-width: 0;
}

.profile-name {
  margin: 0;
}

.profile-username {
  color: var(--muted);
  margin-top: 4px;
}

.profile-account-status {
  padding: 16px;
  border-radius: 12px;
  background: var(--surface-2);
  margin-bottom: 20px;
}

.profile-section-title {
  font-weight: 700;
  margin-bottom: 6px;
}

.profile-linked-status {
  color: var(--green);
  font-weight: 600;
}

.profile-guest-status {
  font-weight: 600;
}

.profile-google-email {
  color: var(--muted);
  margin-top: 5px;
}

.profile-description {
  color: var(--muted);
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.5;
}

.profile-information {
  display: grid;
  gap: 10px;
  margin-bottom: 22px;
}

.profile-information-row {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.profile-user-id {
  color: var(--muted);
}

.profile-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.profile-muted {
  color: var(--muted);
}

/* Community Profile Modal */

#community-profile-modal {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 23, 42, 0.4);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

#community-profile-modal .community-profile-modal-card {
  width: min(560px, 100%);
  max-height: min(760px, calc(100vh - 40px));
  overflow-y: auto;
  background: var(--card);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow-lg);
  animation: communityProfileModalIn 0.18s ease-out;
}

@keyframes communityProfileModalIn {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.community-profile-modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 24px;
  border-bottom: 1px solid var(--line);
}

.community-profile-modal-header h2 {
  margin: 0;
  color: var(--text);
  font-size: 22px;
  line-height: 1.25;
}

.community-profile-modal-header p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.community-profile-modal-close {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.community-profile-modal-close:hover {
  background: var(--surface-2);
  color: var(--text);
}

.community-profile-modal-body {
  padding: 24px;
}

.community-profile-preview {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.community-profile-preview-avatar {
  width: 72px;
  height: 72px;
  flex: 0 0 72px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  border-radius: 50%;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: 28px;
  font-weight: 700;
}

.community-profile-preview-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.community-profile-preview-info {
  min-width: 0;
}

.community-profile-preview-name {
  display: block;
  font-size: 18px;
  font-weight: 700;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.community-profile-preview-username {
  margin-top: 3px;
  color: var(--muted);
  font-size: 14px;
}

.community-profile-form {
  display: grid;
  gap: 18px;
}

.community-profile-field {
  display: grid;
  gap: 7px;
}

.community-profile-field > span {
  font-size: 14px;
  font-weight: 600;
}

.community-profile-field input,
.community-profile-field textarea {
  width: 100%;
  box-sizing: border-box;
  padding: 11px 13px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--card);
  color: var(--text);
  font: inherit;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.community-profile-field input {
  height: 44px;
}

.community-profile-field textarea {
  min-height: 110px;
  resize: vertical;
}

.community-profile-field input:focus,
.community-profile-field textarea:focus {
  border-color: var(--purple);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.community-profile-username-status {
  display: block;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
}

.community-profile-error {
  display: none;
  padding: 11px 13px;
  border-radius: 10px;
  background: rgba(220, 38, 38, 0.1);
  color: var(--danger);
  font-size: 13px;
  line-height: 1.45;
}

.community-profile-modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 22px;
}

@media (max-width: 600px) {
  #community-profile-modal {
    padding: 12px;
  }

  #community-profile-modal .community-profile-modal-card {
    max-height: calc(100vh - 24px);
    border-radius: 15px;
  }

  .community-profile-modal-header {
    padding: 18px;
  }

  .community-profile-modal-body {
    padding: 18px;
  }

  .community-profile-preview-avatar {
    width: 60px;
    height: 60px;
    flex-basis: 60px;
    font-size: 23px;
  }

  .community-profile-modal-actions {
    flex-direction: column-reverse;
  }

  .community-profile-modal-actions .btn {
    width: 100%;
  }
}

/* Topbar profile */

.profile[data-action="edit-profile"] {
  background-image: none !important;
  background-color: transparent;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 4px 6px;
  border: 0;
  cursor: pointer;
  border-radius: 10px;
  font: inherit;
  transition: background 0.15s ease, transform 0.15s ease;
}

.profile[data-action="edit-profile"]:hover {
  background-color: var(--surface-2);
}

.profile[data-action="edit-profile"]:active {
  transform: scale(0.98);
}

.profile-info {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  min-width: 0;
}

.profile-info #displayName {
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.profile-info #headerUsername {
  margin-top: 2px;
  font-size: 11px;
  color: var(--muted);
  white-space: nowrap;
}

#communityProfileAvatar {
  width: 38px;
  height: 38px;
  min-width: 38px;
  min-height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  user-select: none;
}

#communityProfileAvatar img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

#communityProfileAvatar .profile-avatar-fallback {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--purple-soft);
  color: var(--purple);
  font-size: 15px;
  font-weight: 700;
}

.community-profile-avatar {
  width: 36px;
  height: 36px;
  min-width: 36px;
  border-radius: 50%;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.community-profile-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.community-profile-avatar .profile-avatar-fallback,
.profile-avatar-fallback {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

#resetData {
  background: var(--danger-soft);
  color: var(--danger);
  border: 1px solid #fecaca;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: var(--font-small);
  font-weight: 600;
  cursor: pointer;
}

.btn.primary[data-action="edit-profile"] {
  background-image: none !important;
  background-color: var(--purple);
  color: #fff;
}

.btn.primary[data-action="edit-profile"].has-avatar {
  padding: 0.6rem 1.2rem;
}

/* =========================================================
   Explore
   ========================================================= */

.explore-page {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.explore-featured {
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 260px;
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--card);
}

.explore-featured-content {
  position: relative;
  z-index: 2;
  max-width: 620px;
}

.explore-game-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  border-radius: 14px;
  background: var(--bg);
  border: 1px solid var(--line);
  font-size: var(--font-subheading);
}

.explore-eyebrow,
.explore-card-category {
  display: inline-block;
  font-size: 11px;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.explore-featured h2 {
  margin: 7px 0 8px;
  font-size: var(--font-heading);
}

.explore-featured p {
  max-width: 540px;
  margin: 0 0 18px;
  color: var(--muted);
  font-size: var(--font-body);
}

.explore-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.explore-meta span {
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-full);
  color: var(--muted);
  font-size: var(--font-small);
}

.explore-play-btn {
  min-width: 120px;
}

.explore-featured-decoration {
  position: absolute;
  right: 5%;
  top: 50%;
  transform: translateY(-50%);
  font-size: var(--font-superheading);
  opacity: 0.06;
  pointer-events: none;
}

.explore-section {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.explore-section-subtitle {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: var(--font-small);
}

.explore-game-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.explore-game-card {
  display: flex;
  gap: 16px;
  min-height: 180px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--card);
  transition: border-color var(--duration) var(--ease);
}

.explore-game-card:hover {
  border-color: var(--purple);
}

.explore-game-disabled {
  opacity: 0.65;
}

.explore-card-icon {
  flex: 0 0 48px;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--bg);
  font-size: var(--font-subheading);
}

.explore-card-body {
  min-width: 0;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.explore-card-body h3 {
  margin: 6px 0;
  font-size: var(--font-subheading);
}

.explore-card-body p {
  margin: 0;
  color: var(--muted);
  font-size: var(--font-body);
  line-height: 1.55;
}

.explore-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: auto;
  padding-top: 18px;
  color: var(--muted);
  font-size: var(--font-small);
}

.explore-coming-soon {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px;
  border: 1px dashed var(--line);
  border-radius: 13px;
}

.explore-coming-icon {
  font-size: var(--font-subheading);
}

.explore-coming-soon h3 {
  margin: 0 0 4px;
}

.explore-coming-soon p {
  margin: 0;
  color: var(--muted);
  font-size: var(--font-body);
}

/* =========================================================
   Circuit Challenge
   ========================================================= */

.circuit-game {
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 1000px;
  margin: 0 auto;
}

.circuit-game-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
}

.circuit-game-progress {
  display: flex;
  flex-direction: column;
  gap: 6px;
  text-align: center;
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-progress {
  width: 100%;
  height: 5px;
  overflow: hidden;
  border-radius: var(--radius-full);
  background: var(--surface-2);
}

.circuit-progress i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--purple);
  transition: width 0.25s ease;
}

.circuit-game-score {
  font-weight: 700;
}

.circuit-question-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--card);
}

.circuit-question-heading {
  margin-bottom: 20px;
}

.circuit-question-heading h1 {
  margin: 5px 0 6px;
  font-size: var(--font-subheading);
}

.circuit-question-heading p {
  margin: 0;
  color: var(--muted);
}

.circuit-image-container {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  margin-bottom: 24px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
}

.circuit-question-image,
.circuit-answer-image {
  display: block;
  max-width: 100%;
  max-height: 650px;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 8px;
}

.circuit-answer-area {
  max-width: 650px;
  margin: 0 auto;
}

.circuit-answer-area label {
  display: block;
  margin-bottom: 7px;
  font-weight: 600;
  font-size: var(--font-label);
}

.circuit-answer-row {
  display: flex;
  gap: 9px;
}

.circuit-answer-row input {
  flex: 1;
  min-width: 0;
}

.circuit-answer-area small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-result-panel {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 18px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.circuit-result-icon {
  width: 38px;
  height: 38px;
  flex: 0 0 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg);
  font-weight: 800;
}

.circuit-result-panel h3 {
  margin: 0 0 5px;
}

.circuit-result-panel p {
  margin: 4px 0;
  color: var(--muted);
  font-size: var(--font-body);
}

.circuit-solution {
  margin-top: 18px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
}

.circuit-solution-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.circuit-solution-header h2 {
  margin: 0;
}

.circuit-solution-header span {
  color: var(--muted);
  font-size: var(--font-body);
}

.circuit-next-area {
  display: flex;
  justify-content: flex-end;
  margin-top: 20px;
}

.circuit-game-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.circuit-game-stats > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
}

.circuit-game-stats strong {
  font-size: var(--font-subheading);
}

.circuit-game-stats span {
  margin-top: 3px;
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-results-card {
  padding: 40px 24px;
  text-align: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--card);
}

.circuit-results-icon {
  margin-bottom: 14px;
  font-size: var(--font-heading);
}

.circuit-results-card h1 {
  margin: 8px 0;
  font-size: var(--font-subheading);
}

.circuit-results-card > p {
  color: var(--muted);
}

.circuit-final-score {
  display: flex;
  flex-direction: column;
  margin: 28px 0;
}

.circuit-final-score strong {
  font-size: var(--font-heading);
}

.circuit-final-score span {
  color: var(--muted);
}

.circuit-final-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  max-width: 600px;
  margin: 0 auto 28px;
}

.circuit-final-stats > div {
  display: flex;
  flex-direction: column;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.circuit-final-stats strong {
  font-size: var(--font-subheading);
}

.circuit-final-stats span {
  margin-top: 3px;
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-results-actions {
  display: flex;
  justify-content: center;
  gap: 9px;
  flex-wrap: wrap;
}

.circuit-answer-heading {
  margin-bottom: 16px;
}

.circuit-answer-heading h3 {
  margin: 0 0 4px;
}

.circuit-answer-heading p {
  margin: 0;
  color: var(--muted);
  font-size: var(--font-label);
}

.circuit-answer-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}

.circuit-answer-field {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.circuit-answer-field label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.circuit-answer-label {
  font-weight: 700;
  font-size: var(--font-body);
}

.circuit-answer-unit {
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-answer-field input {
  width: 100%;
}

.circuit-submit-btn {
  width: 100%;
}

.circuit-grading-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 18px 0;
}

.circuit-grading-item {
  display: grid;
  grid-template-columns: 70px 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg);
}

.circuit-grading-answer {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--muted);
  font-size: var(--font-small);
}

.circuit-grading-status {
  font-weight: 500;
  font-size: var(--font-small);
}

.circuit-grading-item.correct .circuit-grading-status {
  color: var(--green);
}

.circuit-grading-item.incorrect .circuit-grading-status {
  color: var(--danger);
}

@media (max-width: 700px) {
  .explore-featured {
    padding: 24px;
    min-height: auto;
  }

  .explore-featured-decoration {
    display: none;
  }

  .explore-game-grid {
    grid-template-columns: 1fr;
  }

  .circuit-game-header {
    grid-template-columns: auto 1fr;
  }

  .circuit-game-score {
    grid-column: 2;
    justify-self: end;
  }

  .circuit-question-card {
    padding: 16px;
  }

  .circuit-question-heading h1 {
    font-size: var(--font-subheading);
  }

  .circuit-answer-row {
    flex-direction: column;
  }

  .circuit-answer-row .btn {
    width: 100%;
  }

  .circuit-game-stats {
    grid-template-columns: 1fr;
  }

  .circuit-final-stats {
    grid-template-columns: 1fr;
  }

  .circuit-answer-list {
    grid-template-columns: 1fr;
  }

  .circuit-grading-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

/* =========================================================
   Electronics Crossword
   ========================================================= */

:root {
  --cw-bg: #0b1428;
  --cw-surface: #111d35;
  --cw-surface-2: #16233f;
  --cw-border: rgba(148, 163, 184, 0.16);
  --cw-text: #f8fafc;
  --cw-muted: #94a3b8;
  --cw-accent: #22b8f0;
  --cw-accent-strong: #0ea5e9;
  --cw-cell: #f1f5f9;
  --cw-cell-hover: #dbeafe;
  --cw-cell-selected: #38bdf8;
  --cw-cell-word: #d9f2ff;
  --cw-correct: #bbf7d0;
  --cw-incorrect: #fecaca;
  --cw-block: #0b1428;
  --cw-radius: 14px;
}

.electronics-crossword-page {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 3rem;
  box-sizing: border-box;
  color: var(--cw-text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.electronics-crossword-header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.electronics-crossword-header .btn {
  flex-shrink: 0;
}

.electronics-crossword-header h1 {
  margin: 0.15rem 0 0.4rem;
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  line-height: 1.15;
  font-weight: 750;
  letter-spacing: -0.025em;
}

.electronics-crossword-header p {
  margin: 0;
  color: var(--cw-muted);
  font-size: 0.95rem;
  line-height: 1.5;
}

.electronics-crossword-instructions {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  width: 100%;
  box-sizing: border-box;
  padding: 1rem 1.15rem;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, rgba(34, 184, 240, 0.09), rgba(17, 29, 53, 0.95));
  border: 1px solid var(--cw-border);
  border-radius: var(--cw-radius);
}

.electronics-crossword-instruction-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  flex: 0 0 42px;
  border-radius: 12px;
  background: #eef2ff;
  font-size: 1.35rem;
}

.electronics-crossword-instructions h2 {
  margin: 0 0 0.3rem;
  font-size: 0.98rem;
  font-weight: 750;
}

.electronics-crossword-instructions p {
  margin: 0 0 0.25rem;
  color: var(--cw-muted);
  font-size: 0.88rem;
  line-height: 1.45;
}

.electronics-crossword-instructions p:last-child {
  margin-bottom: 0;
}

.electronics-crossword-game {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 350px);
  gap: 1rem;
  align-items: start;
  width: 100%;
}

.electronics-crossword-board-wrapper {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  padding: 1rem;
  background: var(--cw-surface);
  border: 1px solid var(--cw-border);
  border-radius: var(--cw-radius);
  box-sizing: border-box;
}

.electronics-crossword-board-wrapper::before {
  content: "Crossword";
  display: flex;
  align-items: center;
  min-height: 24px;
  color: var(--cw-text);
  font-size: 0.95rem;
  font-weight: 750;
  letter-spacing: -0.01em;
}

.electronics-crossword-board {
  --board-size: min(100%, 560px);
  width: var(--board-size);
  max-width: 100%;
  aspect-ratio: 1 / 1;
  display: grid;
  grid-template-columns: repeat(var(--crossword-cols, 15), minmax(0, 1fr));
  grid-template-rows: repeat(var(--crossword-rows, 15), minmax(0, 1fr));
  gap: 2px;
  padding: 2px;
  box-sizing: border-box;
  background: var(--cw-block);
  border: 1px solid rgba(148, 163, 184, 0.14);
  border-radius: 10px;
  overflow: hidden;
  user-select: none;
  margin: 0 auto;
}

.electronics-crossword-block {
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  background: var(--cw-block);
  border-radius: 1px;
}

.electronics-crossword-cell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 1px;
  background: var(--cw-cell);
  color: #0f172a;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: clamp(0.72rem, 1.8vw, 1.05rem);
  font-weight: 750;
  cursor: pointer;
  box-sizing: border-box;
  transition: background 0.12s ease, box-shadow 0.12s ease, transform 0.08s ease;
}

.electronics-crossword-cell:hover {
  background: var(--cw-cell-hover);
}

.electronics-crossword-cell:active {
  transform: scale(0.96);
}

.electronics-crossword-cell.word-selected {
  background: var(--cw-cell-word);
  color: #0f172a;
}

.electronics-crossword-cell.selected {
  background: var(--cw-cell-selected);
  color: #082f49;
  box-shadow: inset 0 0 0 2px #0284c7;
  z-index: 2;
}

.electronics-crossword-cell.correct {
  background: var(--cw-correct) !important;
  color: #14532d !important;
  box-shadow: inset 0 0 0 2px #22c55e;
}

.electronics-crossword-cell.incorrect {
  background: var(--cw-incorrect) !important;
  color: #7f1d1d !important;
  box-shadow: inset 0 0 0 2px #ef4444;
}

.electronics-crossword-number {
  position: absolute;
  top: 2px;
  left: 3px;
  color: #475569;
  font-size: 0.65rem;
  font-weight: 750;
  line-height: 1;
  pointer-events: none;
  z-index: 3;
}

.electronics-crossword-letter {
  display: block;
  line-height: 1;
  pointer-events: none;
}

.electronics-crossword-status {
  width: 100%;
  min-height: 0;
}

.crossword-success,
.crossword-progress {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0.9rem;
  border-radius: 10px;
  font-size: var(--font-subheading);
  box-sizing: border-box;
}

.crossword-success {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.25);
  color: #86efac;
}

.crossword-progress {
  background: rgba(34, 184, 240, 0.07);
  border: 1px solid rgba(34, 184, 240, 0.18);
  color: var(--cw-muted);
}

.crossword-success strong,
.crossword-progress strong {
  color: var(--cw-text);
}

.electronics-crossword-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.electronics-crossword-actions .btn {
  min-height: 40px;
}

.electronics-crossword-clues {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  padding: 1rem;
  background: var(--cw-surface);
  border: 1px solid var(--cw-border);
  border-radius: var(--cw-radius);
  box-sizing: border-box;
  max-height: 680px;
  overflow-y: auto;
  scrollbar-width: thin;
}

.electronics-crossword-clues::before {
  content: "🧩  How to play";
  display: block;
  padding: 0.8rem 0.85rem;
  background: var(--cw-surface-2);
  border: 1px solid var(--cw-border);
  border-radius: 10px;
  color: var(--cw-text);
  font-size: var(--font-subheading);
  font-weight: 750;
}

.electronics-crossword-clue-section {
  padding: 0.15rem 0;
}

.electronics-crossword-clue-section h2 {
  position: sticky;
  top: 0;
  z-index: 4;
  margin: 0;
  padding: 0.65rem 0.7rem;
  background: var(--cw-surface);
  color: var(--cw-accent);
  font-size: var(--font-subheading);
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.electronics-crossword-clue-list {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.electronics-crossword-clue {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  align-items: start;
  width: 100%;
  padding: 0.65rem;
  margin: 0;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--cw-muted);
  text-align: left;
  font-family: inherit;
  font-size: var(--font-subheading);
  line-height: 1.4;
  cursor: pointer;
  box-sizing: border-box;
  transition: background 0.12s ease, color 0.12s ease;
}

.electronics-crossword-clue:hover {
  background: rgba(34, 184, 240, 0.08);
  color: var(--cw-text);
}

.electronics-crossword-clue.active {
  background: rgba(34, 184, 240, 0.12);
  box-shadow: inset 3px 0 0 var(--cw-accent);
  color: var(--cw-text);
}

.electronics-crossword-clue-number {
  color: var(--cw-accent);
  font-weight: 800;
}

.electronics-crossword-clue-text {
  color: inherit;
}

.electronics-crossword-page .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 40px;
  padding: 0.55rem 0.9rem;
  border-radius: 9px;
  border: 1px solid var(--cw-border);
  background: var(--cw-surface);
  color: var(--cw-text);
  font-family: inherit;
  font-size: var(--font-body);
  font-weight: 700;
  cursor: pointer;
  box-sizing: border-box;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.1s ease;
}

.electronics-crossword-page .btn:hover {
  background: var(--cw-surface-2);
  border-color: rgba(148, 163, 184, 0.3);
}

.electronics-crossword-page .btn:active {
  transform: scale(0.98);
}

.electronics-crossword-page .btn.primary {
  background: var(--cw-accent-strong);
  border-color: var(--cw-accent);
  color: #031525;
}

.electronics-crossword-page .btn.primary:hover {
  background: var(--cw-accent);
}

.electronics-crossword-clues::-webkit-scrollbar {
  width: 6px;
}

.electronics-crossword-clues::-webkit-scrollbar-track {
  background: transparent;
}

.electronics-crossword-clues::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.25);
  border-radius: 999px;
}

@media (max-width: 900px) {
  .electronics-crossword-game {
    grid-template-columns: 1fr;
  }

  .electronics-crossword-clues {
    max-height: none;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: start;
  }

  .electronics-crossword-clues::before {
    grid-column: 1 / -1;
  }
}

@media (max-width: 620px) {
  .electronics-crossword-page {
    padding: 1rem 0.75rem 2rem;
  }

  .electronics-crossword-header {
    flex-direction: column;
    gap: 0.7rem;
  }

  .electronics-crossword-header h1 {
    font-size: var(--font-heading);
  }

  .electronics-crossword-instructions {
    padding: 0.85rem;
  }

  .electronics-crossword-board-wrapper {
    padding: 0.7rem;
  }

  .electronics-crossword-board {
    width: 100%;
    max-width: 520px;
  }

  .electronics-crossword-clues {
    display: flex;
  }
}

@media (max-width: 390px) {
  .electronics-crossword-page {
    padding-left: 0.5rem;
    padding-right: 0.5rem;
  }

  .electronics-crossword-board-wrapper {
    padding: 0.5rem;
  }

  .electronics-crossword-board {
    gap: 1px;
    padding: 1px;
  }

  .electronics-crossword-number {
    top: 1px;
    left: 2px;
  }

  .electronics-crossword-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .electronics-crossword-actions .btn {
    width: 100%;
  }
}

/* =========================================================
   Responsive breakpoints
   ========================================================= */

@media (max-width: 1150px) {
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .class-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .home-grid {
    grid-template-columns: 1fr;
  }

  .side-stack {
    display: grid;
    grid-template-columns: 1fr 1fr;
    margin-top: 18px;
  }

  .library-grid,
  .set-grid,
  .note-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 850px) {
  .sidebar {
    transform: translateX(-100%);
    transition: 0.25s;
  }

  .sidebar.open {
    transform: none;
  }

  .main {
    margin-left: 0;
  }

  .topbar {
    padding: 0 17px;
  }

  .profile-divider,
  .profile {
    display: none;
  }

  .content {
    padding: 22px 18px;
  }

  .side-stack {
    display: block;
  }

  .side-stack .card {
    margin-bottom: 18px;
  }

  .quiz-list,
  .tool-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .stats,
  .class-grid,
  .library-grid,
  .set-grid,
  .note-grid,
  .form-grid.two {
    grid-template-columns: 1fr;
  }

  .page-title {
    display: block;
  }

  .actions {
    margin-top: 13px;
  }

  .continue {
    height: 150px;
  }

  .continue-art {
    display: none;
  }
}

@media (max-width: 768px) {
  :root {
    --font-body: 14px;
    --font-small: 12px;
    --font-label: 13px;
    --font-title: 24px;
    --font-heading: 20px;
    --font-subheading: 16px;
    --font-nav: 13px;
    --font-button: 13px;
  }
}

@media (max-width: 480px) {
  :root {
    --font-body: 13px;
    --font-small: 11px;
    --font-label: 12px;
    --font-title: 22px;
    --font-heading: 18px;
    --font-subheading: 15px;
    --font-nav: 12px;
    --font-button: 12px;
  }
}

@media (min-width: 769px) and (max-width: 1100px) {
  :root {
    --font-body: 15px;
    --font-small: 12px;
    --font-label: 13px;
    --font-title: 28px;
    --font-heading: 22px;
    --font-subheading: 17px;
    --font-nav: 14px;
    --font-button: 14px;
  }
}

.card-title {
  font-size: var(--font-subheading);
}

.card-description {
  font-size: var(--font-small);
}