/* CET Navigator design system. Shared by the landing page and learning workspace. */
:root {
  color-scheme: light;
  --c-primary: #2563eb;
  --c-primary-dark: #1d4ed8;
  --c-primary-hover: #1d4ed8;
  --c-primary-light: #eff6ff;
  --c-on-primary: #fff;
  --c-bg: #f8fafc;
  --c-surface: #fff;
  --c-border: #e2e8f0;
  --c-text: #0f172a;
  --c-text-sec: #64748b;
  --c-text-mute: #64748b;
  --c-pending-bg: #f1f5f9;
  --c-pending: #cbd5e1;
  --c-master: #059669;
  --c-master-bg: #ecfdf5;
  --c-mistake: #d97706;
  --c-mistake-bg: #fffbeb;
  --body-bg: #f8fafc;
  --c-shadow: 0 1px 3px #0f172a06;
  --c-shadow-lg: 0 20px 50px #0f172a14;
  --c-tag-bg: #2563eb;
  --c-tag-fg: #fff;
  --r-sm: 8px;
  --r-md: 16px;
  --r-lg: 24px;
  --glass-bg: #fff;
  --glass-border: #e2e8f0;
  --glass-shadow: 0 24px 64px #0f172a26;
  --glass-divider: #e2e8f0;
  --glass-chip-bg: #f8fafc;
  --glass-chip-border: #e2e8f0;
  --glass-btn-bg: #f8fafc;
  --glass-muted-bg: #f8fafc;
  --glass-muted-border: #e2e8f0;
  --glass-icon-bg: #eff6ff;
  --glass-icon-hover: #dbeafe;
  --navy: #0f172a;
  --hero-glow: #dbeafe;
  --player-bg: #0f172a;
}
[data-theme="dark"] {
  color-scheme: dark;
  --c-primary: #60a5fa;
  --c-primary-dark: #3b82f6;
  --c-primary-hover: #3b82f6;
  --c-primary-light: #172554;
  --c-on-primary: #07152d;
  --c-bg: #020617;
  --c-surface: #0f172a;
  --c-border: #1e293b;
  --c-text: #f8fafc;
  --c-text-sec: #94a3b8;
  --c-text-mute: #94a3b8;
  --c-pending-bg: #172033;
  --c-pending: #475569;
  --c-master: #34d399;
  --c-master-bg: #052e25;
  --c-mistake: #fbbf24;
  --c-mistake-bg: #33250b;
  --body-bg: #020617;
  --c-tag-bg: #2563eb;
  --glass-bg: #0f172a;
  --glass-border: #334155;
  --glass-divider: #1e293b;
  --glass-chip-bg: #172033;
  --glass-chip-border: #334155;
  --glass-btn-bg: #172033;
  --glass-muted-bg: #020617;
  --glass-muted-border: #1e293b;
  --glass-icon-bg: #172554;
  --glass-icon-hover: #1e3a8a;
  --navy: #f8fafc;
  --hero-glow: #172554;
  --player-bg: #070d1d;
}
html,
body {
  height: auto;
  min-height: 100%;
  overflow: visible;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}
body {
  font-family:
    Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--c-bg);
  font-size: 14px;
  line-height: 1.6;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input,
select {
  font: inherit;
}
button,
a,
input,
select {
  touch-action: manipulation;
}
button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}
button:focus-visible,
a:focus-visible,
[tabindex]:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 3px solid #60a5fa;
  outline-offset: 3px;
}
button:hover:not(:disabled) {
  transition:
    background 0.15s,
    color 0.15s,
    border-color 0.15s;
}
input,
select {
  color: var(--c-text);
  background: var(--c-surface);
}
[hidden] {
  display: none !important;
}
.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 300;
  background: var(--c-surface);
  padding: 12px 20px;
  border-radius: 10px;
}
.skip-link:focus {
  top: 12px;
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--c-surface) 94%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--c-border);
}
body[data-page="home"] .site-header {
  background: transparent;
  backdrop-filter: blur(12px);
  border-bottom-color: transparent;
}
.header-inner {
  max-width: 1152px;
  margin: auto;
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.brand-icon {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: #2563eb;
  color: #fff;
  box-shadow: 0 2px 4px #2563eb14;
}
.brand-icon svg {
  width: 21px;
  height: 21px;
}
.brand strong {
  display: block;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: -0.35px;
  line-height: 1.5;
}
.brand em {
  font-style: normal;
  color: var(--c-primary);
}
.brand small {
  display: block;
  color: var(--c-text-sec);
  font-size: 12px;
  line-height: 1.7;
}
.site-nav {
  display: flex;
  gap: 4px;
  align-items: center;
}
.site-nav a {
  white-space: nowrap;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 700;
  color: var(--c-text-sec);
  border-radius: 8px;
}
.site-nav a:hover {
  background: var(--c-pending-bg);
}
.site-nav a[aria-current="page"] {
  background: var(--c-primary-light);
  color: var(--c-primary);
}
#navMistakeCount {
  margin-left: 5px;
  border-radius: 12px;
  padding: 1px 5px;
  background: var(--c-mistake-bg);
  color: var(--c-mistake);
  font-size: 10px;
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.theme-toggle {
  border-radius: 12px;
  width: 40px;
  height: 40px;
  background: var(--c-surface);
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 11px 20px;
  min-height: 44px;
  font-weight: 750;
  font-size: 13px;
  line-height: 1.4;
  transition:
    background 0.15s,
    box-shadow 0.15s;
}
.button:hover {
  box-shadow: 0 3px 12px #2563eb12;
}
.button-primary {
  background: #2563eb;
  color: white;
}
.button-primary:hover {
  background: #1d4ed8;
}
.button-dark {
  background: var(--navy);
  color: var(--c-bg);
}
.button-dark:hover {
  background: #2563eb;
  color: #fff;
}
.button-secondary {
  border-color: var(--c-border);
  background: var(--c-surface);
  color: var(--c-text-sec);
}
.button-secondary:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.button-sm {
  min-height: 36px;
  padding: 8px 12px;
  font-size: 12px;
  border-radius: 10px;
}
.icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  vertical-align: middle;
}
.icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--c-primary-light);
  color: var(--c-primary);
  border-radius: 12px;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 1.7px;
  font-size: 11px;
  font-weight: 800;
  color: var(--c-primary);
}
.home-page {
  background: radial-gradient(
    ellipse 650px 500px at 50% -80px,
    var(--hero-glow),
    transparent
  );
  margin-top: -81px;
  padding-top: 81px;
}
.landing-main {
  max-width: 1152px;
  margin: auto;
  padding: 74px 20px 64px;
}
.hero {
  text-align: center;
  max-width: 896px;
  margin: auto;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid color-mix(in srgb, var(--c-primary) 25%, var(--c-border));
  background: var(--c-surface);
  color: var(--c-primary);
  padding: 5px 12px;
  border-radius: 40px;
  font-size: 12px;
  font-weight: 750;
  box-shadow: 0 1px 3px #0f172a08;
  margin-bottom: 20px;
}
.hero-badge .icon {
  width: 14px;
  height: 14px;
}
.hero h1 {
  font-size: 60px;
  line-height: 1.1;
  font-weight: 900;
  letter-spacing: -2.2px;
  max-width: 650px;
  margin: auto;
  text-wrap: balance;
}
.hero h1 span {
  color: #2563eb;
}
.hero > p {
  max-width: 672px;
  margin: 24px auto 0;
  color: var(--c-text-sec);
  font-size: 18px;
  line-height: 1.75;
}
.upload-shell {
  max-width: 768px;
  margin: 40px auto 0;
  border: 1px solid var(--c-border);
  border-radius: 24px;
  background: var(--c-surface);
  padding: 20px;
  box-shadow: 0 20px 32px #17255408;
}
.upload-drop {
  width: 100%;
  min-height: 288px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0;
  padding: 28px;
  border: 2px dashed #bfdbfe;
  border-radius: 16px;
  background: color-mix(in srgb, var(--c-primary-light) 50%, var(--c-surface));
  text-align: center;
  cursor: pointer;
}
.upload-drop:hover,
.upload-drop.is-dragover {
  border-color: #60a5fa;
  background: var(--c-primary-light);
}
.upload-drop.is-dragover {
  box-shadow: 0 0 0 5px #2563eb12;
}
.upload-symbols {
  display: flex;
  gap: 12px;
}
.upload-symbols span {
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: #2563eb;
  color: #fff;
  box-shadow: 0 7px 15px #2563eb26;
}
.upload-symbols span:last-child {
  background: #0f172a;
  box-shadow: none;
}
.upload-symbols .icon {
  width: 28px;
  height: 28px;
}
.upload-drop h2 {
  margin: 20px 0 6px;
  font-size: 20px;
  line-height: 1.5;
  font-weight: 850;
}
.upload-drop p {
  font-size: 13px;
  color: var(--c-text-sec);
  line-height: 1.8;
  max-width: 540px;
}
.upload-drop small {
  font-size: 12px;
  margin-top: 4px;
  color: var(--c-text-mute);
}
.upload-drop .button {
  margin-top: 24px;
}
.upload-note {
  text-align: center;
  color: var(--c-text-mute);
  font-size: 11px;
  line-height: 1.8;
  margin-top: 12px;
}
.upload-note a,
.text-link {
  color: var(--c-primary);
  font-weight: 750;
}
.text-link:hover {
  text-decoration: underline;
}
.upload-note + .upload-note {
  margin-top: 6px;
}
.section-block {
  margin-top: 80px;
}
.section-title {
  text-align: center;
}
.section-title h2 {
  margin-top: 8px;
  font-size: 26px;
  line-height: 1.4;
  font-weight: 850;
  letter-spacing: -0.6px;
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 32px;
}
.surface-card {
  border: 1px solid var(--c-border);
  border-radius: 16px;
  padding: 24px;
  background: var(--c-surface);
  box-shadow: 0 1px 3px #0f172a04;
}
.feature-card h3 {
  margin: 20px 0 8px;
  font-size: 16px;
  font-weight: 800;
}
.feature-card p {
  font-size: 13px;
  color: var(--c-text-sec);
  line-height: 1.8;
}
.steps-section {
  border-radius: 24px;
  background: #0f172a;
  padding: 40px 48px;
  color: #fff;
}
.steps-section .eyebrow {
  color: #93c5fd;
}
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 36px;
}
.step-number {
  font-size: 13px;
  font-weight: 850;
  color: #60a5fa;
  letter-spacing: 2px;
}
.steps-grid h3 {
  margin-top: 12px;
  font-size: 15px;
}
.steps-grid p {
  margin-top: 8px;
  font-size: 13px;
  color: #94a3b8;
}
.site-footer {
  max-width: 1152px;
  margin: auto;
  padding: 24px 20px 32px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  color: var(--c-text-mute);
  font-size: 11px;
}
.site-footer a:hover {
  color: var(--c-primary);
}
.page-container {
  max-width: 1152px;
  margin: auto;
  padding: 44px 20px 72px;
  min-height: calc(100vh - 175px);
}
.page-intro {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 32px;
}
.page-intro h1 {
  margin-top: 5px;
  font-size: 30px;
  letter-spacing: -0.7px;
  line-height: 1.5;
  font-weight: 850;
}
.page-intro p {
  margin-top: 8px;
  color: var(--c-text-sec);
  font-size: 14px;
  max-width: 720px;
}
.filter-bar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.filter-bar button {
  padding: 8px 12px;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  border-radius: 10px;
  font-size: 12px;
  font-weight: 700;
}
.filter-bar button.active {
  border-color: #2563eb;
  background: #2563eb;
  color: #fff;
}
.empty-state {
  text-align: center;
  border: 1px dashed var(--c-border);
  border-radius: 16px;
  background: var(--c-surface);
  padding: 64px 24px;
  margin-top: 28px;
}
.empty-state .icon-box {
  width: 56px;
  height: 56px;
  background: var(--c-pending-bg);
  color: var(--c-text-mute);
  border-radius: 16px;
}
.empty-state h2 {
  font-size: 18px;
  margin: 20px 0 8px;
}
.empty-state p {
  color: var(--c-text-sec);
  font-size: 13px;
  max-width: 500px;
  margin: 0 auto 24px;
}
.mistake-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}
.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.question-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 8px;
  padding: 4px 10px;
  background: var(--c-primary-light);
  color: var(--c-primary);
  font-size: 12px;
  font-weight: 800;
}
.mistake-card .question-chip {
  background: var(--c-mistake-bg);
  color: var(--c-mistake);
}
.muted {
  font-size: 12px;
  color: var(--c-text-sec);
}
.mistake-card h2 {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.7;
}
.mistake-card p {
  margin-top: 8px;
  color: var(--c-text-sec);
  font-size: 12px;
}
.card-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 20px;
}
.card-actions > * {
  flex: 1;
}
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-bottom: 16px;
}
.metric-value {
  font-size: 26px;
  font-weight: 850;
  line-height: 1.4;
  margin: 8px 0;
}
.metric-detail {
  font-size: 12px;
  color: var(--c-primary);
}
.advice-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 16px;
}
.advice-grid h2,
.surface-card > h2 {
  font-size: 17px;
  font-weight: 800;
}
.section-performance {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--c-border);
}
.section-performance:last-child {
  border-bottom: 0;
}
.section-performance-info {
  flex: 1;
}
.section-performance strong {
  font-size: 13px;
}
.section-performance p {
  font-size: 12px;
  color: var(--c-text-sec);
}
.performance-track {
  height: 6px;
  border-radius: 6px;
  background: var(--c-pending-bg);
  margin-top: 8px;
  overflow: hidden;
}
.performance-track i {
  display: block;
  height: 100%;
  background: #2563eb;
  border-radius: 6px;
}
.advice-summary {
  margin-top: 16px;
  line-height: 1.9;
  font-size: 13px;
  color: var(--c-text-sec);
}
.advice-status {
  border: 1px solid var(--c-border);
  background: var(--c-pending-bg);
  padding: 16px;
  border-radius: 12px;
  margin-top: 20px;
  color: var(--c-text-sec);
  font-size: 13px;
}
.page-container .mistake-review-head {
  margin-top: 24px;
}
.page-container .mistake-review-section h4 {
  font-size: 14px;
}
.page-container .mistake-review-overview {
  border-radius: 12px;
}
.settings-page {
  max-width: 808px;
}
.setting-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--c-border);
}
.setting-row:first-child {
  padding-top: 0;
}
.setting-row:last-child {
  padding-bottom: 0;
  border: 0;
}
.setting-copy {
  flex: 1;
  min-width: 0;
}
.setting-copy strong {
  font-size: 14px;
}
.setting-copy p {
  color: var(--c-text-sec);
  font-size: 12px;
  margin-top: 4px;
}
.switch {
  width: 40px;
  height: 24px;
  background: #cbd5e1;
  padding: 2px;
  border-radius: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
}
.switch span {
  display: block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: white;
  box-shadow: 0 1px 2px #0f172a26;
  transition: transform 0.15s;
}
.switch[aria-checked="true"] {
  background: #2563eb;
}
.switch[aria-checked="true"] span {
  transform: translateX(16px);
}
.field-label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 12px;
  font-weight: 750;
  flex: 1;
}
.field-label input,
.field-label select {
  padding: 11px 12px;
  min-height: 44px;
  border: 1px solid var(--c-border);
  border-radius: 10px;
  min-width: 0;
  width: 100%;
}
.teacher-form {
  display: flex;
  align-items: flex-end;
  gap: 16px;
  flex-wrap: wrap;
}
.teacher-form .field-label {
  min-width: 160px;
}
.privacy-note {
  font-size: 12px;
  color: var(--c-text-sec);
  margin-top: 16px;
}
.teacher-feedback {
  margin-top: 18px;
  font-size: 13px;
  color: var(--c-primary);
}
.teacher-feedback.error,
.field-error {
  color: #ef4444;
}
.teacher-help {
  margin-top: 24px;
  padding: 24px;
  border: 1px dashed var(--c-border);
  border-radius: 16px;
}
.teacher-help h2 {
  font-size: 16px;
  margin-bottom: 8px;
}
.teacher-help p {
  font-size: 13px;
  color: var(--c-text-sec);
  line-height: 1.9;
}
.history-section {
  max-width: 768px;
  margin: 24px auto 0;
}
.history-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}
.history-title h2 {
  font-size: 13px;
}
.history-list {
  display: grid;
  gap: 8px;
}
.history-item {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 12px;
  text-align: left;
}
.history-item:hover {
  border-color: var(--c-primary);
}
.history-item strong {
  display: block;
  font-size: 12px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 520px;
}
.history-item small {
  color: var(--c-text-sec);
  font-size: 11px;
}
.history-item .history-info {
  min-width: 0;
  flex: 1;
}
.history-loading {
  font-size: 12px;
  color: var(--c-text-sec);
}
/* Workspace preserves the real audio, transcript, and AI pipelines. */
body[data-page="practice"] {
  background: var(--c-pending-bg);
}
body[data-page="practice"] .header-inner {
  max-width: 1500px;
}
body[data-page="practice"] .header-start {
  display: none;
}
body[data-page="practice"] .site-footer {
  display: none;
}
.app {
  height: auto;
  min-height: calc(100dvh - 81px);
  background: transparent;
  max-width: 1500px;
  margin: auto;
}
.workspace-toolbar {
  padding: 24px 20px 8px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.workspace-label h1 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 23px;
  line-height: 1.5;
  margin-top: 2px;
  letter-spacing: -0.5px;
}
.workspace-label .eyebrow {
  font-size: 10px;
}
.workspace-tools {
  display: flex;
  align-items: center;
  gap: 8px;
}
.workspace-tools .btn {
  min-height: 38px;
  padding: 8px 14px;
  font-size: 12px;
  border-radius: 10px;
}
.demo-badge {
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0;
}
.main {
  display: grid;
  grid-template-columns: 244px minmax(0, 1fr) 310px;
  gap: 16px;
  padding: 16px 20px 28px;
  overflow: visible;
  flex: initial;
  align-items: start;
}
.panel {
  border-radius: 16px;
  box-shadow: 0 1px 3px #0f172a04;
  width: auto;
  max-height: none;
}
.panel-head {
  padding: 18px 20px;
  border-bottom: 1px solid var(--c-border);
  min-height: 58px;
}
.panel-title {
  font-size: 13px;
  font-weight: 800;
  text-transform: none;
  letter-spacing: 0;
  color: var(--c-text);
}
.panel-body {
  padding: 20px;
  overflow: visible;
}
.left-panel {
  width: auto;
  position: sticky;
  top: 98px;
}
.q-stats {
  gap: 6px;
  margin-bottom: 24px;
}
.q-stat {
  border: 0;
  border-radius: 10px;
  padding: 10px 2px;
}
.q-stat-num {
  font-size: 20px;
}
.q-stat-label {
  font-size: 10px;
  color: var(--c-text-sec);
}
.q-section-label {
  font-size: 10px;
  letter-spacing: 0.1px;
  color: var(--c-text-sec);
  margin: 18px 0 10px;
}
.q-grid {
  gap: 8px;
  grid-template-columns: repeat(5, minmax(0, 1fr));
}
.q-btn {
  min-width: 0;
  width: 100%;
  border-radius: 8px;
  font-size: 12px;
  min-height: 34px;
  font-weight: 750;
}
.q-btn.heard {
  background: var(--c-master-bg);
  color: var(--c-master);
  border-color: color-mix(in srgb, var(--c-master) 24%, var(--c-border));
}
.q-btn.mistake {
  background: var(--c-mistake-bg);
  color: var(--c-mistake);
  border-color: color-mix(in srgb, var(--c-mistake) 24%, var(--c-border));
}
.q-btn.current {
  background: #2563eb;
  color: #fff;
  border-color: #2563eb;
  outline: 0;
  box-shadow: 0 3px 8px #2563eb26;
}
.q-btn.mistake .q-dot {
  background: #f59e0b;
  top: -4px;
  right: -3px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--c-surface);
}
.center-panel {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.center-panel > .panel-head {
  gap: 10px;
}
.center-panel > .panel-head .panel-title {
  font-size: 12px;
  line-height: 1.6;
}
.center-panel #durationLabel {
  font-size: 10px !important;
  white-space: nowrap;
}
.practice-question-heading {
  padding: 20px 24px 0;
}
.practice-question-heading h2 {
  font-size: 17px;
  line-height: 1.65;
  letter-spacing: -0.3px;
  margin: 12px 0 0;
  font-weight: 800;
}
.wave-container {
  margin: 24px 24px 0;
  border-radius: 16px 16px 0 0;
  border: 0;
  background: var(--player-bg);
  padding-top: 8px;
}
.wave-viewport::before,
.wave-viewport::after {
  display: none;
}
#waveCanvas {
  height: 138px;
}
.anchor-label {
  font-size: 9px;
  background: #2563eb;
  color: #fff;
}
.anchor-bar {
  background: #334155;
}
.desktop-wave-hint {
  margin: 0 24px;
  background: var(--player-bg);
  color: #94a3b8;
  padding: 0 14px 10px;
}
.desktop-wave-hint .speed-btn {
  color: #cbd5e1;
  border-color: #334155;
  background: transparent;
}
.player-controls {
  margin: 0 24px;
  padding: 16px;
  background: var(--player-bg);
  border: 0;
  border-radius: 0 0 16px 16px;
  gap: 10px;
  color: #fff;
}
.player-controls .speed-btn,
.player-controls .btn {
  background: transparent;
  color: #cbd5e1;
  border: 1px solid #334155;
  border-radius: 8px;
  font-size: 11px;
  min-height: 32px;
  padding: 4px 8px;
}
.player-controls .time-display {
  font-size: 11px;
  color: #94a3b8;
  min-width: 0;
  white-space: nowrap;
}
.play-btn {
  background: #2563eb;
  color: #fff;
  width: 44px;
  height: 44px;
  box-shadow: 0 3px 12px #2563eb22;
}
.play-btn:hover {
  background: #1d4ed8;
}
.transcript-heading {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  padding: 24px 24px 12px;
  font-size: 13px;
}
.transcript-heading span {
  font-size: 10px;
  color: var(--c-text-sec);
}
.transcript-area {
  margin: 0 24px 24px;
  padding: 10px;
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: 16px;
  height: 390px;
  min-height: 220px;
  flex: initial;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}
.transcript-seg {
  padding: 9px 10px;
  margin-bottom: 4px;
  border-radius: 10px;
  font-size: 13px;
  line-height: 1.9;
}
.transcript-seg.active {
  background: color-mix(in srgb, var(--c-primary) 12%, var(--c-surface));
  color: var(--c-text);
  border-left: 0;
  box-shadow: inset 0 0 0 1px
    color-mix(in srgb, var(--c-primary) 25%, transparent);
}
.transcript-seg-main {
  cursor: pointer;
}
.transcript-seg-main .ts {
  display: block;
  font-size: 10px;
  color: var(--c-text-mute);
  margin-bottom: 2px;
}
.transcript-seg-play {
  margin-top: 6px;
}
.right-panel .panel-body {
  padding: 20px;
}
.right-panel .source-card {
  margin-top: 24px;
  background: var(--c-bg);
  padding: 14px;
  border: 1px solid var(--c-border);
  border-radius: 12px;
}
.source-card-title {
  font-size: 11px;
}
.source-row {
  font-size: 11px;
}
.right-panel .q-info-card {
  display: none;
}
.exam-view-btn {
  margin-top: 12px;
  min-height: 36px;
  background: var(--c-pending-bg);
  color: var(--c-text-sec);
  border: 1px solid var(--c-border);
}
.right-panel .mistake-toggle {
  margin-top: 10px;
  gap: 8px;
}
.mistake-btn {
  border-radius: 10px;
  font-size: 11px;
  padding: 9px 5px;
}
.answer-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.answer-heading h2 {
  font-size: 15px;
}
.answer-heading span {
  font-size: 10px;
  color: var(--c-text-sec);
  padding: 3px 8px;
  background: var(--c-pending-bg);
  border-radius: 6px;
}
.answer-options {
  display: grid;
  gap: 10px;
}
.answer-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  border: 1px solid var(--c-border);
  border-radius: 12px;
  text-align: left;
  padding: 12px;
  background: var(--c-surface);
  width: 100%;
}
.answer-option .letter {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--c-pending-bg);
  font-weight: 800;
  font-size: 12px;
  flex-shrink: 0;
  color: var(--c-text-sec);
}
.answer-option .option-copy {
  font-size: 12px;
  line-height: 1.75;
  padding-top: 3px;
  color: var(--c-text-sec);
  overflow-wrap: anywhere;
}
.answer-option:hover {
  border-color: #93c5fd;
}
.answer-option.selected {
  border-color: #3b82f6;
  background: var(--c-primary-light);
  box-shadow: 0 0 0 2px #2563eb0c;
}
.answer-option.selected .letter {
  background: #2563eb;
  color: #fff;
}
.answer-option.correct {
  border-color: var(--c-master);
  background: var(--c-master-bg);
}
.answer-option.correct .letter {
  background: var(--c-master);
  color: #fff;
}
.answer-option.wrong {
  border-color: #ef4444;
  background: color-mix(in srgb, #ef4444 8%, var(--c-surface));
}
.answer-option.wrong .letter {
  background: #ef4444;
  color: white;
}
.answer-submit {
  width: 100%;
  margin-top: 16px;
}
.answer-explanation {
  margin-top: 16px;
  border-radius: 12px;
  background: var(--c-primary-light);
  padding: 16px;
  font-size: 12px;
  line-height: 1.9;
  color: var(--c-text-sec);
}
.practice-notice {
  font-size: 12px;
  line-height: 1.8;
  color: var(--c-mistake);
  background: var(--c-mistake-bg);
  padding: 10px 12px;
  margin-top: 12px;
  border-radius: 10px;
}
.teacher-table-card h2 {
  font-size: 17px;
  margin-bottom: 4px;
}
.table-scroll {
  overflow-x: auto;
  margin-top: 20px;
}
.teacher-table {
  border-collapse: collapse;
  width: 100%;
  min-width: 560px;
  font-size: 13px;
  text-align: left;
}
.teacher-table th {
  background: var(--c-bg);
  color: var(--c-text-sec);
  font-size: 11px;
  font-weight: 750;
}
.teacher-table th,
.teacher-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--c-border);
}
.teacher-table td strong {
  color: var(--c-primary);
}
.answer-explanation strong {
  display: block;
  color: var(--c-primary);
  margin-bottom: 6px;
}
.answer-reveal {
  font-size: 11px;
  margin-top: 12px;
  display: block;
  width: 100%;
  color: var(--c-text-sec);
  text-align: center;
}
.answer-empty {
  font-size: 12px;
  color: var(--c-text-sec);
  line-height: 1.8;
  padding: 16px;
  background: var(--c-bg);
  border-radius: 12px;
}
.nav-legend {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--c-border);
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 10px;
  color: var(--c-text-sec);
}
.legend-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #2563eb;
  margin-right: 5px;
}
.legend-dot.green {
  background: #10b981;
}
.legend-dot.amber {
  background: #f59e0b;
}
.left-settings {
  padding: 18px 20px;
  border-top: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 11px;
  color: var(--c-text-sec);
}
.collapse-nav .main {
  grid-template-columns: minmax(0, 1fr) 310px;
}
.collapse-nav .left-panel {
  display: none;
}
.mobile-tabs {
  display: none;
}
.seg-insight {
  border-radius: 20px;
  backdrop-filter: none;
}
.seg-insight-head {
  padding: 18px 22px;
}
.seg-insight-body {
  padding: 18px 22px;
}
.modal {
  border-radius: 20px;
  padding: 28px;
  max-height: 85dvh;
  overflow: auto;
  box-shadow: var(--c-shadow-lg);
}
.modal-title {
  font-size: 18px;
  margin-bottom: 20px;
}
.modal-close {
  cursor: pointer;
}
.modal-close:focus-visible {
  outline: 3px solid #60a5fa;
}
.upload-card {
  border-radius: 20px;
  max-width: calc(100vw - 32px);
  width: 440px;
  padding: 28px;
}
.upload-progress-wrap {
  height: 6px;
  background: var(--c-pending-bg);
}
.upload-title {
  overflow-wrap: anywhere;
  line-height: 1.7;
}
.upload-sub {
  margin-top: 10px;
  line-height: 1.8;
}
.upload-pct {
  font-size: 12px;
}
.toast {
  z-index: 300;
  max-width: calc(100vw - 32px);
  white-space: normal;
  font-size: 13px;
  border-radius: 12px;
  background: var(--navy);
  color: var(--c-bg);
}
.material-picker {
  border-radius: 16px;
  box-shadow: var(--c-shadow-lg);
}
.material-picker-level {
  min-height: 36px;
}
.material-picker-item {
  min-height: 48px;
}
.answer-explanation {
  max-height: 320px;
  overflow-y: auto;
  scrollbar-width: thin;
  white-space: pre-line;
}
.center-panel {
  position: relative;
}
.app {
  overflow-anchor: none;
}
.mobile-tab.active {
  border-top-color: transparent;
}
.seg-insight:focus {
  outline: none;
}
@media (max-width: 768px) {
  .seg-insight {
    top: auto;
    bottom: 12px;
    left: 12px;
    right: 12px;
    width: auto;
    max-height: 80dvh;
    transform: translateY(12px);
  }
  .seg-insight.show {
    transform: none;
  }
  .mobile-seek-wrap {
    display: block;
  }
  .app {
    overflow: visible;
  }
  .mobile-seek {
    height: 26px;
  }
  .mobile-wave-meta {
    border: 0;
  }
}
.modal-overlay:not(.show),
.upload-overlay:not(.show),
.material-picker-backdrop:not(.show),
.seg-insight:not(.show),
.seg-insight-backdrop:not(.show) {
  visibility: hidden;
}
@media (min-width: 1600px) {
  .transcript-area {
    height: 460px;
  }
}
@media (max-width: 1190px) {
  .site-nav a {
    padding: 8px;
  }
  .header-inner {
    gap: 14px;
  }
  .main {
    grid-template-columns: 210px minmax(0, 1fr) 280px;
    gap: 12px;
    padding: 16px;
  }
  .panel-body,
  .right-panel .panel-body {
    padding: 16px;
  }
  .practice-question-heading {
    padding: 18px 18px 0;
  }
  .wave-container {
    margin: 20px 18px 0;
  }
  .desktop-wave-hint,
  .player-controls {
    margin-left: 18px;
    margin-right: 18px;
  }
  .transcript-heading {
    padding: 20px 18px 12px;
  }
  .transcript-area {
    margin: 0 18px 18px;
  }
  .player-controls {
    gap: 7px;
    padding: 12px;
  }
  .player-controls .speed-btn:first-child {
    display: none;
  }
  .left-settings {
    padding: 16px;
  }
}
@media (max-width: 1000px) {
  .main {
    grid-template-columns: 190px minmax(0, 1fr);
  }
  .right-panel {
    grid-column: 2;
    grid-row: 2;
  }
  .center-panel {
    grid-column: 2;
    grid-row: 1;
  }
  .left-panel {
    grid-row: 1 / span 2;
  }
  .right-panel #practiceAnswer {
    display: block;
  }
  .right-panel .source-card,
  .right-panel .exam-view-btn {
    display: none;
  }
  .right-panel .panel-body {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0;
  }
  .right-panel .answer-options {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .right-panel .panel-head {
    display: none;
  }
  .right-panel .mistake-toggle {
    margin-top: 20px;
  }
  .right-panel #practiceAnswer ~ div[style] {
    border-top: 1px solid var(--c-border);
    padding-top: 18px;
  }
  .collapse-nav .main {
    grid-template-columns: minmax(0, 1fr);
  }
  .collapse-nav .center-panel,
  .collapse-nav .right-panel {
    grid-column: 1;
  }
  .site-nav {
    gap: 0;
  }
  .brand small {
    font-size: 10px;
  }
  .brand strong {
    font-size: 12px;
  }
  .site-nav a {
    font-size: 11px;
  }
  .header-start {
    font-size: 12px;
    padding: 10px 12px;
  }
  .header-inner {
    gap: 10px;
  }
  .hero h1 {
    font-size: 54px;
  }
  .teacher-form {
    align-items: stretch;
  }
  .teacher-form .button {
    align-self: flex-end;
  }
}
@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    min-height: 72px;
    padding: 14px 20px;
    gap: 12px;
  }
  .brand strong {
    font-size: 13px;
  }
  .brand small {
    font-size: 11px;
  }
  .site-nav {
    order: 3;
    width: 100%;
    justify-content: center;
    gap: 4px;
    border-top: 1px solid var(--c-border);
    padding-top: 10px;
    overflow: auto;
  }
  .site-nav a {
    padding: 7px 12px;
    font-size: 12px;
  }
  .header-actions {
    margin-left: auto;
  }
  .header-start {
    padding: 10px 14px;
  }
  .home-page {
    margin-top: -124px;
    padding-top: 124px;
  }
  .landing-main {
    padding: 48px 20px;
  }
  .hero h1 {
    font-size: 40px;
    letter-spacing: -1px;
    max-width: 450px;
    line-height: 1.2;
  }
  .hero > p {
    font-size: 15px;
    margin-top: 20px;
    max-width: 430px;
  }
  .upload-shell {
    padding: 12px;
    border-radius: 24px;
    margin-top: 32px;
  }
  .upload-drop {
    padding: 24px 18px;
    min-height: 288px;
  }
  .upload-drop h2 {
    font-size: 18px;
  }
  .upload-drop p {
    font-size: 12px;
  }
  .upload-drop small {
    font-size: 11px;
  }
  .upload-note {
    font-size: 10px;
  }
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .feature-card {
    display: grid;
    grid-template-columns: 44px 1fr;
    column-gap: 16px;
    padding: 20px;
  }
  .feature-card .icon-box {
    grid-row: 1 / span 2;
  }
  .feature-card h3 {
    margin: 0 0 5px;
    font-size: 15px;
  }
  .section-block {
    margin-top: 56px;
  }
  .section-title h2 {
    font-size: 24px;
  }
  .steps-section {
    padding: 32px 24px;
  }
  .steps-grid {
    grid-template-columns: 1fr;
    gap: 26px;
  }
  .steps-grid > div {
    padding-left: 42px;
    position: relative;
  }
  .step-number {
    position: absolute;
    left: 0;
    top: 2px;
  }
  .steps-grid h3 {
    margin: 0;
  }
  .site-footer {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding-top: 16px;
    gap: 8px;
  }
  .page-container {
    padding: 32px 20px 48px;
    min-height: calc(100dvh - 220px);
  }
  .page-intro {
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 24px;
  }
  .page-intro h1 {
    font-size: 26px;
  }
  .page-intro p {
    font-size: 13px;
  }
  .mistake-grid,
  .advice-grid {
    grid-template-columns: 1fr;
  }
  .metrics-grid {
    gap: 10px;
  }
  .metrics-grid .surface-card {
    padding: 16px 12px;
  }
  .metric-value {
    font-size: 21px;
  }
  .metric-detail {
    font-size: 10px;
  }
  .surface-card {
    padding: 20px;
  }
  .teacher-form {
    flex-direction: column;
  }
  .teacher-form .button {
    align-self: stretch;
  }
  .setting-row {
    gap: 12px;
  }
  .setting-copy p {
    font-size: 11px;
  }
  .setting-row .icon-box {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
  }
  .history-item strong {
    max-width: 100%;
    font-size: 11px;
  }
  .history-item {
    padding: 12px;
  }
  .workspace-toolbar {
    padding: 20px 16px 4px;
    align-items: flex-start;
  }
  .workspace-label h1 {
    font-size: 20px;
    gap: 8px;
  }
  .workspace-label .eyebrow {
    font-size: 8px;
  }
  .workspace-tools {
    gap: 6px;
    flex-wrap: wrap;
    justify-content: flex-end;
  }
  .workspace-tools .btn {
    min-height: 36px;
    padding: 8px 10px;
    font-size: 11px;
  }
  .workspace-tools .btn:first-child {
    display: none;
  }
  .workspace-label .demo-badge {
    display: none;
  }
  .main,
  .collapse-nav .main {
    display: flex;
    flex-direction: column;
    padding: 12px 12px 88px;
    gap: 12px;
    overflow: visible;
  }
  .app {
    height: auto;
    min-height: calc(100dvh - 130px);
    padding: 0;
  }
  .panel {
    width: 100%;
    border-radius: 16px;
    min-height: 0;
    flex: none;
    max-height: none;
  }
  .left-panel {
    position: static;
    display: none !important;
  }
  .center-panel,
  .right-panel {
    display: none !important;
  }
  .panel.mobile-active {
    display: flex !important;
  }
  .left-panel.mobile-active {
    display: flex !important;
  }
  .panel-body {
    overflow: visible;
  }
  .panel-head {
    padding: 16px 18px;
  }
  .q-grid {
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
  }
  .q-btn {
    min-height: 42px;
    font-size: 14px;
    aspect-ratio: 1.2;
  }
  .q-stats {
    margin-bottom: 16px;
  }
  .q-stat-label {
    font-size: 12px;
  }
  .q-section-label {
    font-size: 12px;
  }
  .transcript-area {
    height: 360px;
    max-height: none;
    min-height: 200px;
    margin: 0 16px 18px;
    padding: 8px;
    overflow-y: auto;
  }
  .transcript-seg {
    font-size: 13px;
  }
  .transcript-heading {
    padding: 20px 16px 10px;
  }
  .transcript-heading span {
    font-size: 9px;
  }
  .practice-question-heading {
    padding: 18px 16px 0;
  }
  .practice-question-heading h2 {
    font-size: 16px;
  }
  .wave-container {
    margin: 20px 16px 0;
    padding: 0;
    background: var(--player-bg);
    border: 0;
    border-radius: 16px 16px 0 0;
  }
  .wave-viewport {
    height: auto;
    background: transparent;
  }
  .wave-viewport::before,
  .wave-viewport::after {
    display: none;
  }
  #waveCanvas {
    height: 120px !important;
  }
  .mobile-wave-meta {
    display: block;
    margin: 0 16px;
    background: var(--player-bg);
    padding: 4px;
  }
  .mobile-wave-time {
    color: #93c5fd;
    font-size: 12px;
  }
  .mobile-seek-wrap {
    display: block;
    margin: 0 16px;
    background: var(--player-bg);
    padding: 0 14px;
  }
  .mobile-seek::-webkit-slider-runnable-track {
    background: #334155;
  }
  .mobile-seek::-webkit-slider-thumb {
    border-color: #2563eb;
    background: #93c5fd;
    width: 18px;
    height: 18px;
    margin-top: -6px;
  }
  .player-controls {
    margin: 0 16px;
    padding: 12px;
    gap: 8px;
    flex-wrap: nowrap;
  }
  .player-controls .time-display {
    font-size: 10px;
  }
  .player-controls .play-btn {
    height: 40px;
    width: 40px;
  }
  .player-controls .speed-btn {
    padding: 3px 7px;
  }
  .right-panel .answer-options {
    grid-template-columns: 1fr;
  }
  .right-panel .source-card {
    display: block;
  }
  .right-panel .panel-body {
    display: block;
    padding: 20px;
  }
  .right-panel .panel-head {
    display: flex;
  }
  .mobile-tabs {
    display: flex;
    position: fixed;
    left: 12px;
    right: 12px;
    bottom: max(12px, env(safe-area-inset-bottom));
    height: 64px;
    padding: 5px;
    background: var(--c-surface);
    border: 1px solid var(--c-border);
    border-radius: 18px;
    box-shadow: 0 8px 28px #0f172a1a;
    z-index: 35;
  }
  .mobile-tab {
    flex: 1;
    color: var(--c-text-sec);
    border-radius: 12px;
    padding: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex-direction: row;
  }
  .mobile-tab.active {
    background: var(--c-primary-light);
    color: var(--c-primary);
  }
  .mobile-tab-icon {
    width: 18px;
    height: 18px;
  }
  .mobile-tab-icon svg {
    width: 18px;
    height: 18px;
  }
  .mobile-tab-label {
    font-size: 12px;
    font-weight: 750;
  }
  .collapse-nav .left-panel.mobile-active {
    display: flex !important;
  }
  .seg-insight {
    max-height: 80dvh;
    bottom: 12px;
    left: 12px;
    right: 12px;
    width: auto;
    max-width: none;
    border-radius: 20px;
  }
  .seg-insight-body {
    padding: 18px;
  }
  .seg-insight-head {
    padding: 16px 18px;
  }
  .modal {
    width: calc(100vw - 24px) !important;
    max-width: 560px;
    padding: 22px;
    max-height: 85dvh;
  }
  .setting-row .field-label {
    min-width: 0;
  }
  .teacher-help {
    padding: 20px;
  }
}
@media (max-width: 390px) {
  .header-inner {
    padding-left: 12px;
    padding-right: 12px;
    gap: 8px;
  }
  .brand {
    gap: 8px;
  }
  .brand-icon {
    width: 34px;
    height: 34px;
    border-radius: 10px;
  }
  .brand strong {
    font-size: 11px;
  }
  .brand small {
    font-size: 10px;
  }
  .header-actions {
    gap: 6px;
  }
  .header-actions .theme-toggle {
    width: 34px;
    height: 36px;
  }
  .header-start {
    min-height: 36px;
    padding: 8px 10px;
    font-size: 10px;
  }
  .site-nav {
    gap: 0;
    justify-content: space-between;
  }
  .site-nav a {
    padding: 7px 8px;
    font-size: 11px;
  }
  .hero h1 {
    font-size: 35px;
  }
  .landing-main {
    padding-left: 16px;
    padding-right: 16px;
  }
  .upload-drop h2 {
    font-size: 17px;
  }
  .upload-drop {
    padding: 24px 12px;
  }
  .workspace-tools .btn {
    padding: 8px;
  }
  .workspace-label h1 {
    font-size: 18px;
  }
  .metrics-grid {
    grid-template-columns: 1fr;
  }
  .metrics-grid .surface-card {
    padding: 16px 20px;
  }
  .metric-value {
    font-size: 26px;
  }
  .player-controls .btn {
    padding: 3px 5px !important;
  }
  .setting-row {
    gap: 10px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}