@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

  :root {
    --bg: #0d1117;
    --bg2: #161b22;
    --bg3: #21262d;
    --border: #30363d;
    --text: #e6edf3;
    --text2: #8b949e;
    --text3: #6e7681;
    --accent: #58a6ff;
    --accent2: #1f6feb;
    --green: #3fb950;
    --red: #f85149;
    --yellow: #d29922;
    --purple: #bc8cff;
    --orange: #e3b341;
    --cyan: #39d353;
    --key-bg: #21262d;
    --key-hover: #30363d;
    --key-active: #388bfd;
    --key-correct: #238636;
    --key-wrong: #da3633;
    --shadow: 0 8px 24px rgba(0,0,0,0.4);
  }

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

  body {
    font-family: 'Noto Sans SC', sans-serif;
    background: radial-gradient(circle at top right, #1a2035 0%, #0d1117 40%, #090c10 100%);
    color: var(--text);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }

  /* TOP BAR */
  #topbar {
    display: flex;
    align-items: center;
    padding: 0 20px;
    height: 52px;
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    gap: 24px;
    flex-shrink: 0;
    z-index: 10;
  }
  #topbar .logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 16px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 2px;
    white-space: nowrap;
  }
  .topbar-tools {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
  }
  .stat-group {
    display: flex;
    gap: 20px;
    align-items: center;
  }
  .stat-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
  }
  .stat-label { color: var(--text3); font-size: 11px; text-transform: uppercase; letter-spacing: 1px; }
  .stat-val { font-family: 'JetBrains Mono', monospace; font-size: 15px; font-weight: 600; color: var(--accent); }
  #btn-reset {
    margin-left: 16px;
    padding: 6px 14px;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text2);
    border-radius: 6px;
    cursor: pointer;
    font-size: 12px;
    font-family: 'Noto Sans SC', sans-serif;
    transition: all .2s;
  }
  #btn-reset:hover { border-color: var(--accent); color: var(--accent); }
  .top-toggle-btn { background:transparent; border:1px solid var(--border); color:var(--text2); padding:5px 12px; border-radius:14px; font-size:12px; cursor:pointer; font-family:'Noto Sans SC',sans-serif; transition:all .2s; }
  .top-toggle-btn:hover { border-color:var(--accent); color:var(--accent); }
  .top-toggle-btn.active { background:rgba(88,166,255,0.15); border-color:var(--accent); color:var(--accent); }
  #btn-data-center, #btn-about-app {
    padding: 5px 10px;
    min-width: 44px;
  }

  .desktop-modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 260;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: rgba(5, 8, 12, 0.6);
    backdrop-filter: blur(10px);
  }
  .desktop-modal-card {
    width: min(560px, 100%);
    background: linear-gradient(180deg, rgba(24, 30, 41, 0.96), rgba(15, 19, 28, 0.98));
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 18px;
    box-shadow: 0 24px 80px rgba(0,0,0,0.38);
    overflow: hidden;
  }
  .desktop-modal-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    padding: 18px 20px 14px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .desktop-modal-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
  }
  .desktop-modal-subtitle {
    font-size: 12px;
    color: var(--text3);
    margin-top: 4px;
    line-height: 1.5;
  }
  .desktop-modal-close {
    width: 34px;
    height: 34px;
    border-radius: 10px;
    border: 1px solid rgba(255,255,255,0.08);
    background: rgba(255,255,255,0.04);
    color: var(--text2);
    cursor: pointer;
    transition: all .18s;
    flex-shrink: 0;
  }
  .desktop-modal-close:hover {
    color: var(--text);
    border-color: rgba(88,166,255,0.45);
  }
  .desktop-modal-body {
    padding: 18px 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
  }
  .desktop-modal-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 12px;
  }
  .desktop-mini-stat {
    padding: 12px 14px;
    border-radius: 14px;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.06);
  }
  .desktop-mini-stat .value {
    font-size: 22px;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 4px;
  }
  .desktop-mini-stat .label {
    font-size: 11px;
    color: var(--text3);
    letter-spacing: .6px;
    text-transform: uppercase;
  }
  .desktop-modal-section {
    display: flex;
    flex-direction: column;
    gap: 10px;
  }
  .desktop-modal-section p {
    font-size: 13px;
    color: var(--text2);
    line-height: 1.7;
  }
  .desktop-modal-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
  }
  .desktop-modal-btn {
    height: 38px;
    padding: 0 14px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.08);
    background: rgba(255,255,255,0.04);
    color: var(--text);
    cursor: pointer;
    font-size: 13px;
    font-family: 'Noto Sans SC', sans-serif;
    transition: all .18s;
  }
  .desktop-modal-btn:hover {
    border-color: rgba(88,166,255,0.45);
    color: var(--accent);
  }
  .desktop-modal-btn.primary {
    background: rgba(88,166,255,0.12);
    border-color: rgba(88,166,255,0.32);
    color: #cfe4ff;
  }
  .desktop-modal-input {
    width: 100%;
    height: 42px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.08);
    background: rgba(255,255,255,0.04);
    color: var(--text);
    padding: 0 14px;
    font-size: 14px;
    outline: none;
    transition: border-color .18s, background .18s;
  }
  .desktop-modal-input:focus {
    border-color: rgba(88,166,255,0.45);
    background: rgba(255,255,255,0.06);
  }
  .desktop-modal-input::placeholder {
    color: var(--text3);
  }
  .desktop-modal-note {
    font-size: 12px;
    color: var(--text3);
    line-height: 1.7;
    padding: 12px 14px;
    border-radius: 14px;
    background: rgba(255,255,255,0.03);
    border: 1px dashed rgba(255,255,255,0.08);
  }

  /* MAIN LAYOUT */
  #main {
    display: flex;
    flex: 1;
    overflow: hidden;
  }

  /* SIDEBAR */
  #sidebar {
    width: 180px;
    background: var(--bg2);
    border-right: 1px solid var(--border);
    padding: 12px 0;
    flex-shrink: 0;
    overflow-y: auto;
  }
  .nav-section { padding: 8px 14px 4px; }
  .nav-section-title {
    font-size: 10px;
    color: var(--text3);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: 500;
  }
  .nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 14px;
    cursor: pointer;
    border-radius: 6px;
    margin: 2px 8px;
    font-size: 13px;
    color: var(--text2);
    transition: all .15s;
    user-select: none;
  }
  .nav-item:hover { background: var(--bg3); color: var(--text); }
  .nav-item.active { background: rgba(88,166,255,0.12); color: var(--accent); }
  .nav-item .icon { font-size: 15px; width: 18px; text-align: center; flex-shrink: 0; }
  .nav-badge {
    margin-left: auto;
    font-size: 10px;
    background: var(--bg3);
    color: var(--text3);
    padding: 1px 5px;
    border-radius: 8px;
  }
  .nav-item.active .nav-badge { background: rgba(88,166,255,0.2); color: var(--accent); }

  /* CONTENT AREA */
  #content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }

  /* PRACTICE AREA */
  #practice-area {
    flex: 1;
    padding: 16px 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    background: transparent;
  }

  /* HEADERS & COMPACT LAYOUT */
  #header-area {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 10px;
    flex-shrink: 0;
  }
  .header-text { display: flex; flex-direction: column; gap: 4px; }
  #desc-text { font-size: 13px; color: var(--text2); line-height: 1.5; }
  #mode-title { font-size: 20px; font-weight: 700; background: linear-gradient(90deg, #58a6ff, #bc8cff); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

  /* SUB MODE TABS */
  #submode-panel { display: flex; align-items: center; }

  .panel {
    background: rgba(22, 27, 34, 0.4);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255,255,255,0.06);
    box-shadow: 0 8px 32px rgba(0,0,0,0.15);
    border-radius: 16px;
    padding: 24px;
  }
  .panel-title {
    font-size: 11px;
    color: var(--text3);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 8px;
    font-weight: 600;
  }

  /* EXERCISE DISPLAY */
  #exercise-panel { flex: 1; display: flex; flex-direction: column; min-height: 0; }
  #exercise-display {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    gap: 6px;
    padding-top: 4px;
  }
  .exercise-char-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
  }
  .ex-char {
    font-size: 36px;
    font-weight: 700;
    color: var(--text);
    padding: 8px 16px;
    background: var(--bg3);
    border-radius: 8px;
    border: 2px solid var(--border);
    min-width: 60px;
    text-align: center;
    transition: all .2s;
    line-height: 1;
  }
  .ex-char.current { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(88,166,255,0.15); }
  .ex-char.correct { border-color: var(--green); color: var(--green); background: rgba(63,185,80,0.08); }
  .ex-char.wrong { border-color: var(--red); color: var(--red); background: rgba(248,81,73,0.08); }

  .ex-code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    color: var(--text3);
    text-align: center;
    margin-top: 4px;
    letter-spacing: 2px;
  }
  .ex-hint {
    font-size: 12px;
    color: var(--yellow);
    text-align: center;
    margin-top: 2px;
  }

  /* Article/sentence practice text */
  #text-scroll-wrap {
    width: 100%;
    height: 156px;
    overflow: hidden;
    position: relative;
  }
  #text-scroll-wrap.compact-text-wrap {
    height: auto;
    min-height: 72px;
    max-height: 156px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  #text-display {
    font-size: 26px;
    line-height: 2.08;
    letter-spacing: 1px;
    padding: 4px 0;
    font-family: 'Noto Sans SC', sans-serif;
    width: 100%;
    text-align: left;
  }
  #text-display.compact-text-display {
    width: fit-content;
    max-width: 100%;
    margin: 0 auto;
    text-align: center;
  }
  #text-display span {
    display: inline-block;
    border-bottom: 2px solid transparent;
    padding: 0 1px;
    transition: color .1s;
    position: relative;
  }
  #text-display span.article-annotated-char {
    padding-top: 18px;
    vertical-align: bottom;
  }
  #text-display span.article-annotated-char ruby {
    ruby-position: over;
  }
  #text-display span.article-annotated-char rt {
    font-size: 13px;
    line-height: 1;
    color: var(--accent);
    letter-spacing: 0;
    user-select: none;
  }
  #text-display span.article-annotated-char .article-ruby-char {
    color: inherit;
  }
  #text-display span.done { color: var(--text3); }
  #text-display span.current {
    color: var(--text);
    border-bottom-color: var(--accent);
    background: rgba(88,166,255,0.08);
    border-radius: 2px;
  }
  #text-display span.wrong-char { color: var(--red); background: rgba(248,81,73,0.12); border-radius: 2px; }

  /* Space character: show as visible blank with underline */
  #text-display span.space-char {
    display: inline-block;
    min-width: 18px;
    border-bottom: 2px dashed var(--border);
    margin: 0 2px;
  }
  #text-display span.space-char.current {
    border-bottom: 2px solid var(--accent);
    background: rgba(88,166,255,0.08);
    border-radius: 2px;
  }
  #text-display span.space-char.done {
    border-bottom-color: var(--text3);
    background: transparent;
  }
  
  /* 英文指法练习专属：已练习内容显示为绿色 */
  body[data-mode="english"] #text-display span.done,
  body[data-mode="article"] #text-display span.done { color: var(--green); }
  body[data-mode="english"] #text-display span.space-char.done,
  body[data-mode="article"] #text-display span.space-char.done { border-bottom-color: var(--green); }

  /* KEYBOARD KEY practice */
  .key-practice-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    padding: 8px 0;
  }
  .key-target {
    font-family: 'JetBrains Mono', monospace;
    font-size: 28px;
    font-weight: 700;
    width: 64px;
    height: 64px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg3);
    border: 2px solid var(--border);
    border-radius: 8px;
    cursor: default;
    transition: all .15s;
    color: var(--text);
    line-height: 1;
    position: relative;
  }
  .key-target .sub { font-size: 10px; color: var(--text3); margin-top: 2px; font-weight: 400; font-family: 'Noto Sans SC', sans-serif; }
  .key-target.current { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(88,166,255,0.2); color: var(--accent); }
  .key-target.correct { border-color: var(--green); color: var(--green); background: rgba(63,185,80,0.1); }
  .key-target.wrong { border-color: var(--red); color: var(--red); background: rgba(248,81,73,0.1); }

  /* INPUT AREA */
  #input-area {
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 10px 0 0 0;
  }
  #input-wrap {
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: center;
    width: 100%;
  }
  #input-box {
    width: 100%;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 24px;
    font-family: 'JetBrains Mono', monospace;
    text-align: center;
    border-radius: 12px;
    padding: 12px 15px;
    outline: none;
    transition: all .2s;
    letter-spacing: 1px;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
  }
  #input-box:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(88,166,255,0.15); }
  #input-box.input-correct { border-color: var(--green); background: rgba(63,185,80,0.06); }
  #input-box.input-wrong { border-color: var(--red); background: rgba(248,81,73,0.06); }

  #btn-next {
    padding: 12px 24px;
    background: var(--accent2);
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-family: 'Noto Sans SC', sans-serif;
    font-weight: 500;
    transition: all .2s;
    white-space: nowrap;
  }
  #btn-next:hover { background: var(--accent); }

  .input-hint { font-size: 12px; color: var(--text3); margin-top: 8px; text-align: center; }
  .input-hint .key-pill {
    display: inline-block;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1px 6px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--text2);
  }

  /* FEEDBACK */
  #feedback-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .feedback-tag {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
  }
  .feedback-correct { background: rgba(63,185,80,0.15); color: var(--green); }
  .feedback-wrong { background: rgba(248,81,73,0.15); color: var(--red); }
  .feedback-neutral { background: var(--bg3); color: var(--text3); }

  /* VIRTUAL KEYBOARD */
  #keyboard-area {
    background: var(--bg2);
    border-top: 1px solid var(--border);
    padding: 12px 20px 14px;
    flex-shrink: 0;
  }
  .kb-row {
    display: flex;
    justify-content: center;
    gap: 5px;
    margin-bottom: 5px;
  }
  .kb-key {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--key-bg, var(--bg3));
    border: 1px solid var(--border);
    border-bottom: 3px solid rgba(0,0,0,0.4);
    border-radius: 6px;
    cursor: default;
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    font-weight: 600;
    color: var(--text2);
    transition: all .08s;
    user-select: none;
    position: relative;
    min-width: 42px;
    height: 42px;
  }
  .kb-key .wubi-hint {
    font-size: 8px;
    color: var(--text3);
    font-family: 'Noto Sans SC', sans-serif;
    font-weight: 300;
    line-height: 1;
    margin-top: 1px;
    letter-spacing: 0;
  }
  .kb-key.wide { min-width: 70px; font-size: 11px; }
  .kb-key.wider { min-width: 100px; }
  .kb-key.space { min-width: 200px; font-size: 11px; }
  .kb-key.highlight {
    background: var(--key-active, var(--accent)) !important;
    border-color: #58a6ff;
    border-bottom-color: var(--accent2);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(88,166,255,0.3);
  }
  .kb-key.pressed {
    transform: translateY(1px);
    border-bottom-width: 1px;
    background: var(--key-correct, var(--green)) !important;
    color: #fff;
  }
  .kb-key.wrong-press {
    background: var(--key-wrong, var(--red)) !important;
    color: #fff;
    transform: translateY(1px);
    border-bottom-width: 1px;
  }

  /* Finger color zones */
  .finger-0 { --fc: #ff7b72; } /* 左小 */
  .finger-1 { --fc: #ffa657; } /* 左无 */
  .finger-2 { --fc: #e3b341; } /* 左中 */
  .finger-3 { --fc: #7ee787; } /* 左食 */
  .finger-4 { --fc: #7ee787; } /* 左食延伸 */
  .finger-5 { --fc: #58a6ff; } /* 右食延伸 */
  .finger-6 { --fc: #58a6ff; } /* 右食 */
  .finger-7 { --fc: #bc8cff; } /* 右中 */
  .finger-8 { --fc: #d2a8ff; } /* 右无 */
  .finger-9 { --fc: #ff7b72; } /* 右小 */
  .kb-key { border-top: 2px solid var(--fc, transparent); }

  /* STATS PANEL */
  #stats-panel { flex-shrink: 0; }
  .stats-grid {
    display: grid;
    grid-template-columns: repeat(6,1fr);
    gap: 10px;
  }
  .stat-box {
    background: var(--bg3);
    border-radius: 8px;
    padding: 10px;
    text-align: center;
  }
  .stat-box .sval {
    font-family: 'JetBrains Mono', monospace;
    font-size: 22px;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
  }
  .stat-box .slabel {
    font-size: 10px;
    color: var(--text3);
    margin-top: 4px;
    text-transform: uppercase;
    letter-spacing: 1px;
  }
  .dashboard-scope-note {
    font-size: 13px;
    color: var(--text3);
    padding: 10px 14px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,.06);
    background: linear-gradient(135deg, rgba(88,166,255,.08), rgba(255,255,255,.02));
  }
  .dashboard-track-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
  .dashboard-track-card {
    border-radius: 20px;
    border: 1px solid var(--border);
    background: linear-gradient(180deg, rgba(255,255,255,.04), rgba(255,255,255,.02));
    padding: 18px 18px 16px;
  }
  .dashboard-track-card.is-english {
    box-shadow: inset 0 1px 0 rgba(88,166,255,.08);
  }
  .dashboard-track-card.is-chinese {
    box-shadow: inset 0 1px 0 rgba(242,204,96,.1);
  }
  .dashboard-track-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
  }
  .dashboard-track-side {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
    flex-shrink: 0;
  }
  .dashboard-track-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 4px;
  }
  .dashboard-track-subtitle {
    font-size: 12px;
    color: var(--text3);
  }
  .dashboard-track-meta {
    margin-top: 8px;
    font-size: 11px;
    color: var(--text3);
  }
  .dashboard-track-badge {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--accent);
    background: rgba(88,166,255,.12);
    border: 1px solid rgba(88,166,255,.24);
    padding: 5px 9px;
    border-radius: 999px;
    white-space: nowrap;
  }
  .dashboard-mini-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
  }
  .dashboard-mini-stat {
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.05);
    border-radius: 14px;
    padding: 12px 12px 10px;
    min-height: 78px;
  }
  .dashboard-mini-stat .mini-label {
    font-size: 11px;
    color: var(--text3);
    margin-bottom: 8px;
    letter-spacing: .4px;
  }
  .dashboard-mini-stat .mini-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
    line-height: 1.1;
  }
  .dashboard-mini-stat .mini-value-text {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 16px;
    font-weight: 600;
  }
  .dashboard-charts-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
  .dashboard-chart-card {
    min-height: 340px;
    display: flex;
    flex-direction: column;
  }
  .dashboard-chart-wrap {
    position: relative;
    flex: 1;
    min-height: 260px;
    width: 100%;
  }
  .dashboard-trend-preview {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 12px;
  }
  .dashboard-trend-row {
    display: grid;
    grid-template-columns: 52px 1fr auto;
    gap: 10px;
    align-items: center;
    font-size: 12px;
    color: var(--text2);
  }
  .dashboard-trend-date {
    color: var(--text3);
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
  }
  .dashboard-trend-bar {
    position: relative;
    height: 10px;
    border-radius: 999px;
    background: rgba(255,255,255,.06);
    overflow: hidden;
  }
  .dashboard-trend-bar-fill {
    position: absolute;
    inset: 0 auto 0 0;
    width: 0%;
    border-radius: 999px;
  }
  .dashboard-trend-bar-fill.speed {
    background: linear-gradient(90deg, rgba(88,166,255,.3), rgba(88,166,255,.9));
  }
  .dashboard-trend-bar-fill.acc {
    background: linear-gradient(90deg, rgba(63,185,80,.3), rgba(63,185,80,.95));
    opacity: .75;
  }
  .dashboard-trend-values {
    white-space: nowrap;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--text3);
  }
  .dashboard-radar-card {
    grid-column: 1 / -1;
  }
  .dashboard-radar-wrap {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  /* ZIGENS (character roots) display */
  .root-card {
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px 20px;
    display: flex;
    gap: 20px;
    align-items: center;
    justify-content: center;
  }
  .root-key-big {
    font-family: 'JetBrains Mono', monospace;
    font-size: 48px;
    font-weight: 700;
    color: var(--accent);
    width: 70px;
    height: 70px;
    background: rgba(88,166,255,0.1);
    border: 2px solid rgba(88,166,255,0.3);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
  }
  .root-info { }
  .root-mnemonic { font-size: 16px; color: var(--orange); margin-bottom: 6px; font-weight: 500; }
  .root-chars { font-size: 20px; color: var(--text); letter-spacing: 4px; }
  .root-zone {
    font-size: 11px;
    color: var(--text3);
    margin-top: 4px;
  }

  /* Progress bar */
  .progress-wrap { display: flex; align-items: center; gap: 10px; }
  .progress-bar {
    flex: 1;
    height: 4px;
    background: var(--bg3);
    border-radius: 2px;
    overflow: hidden;
  }
  .progress-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    transition: width .3s;
  }
  .progress-text { font-size: 12px; color: var(--text3); font-family: 'JetBrains Mono', monospace; white-space: nowrap; }

  /* WORD/PHRASE PRACTICE */
  .word-display {
    display: flex;
    gap: 4px;
    align-items: center;
    flex-wrap: wrap;
  }
  .word-char {
    font-size: 32px;
    font-weight: 700;
    color: var(--text);
    padding: 8px;
    min-width: 48px;
    text-align: center;
    line-height: 1;
  }
  .word-code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--text3);
    text-align: center;
    letter-spacing: 2px;
    margin-top: 2px;
  }

  /* Sub-mode tabs */
  .tab-row {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin-bottom: 10px;
  }
  .tab-btn {
    padding: 5px 12px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text2);
    font-size: 12px;
    cursor: pointer;
    font-family: 'Noto Sans SC', sans-serif;
    transition: all .15s;
  }
  .tab-btn:hover { border-color: var(--accent); color: var(--accent); }
  .tab-btn.active { background: rgba(88,166,255,0.15); border-color: var(--accent); color: var(--accent); }
  .english-menu-wrap {
    position: relative;
    display: inline-flex;
    align-items: center;
  }
  .english-menu-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-width: 168px;
    justify-content: space-between;
    padding: 7px 12px;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: rgba(255,255,255,.03);
    color: var(--text);
    cursor: pointer;
    font-size: 12px;
    font-family: 'Noto Sans SC', sans-serif;
    transition: all .15s;
  }
  .english-menu-btn:hover,
  .english-menu-btn.open {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(88,166,255,.08);
  }
  .english-menu-btn .menu-icon {
    font-size: 14px;
    line-height: 1;
    color: inherit;
  }
  .english-menu-btn .menu-label {
    flex: 1;
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .english-menu-btn .menu-caret {
    font-size: 10px;
    color: inherit;
  }
  .english-menu-list {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 210px;
    max-width: 280px;
    max-height: 320px;
    overflow-y: auto;
    padding: 8px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: rgba(13,17,23,.98);
    box-shadow: 0 18px 40px rgba(0,0,0,.28);
    z-index: 40;
    display: none;
  }
  .english-menu-list.open { display: block; }
  .english-menu-item {
    padding: 8px 10px;
    border-radius: 8px;
    color: var(--text2);
    font-size: 12px;
    cursor: pointer;
    transition: all .15s;
    user-select: none;
  }
  .english-menu-item:hover {
    background: rgba(255,255,255,.05);
    color: var(--text);
  }
  .english-menu-item.active {
    background: rgba(88,166,255,.14);
    color: var(--accent);
  }
  #custom-library-panel { display: none; }
  .custom-library-shell {
    margin: 4px 0 0;
    padding: 10px 12px;
    border-radius: 14px;
    border: 1px solid rgba(255,255,255,.06);
    background: rgba(22,27,34,.38);
    box-shadow: 0 8px 24px rgba(0,0,0,.12);
  }
  .custom-library-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
  }
  .custom-library-title {
    font-size: 13px;
    color: var(--text2);
    font-weight: 700;
  }
  .custom-lib-quick { display: flex; gap: 8px; flex-wrap: wrap; }
  .custom-lib-btn {
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: rgba(255,255,255,.03);
    color: var(--text2);
    font-size: 11px;
    cursor: pointer;
    font-family: 'Noto Sans SC', sans-serif;
    transition: all .15s;
  }
  .custom-lib-btn:hover { border-color: var(--accent); color: var(--accent); }
  .custom-lib-btn.primary {
    background: rgba(88,166,255,.12);
    border-color: rgba(88,166,255,.35);
    color: var(--accent);
  }
  .custom-lib-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
    max-height: 260px;
    overflow-y: auto;
    padding-right: 2px;
  }
  .custom-lib-card {
    padding: 8px 10px;
    border-radius: 10px;
    border: 1px solid rgba(255,255,255,.06);
    background: rgba(255,255,255,.025);
    transition: all .15s;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }
  .custom-lib-card.active {
    border-color: rgba(88,166,255,.35);
    background: rgba(88,166,255,.08);
  }
  .custom-lib-card-top {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
    flex: 1 1 auto;
  }
  .custom-lib-name {
    font-size: 13px;
    font-weight: 700;
    color: var(--text);
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .custom-lib-badge {
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 999px;
    color: var(--text3);
    background: rgba(255,255,255,.05);
  }
  .custom-lib-badge.active { color: var(--accent); background: rgba(88,166,255,.12); }
  .custom-lib-actions {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    flex-shrink: 0;
    justify-content: flex-end;
  }
  .custom-lib-empty { font-size: 12px; color: var(--text3); padding: 8px 2px 2px; }

  /* Misc */
  .flex-row { display: flex; gap: 10px; align-items: center; }
  .badge {
    padding: 3px 9px;
    border-radius: 10px;
    font-size: 11px;
    font-weight: 500;
  }
  .badge-blue { background: rgba(88,166,255,0.15); color: var(--accent); }
  .badge-green { background: rgba(63,185,80,0.15); color: var(--green); }
  .badge-red { background: rgba(248,81,73,0.15); color: var(--red); }
  .badge-yellow { background: rgba(210,153,34,0.15); color: var(--yellow); }

  /* 错题本 flash */
  @keyframes flash-correct { 0%,100%{background:transparent} 50%{background:rgba(63,185,80,0.15)} }
  @keyframes flash-wrong { 0%,100%{background:transparent} 50%{background:rgba(248,81,73,0.15)} }
  .flash-c { animation: flash-correct .4s; }
  .flash-w { animation: flash-wrong .4s; }

  /* Scrollbar */
  ::-webkit-scrollbar { width: 6px; height: 6px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
  ::-webkit-scrollbar-thumb:hover { background: var(--text3); }

  /* 入场动画 */
  @keyframes fadeSlideIn {
    from { opacity:0; transform: translateY(8px); }
    to   { opacity:1; transform: translateY(0); }
  }
  @keyframes popIn {
    0%  { opacity:0; transform: scale(.92); }
    70% { transform: scale(1.02); }
    100%{ opacity:1; transform: scale(1); }
  }
  .panel     { animation: fadeSlideIn .25s ease both; }
  #input-area{ animation: fadeSlideIn .3s .05s ease both; }

  /* nav 涂层动画 */
  .nav-item {
    transition: all .18s cubic-bezier(.4,0,.2,1);
  }
  .nav-item.active {
    background: rgba(88,166,255,0.14);
    color: var(--accent);
    box-shadow: inset 3px 0 0 var(--accent);
  }

  /* 键盘按键动画 */
  .kb-key {
    transition: all .08s cubic-bezier(.4,0,.2,1);
  }
  .kb-key.highlight {
    animation: popIn .18s ease both;
  }

  /* ex-char 入场 */
  .ex-char {
    animation: popIn .2s ease both;
  }

  /* 移动端适配 */
  @media (max-width: 768px) {
    body { overflow: auto; height: auto; min-height: 100dvh; }
    #main { flex-direction: column; overflow: visible; }

    #topbar {
      height: auto;
      padding: 8px 12px;
      flex-wrap: wrap;
      gap: 8px;
    }
    #topbar .logo { font-size: 14px; }
    .stat-group { gap: 10px; margin-left: 0; width: 100%; flex-wrap: wrap; }
    .stat-item { font-size: 11px; }
    .stat-val { font-size: 13px; }
    #best-wrap { display: none; } /* 移动端隐藏历史最佳 */

    #sidebar {
      width: 100%;
      border-right: none;
      border-bottom: 1px solid var(--border);
      padding: 8px 4px;
      display: flex;
      flex-wrap: wrap;
      gap: 4px;
      overflow-x: auto;
      gap: 4px;
    }
    .nav-section { display: none; } /* 移动端隐藏分组标题 */
    .nav-item {
      margin: 0;
      padding: 6px 10px;
      font-size: 12px;
      border-radius: 20px;
      white-space: nowrap;
    }
    .nav-item.active { box-shadow: none; }

    #practice-area { padding: 10px 12px; gap: 8px; }
    .panel { padding: 14px; border-radius: 10px; }

    .ex-char { font-size: 28px; padding: 6px 12px; min-width: 48px; }
    #input-box { font-size: 18px; padding: 10px 12px; }
    #btn-next { padding: 10px 16px; font-size: 13px; }

    #keyboard-area {
      padding: 8px 6px 10px;
      overflow-x: auto;
    }
    .kb-key { min-width: 32px; height: 36px; font-size: 11px; }
    .kb-key.wide { min-width: 54px; font-size: 10px; }
    .kb-key.wider { min-width: 70px; }
    .kb-key.space { min-width: 120px; }

    .key-target { width: 48px; height: 48px; font-size: 22px; }
    #mode-title { font-size: 16px; }

    /* 移动端滚动解锁 */
    .stats-grid { grid-template-columns: repeat(3,1fr); }
    .dashboard-track-grid,
    .dashboard-charts-grid { grid-template-columns: 1fr; }
    .dashboard-mini-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    #chart-overlay { padding: 16px 12px; }
    #chart-mini-kb { padding: 10px; }
    #chart-mini-kb > div > div { width: 28px; height: 26px; font-size: 10px; }
  }

  @media (max-width: 480px) {
    .kb-key { min-width: 26px; height: 30px; font-size: 10px; }
    .kb-key.wide { min-width: 42px; }
    .ex-char { font-size: 24px; padding: 5px 10px; }
    #input-box { font-size: 16px; }
    .key-target { width: 40px; height: 40px; font-size: 18px; }
    .dashboard-mini-grid { grid-template-columns: 1fr; }
  }

  /* 5分钟倒计时 */
  #countdown-5min {
    font-family: 'JetBrains Mono', monospace;
    font-size: 16px;
    font-weight: 700;
    color: var(--green);
    letter-spacing: 1px;
    transition: color .3s;
  }
  #countdown-5min.warn { color: var(--yellow); }
  #countdown-5min.danger { color: var(--red); animation: pulse-danger .8s infinite; }
  @keyframes pulse-danger { 0%,100%{opacity:1} 50%{opacity:.5} }
  #btn-5min.active { background:rgba(63,185,80,0.15); border-color:var(--green); color:var(--green); }

  /* 轮次提示 toast —— 右下角小动态通知 */
  .round-toast {
    position: fixed;
    bottom: 28px;
    right: 28px;
    background: rgba(13,17,23,0.92);
    border: 1px solid var(--accent);
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: 20px;
    pointer-events: none;
    letter-spacing: .5px;
    animation: roundToastAnim 1.6s ease forwards;
    z-index: 9999;
    white-space: nowrap;
    box-shadow: 0 2px 12px rgba(88,166,255,0.18);
  }
  @keyframes roundToastAnim {
    0%  { opacity:0; transform: translateY(8px); }
    15% { opacity:1; transform: translateY(0); }
    70% { opacity:1; transform: translateY(0); }
    100%{ opacity:0; transform: translateY(4px); }
  }