/* ========== Design Tokens (Minimal) ========== */
:root {
  --c-primary: #0c0c09; /* 近黑主色 */
  --c-primary-dark: #0c0c09;
  --c-primary-light: #eeeee8;
  --c-on-primary: #ffffff;
  --c-primary-hover: #26261f;
  --c-bg: #f4f4f1; /* 暖白底 */
  --c-surface: #ffffff;
  --c-border: #dbdbd3;
  --c-text: #0c0c09;
  --c-text-sec: #57534e;
  --c-text-mute: #a8a29e;
  --c-mistake: #dc2626;
  --c-mistake-bg: #fef2f2;
  --c-master: #16a34a;
  --c-master-bg: #f0fdf4;
  --c-pending: #d6d3cd;
  --c-pending-bg: #efefeb;
  --c-warn: #d97706;
  --c-shadow: none;
  --c-shadow-lg: none;
  --body-bg: linear-gradient(
    135deg,
    #e0f2fe 0%,
    #ede9fe 35%,
    #fce7f3 70%,
    #e0f2fe 100%
  );
  --overlay-bg: rgba(15, 23, 42, 0.3);
  --c-tag-bg: #0c0c09;
  --c-tag-fg: #ffffff;
  --glass-bg: rgba(255, 255, 255, 0.78);
  --glass-border: rgba(255, 255, 255, 0.45);
  --glass-shadow:
    0 18px 48px rgba(12, 12, 9, 0.16), inset 0 1px 0 rgba(255, 255, 255, 0.65);
  --glass-divider: rgba(12, 12, 9, 0.08);
  --glass-chip-bg: rgba(255, 255, 255, 0.55);
  --glass-chip-border: rgba(12, 12, 9, 0.1);
  --glass-btn-bg: rgba(255, 255, 255, 0.7);
  --glass-muted-bg: rgba(12, 12, 9, 0.04);
  --glass-muted-border: rgba(12, 12, 9, 0.08);
  --glass-icon-bg: rgba(12, 12, 9, 0.06);
  --glass-icon-hover: rgba(12, 12, 9, 0.1);
  --r-sm: 4px;
  --r-md: 8px;
  --r-lg: 8px;
  --t-fast: 0.15s;
  --t-norm: 0.25s;
  --t-slow: 0.4s;
}
[data-theme="dark"] {
  color-scheme: dark;
  --c-primary: #eeeee8;
  --c-primary-dark: #d6d3cd;
  --c-primary-light: #2a2a26;
  --c-on-primary: #0c0c09;
  --c-primary-hover: #d6d3cd;
  --c-bg: #141412;
  --c-surface: #1e1e1b;
  --c-border: #3a3934;
  --c-text: #f4f4f1;
  --c-text-sec: #a8a29e;
  --c-text-mute: #78716c;
  --c-mistake: #f87171;
  --c-mistake-bg: #3b1515;
  --c-master: #4ade80;
  --c-master-bg: #142818;
  --c-pending: #57534e;
  --c-pending-bg: #2a2a26;
  --body-bg: linear-gradient(
    135deg,
    #0c1222 0%,
    #15102b 38%,
    #1a1510 72%,
    #0c1222 100%
  );
  --overlay-bg: rgba(0, 0, 0, 0.58);
  --c-tag-bg: #eeeee8;
  --c-tag-fg: #0c0c09;
  --glass-bg: rgba(30, 30, 27, 0.94);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow:
    0 18px 48px rgba(0, 0, 0, 0.5), inset 0 1px 0 rgba(255, 255, 255, 0.06);
  --glass-divider: rgba(255, 255, 255, 0.08);
  --glass-chip-bg: rgba(255, 255, 255, 0.08);
  --glass-chip-border: rgba(255, 255, 255, 0.14);
  --glass-btn-bg: rgba(255, 255, 255, 0.06);
  --glass-muted-bg: rgba(255, 255, 255, 0.05);
  --glass-muted-border: rgba(255, 255, 255, 0.1);
  --glass-icon-bg: rgba(255, 255, 255, 0.08);
  --glass-icon-hover: rgba(255, 255, 255, 0.14);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html,
body {
  height: 100%;
  overflow: hidden;
}
body {
  font-family:
    "Plus Jakarta Sans",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    "PingFang SC",
    "Microsoft YaHei",
    sans-serif;
  background: var(--body-bg);
  background-attachment: fixed;
  color: var(--c-text);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition:
    background var(--t-slow),
    color var(--t-norm);
}

.tnum {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}
button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
  transition: all var(--t-fast);
}
input {
  font-family: inherit;
  outline: none;
}

/* Upload overlay */
.upload-overlay {
  position: fixed;
  inset: 0;
  z-index: 150;
  background: var(--overlay-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-norm);
}
.upload-overlay.show {
  opacity: 1;
  pointer-events: all;
}
.upload-card {
  background: var(--c-surface);
  border-radius: var(--r-md);
  padding: 28px 36px;
  width: 380px;
  max-width: 90vw;
  text-align: center;
}
.upload-title {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 6px;
}
.upload-sub {
  font-size: 12px;
  color: var(--c-text-mute);
  margin-bottom: 16px;
}
.upload-progress-wrap {
  height: 6px;
  background: var(--c-pending-bg);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 8px;
}
.upload-progress-bar {
  height: 100%;
  width: 0%;
  background: var(--c-primary);
  transition: width 0.4s ease;
  border-radius: 3px;
}
.upload-pct {
  font-size: 13px;
  font-weight: 700;
  color: var(--c-primary);
}

/* ========== Layout ========== */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: relative;
  z-index: 1;
  background: var(--c-bg);
}
.topbar {
  height: 52px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  z-index: 10;
}
.topbar-left {
  display: flex;
  align-items: center;
  gap: 12px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo-mark {
  width: 28px;
  height: 28px;
  border-radius: var(--r-sm);
  display: block;
  object-fit: contain;
  flex-shrink: 0;
}
.logo-text {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.3px;
}
.logo-text span {
  color: var(--c-primary);
}
.demo-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-text-sec);
  display: flex;
  align-items: center;
  gap: 4px;
}
.demo-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-primary);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.4;
  }
}
.topbar-end {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}
.topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  flex-shrink: 0;
  border: 1px solid var(--c-border);
  background: var(--c-pending-bg);
  color: var(--c-text-sec);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  transition:
    border-color var(--t-fast),
    background var(--t-fast),
    box-shadow var(--t-fast),
    transform var(--t-fast),
    color var(--t-fast);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.theme-toggle:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  box-shadow: 0 2px 12px rgba(12, 12, 9, 0.08);
}
.theme-toggle:active {
  transform: scale(0.92);
}
[data-theme="dark"] .theme-toggle {
  background: var(--c-surface);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.06),
    0 1px 4px rgba(0, 0, 0, 0.2);
}
[data-theme="dark"] .theme-toggle:hover {
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 2px 12px rgba(0, 0, 0, 0.35);
}
.theme-toggle-track {
  position: relative;
  width: 18px;
  height: 18px;
}
.theme-icon {
  position: absolute;
  inset: 0;
  width: 18px;
  height: 18px;
  display: block;
  transition:
    opacity var(--t-norm),
    transform var(--t-norm);
}
.theme-icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}
.theme-icon-moon {
  opacity: 0;
  transform: rotate(-70deg) scale(0.55);
}
[data-theme="dark"] .theme-icon-sun {
  opacity: 0;
  transform: rotate(70deg) scale(0.55);
}
[data-theme="dark"] .theme-icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}
.class-code-input {
  width: 100px;
  padding: 5px 10px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  font-size: 12px;
  text-align: center;
  letter-spacing: 2px;
  color: var(--c-text);
  background: var(--c-surface);
}
.class-code-input:focus {
  border-color: var(--c-primary);
  outline: none;
}
.btn {
  padding: 6px 14px;
  border-radius: var(--r-sm);
  font-size: 12px;
  font-weight: 600;
  transition: all var(--t-fast);
}
.btn-primary {
  background: var(--c-primary);
  color: var(--c-on-primary);
}
.btn-primary:hover {
  background: var(--c-primary-hover);
}
.btn-ghost {
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-text-sec);
}
.btn-ghost:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
}

/* ========== Main 3-column ========== */
.main {
  flex: 1;
  display: flex;
  gap: 12px;
  padding: 12px;
  overflow: hidden;
}
.panel {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.panel-head {
  padding: 10px 14px;
  border-bottom: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.panel-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--c-text-sec);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 12px 14px;
}

/* ========== Left: Question Grid ========== */
.left-panel {
  width: 240px;
  flex-shrink: 0;
}
.q-stats {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}
.q-stat {
  flex: 1;
  text-align: center;
  padding: 8px 4px;
  border-radius: var(--r-sm);
  font-size: 11px;
  border: 1px solid var(--c-border);
}
.q-stat-num {
  font-size: 18px;
  font-weight: 800;
}
.q-stat-label {
  color: var(--c-text-mute);
  margin-top: 2px;
}
.q-stat.master {
  background: var(--c-master-bg);
}
.q-stat.master .q-stat-num {
  color: var(--c-master);
}
.q-stat.mistake {
  background: var(--c-mistake-bg);
}
.q-stat.mistake .q-stat-num {
  color: var(--c-mistake);
}
.q-stat.pending {
  background: var(--c-pending-bg);
}
.q-stat.pending .q-stat-num {
  color: var(--c-text-sec);
}

.q-section-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--c-text-mute);
  margin: 10px 0 6px;
  padding-left: 2px;
}
.q-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}
.q-btn {
  aspect-ratio: 1;
  border-radius: var(--r-sm);
  font-size: 13px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  border: 1px solid var(--c-border);
  transition: all var(--t-fast);
  background: var(--c-surface);
  color: var(--c-text-mute);
}
.q-btn.pending {
  background: var(--c-surface);
  color: var(--c-text-mute);
  border-color: var(--c-border);
}
.q-btn.heard {
  background: var(--c-primary);
  color: var(--c-on-primary);
  border-color: var(--c-primary);
}
.q-btn.mistake {
  background: var(--c-mistake);
  color: #fff;
  border-color: var(--c-mistake);
}
.q-btn.current {
  outline: 2px solid var(--c-text);
  outline-offset: 2px;
}
.q-btn:hover {
  border-color: var(--c-text);
}
.q-btn .q-dot {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
}
.q-btn.mistake .q-dot {
  background: var(--c-mistake);
}

/* ========== Center: Waveform ========== */
.center-panel {
  flex: 1;
  min-width: 0;
}
.wave-container {
  position: relative;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  overflow: hidden;
}
.wave-viewport {
  position: relative;
  width: 100%;
  overflow: hidden;
}
.wave-track {
  position: relative;
  will-change: transform;
}
#waveCanvas {
  display: block;
  width: 100%;
  height: 120px;
  cursor: pointer;
}
@media (min-width: 769px) {
  #waveCanvas {
    height: 168px;
  }
}
.wave-time-axis {
  display: flex;
  justify-content: space-between;
  padding: 4px 8px;
  font-size: 10px;
  color: var(--c-text-mute);
}
.mobile-wave-meta {
  display: none;
}
.mobile-wave-time {
  font-size: 16px;
  font-weight: 800;
  color: var(--c-primary);
  text-align: center;
  padding: 8px 0 2px;
}
.playhead-fixed {
  left: 50% !important;
  transform: translateX(-50%);
  z-index: 5;
}
.playhead-fixed::before {
  left: -6px;
  width: 14px;
  height: 10px;
}
.wave-viewport::before,
.wave-viewport::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  width: 20px;
  z-index: 4;
  pointer-events: none;
}
.wave-viewport::before {
  left: 0;
  background: linear-gradient(90deg, var(--c-surface) 10%, transparent);
}
.wave-viewport::after {
  right: 0;
  background: linear-gradient(-90deg, var(--c-surface) 10%, transparent);
}
.anchor-bar {
  position: absolute;
  top: 0;
  height: 100%;
  width: 2px;
  background: var(--c-text-sec);
  cursor: pointer;
  transition: all var(--t-fast);
  z-index: 2;
}
.anchor-bar:hover {
  width: 4px;
  background: var(--c-text);
}
.anchor-bar.mistake {
  background: var(--c-mistake);
}
.anchor-bar.mistake:hover {
  background: var(--c-mistake);
}
.anchor-label {
  position: absolute;
  top: 2px;
  transform: translateX(-50%);
  font-size: 9px;
  font-weight: 700;
  padding: 1px 5px;
  border-radius: 3px;
  background: var(--c-tag-bg);
  color: var(--c-tag-fg);
  border: 1px solid rgba(0, 0, 0, 0.08);
  white-space: nowrap;
  pointer-events: none;
  z-index: 4;
}
@media (min-width: 769px) {
  .anchor-label {
    font-size: 10px;
    padding: 2px 6px;
  }
  .anchor-label.anchor-label-row-0 {
    top: 8px;
  }
  .anchor-label.anchor-label-row-1 {
    top: 32px;
  }
  .anchor-label.anchor-label-row-2 {
    bottom: 32px;
    top: auto;
  }
  .anchor-label.anchor-label-row-3 {
    bottom: 8px;
    top: auto;
  }
}
.anchor-bar.mistake .anchor-label {
  background: var(--c-mistake);
  color: #fff;
  border-color: transparent;
}
.desktop-wave-hint {
  display: none;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  padding: 2px 12px 6px;
  font-size: 11px;
  color: var(--c-text-mute);
}
@media (min-width: 769px) {
  .desktop-wave-hint {
    display: flex;
  }
}
.wave-zoom-controls {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}
.wave-zoom-controls .speed-btn {
  min-width: 28px;
  padding: 2px 8px;
}
.playhead {
  position: absolute;
  top: 0;
  height: 100%;
  width: 2px;
  background: #f59e0b;
  z-index: 3;
  pointer-events: none;
  transition: left var(--t-norm) linear;
  touch-action: none;
}
.playhead::before {
  content: "";
  position: absolute;
  top: -4px;
  left: -5px;
  width: 12px;
  height: 8px;
  background: #f59e0b;
  border-radius: 2px;
}
@media (min-width: 769px) {
  .wave-viewport {
    cursor: crosshair;
    user-select: none;
    -webkit-user-select: none;
  }
  .wave-viewport.dragging {
    cursor: grabbing;
  }
  .playhead {
    pointer-events: auto;
    cursor: ew-resize;
    z-index: 6;
  }
  .playhead::before {
    left: -7px;
    width: 16px;
    height: 14px;
    top: -5px;
    cursor: grab;
  }
  .playhead.scrubbing,
  .playhead.scrubbing::before {
    cursor: grabbing;
  }
  .playhead.scrubbing {
    transition: none !important;
  }
}

.player-controls {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-top: 1px solid var(--c-border);
}
.play-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--c-primary);
  color: var(--c-on-primary);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(12, 12, 9, 0.18);
  transition:
    transform var(--t-fast),
    box-shadow var(--t-fast),
    background var(--t-fast);
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
.play-btn:hover {
  background: var(--c-primary-hover);
  box-shadow: 0 4px 12px rgba(12, 12, 9, 0.22);
}
.play-btn:active {
  transform: scale(0.94);
}
.play-btn-icon {
  position: relative;
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}
.play-btn-icon svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}
.play-btn .pause-icon {
  opacity: 0;
}
.play-btn.playing .play-icon {
  opacity: 0;
}
.play-btn.playing .pause-icon {
  opacity: 1;
}
.time-display {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-text-sec);
  min-width: 80px;
}
.speed-btn {
  padding: 3px 10px;
  border-radius: var(--r-sm);
  font-size: 12px;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-text-sec);
}
.speed-btn:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.mobile-seek-wrap {
  display: none;
  padding: 0 14px;
}
.mobile-seek {
  width: 100%;
  height: 36px;
  margin: 0;
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  cursor: pointer;
  touch-action: none;
}
.mobile-seek::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 3px;
  background: var(--c-pending-bg);
}
.mobile-seek::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--c-primary);
  margin-top: -9px;
  border: 2px solid var(--c-surface);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.18);
}
.mobile-seek::-moz-range-track {
  height: 6px;
  border-radius: 3px;
  background: var(--c-pending-bg);
  border: none;
}
.mobile-seek::-moz-range-thumb {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--c-primary);
  border: 2px solid var(--c-surface);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.18);
}

.transcript-area {
  flex: 1;
  overflow-y: auto;
  padding: 8px 14px;
}
.transcript-seg {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 5px 8px;
  margin-bottom: 2px;
  border-radius: var(--r-sm);
  font-size: 13px;
  transition: background var(--t-fast);
  line-height: 1.6;
}
.transcript-seg:hover {
  background: var(--c-pending-bg);
}
.transcript-seg.active {
  background: var(--c-primary-light);
  border-left: 3px solid var(--c-primary);
}
.transcript-seg-main {
  flex: 1;
  min-width: 0;
  cursor: pointer;
}
.transcript-seg .ts {
  font-size: 11px;
  color: var(--c-text-mute);
  margin-right: 8px;
}
.transcript-seg.anchor-seg .transcript-seg-main {
  font-weight: 600;
}
.transcript-seg-play {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  margin-top: 1px;
  padding: 0;
  border: none;
  border-radius: 999px;
  background: rgba(12, 12, 9, 0.06);
  color: var(--c-text-sec);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition:
    background var(--t-fast),
    color var(--t-fast);
  -webkit-tap-highlight-color: transparent;
}
.transcript-seg-play svg {
  width: 12px;
  height: 12px;
  display: block;
}
.transcript-seg-play:hover {
  background: var(--c-primary);
  color: var(--c-on-primary);
}
.transcript-hidden-msg {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 120px;
  padding: 24px 14px;
  font-size: 13px;
  color: var(--c-text-mute);
  text-align: center;
}

/* ========== Right: Info Panel ========== */
.right-panel {
  width: 300px;
  flex-shrink: 0;
}
.source-card {
  padding: 12px;
  border-radius: var(--r-sm);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  margin-bottom: 12px;
}
.source-card-title {
  font-size: 11px;
  font-weight: 700;
  color: var(--c-text-mute);
  margin-bottom: 8px;
  letter-spacing: 0.02em;
}
.source-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  font-size: 12px;
  line-height: 1.5;
  padding: 5px 0;
  border-bottom: 1px dashed var(--c-border);
}
.source-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.source-label {
  flex-shrink: 0;
  color: var(--c-text-mute);
  min-width: 56px;
}
.source-value {
  flex: 1;
  text-align: right;
  color: var(--c-text-sec);
  word-break: break-all;
}
.source-link {
  color: var(--c-primary);
  font-weight: 600;
  text-decoration: none;
}
.source-link:hover {
  text-decoration: underline;
}
.source-link-btn {
  border: none;
  background: none;
  padding: 0;
  font: inherit;
  color: var(--c-primary);
  font-weight: 600;
  cursor: pointer;
  text-align: right;
}
.source-link-btn:hover {
  text-decoration: underline;
}
.q-info-card {
  padding: 12px;
  border-radius: var(--r-sm);
  background: var(--c-pending-bg);
  border: 1px solid var(--c-border);
  margin-bottom: 12px;
  transition: all var(--t-norm);
}
.q-info-card.has-data {
  background: var(--c-primary-light);
  border-color: var(--c-border);
}
.q-info-num {
  font-size: 28px;
  font-weight: 800;
  line-height: 1;
}
.q-info-type {
  font-size: 12px;
  color: var(--c-text-sec);
  margin-top: 4px;
}
.q-info-time {
  font-size: 12px;
  color: var(--c-text-mute);
  margin-top: 4px;
  font-variant-numeric: tabular-nums;
}
.exam-view-btn {
  width: 100%;
  margin-bottom: 12px;
}
.exam-view-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.exam-modal {
  width: min(520px, calc(100vw - 24px));
  max-height: min(82vh, 720px);
  display: flex;
  flex-direction: column;
}
.exam-modal .modal-title {
  flex-shrink: 0;
}
.exam-modal-body {
  flex: 1;
  overflow-y: auto;
  padding-right: 2px;
}
.exam-stem {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.65;
  color: var(--c-text);
  margin-bottom: 6px;
}
.exam-stem-zh {
  font-size: 12px;
  color: var(--c-text-sec);
  line-height: 1.6;
  margin-bottom: 12px;
}
.exam-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}
.exam-opt {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  background: var(--c-surface);
  color: var(--c-text);
  text-align: left;
  cursor: pointer;
  transition: all var(--t-fast);
}
.exam-opt:hover:not(:disabled) {
  border-color: var(--c-primary);
  background: var(--c-pending-bg);
}
.exam-opt-key {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  background: var(--c-pending-bg);
  color: var(--c-text-sec);
}
.exam-opt-text {
  flex: 1;
  font-size: 13px;
  line-height: 1.55;
}
.exam-opt.correct {
  border-color: var(--c-master);
  background: var(--c-master-bg);
}
.exam-opt.correct .exam-opt-key {
  background: var(--c-master);
  color: #fff;
}
.exam-opt.wrong {
  border-color: var(--c-mistake);
  background: var(--c-mistake-bg);
}
.exam-opt.wrong .exam-opt-key {
  background: var(--c-mistake);
  color: #fff;
}
.exam-opt.dim {
  opacity: 0.55;
}
.exam-opt:disabled {
  cursor: default;
}
.exam-result {
  padding: 10px 12px;
  border-radius: var(--r-sm);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 12px;
}
.exam-result.ok {
  background: var(--c-master-bg);
  color: var(--c-master);
  border: 1px solid var(--c-master);
}
.exam-result.bad {
  background: var(--c-mistake-bg);
  color: var(--c-mistake);
  border: 1px solid var(--c-mistake);
}
.exam-answer-panel {
  padding: 12px;
  border-radius: var(--r-sm);
  background: var(--c-pending-bg);
  border: 1px solid var(--c-border);
  margin-bottom: 12px;
}
.exam-answer-head {
  font-size: 12px;
  font-weight: 700;
  color: var(--c-text-sec);
  margin-bottom: 8px;
}
.exam-answer-meta {
  font-size: 13px;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: 8px;
  line-height: 1.5;
}
.exam-explanation {
  font-size: 12px;
  color: var(--c-text-sec);
  line-height: 1.7;
  white-space: pre-wrap;
}
.exam-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
  padding-top: 4px;
}

.mistake-toggle {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}
.mistake-btn {
  flex: 1;
  padding: 8px;
  border-radius: var(--r-sm);
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  color: var(--c-text-sec);
  text-align: center;
  transition: all var(--t-fast);
}
.mistake-btn.mark-mistake {
  border-color: var(--c-mistake);
  color: var(--c-mistake);
  background: var(--c-mistake-bg);
}
.mistake-btn.mark-master {
  border-color: var(--c-master);
  color: var(--c-master);
  background: var(--c-master-bg);
}
.mistake-btn:hover {
  border-color: var(--c-text);
  color: var(--c-text);
}

.seg-insight {
  position: fixed;
  z-index: 120;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%) scale(0.96);
  width: min(420px, calc(100vw - 28px));
  max-height: min(78vh, 640px);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: 16px;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--glass-shadow);
  opacity: 0;
  pointer-events: none;
  transition:
    opacity var(--t-fast),
    transform var(--t-fast);
}
.seg-insight.show {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, -50%) scale(1);
}
.seg-insight:not(.show) .seg-insight-text.seg-insight-loading,
.modal-overlay:not(.show) .ai-scan-text,
.modal-overlay:not(.show) .mistake-review-scan-text {
  animation: none !important;
  background-image: none !important;
  color: var(--c-text-sec);
  -webkit-text-fill-color: var(--c-text-sec);
}
.modal-overlay:not(.show),
.seg-insight:not(.show),
.seg-insight-backdrop:not(.show) {
  backdrop-filter: none !important;
  -webkit-backdrop-filter: none !important;
}
.seg-insight-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 14px 10px;
  border-bottom: 1px solid var(--glass-divider);
  flex-shrink: 0;
}
.seg-insight-head img {
  width: 18px;
  height: 18px;
  display: block;
  flex-shrink: 0;
}
.seg-insight-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--c-text);
  flex: 1;
}
.seg-insight-close {
  width: 28px;
  height: 28px;
  border: none;
  border-radius: 8px;
  background: var(--glass-icon-bg);
  color: var(--c-text-sec);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  flex-shrink: 0;
}
.seg-insight-close:hover {
  background: var(--glass-icon-hover);
  color: var(--c-text);
}
.seg-insight-body {
  padding: 12px 14px 14px;
  overflow-y: auto;
  flex: 1;
}
.seg-insight-original {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.65;
  color: var(--c-text);
  margin-bottom: 10px;
}
.seg-insight-words {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 10px;
}
.seg-word {
  padding: 4px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--glass-chip-border);
  background: var(--glass-chip-bg);
  color: var(--c-text);
  cursor: pointer;
  transition: all var(--t-fast);
}
.seg-word:hover,
.seg-word.active {
  background: var(--c-primary);
  color: var(--c-on-primary);
  border-color: var(--c-primary);
}
.seg-word-audio {
  width: 24px;
  height: 24px;
  padding: 0;
  border: none;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  background: var(--glass-icon-bg);
  color: var(--c-text-sec);
  cursor: pointer;
  transition: all var(--t-fast);
}
.seg-word-audio svg {
  width: 13px;
  height: 13px;
  display: block;
}
.seg-word-audio:hover {
  background: var(--c-primary-light);
  color: var(--c-primary);
}
.seg-insight-btn.speaking {
  background: #dc2626;
  border-color: #dc2626;
  color: #fff;
}
.seg-insight-actions {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.seg-insight-btn {
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--c-border);
  background: var(--glass-btn-bg);
  color: var(--c-text-sec);
  cursor: pointer;
}
.seg-insight-btn:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.seg-insight-btn.primary {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-on-primary);
}
.seg-insight-section {
  margin-bottom: 10px;
}
.seg-insight-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--c-text-mute);
  margin-bottom: 4px;
}
.seg-insight-text {
  font-size: 13px;
  line-height: 1.65;
  color: var(--c-text);
}
.seg-insight-word-panel {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 12px;
  background: var(--glass-muted-bg);
  border: 1px solid var(--glass-muted-border);
}
.seg-insight-word-head {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}
.seg-insight-word-head strong {
  font-size: 15px;
  color: var(--c-text);
}
.seg-insight-word-pos {
  font-size: 11px;
  font-weight: 700;
  color: var(--c-primary);
  padding: 1px 6px;
  border-radius: 999px;
  background: var(--c-primary-light);
}
.seg-insight-word-head em {
  font-size: 12px;
  color: var(--c-text-mute);
  font-style: normal;
}
.seg-insight-backdrop {
  position: fixed;
  inset: 0;
  z-index: 119;
  background: var(--overlay-bg);
  backdrop-filter: blur(2px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-fast);
}
.seg-insight-backdrop.show {
  opacity: 1;
  pointer-events: auto;
}
@media (max-width: 768px) {
  .seg-insight {
    top: 50%;
    bottom: auto;
    max-height: min(
      68vh,
      calc(100dvh - 140px - env(safe-area-inset-bottom, 0px))
    );
    width: min(420px, calc(100vw - 24px));
  }
}

/* ========== Toast ========== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  padding: 10px 20px;
  border-radius: var(--r-md);
  background: var(--c-tag-bg);
  color: var(--c-tag-fg);
  border: 1px solid var(--c-border);
  font-size: 13px;
  font-weight: 600;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  opacity: 0;
  transition: all var(--t-norm);
  z-index: 100;
  pointer-events: none;
}
.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ========== Material Picker ========== */
.material-picker-backdrop {
  position: fixed;
  inset: 0;
  z-index: 110;
  background: transparent;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-norm);
}
.material-picker-backdrop.show {
  opacity: 1;
  pointer-events: all;
}
.material-picker {
  position: fixed;
  z-index: 111;
  width: min(320px, calc(100vw - 24px));
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.18);
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition:
    opacity var(--t-fast),
    transform var(--t-fast);
  overflow: hidden;
}
.material-picker.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}
.material-picker-head {
  padding: 12px 14px 10px;
  font-size: 13px;
  font-weight: 700;
  color: var(--c-text);
  border-bottom: 1px solid var(--c-border);
}
.material-picker-levels {
  display: flex;
  gap: 6px;
  padding: 10px 12px 8px;
}
.material-picker-level {
  flex: 1;
  padding: 6px 10px;
  border-radius: var(--r-sm);
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  border: 1px solid var(--c-border);
  background: var(--c-pending-bg);
  color: var(--c-text-sec);
  cursor: pointer;
  transition: all var(--t-fast);
}
.material-picker-level:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.material-picker-level.active {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-on-primary);
}
.material-picker-list {
  max-height: min(52vh, 280px);
  overflow-y: auto;
  padding: 4px 8px 10px;
}
.material-picker-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  width: 100%;
  padding: 10px 10px;
  border: none;
  border-radius: var(--r-sm);
  background: transparent;
  color: var(--c-text);
  font-size: 13px;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: background var(--t-fast);
}
.material-picker-item:hover {
  background: var(--c-pending-bg);
}
.material-picker-item.active {
  background: var(--c-primary-light);
  color: var(--c-primary);
  font-weight: 700;
}
.material-picker-item-check {
  flex-shrink: 0;
  font-size: 12px;
  color: var(--c-primary);
  opacity: 0;
}
.material-picker-item.active .material-picker-item-check {
  opacity: 1;
}
.material-picker-empty {
  padding: 20px 14px 24px;
  text-align: center;
  font-size: 12px;
  color: var(--c-text-mute);
  line-height: 1.6;
}
@media (max-width: 768px) {
  .material-picker-backdrop.show {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--overlay-bg);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    padding: 16px;
  }
  .material-picker {
    position: relative;
    top: auto !important;
    left: auto !important;
    right: auto !important;
  }
}

/* ========== Modal (Glass) ========== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--overlay-bg);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--t-norm);
  z-index: 200;
  pointer-events: none;
}
.modal-overlay.show {
  opacity: 1;
  pointer-events: all;
}
.modal {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
  padding: 24px;
  width: 520px;
  max-width: 90vw;
  max-height: 80vh;
  overflow-y: auto;
}
.modal-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 12px;
}
.modal-close {
  float: right;
  font-size: 20px;
  color: var(--c-text-mute);
  cursor: pointer;
  line-height: 1;
}
.modal-close:hover {
  color: var(--c-text);
}

.profile-modal-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px 10px;
  margin-bottom: 16px;
}
.profile-modal-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  min-width: 0;
  padding: 0 2px;
}
.profile-ring-wrap {
  position: relative;
  margin: 0 auto;
  flex-shrink: 0;
}
.profile-ring-wrap svg {
  display: block;
}
.profile-ring-text {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  line-height: 1;
  pointer-events: none;
}
.profile-modal-label {
  margin-top: 10px;
  font-size: 12px;
  font-weight: 600;
  line-height: 1.35;
  max-width: 100%;
  word-break: break-word;
}
.profile-modal-stats {
  font-size: 11px;
  color: var(--c-text-mute);
  margin-top: 4px;
  line-height: 1.4;
}

.csv-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
  margin-top: 8px;
}
.csv-table th,
.csv-table td {
  padding: 6px 8px;
  text-align: left;
  border-bottom: 1px solid var(--c-border);
}
.csv-table th {
  font-weight: 600;
  color: var(--c-text-sec);
  background: var(--c-bg);
}

.mistake-review-head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.mistake-review-badge {
  font-size: 11px;
  color: var(--c-text-mute);
  font-weight: 600;
}
.mistake-review-overview {
  padding: 10px 12px;
  border-radius: var(--r-sm);
  background: var(--c-primary-light);
  font-size: 13px;
  line-height: 1.6;
  margin-bottom: 14px;
}
.mistake-review-section {
  margin-bottom: 14px;
}
.mistake-review-section h4 {
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 8px;
}
.mistake-review-card {
  padding: 10px 12px;
  border-radius: var(--r-sm);
  background: var(--c-pending-bg);
  border: 1px solid var(--c-border);
  margin-bottom: 8px;
  font-size: 13px;
  line-height: 1.6;
}
.mistake-review-card.mistake {
  border-color: rgba(220, 38, 38, 0.2);
  background: var(--c-mistake-bg);
}
.mistake-review-card.correct {
  border-color: rgba(34, 197, 94, 0.2);
  background: var(--c-master-bg);
}
.mistake-review-q {
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--c-text-sec);
}
.mistake-review-focus {
  margin-top: 6px;
  font-size: 12px;
  color: var(--c-primary);
  font-weight: 600;
}
.mistake-review-plan {
  margin: 0;
  padding-left: 18px;
  font-size: 13px;
  line-height: 1.7;
}
.mistake-review-plan li {
  margin-bottom: 6px;
}
.mistake-review-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 36px 0;
  font-size: 13px;
}
.mistake-review-loading-icon {
  flex-shrink: 0;
  animation: mistakeReviewPulse 2.4s ease-in-out infinite;
}
.ai-scan-text,
.mistake-review-scan-text,
.seg-insight-loading {
  font-weight: 600;
  letter-spacing: 0.02em;
  background: linear-gradient(
    105deg,
    var(--c-text-mute) 0%,
    var(--c-text-mute) 38%,
    #4f8ef7 46%,
    #b8d4ff 50%,
    #4f8ef7 54%,
    var(--c-text-mute) 62%,
    var(--c-text-mute) 100%
  );
  background-size: 280% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  animation: aiScan 2.2s ease-in-out infinite;
}
.mistake-review-scan-text {
  font-size: 14px;
}
@keyframes aiScan {
  0% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}
@keyframes mistakeReviewPulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.65;
    transform: scale(0.94);
  }
}
@media (prefers-reduced-motion: reduce) {
  .ai-scan-text,
  .mistake-review-scan-text,
  .seg-insight-loading {
    animation: none;
    background: none;
    color: var(--c-text-sec);
    -webkit-text-fill-color: var(--c-text-sec);
  }
  .mistake-review-loading-icon {
    animation: none;
  }
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--c-pending);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--c-text-mute);
}

/* ========== Mobile helpers (hidden on desktop) ========== */
.mobile-tabs {
  display: none;
}
.mobile-menu-btn {
  display: none;
}