/* ==========================================================================
   标注学院 · 设计系统
   纯手写 CSS，无外部依赖，可离线使用
   ========================================================================== */

/* ---------- 1. 主题变量 ---------- */
:root {
  --bg: #0a0e1a;
  --bg-2: #0f1526;
  --surface: #141b2e;
  --surface-2: #1a2237;
  --surface-3: #212b44;
  --line: #263149;
  --line-soft: #1e2739;

  --text: #e8edf7;
  --text-2: #b3bdd1;
  --text-3: #7d879e;

  --brand: #4ea1ff;
  --brand-2: #7b6cff;
  --brand-soft: rgba(78, 161, 255, 0.14);
  --accent: #2dd4bf;
  --warn: #fbbf24;
  --danger: #fb7185;
  --ok: #34d399;
  --violet: #a78bfa;
  --pink: #f472b6;

  --radius: 14px;
  --radius-sm: 9px;
  --radius-lg: 22px;
  --shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.85);
  --shadow-soft: 0 10px 26px -18px rgba(0, 0, 0, 0.9);

  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC",
    -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --siderbar-w: 306px;
  --topbar-h: 62px;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  background:
    radial-gradient(1100px 620px at 12% -8%, rgba(78, 161, 255, 0.13), transparent 62%),
    radial-gradient(980px 560px at 100% 0%, rgba(123, 108, 255, 0.13), transparent 58%),
    var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15.5px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 99;
  background: var(--brand); color: #04121f; padding: 10px 16px; border-radius: 0 0 10px 0; font-weight: 700;
}
.skip-link:focus { left: 0; }

.noscript {
  margin: 60px auto; max-width: 620px; padding: 24px; border: 1px solid var(--warn);
  border-radius: var(--radius); background: rgba(251, 191, 36, 0.08); color: #ffe9b0;
}

/* ---------- 2. 顶栏 ---------- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 12px;
  padding: 0 16px;
  background: rgba(10, 14, 26, 0.84);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-soft);
}

.brand { display: flex; align-items: center; gap: 11px; color: var(--text); text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 34px; height: 34px; flex: none; border-radius: 11px;
  display: grid; place-items: center;
  font-weight: 800; font-size: 17px; color: #05121f;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: 0 8px 20px -10px var(--brand);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.18; }
.brand-text strong { font-size: 15.5px; letter-spacing: 0.2px; }
.brand-text small { color: var(--text-3); font-size: 11.5px; }

.topbar-spacer { flex: 1; }

.progress-pill {
  display: flex; align-items: center; gap: 9px;
  padding: 6px 13px 6px 8px; border: 1px solid var(--line);
  border-radius: 999px; background: var(--surface);
}
.pp-ring {
  --p: 0;
  width: 22px; height: 22px; border-radius: 50%; flex: none;
  background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--surface-3) 0);
  position: relative;
}
.pp-ring::after {
  content: ""; position: absolute; inset: 4px; border-radius: 50%; background: var(--surface);
}
.pp-text { font-size: 12.5px; color: var(--text-2); font-variant-numeric: tabular-nums; }

.ghost-btn, .icon-btn, .btn {
  font-family: inherit; font-size: 13.5px; cursor: pointer;
  border-radius: 10px; border: 1px solid var(--line);
  background: var(--surface); color: var(--text-2);
  padding: 7px 13px; transition: 0.16s ease;
}
.ghost-btn:hover, .icon-btn:hover, .btn:hover { border-color: var(--brand); color: var(--text); background: var(--surface-2); }
.icon-btn { padding: 6px 10px; font-size: 16px; line-height: 1; }
.only-mobile { display: none; }

/* ---------- 3. 布局 ---------- */
.layout { display: flex; align-items: flex-start; }

.sidebar {
  width: var(--siderbar-w); flex: none;
  position: sticky; top: var(--topbar-h);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto; overscroll-behavior: contain;
  border-right: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(20, 27, 46, 0.55), rgba(10, 14, 26, 0.2));
}
.sidebar-inner { padding: 16px 14px 46px; }

.content {
  flex: 1; min-width: 0;
  padding: 30px clamp(16px, 4vw, 54px) 40px;
}
.view { max-width: 940px; margin: 0 auto; }

.site-foot {
  max-width: 940px; margin: 54px auto 0; padding-top: 18px;
  border-top: 1px solid var(--line-soft);
  color: var(--text-3); font-size: 12.5px;
  display: flex; gap: 8px; flex-wrap: wrap;
}
.dot { opacity: 0.5; }

/* ---------- 4. 侧栏目录 ---------- */
.nav-group { margin-bottom: 18px; }
.nav-group-title {
  font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--text-3); padding: 0 10px 8px; font-weight: 700;
}
.nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 10px; border-radius: 10px; color: var(--text-2);
  text-decoration: none; font-size: 14px; line-height: 1.4;
  border: 1px solid transparent; transition: 0.15s ease;
}
.nav-item:hover { background: var(--surface); color: var(--text); text-decoration: none; }
.nav-item.active {
  background: var(--brand-soft); color: #d8ebff;
  border-color: rgba(78, 161, 255, 0.4);
}
.nav-idx {
  width: 22px; height: 22px; flex: none; border-radius: 7px;
  display: grid; place-items: center;
  font-size: 11.5px; font-weight: 700; font-variant-numeric: tabular-nums;
  background: var(--surface-3); color: var(--text-3);
}
.nav-item.active .nav-idx { background: var(--brand); color: #06192b; }
.nav-label { flex: 1; min-width: 0; }
.nav-tick { color: var(--ok); font-size: 13px; font-weight: 700; }
.nav-item.done .nav-label { color: var(--text); }

.nav-sub { margin: 2px 0 6px 32px; display: flex; flex-direction: column; gap: 1px; }
.nav-sub-item {
  font-size: 12.5px; color: var(--text-3); padding: 4px 8px; border-radius: 7px;
  text-decoration: none; border-left: 2px solid transparent;
}
.nav-sub-item:hover { color: var(--text-2); background: var(--surface); text-decoration: none; }
.nav-sub-item.active { color: var(--brand); border-left-color: var(--brand); background: var(--surface); }

/* ---------- 5. 页面标题与通用块 ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--brand); background: var(--brand-soft);
  padding: 4px 11px; border-radius: 999px; margin-bottom: 14px;
}
.page-title { font-size: clamp(24px, 3.4vw, 34px); line-height: 1.25; margin: 0 0 10px; letter-spacing: -0.4px; }
.page-lead { color: var(--text-2); font-size: 16px; margin: 0 0 22px; }
.meta-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 26px; }
.chip {
  font-size: 12px; color: var(--text-2); background: var(--surface);
  border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px;
}
.chip.ok { color: #b9f6e0; border-color: rgba(52, 211, 153, 0.4); background: rgba(52, 211, 153, 0.1); }

.section { margin: 34px 0 0; scroll-margin-top: calc(var(--topbar-h) + 14px); }
.section > h2 {
  font-size: 21px; margin: 0 0 12px; padding-bottom: 9px;
  border-bottom: 1px solid var(--line-soft); letter-spacing: -0.2px;
}
.section > h3 { font-size: 16.5px; margin: 22px 0 8px; color: #dbe6fb; }
.section p { margin: 10px 0; color: var(--text-2); }
.section strong { color: var(--text); }
.section ul, .section ol { margin: 10px 0; padding-left: 22px; color: var(--text-2); }
.section li { margin: 5px 0; }
.section li::marker { color: var(--brand); }
.hl { color: #ffd88a; font-weight: 600; }
.mono { font-family: var(--mono); font-size: 0.9em; background: var(--surface-2); padding: 1px 5px; border-radius: 5px; color: #cfe4ff; }
kbd {
  font-family: var(--mono); font-size: 11.5px; padding: 2px 6px;
  border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 6px;
  background: var(--surface-2); color: var(--text);
}

/* 卡片 / 网格 */
.grid { display: grid; gap: 14px; align-items: stretch; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 17px; box-shadow: var(--shadow-soft);
  height: 100%;
}
.grid > .card { display: flex; flex-direction: column; }
.grid > .card .toolbar { margin-top: auto; }
.card h4 { margin: 0 0 7px; font-size: 15px; }
.card p { margin: 0; color: var(--text-2); font-size: 14px; }
.card-tag { font-size: 11px; color: var(--text-3); letter-spacing: 0.08em; text-transform: uppercase; }

/* 提示框 */
.callout {
  border-radius: var(--radius); padding: 14px 16px; margin: 16px 0;
  border: 1px solid var(--line); background: var(--surface-2);
  border-left: 3px solid var(--brand);
}
.callout .co-title { font-weight: 700; font-size: 13.5px; margin-bottom: 4px; color: #dbe9ff; }
.callout p { margin: 6px 0 0; color: var(--text-2); }
.callout p:first-of-type { margin-top: 0; }
.callout.tip { border-left-color: var(--ok); background: rgba(52, 211, 153, 0.07); }
.callout.tip .co-title { color: #a9f2d5; }
.callout.warn { border-left-color: var(--warn); background: rgba(251, 191, 36, 0.07); }
.callout.warn .co-title { color: #ffe1a3; }
.callout.danger { border-left-color: var(--danger); background: rgba(251, 113, 133, 0.07); }
.callout.danger .co-title { color: #ffc2cb; }
.callout.case { border-left-color: var(--violet); background: rgba(167, 139, 250, 0.08); }
.callout.case .co-title { color: #d8ccff; }

/* 表格 */
.table-wrap { overflow-x: auto; margin: 16px 0; border: 1px solid var(--line); border-radius: var(--radius); }
table { border-collapse: collapse; width: 100%; font-size: 13.8px; min-width: 460px; }
th, td { text-align: left; padding: 9px 13px; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
th { background: var(--surface-2); color: #d7e3f8; font-weight: 700; font-size: 13px; white-space: nowrap; }
td { color: var(--text-2); }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover td { background: rgba(78, 161, 255, 0.045); }

/* 步骤条 */
.steps { counter-reset: st; margin: 18px 0; padding: 0; list-style: none; }
.steps li {
  position: relative; padding: 0 0 18px 44px; border-left: 1px solid var(--line);
  margin-left: 13px;
}
.steps li:last-child { border-left-color: transparent; padding-bottom: 0; }
.steps li::before {
  counter-increment: st; content: counter(st);
  position: absolute; left: -13px; top: -2px;
  width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center; font-size: 12.5px; font-weight: 700;
  background: var(--surface-3); color: var(--brand); border: 1px solid var(--line);
}
.steps b { display: block; color: var(--text); font-size: 14.5px; }
.steps span { color: var(--text-2); font-size: 14px; }

/* 定义列表 */
.dl { margin: 14px 0; display: grid; gap: 10px; }
.dl-item { display: grid; grid-template-columns: 132px 1fr; gap: 12px; align-items: start; }
.dl-key { color: var(--accent); font-weight: 700; font-size: 14px; }
.dl-val { color: var(--text-2); font-size: 14px; }

/* 代码块 */
pre {
  margin: 14px 0; padding: 14px 16px; overflow-x: auto;
  background: #080c16; border: 1px solid var(--line); border-radius: var(--radius);
  font-family: var(--mono); font-size: 12.8px; line-height: 1.62; color: #cfe0f5;
}
pre .k { color: var(--violet); }
pre .s { color: #7ee0b8; }
pre .n { color: #ffcf8a; }
pre .c { color: var(--text-3); font-style: italic; }

/* 小节锚点标题 */
.anchor-h { display: flex; align-items: baseline; gap: 8px; }
.anchor-h .a-link { font-size: 12px; opacity: 0; transition: 0.15s; }
.anchor-h:hover .a-link { opacity: 1; }

/* ---------- 6. 测验 ---------- */
.quiz {
  margin: 18px 0 0; border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(123, 108, 255, 0.09), rgba(20, 27, 46, 0.6));
  padding: 18px 20px;
}
.quiz-head { display: flex; align-items: center; gap: 10px; margin-bottom: 4px; }
.quiz-head h3 { margin: 0; font-size: 16.5px; }
.quiz-score { margin-left: auto; font-size: 12.5px; color: var(--text-3); font-variant-numeric: tabular-nums; }
.quiz-sub { color: var(--text-3); font-size: 13px; margin: 0 0 12px; }

.qitem { border-top: 1px dashed var(--line); padding: 14px 0 4px; }
.qitem:first-of-type { border-top: none; }
.q-stem { display: flex; gap: 9px; font-size: 14.6px; color: var(--text); margin-bottom: 9px; }
.q-no {
  flex: none; width: 22px; height: 22px; border-radius: 6px; margin-top: 2px;
  display: grid; place-items: center; font-size: 11.5px; font-weight: 700;
  background: var(--surface-3); color: var(--text-3);
}
.q-opts { display: grid; gap: 7px; }
.q-opt {
  display: flex; gap: 10px; align-items: flex-start;
  padding: 9px 12px; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--surface); cursor: pointer; font-size: 14px; color: var(--text-2);
  transition: 0.14s ease;
}
.q-opt:hover { border-color: var(--brand); color: var(--text); }
.q-opt input { margin: 5px 0 0; accent-color: var(--brand); flex: none; }
.q-opt.picked { border-color: var(--brand); background: var(--brand-soft); color: var(--text); }
.q-opt.right { border-color: var(--ok); background: rgba(52, 211, 153, 0.12); color: #d6ffee; }
.q-opt.wrong { border-color: var(--danger); background: rgba(251, 113, 133, 0.12); color: #ffdbe1; }
.q-opt .mark { margin-left: auto; font-weight: 700; font-size: 12.5px; }

.q-blank { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.q-input {
  font-family: inherit; font-size: 14px; color: var(--text);
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 8px 12px; min-width: 220px; flex: 1;
}
.q-input:focus { outline: 2px solid rgba(78, 161, 255, 0.5); outline-offset: 1px; border-color: var(--brand); }

.q-fb { margin-top: 9px; font-size: 13.4px; padding: 9px 12px; border-radius: var(--radius-sm); display: none; }
.q-fb.show { display: block; }
.q-fb.ok { background: rgba(52, 211, 153, 0.1); color: #b7f4dc; border: 1px solid rgba(52, 211, 153, 0.35); }
.q-fb.no { background: rgba(251, 113, 133, 0.1); color: #ffc9d2; border: 1px solid rgba(251, 113, 133, 0.35); }

.quiz-actions { display: flex; gap: 10px; align-items: center; margin-top: 16px; flex-wrap: wrap; }
.btn.primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  border: none; color: #04121f; font-weight: 700; padding: 9px 20px;
}
.btn.primary:hover { filter: brightness(1.09); color: #04121f; }
.btn.lg { padding: 11px 24px; font-size: 15px; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.quiz-result { margin-left: auto; font-weight: 700; font-size: 14px; }

/* ---------- 7. 实验室 ---------- */
.lab {
  border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(45, 212, 191, 0.06), rgba(20, 27, 46, 0.72));
  padding: 20px; margin: 20px 0 0;
}
.lab-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 6px; }
.lab-head h3 { margin: 0; font-size: 17.5px; }
.lab-badge {
  font-size: 11px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase;
  background: rgba(45, 212, 191, 0.16); color: #9df0e2; border: 1px solid rgba(45, 212, 191, 0.35);
  padding: 3px 9px; border-radius: 999px;
}
.lab-goal { color: var(--text-2); font-size: 14px; margin: 0 0 14px; }
.lab-steps { background: var(--surface); border: 1px solid var(--line-soft); border-radius: var(--radius); padding: 11px 15px; margin-bottom: 16px; }
.lab-steps b { font-size: 13px; color: #cfe0f5; }
.lab-steps ol { margin: 6px 0 0; padding-left: 20px; color: var(--text-2); font-size: 13.6px; }

/* 进度条 */
.bar { height: 7px; border-radius: 99px; background: var(--surface-3); overflow: hidden; }
.bar > i { display: block; height: 100%; width: 0; border-radius: 99px; background: linear-gradient(90deg, var(--brand), var(--accent)); transition: width 0.25s ease; }
.bar.thin { height: 5px; }

/* 工具条 / 面板 */
.toolbar { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 12px 0; }
.toolbar .spacer { flex: 1; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--surface); }
.seg button {
  font-family: inherit; font-size: 13px; padding: 7px 13px; cursor: pointer;
  background: transparent; border: none; color: var(--text-2); border-right: 1px solid var(--line-soft);
}
.seg button:last-child { border-right: none; }
.seg button:hover { color: var(--text); background: var(--surface-2); }
.seg button.on { background: var(--brand-soft); color: #cfe8ff; font-weight: 700; }

.panel { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 15px; }
.panel + .panel { margin-top: 12px; }
.panel-title { font-size: 13px; font-weight: 700; color: #d7e3f8; margin: 0 0 9px; display: flex; align-items: center; gap: 8px; }
.panel-title .hint { font-weight: 400; color: var(--text-3); font-size: 12px; }

.stat-row { display: flex; gap: 10px; flex-wrap: wrap; }
.stat {
  flex: 1; min-width: 96px; background: var(--surface-2); border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm); padding: 9px 11px;
}
.stat b { display: block; font-size: 19px; font-variant-numeric: tabular-nums; letter-spacing: -0.3px; }
.stat span { font-size: 11.5px; color: var(--text-3); }
.stat.good b { color: var(--ok); }
.stat.bad b { color: var(--danger); }
.stat.warn b { color: var(--warn); }

/* 标签 / 徽标 */
.tag {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 12px; padding: 2px 9px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface-2); color: var(--text-2);
}
.tag .dotc { width: 8px; height: 8px; border-radius: 50%; background: currentColor; }
.tag.plain { color: var(--text-3); }

/* 文本标注区 */
.span-host {
  background: #0c1220; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 15px 17px; font-size: 15.4px; line-height: 2.35; color: #dbe5f5;
  user-select: none; -webkit-user-select: none;
}
.span-host .tok {
  cursor: pointer; border-radius: 5px; padding: 1px 2px;
  border-bottom: 1px dashed rgba(125, 135, 158, 0.5);
  transition: background 0.12s ease;
}
.span-host .tok:hover { background: rgba(78, 161, 255, 0.18); }
.span-host .tok.picked { background: rgba(78, 161, 255, 0.28); border-bottom-color: var(--brand); }
.span-host .tok.ann {
  border-bottom: 2px solid var(--ent-c, var(--brand));
  background: color-mix(in srgb, var(--ent-c, var(--brand)) 20%, transparent);
}
.span-host .punct { cursor: default; border-bottom: none; }

.legend { display: flex; flex-wrap: wrap; gap: 7px; margin: 9px 0 0; }
.legend button {
  font-family: inherit; font-size: 12.5px; cursor: pointer; color: var(--text-2);
  border: 1px solid var(--line); border-radius: 999px; background: var(--surface-2);
  padding: 4px 11px; display: inline-flex; align-items: center; gap: 6px;
}
.legend button:hover { color: var(--text); }
.legend button.on { border-color: currentColor; font-weight: 700; }
.legend .dotc { width: 9px; height: 9px; border-radius: 50%; background: currentColor; }
.legend kbd { margin-left: 2px; }

/* 列表行 */
.rows { display: grid; gap: 8px; }
.row {
  display: flex; align-items: center; gap: 10px; padding: 9px 12px;
  background: var(--surface-2); border: 1px solid var(--line-soft); border-radius: var(--radius-sm);
  font-size: 13.8px; color: var(--text-2);
}
.row .grow { flex: 1; min-width: 0; }
.row .num { font-variant-numeric: tabular-nums; color: var(--text); font-weight: 600; }
.row.dim { opacity: 0.6; }

/* 画布 */
.canvas-wrap {
  position: relative; background: #05080f; border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; touch-action: none;
}
.canvas-wrap canvas { display: block; width: 100%; height: auto; cursor: crosshair; }
.canvas-hint {
  position: absolute; left: 10px; bottom: 10px; z-index: 3;
  background: rgba(6, 10, 20, 0.78); border: 1px solid var(--line);
  color: var(--text-2); font-size: 11.8px; padding: 4px 10px; border-radius: 999px;
  pointer-events: none;
}
.thumbs { display: flex; gap: 7px; flex-wrap: wrap; }
.thumb {
  width: 62px; height: 44px; padding: 0; cursor: pointer; overflow: hidden;
  border: 1px solid var(--line); border-radius: 8px; background: #05080f;
  position: relative;
}
.thumb img, .thumb svg { width: 100%; height: 100%; display: block; object-fit: cover; }
.thumb.on { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(45, 212, 191, 0.3); }
.thumb .tn {
  position: absolute; right: 2px; bottom: 0; font-size: 10px; color: var(--text-3);
  background: rgba(6, 10, 20, 0.75); border-radius: 4px; padding: 0 3px;
}

/* 拖拽排序 */
.sortable { display: grid; gap: 9px; }
.sort-item {
  display: flex; gap: 11px; align-items: flex-start; padding: 12px 14px;
  background: var(--surface-2); border: 1px solid var(--line); border-radius: var(--radius);
  cursor: grab; font-size: 14.2px; color: var(--text-2);
}
.sort-item:active { cursor: grabbing; }
.sort-item.dragging { opacity: 0.4; border-style: dashed; }
.sort-item.over { border-color: var(--accent); }
.sort-item.right { border-color: rgba(52, 211, 153, 0.5); }
.sort-item.wrong { border-color: rgba(251, 113, 133, 0.5); }
.sort-rank {
  flex: none; width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center;
  background: var(--surface-3); color: var(--brand); font-weight: 700; font-size: 12.5px;
}
.sort-move { display: flex; flex-direction: column; gap: 2px; }
.sort-move button {
  font-size: 11px; line-height: 1; padding: 3px 6px; cursor: pointer;
  background: var(--surface); color: var(--text-2);
  border: 1px solid var(--line); border-radius: 6px;
}
.sort-move button:hover { border-color: var(--brand); color: var(--text); }

/* 任务列表（挑战） */
.task-list { display: grid; gap: 6px; }
.task-item {
  display: flex; gap: 9px; align-items: center; font-size: 13.4px; color: var(--text-3);
  padding: 7px 11px; border-radius: var(--radius-sm); background: var(--surface-2);
  border: 1px solid var(--line-soft);
}
.task-item.cur { color: var(--text); border-color: var(--brand); background: var(--brand-soft); }
.task-item.done { color: #b7f4dc; border-color: rgba(52, 211, 153, 0.35); }
.task-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--surface-3); flex: none; }
.task-item.cur .task-dot { background: var(--brand); }
.task-item.done .task-dot { background: var(--ok); }

/* 结果横幅 */
.banner {
  border-radius: var(--radius); padding: 16px 18px; margin: 16px 0 0;
  border: 1px solid var(--line); background: var(--surface-2); display: none;
}
.banner.show { display: block; }
.banner h4 { margin: 0 0 6px; font-size: 16px; }
.banner.pass { border-color: rgba(52, 211, 153, 0.45); background: rgba(52, 211, 153, 0.09); }
.banner.pass h4 { color: #a7f3d0; }
.banner.fail { border-color: rgba(251, 191, 36, 0.45); background: rgba(251, 191, 36, 0.08); }
.banner.fail h4 { color: #ffe0a3; }

/* 评分星 */
.stars { letter-spacing: 3px; color: var(--warn); font-size: 17px; }
.stars .off { color: var(--surface-3); }

/* 键位提示 */
.kbd-hint { font-size: 12px; color: var(--text-3); }
.kbd-hint kbd { margin: 0 2px; }

/* 可折叠答案 */
details.reveal {
  margin: 12px 0; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); padding: 11px 15px;
}
details.reveal > summary { cursor: pointer; font-size: 13.5px; color: var(--brand); font-weight: 600; }
details.reveal[open] > summary { margin-bottom: 8px; }
details.reveal .rv-body { color: var(--text-2); font-size: 14px; }

/* ---------- 8. 首页 ---------- */
.hero {
  border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden;
  background:
    radial-gradient(760px 300px at 88% -30%, rgba(123, 108, 255, 0.35), transparent 62%),
    radial-gradient(620px 280px at 4% 110%, rgba(45, 212, 191, 0.26), transparent 60%),
    linear-gradient(160deg, #16203a, #0d1322);
  padding: clamp(22px, 3.6vw, 40px);
  box-shadow: var(--shadow);
}
.hero h1 { font-size: clamp(27px, 4.4vw, 42px); margin: 0 0 12px; letter-spacing: -0.8px; line-height: 1.18; }
.hero h1 em { font-style: normal; background: linear-gradient(115deg, #7ec8ff, #a78bfa 55%, #2dd4bf); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { color: #c3cfe4; font-size: 16.5px; max-width: 62ch; margin: 0 0 20px; }
.hero-actions { display: flex; gap: 11px; flex-wrap: wrap; align-items: center; }
.hero-stats { display: flex; gap: 26px; flex-wrap: wrap; margin-top: 26px; padding-top: 20px; border-top: 1px solid rgba(255, 255, 255, 0.09); }
.hero-stats div b { display: block; font-size: 23px; letter-spacing: -0.5px; }
.hero-stats div span { font-size: 12.5px; color: #9fadc6; }

.path-card { position: relative; }
.path-card .badge-lv {
  position: absolute; top: 14px; right: 15px; font-size: 10.5px; letter-spacing: 0.1em;
  color: var(--text-3); text-transform: uppercase;
}
.path-card ul { margin: 8px 0 0; padding-left: 19px; font-size: 13.6px; color: var(--text-2); }
.path-card ul li { margin: 3px 0; }

.lab-card { display: flex; flex-direction: column; gap: 8px; }
.lab-card .lc-top { display: flex; gap: 10px; align-items: center; }
.lab-card .lc-ico {
  width: 34px; height: 34px; border-radius: 10px; flex: none; display: grid; place-items: center;
  background: var(--surface-3); font-size: 17px;
}
.lab-card h4 { margin: 0; font-size: 15px; }
.lab-card p { font-size: 13.5px; }

.map-legend { display: flex; gap: 14px; flex-wrap: wrap; font-size: 12.5px; color: var(--text-3); margin-top: 10px; }
.map-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 5px; }

/* 时间线 */
.timeline { margin: 18px 0; display: grid; gap: 0; }
.tl-item { display: grid; grid-template-columns: 88px 1fr; gap: 14px; padding: 12px 0; border-top: 1px dashed var(--line); }
.tl-item:first-child { border-top: none; }
.tl-when { color: var(--accent); font-weight: 700; font-size: 13px; }
.tl-what b { display: block; font-size: 14.5px; color: var(--text); }
.tl-what span { color: var(--text-2); font-size: 13.8px; }

/* 检查清单 */
.check-list { display: grid; gap: 8px; margin: 14px 0; }
.check {
  display: flex; gap: 11px; align-items: flex-start; padding: 10px 13px; cursor: pointer;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm);
  font-size: 14px; color: var(--text-2);
}
.check:hover { border-color: var(--brand); }
.check input { margin: 5px 0 0; accent-color: var(--accent); flex: none; }
.check.on { border-color: rgba(52, 211, 153, 0.4); color: var(--text); background: rgba(52, 211, 153, 0.07); }

/* ---------- 9. Toast ---------- */
.toast-wrap { position: fixed; right: 18px; bottom: 18px; z-index: 90; display: grid; gap: 9px; justify-items: end; }
.toast {
  background: var(--surface-2); border: 1px solid var(--line); border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm); padding: 10px 15px; font-size: 13.6px; color: var(--text);
  box-shadow: var(--shadow); max-width: 320px;
  animation: toastIn 0.22s ease;
}
.toast.ok { border-left-color: var(--ok); }
.toast.warn { border-left-color: var(--warn); }
.toast.no { border-left-color: var(--danger); }
.toast.out { animation: toastOut 0.24s ease forwards; }
@keyframes toastIn { from { opacity: 0; transform: translateY(9px); } to { opacity: 1; transform: none; } }
@keyframes toastOut { to { opacity: 0; transform: translateY(7px); } }

/* 屏幕阅读器专用 */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---------- 10. 响应式 ---------- */
@media (max-width: 1080px) {
  :root { --siderbar-w: 262px; }
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .only-mobile { display: inline-flex; }
  .sidebar {
    position: fixed; z-index: 50; top: var(--topbar-h); left: 0;
    width: min(88vw, 330px); height: calc(100vh - var(--topbar-h));
    background: #0c1120; transform: translateX(-102%);
    transition: transform 0.22s ease; box-shadow: var(--shadow);
  }
  .sidebar.open { transform: none; }
  .content { padding: 22px 16px 30px; }
  .brand-text small { display: none; }
}
@media (max-width: 620px) {
  body { font-size: 15px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: minmax(0, 1fr); }
  .dl-item { grid-template-columns: 1fr; gap: 2px; }
  .tl-item { grid-template-columns: 1fr; gap: 3px; }
  .hero-stats { gap: 18px; }
  .progress-pill { display: none; }
  .quiz, .lab { padding: 15px 14px; }
}

@media print {
  .topbar, .sidebar, .site-foot, .toast-wrap { display: none; }
  body { background: #fff; color: #111; }
}