/* =====================================================================
   雅思词汇 · 暗色主题设计体系
   布局尺寸与动画严格对齐原站 (leonwang.cc/ielts-vocab)，仅重做配色：
   原站的 body.dark 是浅色版的补丁（#0f172a 底 + 白卡），这里改为
   以暗色为第一性设计：更深的底色、分层辉光、半透明面板、低饱和描边。
   ===================================================================== */

.flash-dialog { position: fixed; inset: 0; margin: auto; width: min(680px, calc(100vw - 32px)); max-height: calc(100dvh - 32px); padding: 28px; border: 1px solid var(--border-strong); border-radius: 28px; background: var(--card-bg); color: var(--text); box-shadow: var(--shadow); overflow: auto; }
.flash-dialog::backdrop { background: rgba(3, 7, 18, .8); backdrop-filter: blur(8px); }
.flash-header, .flash-meta { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.flash-header { margin-bottom: 22px; }
.flash-eyebrow { color: var(--accent); font-size: .9rem; letter-spacing: .06em; }
.flash-meta { color: var(--text-secondary); font-size: .875rem; }
.flash-content { padding: 24px 0; min-height: 260px; }
.flash-content h2 { margin: 0 0 8px; font-size: clamp(2rem, 6vw, 3rem); line-height: 1.2; overflow-wrap: anywhere; }
.flash-phonetic { color: var(--text-secondary); font-size: 1rem; }
.flash-phonetic span { margin-left: 12px; }
.flash-meaning { font-size: 1.25rem; line-height: 1.6; margin: 22px 0; }
.flash-example { margin: 0; padding: 4px 18px; border-left: 3px solid var(--accent); background: var(--accent-soft); border-radius: 0 12px 12px 0; }
.flash-example p { font-size: 1rem; line-height: 1.7; margin: 10px 0; }
.flash-example p + p, .flash-extra { color: var(--text-secondary); }
.flash-extra { font-size: .9rem; line-height: 1.7; }
.flash-footer { position: sticky; bottom: -28px; background: var(--card-bg); padding: 16px 0 4px; }
.flash-progress { display: block; width: 100%; height: 6px; margin: 12px 0 22px; border: 0; border-radius: 10px; overflow: hidden; background: var(--elevated); accent-color: var(--accent); }
.flash-progress::-webkit-progress-bar { background: var(--elevated); }
.flash-progress::-webkit-progress-value { background: var(--grad); border-radius: 10px; }
.flash-progress::-moz-progress-bar { background: var(--grad); }
.flash-actions { display: flex; gap: 12px; }
.flash-actions button { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px; text-align: center; padding: 14px 8px; font-size: 1rem; }
.flash-actions small { display: block; margin: 0; font-size: .875rem; opacity: .75; }
.flash-known { color: var(--correct); border-color: var(--correct); }
.flash-new { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
.flash-unsure { color: var(--warn); border-color: var(--warn); }
.flash-summary { text-align: center; padding: 28px 0; }
.flash-summary p { margin: 20px 0 28px; color: var(--text-secondary); }
:root {
  /* ---- 底色：三段渐进，避免死黑 ---- */
  --bg: #090e1a;
  --bg-glow-1: rgba(99, 102, 241, 0.13);
  --bg-glow-2: rgba(139, 92, 246, 0.10);
  --bg-glow-3: rgba(56, 189, 248, 0.07);

  /* ---- 面 ---- */
  --panel-bg: rgba(17, 25, 44, 0.78);
  --card-bg: #121b30;
  --card-bg-hover: #18233d;
  --elevated: #1a2540;
  --sidebar-bg: rgba(13, 20, 38, 0.96);

  /* ---- 描边：暗色下用低透明度白，比实心灰更透气 ---- */
  --border: rgba(148, 163, 184, 0.16);
  --border-strong: rgba(148, 163, 184, 0.30);
  --slot-border: #3a4763;

  /* ---- 文字 ---- */
  --text: #e8eefb;
  --text-secondary: #9aa8c4;
  --text-faint: #64748b;

  /* ---- 主色：沿用原站蓝紫渐变这一识别符号 ---- */
  --accent: #818cf8;
  --accent-2: #a78bfa;
  --accent-soft: rgba(129, 140, 248, 0.16);
  --accent-glow: rgba(129, 140, 248, 0.45);
  --grad: linear-gradient(135deg, #60a5fa, #a78bfa);

  /* ---- 语义色 ---- */
  --correct: #34d399;
  --correct-soft: rgba(52, 211, 153, 0.14);
  --wrong: #f87171;
  --wrong-soft: rgba(248, 113, 113, 0.14);
  --warn: #fbbf24;

  /* ---- 考频标签 ---- */
  --tag-core: #fb7185;
  --tag-high: #fbbf24;
  --tag-low: #94a3b8;
  --tag-recog: #34d399;

  --shadow: 0 25px 45px rgba(0, 0, 0, 0.55);
  --shadow-sm: 0 4px 14px rgba(0, 0, 0, 0.35);
  --radius-lg: 32px;
  --radius-md: 20px;
  --radius-sm: 12px;
  --font: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Roboto, system-ui, sans-serif;
  --mono: 'Cascadia Mono', 'JetBrains Mono', Consolas, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: var(--font);
  color: var(--text);
  min-height: 100vh;
  /* 分层辉光：让暗背景有纵深，而不是一块死色 */
  background:
    radial-gradient(900px 600px at 12% -5%, var(--bg-glow-1), transparent 60%),
    radial-gradient(800px 520px at 90% 8%, var(--bg-glow-2), transparent 62%),
    radial-gradient(700px 500px at 50% 108%, var(--bg-glow-3), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  transition: background 0.3s;
}

::selection { background: var(--accent-soft); color: #fff; }

/* ---- 滚动条 ---- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #2a3654; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #3b4a70; }
* { scrollbar-width: thin; scrollbar-color: #2a3654 transparent; }

/* =====================================================================
   通用组件
   ===================================================================== */

h1 {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 700;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 5px;
  letter-spacing: 0.5px;
}

button {
  font-family: inherit;
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 10px 18px;
  border-radius: 30px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
button:hover {
  border-color: var(--border-strong);
  color: var(--text);
  background: var(--elevated);
}
button:active { transform: scale(0.97); }
button:focus-visible, select:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
button.primary {
  background: var(--grad);
  border-color: transparent;
  color: #0b1020;
  font-weight: 700;
  box-shadow: 0 6px 18px rgba(129, 140, 248, 0.30);
}
button.primary:hover { filter: brightness(1.08); }

select {
  font-family: inherit;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 30px;
  padding: 9px 14px;
  font-size: 0.85rem;
  cursor: pointer;
  outline: none;
}
select:hover { border-color: var(--border-strong); }
option { background: #121b30; color: var(--text); }

input[type="text"] {
  font-family: inherit;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 14px;
  padding: 10px 14px;
  font-size: 0.9rem;
  outline: none;
  transition: all 0.2s;
}
input[type="text"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ---- 主面板 ----
   尺寸照搬原站：1000px 宽 / 32px 圆角 / 25px 内距 / 14px 列间距。
   此规则此前缺失（只剩 @media 里的移动端覆盖），导致桌面端没有面板底色、
   没有宽度上限、且 flex 列间距为 0 —— 已由 test-site.mjs 的选择器覆盖检查守住。 */
.container {
  width: 100%;
  max-width: 1000px;
  background: var(--panel-bg);
  backdrop-filter: blur(20px);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow), 0 0 0 1px var(--border);
  padding: 25px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: background 0.3s;
  position: relative;
  overflow: hidden;
}

.top-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

.mode-group, .tool-group {
  display: flex;
  gap: 6px;
  background: rgba(10, 16, 30, 0.55);
  padding: 5px;
  border-radius: 34px;
  border: 1px solid var(--border);
}

.mode-btn, .tool-btn {
  border: none;
  background: transparent;
  padding: 7px 14px;
  border-radius: 26px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  white-space: nowrap;
}
.mode-btn:hover, .tool-btn:hover { background: rgba(255, 255, 255, 0.05); color: var(--text); }
.mode-btn.active, .tool-btn.active {
  background: var(--grad);
  color: #0b1020;
  font-weight: 700;
  box-shadow: 0 4px 12px var(--accent-glow);
}

.user-panel {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-secondary);
}
.user-panel button { padding: 7px 12px; font-size: 0.78rem; }

.goal-progress {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  background: rgba(10, 16, 30, 0.55);
  padding: 6px 14px;
  border-radius: 30px;
  border: 1px solid var(--border);
}
.goal-bar {
  width: 90px;
  height: 6px;
  background: rgba(148, 163, 184, 0.18);
  border-radius: 10px;
  overflow: hidden;
}
.goal-fill {
  height: 100%;
  background: linear-gradient(90deg, #34d399, #60a5fa);
  border-radius: 10px;
  transition: width 0.3s ease;
  width: 0%;
}
.goal-progress button { padding: 3px 8px; font-size: 0.72rem; border-radius: 15px; }

.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(148, 163, 184, 0.14);
  border-radius: 10px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--grad);
  border-radius: 10px;
  transition: width 0.3s ease;
  box-shadow: 0 0 12px var(--accent-glow);
}

.stats {
  display: flex;
  justify-content: space-around;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px;
  font-weight: 500;
  color: var(--text-secondary);
}
.stats strong { color: var(--text); font-variant-numeric: tabular-nums; }

.mode-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 8px 20px;
  align-self: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
  flex-wrap: wrap;
}
.timer-display { font-weight: 700; color: var(--accent); margin-left: 8px; font-variant-numeric: tabular-nums; }
.timer-display.urgent { color: var(--wrong); animation: tick 0.6s infinite; }
@keyframes tick { 50% { opacity: 0.35; } }

.speech-status { font-size: 0.72rem; color: var(--text-faint); }

/* ---- 题干中文 ---- */
.chinese-meaning {
  font-size: 2.2rem;
  font-weight: 600;
  text-align: center;
  color: var(--text);
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1.35;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

/* ---- 字母槽：尺寸严格照原站 45x55 / 2rem / gap 10 ---- */
.letter-slots {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 10px 0;
}
.slot {
  width: 45px;
  height: 55px;
  border-bottom: 3px solid var(--slot-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  transition: all 0.2s;
  text-transform: lowercase;
  animation: fadeInLetter 0.15s ease;
  border-radius: 4px 4px 0 0;
}
@keyframes fadeInLetter {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}
.slot.active-slot {
  border-bottom-color: var(--accent);
  animation: pulse 1s infinite;
}
@keyframes pulse {
  0% { border-bottom-color: var(--accent); }
  50% { border-bottom-color: #93c5fd; box-shadow: 0 6px 18px rgba(129, 140, 248, 0.25); }
  100% { border-bottom-color: var(--accent); }
}
.slot.hint { color: var(--text-faint); font-style: italic; }
.slot.correct {
  border-bottom-color: var(--correct);
  color: var(--correct);
  background: var(--correct-soft);
  animation: bounceCorrect 0.4s ease;
}
.slot.wrong {
  border-bottom-color: var(--wrong);
  color: var(--wrong);
  background: var(--wrong-soft);
  animation: shakeWrong 0.4s ease;
}
.slot.word-separator {
  width: 18px;
  border-bottom-color: transparent;
}
@keyframes bounceCorrect {
  0% { transform: scale(1); } 50% { transform: scale(1.2); } 100% { transform: scale(1); }
}
@keyframes shakeWrong {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* ---- 手机输入用的原生 input：桌面隐藏，靠全局键盘事件驱动槽位 ---- */
.native-answer-input {
  display: none;
  width: min(520px, 100%);
  align-self: center;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 700;
  padding: 12px 16px;
  text-align: center;
  outline: none;
  text-transform: lowercase;
}
.native-answer-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
@media (pointer: coarse) { .native-answer-input { display: block; } }

.result-area {
  text-align: center;
  font-weight: 600;
  min-height: 28px;
  font-size: 1.02rem;
}
.result-area .ok { color: var(--correct); }
.result-area .bad { color: var(--wrong); }
.result-area .warn { color: var(--warn); }
.result-area .hintline { color: var(--text-secondary); font-weight: 400; font-size: 0.82rem; }

.example-box {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  color: var(--text);
  display: none;
  line-height: 1.55;
}
.example-box .en { font-style: italic; }
.example-box .cn { display: block; color: var(--text-secondary); font-size: 0.86rem; margin-top: 4px; }

.actions {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

/* ---- 错题本 / 生词本 ---- */
.book-row { display: flex; gap: 12px; flex-wrap: wrap; }
.book-panel {
  flex: 1;
  min-width: 260px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px;
}
.book-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
}
.book-header h3 { font-size: 0.95rem; color: var(--text); }
.book-header span { color: var(--text-faint); font-size: 0.8rem; }
.book-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
  max-height: 160px;
  overflow-y: auto;
}
.word-chip {
  background: var(--elevated);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 14px;
  font-size: 0.76rem;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 4px;
}
.word-chip:hover { border-color: var(--accent); color: var(--text); }
.word-chip b { color: var(--text); font-weight: 600; }
.word-chip .x { color: var(--text-faint); margin-left: 2px; }
.word-chip .x:hover { color: var(--wrong); }
.empty-note { color: var(--text-faint); font-size: 0.78rem; }

/* ---- 弹窗 ---- */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(3, 6, 14, 0.78);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  padding: 20px;
  animation: fadeInLetter 0.2s ease;
}
.modal-content {
  background: var(--panel-bg);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 28px;
  max-width: 420px;
  width: 100%;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.modal-content h2 { text-align: center; font-size: 1.5rem; }
.modal-content p { color: var(--text-secondary); text-align: center; line-height: 1.6; }
.report-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 6px 0;
}
.report-cell {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 6px;
  text-align: center;
}
.report-cell .v { font-size: 1.5rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.report-cell .l { font-size: 0.72rem; color: var(--text-faint); margin-top: 2px; }

/* ---- 侧边词表抽屉 ---- */
.sidebar-toggle {
  position: fixed;
  top: 18px;
  right: 18px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--panel-bg);
  border: 1px solid var(--border-strong);
  backdrop-filter: blur(10px);
  font-size: 1.2rem;
  padding: 0;
  justify-content: center;
  z-index: 1200;
  box-shadow: var(--shadow-sm);
}
.sidebar {
  position: fixed;
  top: 0;
  right: -380px;
  width: 360px;
  max-width: 92vw;
  height: 100vh;
  background: var(--sidebar-bg);
  backdrop-filter: blur(18px);
  border-left: 1px solid var(--border);
  z-index: 1300;
  transition: right 0.3s ease;
  display: flex;
  flex-direction: column;
  padding: 18px;
  gap: 12px;
}
.sidebar.open { right: 0; }
.sidebar-header { display: flex; justify-content: space-between; align-items: center; }
.sidebar-header h3 { font-size: 1.2rem; color: var(--text); }
.sidebar-header button { padding: 4px 10px; border-radius: 12px; }
.sidebar-search { width: 100%; }
.sidebar-list { overflow-y: auto; flex: 1; display: flex; flex-direction: column; gap: 2px; }
.sidebar-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-secondary);
  border: 1px solid transparent;
}
.sidebar-item:hover { background: var(--accent-soft); border-color: var(--border); }
.sidebar-item .word-text { font-weight: 600; flex: 1; color: var(--text); }
.sidebar-item .meaning-text {
  font-size: 0.75rem;
  color: var(--text-faint);
  max-width: 46%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.status-icon { width: 14px; text-align: center; }
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(3, 6, 14, 0.6);
  backdrop-filter: blur(2px);
  display: none;
  z-index: 1250;
}
.sidebar-overlay.active { display: block; }

/* =====================================================================
   词汇手册页 (handout)
   ===================================================================== */
body.browse {
  display: flex;
  flex-direction: row;
  align-items: stretch;
  justify-content: flex-start;
  padding: 0;
  overflow: hidden;
  height: 100vh;
}
.browse-sidebar {
  width: 220px;
  flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  padding: 26px 14px;
  display: flex;
  flex-direction: column;
  gap: 7px;
  overflow-y: auto;
}
.browse-sidebar h2 {
  font-size: 1.2rem;
  margin-bottom: 8px;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.browse-sidebar button {
  width: 100%;
  justify-content: flex-start;
  border-radius: 10px;
  padding: 9px 12px;
  font-size: 0.86rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.browse-sidebar button.active {
  background: var(--grad);
  color: #0b1020;
  font-weight: 700;
  box-shadow: 0 4px 14px var(--accent-glow);
}
.browse-main {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
}
.browse-main h1 {
  text-align: left;
  font-size: 1.7rem;
  -webkit-text-fill-color: var(--text);
  background: none;
  margin-bottom: 6px;
}
.browse-meta { color: var(--text-faint); font-size: 0.8rem; margin-bottom: 18px; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
  gap: 14px;
}
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 15px 12px;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 6px;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.45), 0 0 0 1px var(--accent-soft);
  background: var(--elevated);
}
.card .word { font-size: 1.35rem; font-weight: 700; color: var(--text); word-break: break-word; }
.card .phonetic { font-size: 0.74rem; color: var(--text-faint); font-family: var(--mono); min-height: 1em; }
.card .meaning { font-size: 0.84rem; color: var(--text-secondary); font-weight: 500; }
.badges { display: flex; gap: 5px; flex-wrap: wrap; justify-content: center; }

.pos {
  font-size: 0.7rem;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 2px 10px;
  border-radius: 20px;
  font-weight: 600;
}
.tag { font-size: 0.66rem; padding: 2px 9px; border-radius: 12px; font-weight: 700; }
.tag-核心 { background: rgba(251, 113, 133, 0.18); color: var(--tag-core); }
.tag-高频 { background: rgba(251, 191, 36, 0.16); color: var(--tag-high); }
.tag-低频 { background: rgba(148, 163, 184, 0.16); color: var(--tag-low); }
.tag-识记 { background: rgba(52, 211, 153, 0.16); color: var(--tag-recog); }
.card .card-actions { display: flex; gap: 10px; align-items: center; margin-top: auto; }

/* ---- 详情弹窗 ---- */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(3, 6, 14, 0.82);
  backdrop-filter: blur(10px);
  z-index: 1000;
  display: none;
  justify-content: center;
  align-items: center;
  padding: 20px;
}
.overlay.active { display: flex; }
.overlay-content {
  background: var(--panel-bg);
  border: 1px solid var(--border-strong);
  border-radius: 20px;
  box-shadow: var(--shadow);
  width: 900px;
  max-width: 92vw;
  max-height: 88vh;
  aspect-ratio: 16 / 9;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}
.overlay-scroll { flex: 1; overflow-y: auto; padding: 30px; }
.overlay-note-area {
  padding: 12px 30px 20px;
  border-top: 1px solid var(--border);
  background: rgba(9, 14, 26, 0.6);
  flex-shrink: 0;
}
.word-main { display: flex; align-items: baseline; gap: 12px; margin-bottom: 12px; flex-wrap: wrap; }
.word-main h2 { font-size: 2.2rem; color: var(--text); background: none; -webkit-text-fill-color: currentColor; }
.word-main .phonetic { font-size: 1.05rem; color: var(--text-faint); font-family: var(--mono); }
.close-btn {
  position: absolute;
  top: 14px;
  right: 18px;
  font-size: 1.5rem;
  background: none;
  border: none;
  color: var(--text-faint);
  z-index: 20;
  padding: 4px 10px;
}
.close-btn:hover { color: var(--text); background: none; }
.meaning-large { font-size: 1.3rem; color: var(--text); font-weight: 500; margin-bottom: 14px; }
.root-box {
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.2);
  padding: 10px 15px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: #fcd34d;
  margin-bottom: 10px;
}
.extra-box { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 10px; }
.lecture-note {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  min-height: 42px;
  resize: none;
  font-family: inherit;
  outline: none;
  overflow: hidden;
  line-height: 1.4;
  background: var(--card-bg);
}
.lecture-note:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.btn-icon {
  border: none;
  background: rgba(148, 163, 184, 0.12);
  cursor: pointer;
  font-size: 1rem;
  padding: 5px 9px;
  border-radius: 50%;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
}
.btn-icon:hover { background: var(--accent-soft); color: var(--text); }

.page-switch {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 1100;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  background: var(--panel-bg);
  border: 1px solid var(--border-strong);
  color: var(--text);
  text-decoration: none;
  font-size: 0.86rem;
  font-weight: 700;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}
.page-switch:hover { color: var(--accent); border-color: var(--accent); }

/* =====================================================================
   学习日历（GitHub 式提交墙）
   绿阶挂在"每日目标"上：达标 = 最亮。色相沿用 --correct(#34d399)，
   与判对时的槽位绿一致，不引入第二套语义色。
   ===================================================================== */
.heatmap-panel {
  --hm-cell: 12px;
  --hm-gap: 3px;
  --hm-label-w: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: rgba(18, 27, 48, 0.55);
  border: 1px solid var(--border);
}

.heatmap-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.heatmap-head h3 { margin: 0; font-size: 0.95rem; font-weight: 700; color: var(--text); }
.heatmap-stats {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  font-size: 0.75rem;
  color: var(--text-faint);
}
.heatmap-stats b { color: var(--text); font-weight: 700; }

/* 窄屏横向滚动，不压缩格子（压到 8px 以下就点不准也看不清） */
.heatmap-scroll { overflow-x: auto; overflow-y: hidden; padding-bottom: 2px; }

.heatmap-months {
  display: flex;
  gap: var(--hm-gap);
  /* 与 .heatmap-body 里"星期列 + 间距"等宽，月份标签才能和列对齐 */
  padding-left: calc(var(--hm-label-w) + var(--hm-gap));
  margin-bottom: 4px;
}
.hm-month {
  flex: 0 0 var(--hm-cell);
  width: var(--hm-cell);
  font-size: 10px;
  line-height: 1.2;
  color: var(--text-faint);
  white-space: nowrap;   /* 标签比格子宽，允许溢出；月份间隔 >=4 列不会互相压盖 */
}

.heatmap-body { display: flex; gap: var(--hm-gap); }
.heatmap-weekdays {
  display: flex;
  flex-direction: column;
  gap: var(--hm-gap);
  flex: 0 0 var(--hm-label-w);
  width: var(--hm-label-w);
}
.hm-wd {
  height: var(--hm-cell);
  font-size: 10px;
  line-height: var(--hm-cell);
  text-align: right;
  color: var(--text-faint);
}

.heatmap-grid { display: flex; gap: var(--hm-gap); }
.hm-col { display: flex; flex-direction: column; gap: var(--hm-gap); }

.hm-cell {
  flex: 0 0 auto;
  width: var(--hm-cell);
  height: var(--hm-cell);
  border-radius: 3px;
  background: rgba(148, 163, 184, 0.09);
}
.hm-cell.lv0 { background: rgba(148, 163, 184, 0.09); }
.hm-cell.lv1 { background: rgba(52, 211, 153, 0.28); }
.hm-cell.lv2 { background: rgba(52, 211, 153, 0.48); }
.hm-cell.lv3 { background: rgba(52, 211, 153, 0.72); }
.hm-cell.lv4 { background: #34d399; box-shadow: 0 0 8px rgba(52, 211, 153, 0.45); }
/* 必须排在 lv* 之后：同为两个 class 的选择器，靠后者覆盖前者 */
.hm-cell.blank { background: transparent; box-shadow: none; }
.hm-cell.today { outline: 1px solid var(--accent); outline-offset: 1px; }
.hm-cell:not(.blank):hover { outline: 1px solid var(--text-secondary); outline-offset: 1px; }

.heatmap-legend { display: flex; align-items: center; justify-content: flex-end; gap: 4px; }
.hm-legend-label { font-size: 0.7rem; color: var(--text-faint); margin: 0 3px; }

/* =====================================================================
   响应式
   ===================================================================== */
@media (max-width: 768px) {
  body { padding: 10px; align-items: flex-start; }
  .container { border-radius: 22px; padding: 16px; gap: 10px; }
  /* 小屏缩格但保持可辨；53 周仍需横向滚动 */
  .heatmap-panel { --hm-cell: 10px; --hm-label-w: 18px; padding: 12px; gap: 8px; }
  .heatmap-stats { gap: 9px; font-size: 0.7rem; }
  .heatmap-legend { justify-content: flex-start; }
  h1 { text-align: left; font-size: 1.08rem; line-height: 1.35; }
  .top-controls, .stats, .mode-indicator, .actions { width: 100%; }
  .mode-group, .tool-group { width: 100%; justify-content: center; }
  .mode-btn, .tool-btn, button { min-height: 42px; }
  .goal-progress { width: 100%; justify-content: center; flex-wrap: wrap; }
  .user-panel { width: 100%; }
  .chinese-meaning { min-height: 58px; font-size: 1.55rem; line-height: 1.35; }
  .letter-slots { gap: 5px; margin: 4px 0; }
  .slot {
    width: clamp(22px, 8vw, 36px);
    height: 44px;
    font-size: clamp(1.15rem, 6vw, 1.75rem);
  }
  .slot.word-separator { width: 10px; }
  .example-box { max-height: 116px; overflow-y: auto; font-size: 0.9rem; }
  .sidebar-toggle { top: auto; right: 14px; bottom: 14px; width: 48px; height: 48px; }

  body.browse { flex-direction: column; height: 100dvh; }
  .browse-sidebar {
    width: 100%;
    height: auto;
    max-height: 150px;
    flex-direction: row;
    overflow-x: auto;
    padding: 60px 10px 10px;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .browse-sidebar h2 { display: none; }
  .browse-sidebar button { width: auto; flex-shrink: 0; }
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .card .word { font-size: 1.05rem; }
  .overlay-content { aspect-ratio: auto; height: 90vh; width: 100%; max-width: 100%; }
  .overlay-scroll { padding: 54px 16px 12px; }
  .word-main h2 { font-size: 1.75rem; }
}

/* 降低动效偏好：原站动画较多，这里给无障碍留出口 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* 词书管理：沿用本地站的暗色面板与蓝紫主色。 */
.library { align-items: stretch; }
.library header { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.library h1 { margin: 0; text-align: left; font-size: 1.8rem; }
.library h2 { font-size: 1.2rem; margin-bottom: 12px; }
.library section { padding: 24px 0; border-bottom: 1px solid var(--border); }
.library p { color: var(--text-secondary); font-size: .95rem; line-height: 1.7; margin: 10px 0; }
.library a, #manageBooks { color: var(--accent); text-decoration: none; padding: 8px; }
.library-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; margin: 16px 0; }
.library label { display: flex; flex-direction: column; gap: 8px; font-size: .95rem; margin: 12px 0; }
.library input, .library select { max-width: 100%; min-width: 0; width: 100%; padding: 10px 12px; background: var(--card-bg); color: var(--text); border: 1px solid var(--border-strong); border-radius: 10px; font: inherit; }
.library-fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(200px, 100%), 1fr)); gap: 8px 18px; margin: 16px 0; }
.library-book { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; padding: 18px; margin: 14px 0; border: 1px solid var(--border); background: var(--card-bg); border-radius: var(--radius-sm); }
.library-book > div { flex: 1; min-width: 160px; overflow-wrap: anywhere; }
.library-table { width: 100%; overflow-x: auto; margin: 18px 0; }
.library table { width: 100%; border-collapse: collapse; text-align: left; }
.library td, .library th { padding: 12px; border-bottom: 1px solid var(--border); overflow-wrap: anywhere; min-width: 90px; }
.library button:disabled { opacity: .45; cursor: not-allowed; }
#libraryStatus { color: var(--accent); min-height: 1.8em; }
#storageWarning { position: fixed; z-index: 9999; left: 16px; right: 16px; bottom: 16px; padding: 14px; border: 1px solid var(--warn); background: var(--card-bg); color: var(--warn); border-radius: 12px; }
#bookSelect { max-width: 100%; min-width: 0; }
.word-group { width: 100%; display: flex; flex-direction: column; gap: 8px; padding: 12px; border: 1px solid var(--border); border-radius: 12px; }
.word-group > strong { color: var(--text); }
.word-group .word-chip { max-width: 100%; flex-wrap: wrap; overflow-wrap: anywhere; }
.word-chip small { color: var(--text-secondary); font-size: .75rem; }
[hidden] { display: none !important; }

/* 模式首页与释义选择练习 */
.mode-home { max-width: 960px; margin: 7vh auto; gap: 22px; text-align: center; }
.home-eyebrow { color: var(--accent); font-size: .9rem; letter-spacing: .12em; margin: 0; }
.home-intro, .home-note, .choice-help { color: var(--text-secondary); line-height: 1.8; }
.home-intro { margin: 0; font-size: 1.05rem; }
.mode-cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; margin: 20px 0 0; }
.mode-card { display: flex; flex-direction: column; align-items: flex-start; gap: 16px; padding: 32px; text-align: left; text-decoration: none; color: var(--text); border: 1px solid var(--border-strong); border-radius: 24px; background: var(--panel-bg); transition: border-color .2s, transform .2s; }
.mode-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.mode-card-icon { font-size: 2.3rem; }
.mode-card h2, .mode-card p { margin: 0; }
.mode-card p { color: var(--text-secondary); line-height: 1.8; flex: 1; }
.mode-card-action { color: var(--accent); font-weight: 700; padding-top: 12px; }
.home-note { font-size: .85rem; }
.home-links { display: flex; gap: 28px; justify-content: center; flex-wrap: wrap; }
.home-links a { color: var(--text-secondary); }
.mode-card:focus-visible, .home-links a:focus-visible, .choice-option:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; }
body[data-practice="choice"] #modeGroup, body[data-practice="choice"] #hintToggle, body[data-practice="choice"] #flashStudyBtn, body[data-practice="choice"] #answerInput, body[data-practice="choice"] #letterSlots { display: none; }
body[data-practice="choice"] #chineseDisplay { font-size: clamp(2rem, 5vw, 3rem); overflow-wrap: anywhere; min-height: 90px; display: grid; place-items: center; }
.choice-options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; width: 100%; }
.choice-option { display: flex; align-items: center; gap: 16px; min-height: 94px; padding: 20px; border-radius: 16px; text-align: left; white-space: normal; overflow-wrap: anywhere; font-size: 1rem; line-height: 1.7; }
.choice-letter { display: grid; place-items: center; flex: 0 0 36px; height: 36px; background: var(--elevated); border-radius: 10px; font-weight: 700; }
.choice-option.correct { border-color: var(--correct); color: var(--correct); }
.choice-option.wrong { border-color: var(--wrong); color: var(--wrong); }
.choice-option:disabled { cursor: default; opacity: 1; }
.choice-help { text-align: center; font-size: .82rem; margin: 0; }
.known-panel { padding: 16px; border: 1px solid var(--border); border-radius: 16px; }
.known-panel summary { cursor: pointer; color: var(--text-secondary); }
.known-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.known-entry { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; padding: 8px; overflow-wrap: anywhere; }
.known-entry span { flex: 1; }
@media (max-width: 640px) { .mode-home { margin: 3vh auto; } .mode-cards, .choice-options { grid-template-columns: 1fr; } .mode-card { padding: 24px; } .choice-option { min-height: 76px; padding: 14px; } }
@media (prefers-reduced-motion: reduce) { .mode-card { transition: none; } .mode-card:hover { transform: none; } }

#homeLink { position: static; align-self: flex-start; margin-bottom: 4px; }
/* 今日安排、词条拓展与掌握记录 */
.today-panel { border: 1px solid var(--border-strong); border-radius: 22px; padding: 24px; text-align: left; background: var(--card-bg); }
.home-selects, .home-actions, .resume-row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.home-selects label { flex: 1; min-width: 130px; display: flex; flex-direction: column; gap: 6px; color: var(--text-secondary); }
.today-numbers { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 14px; margin: 24px 0; text-align: center; }
.today-numbers div { display: flex; flex-direction: column; gap: 6px; }
.today-numbers strong { font-size: 2rem; color: var(--accent); }
.today-numbers span, .resume-row span { color: var(--text-secondary); font-size: .85rem; }
.resume-row { margin: 20px 0; }
.home-actions button { justify-content: center; }
.today-panel button:disabled { opacity: .5; cursor: not-allowed; }
.review-plan { border-top: 1px solid var(--border); padding: 14px 0; }
.review-plan summary { cursor: pointer; }
.review-plan p { line-height: 1.7; overflow-wrap: anywhere; padding: 8px 0; border-bottom: 1px solid var(--border); }
.group-label { color: var(--text-secondary); text-align: center; margin: 0; font-size: .85rem; }
.learning-details { width: 100%; }
.learning-details[hidden] { display: none; }
.mastery-lines { border: 1px solid var(--border); padding: 12px 18px; border-radius: 14px; color: var(--text-secondary); font-size: .85rem; }
.mastery-lines p { margin: 6px 0; }
.word-enrichment { margin: 18px 0; padding: 18px; background: var(--panel-bg); border: 1px solid var(--border); border-radius: 16px; }
.word-detail h4 { margin: 18px 0 6px; color: var(--accent); font-size: .9rem; }
.word-detail p { white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.8; margin: 0; font-size: .9rem; }
.detail-note, .detail-sources { color: var(--text-secondary); font-size: .8rem; line-height: 1.7; }
.detail-sources a, .learning-details > a { color: var(--accent); }
.detail-editor { margin: 18px 0; }
.detail-editor summary { cursor: pointer; }
.detail-editor form, .detail-editor label { display: flex; flex-direction: column; gap: 10px; }
.detail-editor label { margin: 10px 0; font-size: .85rem; }
.detail-editor textarea { box-sizing: border-box; width: 100%; padding: 10px; font: inherit; color: var(--text); background: var(--card-bg); border: 1px solid var(--border); border-radius: 10px; resize: vertical; }
.detail-editor button { align-self: flex-start; }
@media (max-width:640px) { .today-panel { padding: 16px; } .home-actions { flex-direction: column; align-items: stretch; } .today-numbers strong { font-size: 1.6rem; } }

.answer-enrichment { margin: 12px 0; }
.answer-enrichment summary { cursor: pointer; color: var(--accent); font-size: .85rem; line-height: 1.7; }
.answer-enrichment a { color: var(--accent); }

.today-panel .heatmap-panel { margin: 20px 0; text-align: left; }