/* ===========================================================
   大数据技术应用 · 备赛复习平台
   纯 HTML / CSS / JavaScript，无框架、无后端
   =========================================================== */

:root {
  --bg: #f4f6fb;
  --bg-soft: #eef2fa;
  --surface: #ffffff;
  --surface-2: #f8fafd;
  --border: #e3e9f4;
  --border-strong: #cfd8ea;
  --text: #17203a;
  --text-2: #47536b;
  --muted: #7b879c;
  --primary: #2f62ff;
  --primary-dark: #1f47d6;
  --primary-soft: #e9efff;
  --success: #12976a;
  --success-soft: #e2f6ee;
  --danger: #e0403f;
  --danger-soft: #fdecec;
  --warn: #e08700;
  --warn-soft: #fdf3e0;
  --purple: #7a5cf0;
  --purple-soft: #efeaff;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(23, 32, 58, .04), 0 6px 20px rgba(23, 32, 58, .06);
  --shadow-lg: 0 8px 40px rgba(23, 32, 58, .12);
  --header-h: 60px;
  --sidebar-w: 232px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system,
          BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, "Courier New", monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

button, input, select, textarea { font-family: inherit; font-size: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
a { color: var(--primary); text-decoration: none; }

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: #cdd6e6; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #b3bfd4; }
::-webkit-scrollbar-track { background: transparent; }

/* ===================== 布局 ===================== */
.app { min-height: 100%; display: flex; flex-direction: column; }

.header {
  position: sticky; top: 0; z-index: 60;
  height: var(--header-h);
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 12px;
  padding: 0 16px;
}

.brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.brand-txt { min-width: 0; }
.brand-txt b { display: block; font-size: 15px; line-height: 1.2; white-space: nowrap; }
.brand-txt span { font-size: 11.5px; color: var(--muted); white-space: nowrap; }

.hamburger {
  display: none; width: 36px; height: 36px; border-radius: 9px;
  align-items: center; justify-content: center; color: var(--text-2);
}
.hamburger:hover { background: var(--bg-soft); }

.search {
  flex: 1; max-width: 400px; margin-left: auto; position: relative;
}
.search input {
  width: 100%; height: 38px; padding: 0 14px 0 36px;
  border: 1px solid var(--border); background: var(--bg-soft);
  border-radius: 10px; outline: none; transition: .18s;
}
.search input:focus { border-color: var(--primary); background: #fff; box-shadow: 0 0 0 3px var(--primary-soft); }
.search .ico { position: absolute; left: 11px; top: 50%; transform: translateY(-50%); color: var(--muted); }

.body-wrap { display: flex; flex: 1; min-height: 0; align-items: flex-start; }

/* 侧边导航 */
.sidebar {
  width: var(--sidebar-w); flex: none;
  position: sticky; top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  border-right: 1px solid var(--border);
  background: var(--surface);
  padding: 14px 10px 24px;
}
.nav-group { margin-bottom: 16px; }
.nav-title {
  font-size: 11px; font-weight: 600; color: var(--muted);
  letter-spacing: .08em; padding: 0 10px 6px; text-transform: uppercase;
}
.nav-item {
  display: flex; align-items: center; gap: 10px;
  width: 100%; padding: 9px 11px; border-radius: 10px;
  color: var(--text-2); font-size: 14px; text-align: left;
  transition: .15s; margin-bottom: 2px;
}
.nav-item:hover { background: var(--bg-soft); color: var(--text); }
.nav-item.active { background: var(--primary-soft); color: var(--primary-dark); font-weight: 600; }
.nav-item .ni-ico { width: 18px; display: grid; place-items: center; flex: none; }
.nav-item .ni-ico svg { width: 17px; height: 17px; }
.nav-item .badge {
  margin-left: auto; background: var(--danger); color: #fff;
  font-size: 11px; font-weight: 600; padding: 0 6px;
  border-radius: 20px; line-height: 17px; min-width: 18px; text-align: center;
}
.nav-item .badge.mute { background: var(--border-strong); color: var(--text-2); }

.main { flex: 1; min-width: 0; padding: 22px 26px 60px; }
.container { max-width: 1080px; margin: 0 auto; }

.view { display: none; animation: fade .25s ease; }
.view.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.page-head { margin-bottom: 18px; }
.page-head h1 { font-size: 22px; margin: 0 0 4px; letter-spacing: -.3px; }
.page-head p { margin: 0; color: var(--muted); font-size: 13.5px; }

/* ===================== 卡片 / 组件 ===================== */
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.card-pad { padding: 18px; }
.card-head {
  padding: 14px 18px; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
}
.card-head h2 { font-size: 15px; margin: 0; font-weight: 600; }
.card-head .sub { font-size: 12.5px; color: var(--muted); }
.card-head .right { margin-left: auto; display: flex; gap: 8px; align-items: center; }

.grid { display: grid; gap: 14px; }
.g2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.g3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.g4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 36px; padding: 0 15px; border-radius: 10px;
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text-2); font-size: 13.5px; font-weight: 500; transition: .15s;
  white-space: nowrap;
}
.btn:hover { border-color: var(--border-strong); background: var(--surface-2); color: var(--text); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; pointer-events: none; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: #fff; }
.btn-success { background: var(--success); border-color: var(--success); color: #fff; }
.btn-success:hover { background: #0e7c57; color: #fff; }
.btn-danger { background: #fff; border-color: #f3c9c9; color: var(--danger); }
.btn-danger:hover { background: var(--danger-soft); color: var(--danger); }
.btn-ghost { background: transparent; border-color: transparent; }
.btn-ghost:hover { background: var(--bg-soft); }
.btn-sm { height: 30px; padding: 0 11px; font-size: 12.5px; border-radius: 8px; }
.btn-lg { height: 44px; padding: 0 24px; font-size: 15px; border-radius: 11px; }
.btn-block { width: 100%; }
.btn svg { width: 16px; height: 16px; }

.chip {
  display: inline-flex; align-items: center; gap: 5px;
  height: 30px; padding: 0 12px; border-radius: 20px;
  background: var(--surface); border: 1px solid var(--border);
  font-size: 13px; color: var(--text-2); transition: .15s; white-space: nowrap;
}
.chip:hover { border-color: var(--primary); color: var(--primary); }
.chip.on { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 500; }
.chip .cnt { font-size: 11.5px; opacity: .7; }

.tag {
  display: inline-block; padding: 1px 8px; border-radius: 6px;
  font-size: 11.5px; font-weight: 500; line-height: 19px; white-space: nowrap;
}
.t-type { background: var(--primary-soft); color: var(--primary-dark); }
.t-cat  { background: var(--purple-soft); color: var(--purple); }
.t-easy { background: var(--success-soft); color: var(--success); }
.t-mid  { background: var(--warn-soft); color: var(--warn); }
.t-hard { background: var(--danger-soft); color: var(--danger); }
.t-plain{ background: var(--bg-soft); color: var(--muted); }

.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 12.5px; color: var(--text-2); font-weight: 500; }
.field select, .field input {
  height: 38px; padding: 0 11px; border: 1px solid var(--border);
  border-radius: 9px; background: var(--surface); outline: none; transition: .15s;
}
.field select:focus, .field input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }

.empty {
  text-align: center; padding: 56px 20px; color: var(--muted);
}
.empty .e-ico { font-size: 40px; line-height: 1; margin-bottom: 10px; opacity: .5; }
.empty h3 { margin: 0 0 6px; font-size: 16px; color: var(--text-2); }
.empty p { margin: 0 0 16px; font-size: 13.5px; }

/* ===================== 概览 ===================== */
.stat-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px; box-shadow: var(--shadow);
  position: relative; overflow: hidden;
}
.stat-card .sc-label { font-size: 12.5px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
.stat-card .sc-val { font-size: 27px; font-weight: 700; letter-spacing: -.5px; margin-top: 4px; line-height: 1.2; }
.stat-card .sc-val small { font-size: 14px; font-weight: 500; color: var(--muted); margin-left: 2px; }
.stat-card .sc-foot { font-size: 12px; color: var(--muted); margin-top: 2px; }
.stat-card .sc-ico {
  position: absolute; right: 14px; top: 14px; width: 34px; height: 34px;
  border-radius: 10px; display: grid; place-items: center;
}
.stat-card .sc-ico svg { width: 18px; height: 18px; }
.sc-blue .sc-ico { background: var(--primary-soft); color: var(--primary); }
.sc-green .sc-ico { background: var(--success-soft); color: var(--success); }
.sc-red .sc-ico { background: var(--danger-soft); color: var(--danger); }
.sc-amber .sc-ico { background: var(--warn-soft); color: var(--warn); }
.sc-purple .sc-ico { background: var(--purple-soft); color: var(--purple); }

.bar-row { display: flex; align-items: center; gap: 10px; padding: 7px 0; }
.bar-row .br-name { width: 118px; flex: none; font-size: 13px; color: var(--text-2); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.bar-row .br-track { flex: 1; height: 9px; background: var(--bg-soft); border-radius: 6px; overflow: hidden; }
.bar-row .br-fill { height: 100%; border-radius: 6px; background: linear-gradient(90deg, var(--primary), #6f4bff); transition: width .5s ease; }
.bar-row .br-val { width: 62px; text-align: right; font-size: 12.5px; color: var(--muted); flex: none; }

.quick-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; }
.quick {
  display: flex; align-items: center; gap: 12px; padding: 14px;
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); transition: .18s; text-align: left; width: 100%;
}
.quick:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow); }
.quick .q-ico { width: 40px; height: 40px; border-radius: 11px; display: grid; place-items: center; flex: none; }
.quick .q-ico svg { width: 20px; height: 20px; }
.quick b { display: block; font-size: 14px; }
.quick span { font-size: 12px; color: var(--muted); }

/* ===================== 题库 / 题目卡 ===================== */
.filters { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.filter-line { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; padding: 6px 0; }
.filter-line .fl-label { font-size: 12.5px; color: var(--muted); width: 46px; flex: none; }

.q-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); margin-bottom: 12px; overflow: hidden;
  transition: .18s;
}
.q-card:hover { border-color: var(--border-strong); }
.q-card.wrong { border-left: 3px solid var(--danger); }
.q-card.done { border-left: 3px solid var(--success); }
.q-head {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  padding: 12px 16px 0;
}
.q-no {
  width: 26px; height: 26px; flex: none; border-radius: 8px;
  background: var(--bg-soft); color: var(--text-2);
  display: grid; place-items: center; font-size: 12.5px; font-weight: 600;
}
.q-head .right { margin-left: auto; display: flex; gap: 4px; align-items: center; }
.q-body { padding: 10px 16px 14px; }
.q-stem { font-size: 15px; line-height: 1.7; color: var(--text); }
.q-code {
  margin-top: 10px; padding: 11px 13px; background: #1f2437; color: #d7dee9;
  border-radius: 9px; font-family: var(--mono); font-size: 12.5px;
  white-space: pre-wrap; overflow-x: auto; line-height: 1.6;
}
.q-opts { margin-top: 12px; display: flex; flex-direction: column; gap: 8px; }
.opt {
  display: flex; gap: 10px; align-items: flex-start; padding: 10px 13px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface-2); font-size: 14px; line-height: 1.6;
  transition: .15s; width: 100%; text-align: left;
}
.opt:hover { border-color: var(--primary); background: var(--primary-soft); }
.opt .o-key {
  width: 21px; height: 21px; flex: none; border-radius: 6px;
  background: #fff; border: 1px solid var(--border-strong);
  display: grid; place-items: center; font-size: 12px; font-weight: 600;
  color: var(--text-2); margin-top: 1px;
}
.opt.correct { border-color: var(--success); background: var(--success-soft); }
.opt.correct .o-key { background: var(--success); border-color: var(--success); color: #fff; }
.opt.wrong { border-color: var(--danger); background: var(--danger-soft); }
.opt.wrong .o-key { background: var(--danger); border-color: var(--danger); color: #fff; }
.opt.picked { border-color: var(--primary); }
.opt.picked .o-key { background: var(--primary); border-color: var(--primary); color: #fff; }
.opt.disabled { pointer-events: none; }

.q-answer {
  margin-top: 13px; padding: 13px 15px; border-radius: 11px;
  background: var(--surface-2); border: 1px dashed var(--border-strong);
  font-size: 13.5px; line-height: 1.75;
}
.q-answer .qa-line { display: flex; gap: 8px; margin-bottom: 6px; flex-wrap: wrap; align-items: baseline; }
.q-answer .qa-line:last-child { margin-bottom: 0; }
.q-answer b { color: var(--text); flex: none; }
.verdict { font-weight: 600; }
.verdict.ok { color: var(--success); }
.verdict.no { color: var(--danger); }

.q-actions { display: flex; gap: 8px; padding: 0 16px 14px; flex-wrap: wrap; }
.reveal-hint { padding: 0 16px 14px; }

.pager { display: flex; align-items: center; justify-content: center; gap: 6px; margin-top: 18px; flex-wrap: wrap; }
.pager button {
  min-width: 34px; height: 34px; padding: 0 10px; border-radius: 9px;
  border: 1px solid var(--border); background: var(--surface);
  font-size: 13px; color: var(--text-2);
}
.pager button:hover:not(:disabled) { border-color: var(--primary); color: var(--primary); }
.pager button.on { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 600; }
.pager button:disabled { opacity: .4; }
.pager .dots { color: var(--muted); padding: 0 2px; }

/* ===================== 答题 ===================== */
.setup-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px; }
.opt-group { display: flex; gap: 8px; flex-wrap: wrap; }
.radio-card {
  flex: 1; min-width: 130px; padding: 12px; border: 1px solid var(--border);
  border-radius: 11px; background: var(--surface); text-align: center; transition: .15s;
}
.radio-card:hover { border-color: var(--primary); }
.radio-card.on { border-color: var(--primary); background: var(--primary-soft); }
.radio-card b { display: block; font-size: 14px; }
.radio-card span { font-size: 11.5px; color: var(--muted); }

.practice-bar {
  position: sticky; top: var(--header-h); z-index: 40;
  background: rgba(255, 255, 255, .94); backdrop-filter: blur(10px);
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 10px 14px; margin-bottom: 14px;
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  box-shadow: var(--shadow);
}
.pb-progress { flex: 1; min-width: 140px; }
.pb-progress .pb-txt { font-size: 12.5px; color: var(--muted); margin-bottom: 5px; display: flex; justify-content: space-between; }
.pb-track { height: 6px; background: var(--bg-soft); border-radius: 4px; overflow: hidden; }
.pb-fill { height: 100%; background: var(--primary); border-radius: 4px; transition: width .3s; }
.pb-timer { font-variant-numeric: tabular-nums; font-weight: 600; font-size: 14px; color: var(--text-2); }

.sheet {
  width: 100%; border-collapse: collapse; font-size: 13px;
}
.sheet th, .sheet td { border: 1px solid var(--border); padding: 7px 9px; text-align: left; }
.sheet th { background: var(--surface-2); font-weight: 600; font-size: 12.5px; }
.sheet tbody tr:nth-child(even) { background: #fbfcfe; }

.sheet-wrap { overflow-x: auto; margin: 10px 0; border-radius: 9px; }

.qnav { display: grid; grid-template-columns: repeat(auto-fill, minmax(34px, 1fr)); gap: 6px; }
.qnav button {
  height: 34px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--surface); font-size: 12.5px; color: var(--text-2); font-variant-numeric: tabular-nums;
}
.qnav button:hover { border-color: var(--primary); }
.qnav button.cur { border-color: var(--primary); background: var(--primary); color: #fff; font-weight: 600; }
.qnav button.ok { border-color: var(--success); background: var(--success-soft); color: var(--success); }
.qnav button.no { border-color: var(--danger); background: var(--danger-soft); color: var(--danger); }
.qnav button.ok.cur, .qnav button.no.cur { color: #fff; background: var(--primary); }

/* 结果 */
.result-hero {
  text-align: center; padding: 30px 20px;
  background: linear-gradient(160deg, #f3f7ff, #fff 60%);
  border: 1px solid var(--border); border-radius: var(--radius);
}
.rh-score { font-size: 52px; font-weight: 800; letter-spacing: -2px; line-height: 1; }
.rh-score small { font-size: 20px; font-weight: 600; color: var(--muted); }
.rh-sub { color: var(--muted); font-size: 13.5px; margin-top: 6px; }
.rh-ring { display: inline-grid; place-items: center; margin-bottom: 10px; }
.rh-metrics { display: flex; justify-content: center; gap: 26px; margin-top: 18px; flex-wrap: wrap; }
.rh-metrics div { text-align: center; }
.rh-metrics b { display: block; font-size: 19px; font-weight: 700; }
.rh-metrics span { font-size: 12px; color: var(--muted); }

/* ===================== 错题 / 列表行 ===================== */
.row-item {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 13px 16px; border-bottom: 1px solid var(--border);
}
.row-item:last-child { border-bottom: none; }
.row-item .ri-main { flex: 1; min-width: 0; }
.row-item .ri-title { font-size: 14px; line-height: 1.6; }
.row-item .ri-meta { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 6px; align-items: center; }
.row-item .ri-ops { display: flex; gap: 6px; flex: none; }

/* ===================== 实操样题 ===================== */
.lab-item { border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; background: var(--surface); }
.lab-head { display: flex; align-items: center; gap: 12px; padding: 14px 16px; width: 100%; text-align: left; }
.lab-head:hover { background: var(--surface-2); }
.lab-no {
  width: 30px; height: 30px; flex: none; border-radius: 9px; background: linear-gradient(135deg, var(--primary), #6f4bff);
  color: #fff; display: grid; place-items: center; font-weight: 700; font-size: 14px;
}
.lab-head .lh-txt { flex: 1; min-width: 0; }
.lab-head .lh-txt b { display: block; font-size: 14.5px; }
.lab-head .lh-txt span { font-size: 12px; color: var(--muted); }
.lab-body { padding: 6px 18px 20px; border-top: 1px solid var(--border); font-size: 14px; line-height: 1.85; }
.lab-body p { margin: 6px 0; }
.lab-body code.ic {
  font-family: var(--mono); font-size: 12.5px; background: var(--primary-soft);
  color: var(--primary-dark); padding: 1.5px 5px; border-radius: 5px; word-break: break-all;
}

/* 章节标题 */
.lab-body .lb-sec {
  display: flex; align-items: center; gap: 8px;
  margin: 20px 0 10px; padding-bottom: 7px; border-bottom: 1px dashed var(--border-strong);
}
.lab-body .lb-sec i { font-style: normal; font-size: 14px; line-height: 1; }
.lab-body .lb-sec b { color: var(--primary-dark); font-size: 14.5px; letter-spacing: .5px; }

/* 提示条 */
.lab-body .lb-note {
  display: flex; gap: 8px; align-items: flex-start; margin: 10px 0;
  padding: 9px 12px; background: var(--warn-soft); border-left: 3px solid var(--warn);
  border-radius: 0 9px 9px 0; font-size: 13.5px; color: var(--text-2);
}
.lab-body .lb-note i { font-style: normal; line-height: 1.7; }
.lab-body .lb-note code.ic { background: #fff; }

/* 表格标题 */
.lab-body .lb-cap { margin: 16px 0 4px; font-size: 13px; font-weight: 600; color: var(--muted); }

/* 任务步骤 */
.lab-body .lb-step { display: flex; gap: 10px; margin: 14px 0 8px; }
.lab-body .lb-step .sn {
  flex: none; width: 24px; height: 24px; margin-top: 4px; border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), #6f4bff);
  color: #fff; font-size: 13px; font-weight: 700; display: grid; place-items: center;
}
.lab-body .lb-step .st { flex: 1; min-width: 0; font-weight: 600; line-height: 1.8; }

/* 子条目 */
.lab-body .lb-li { display: flex; gap: 9px; margin: 4px 0 4px 34px; }
.lab-body .lb-li .ln {
  flex: none; width: 19px; height: 19px; margin-top: 6px; border-radius: 50%;
  background: var(--bg-soft); color: var(--text-2); font-size: 11.5px;
  font-weight: 700; display: grid; place-items: center;
}
.lab-body .lb-li > span:last-child { flex: 1; min-width: 0; }

/* 命令行 */
.lab-body .lb-cmd {
  display: flex; align-items: center; gap: 10px; margin: 7px 0 7px 34px;
  background: var(--bg-soft); border: 1px solid var(--border);
  border-left: 3px solid var(--primary); border-radius: 0 9px 9px 0; padding: 8px 10px 8px 12px;
}
.lab-body .lb-cmd code {
  flex: 1; min-width: 0; font-family: var(--mono); font-size: 12.5px; color: #1f2d4d;
  white-space: pre-wrap; word-break: break-all; line-height: 1.65;
}
/* 代码块 */
.lab-body .lb-code {
  margin: 8px 0 8px 34px; border: 1px solid var(--border); border-radius: 9px;
  overflow: hidden; background: var(--surface-2);
}
.lab-body .lc-hd {
  display: flex; align-items: center; justify-content: space-between; padding: 5px 8px 5px 12px;
  background: var(--bg-soft); border-bottom: 1px solid var(--border);
  font-size: 11.5px; color: var(--muted); font-family: var(--mono);
}
.lab-body .lb-code pre { margin: 0; padding: 10px 12px; overflow-x: auto; }
.lab-body .lb-code pre code {
  font-family: var(--mono); font-size: 12.5px; line-height: 1.75; color: #1f2d4d; white-space: pre;
}
/* 输出示例 */
.lab-body .lb-out {
  margin: 6px 0 6px 34px; padding: 7px 12px; background: var(--success-soft);
  border: 1px dashed #a9dcc6; border-radius: 9px;
}
.lab-body .lb-out code {
  font-family: var(--mono); font-size: 12.5px; color: #0d6b4f;
  white-space: pre-wrap; word-break: break-all;
}
/* 复制按钮 */
.lab-body .cp {
  flex: none; font-size: 11.5px; line-height: 1.6; padding: 2px 8px; cursor: pointer;
  border: 1px solid var(--border-strong); border-radius: 6px;
  background: var(--surface); color: var(--text-2);
}
.lab-body .cp:hover { background: var(--primary-soft); color: var(--primary-dark); border-color: var(--primary); }

/* 表格单元格内的子列表 */
.sheet .tdlist { margin: 0; padding-left: 17px; }
.sheet .tdlist li { margin: 2px 0; font-size: 13px; line-height: 1.7; }
.sheet td.tk { font-weight: 600; background: var(--surface-2); vertical-align: top; white-space: nowrap; }
.sheet td.tk.mono { font-family: var(--mono); font-size: 12.5px; font-weight: 600; }

@media (max-width: 640px) {
  .lab-body { padding: 6px 12px 16px; }
  .lab-body .lb-li, .lab-body .lb-cmd { margin-left: 0; }
}

/* ===================== 弹窗 ===================== */
.mask {
  position: fixed; inset: 0; background: rgba(15, 23, 42, .45);
  z-index: 200; display: none; align-items: center; justify-content: center;
  padding: 18px; backdrop-filter: blur(2px);
}
.mask.open { display: flex; animation: fade .2s; }
.modal {
  background: var(--surface); border-radius: var(--radius); width: 100%;
  max-width: 560px; max-height: 86vh; display: flex; flex-direction: column;
  box-shadow: var(--shadow-lg); animation: pop .22s ease;
}
@keyframes pop { from { transform: scale(.96) translateY(8px); opacity: 0; } to { transform: none; opacity: 1; } }
.modal-head { padding: 15px 18px; border-bottom: 1px solid var(--border); display: flex; align-items: center; }
.modal-head h3 { margin: 0; font-size: 16px; }
.modal-head .x { margin-left: auto; width: 30px; height: 30px; border-radius: 8px; color: var(--muted); display: grid; place-items: center; }
.modal-head .x:hover { background: var(--bg-soft); color: var(--text); }
.modal-body { padding: 18px; overflow-y: auto; }
.modal-foot { padding: 13px 18px; border-top: 1px solid var(--border); display: flex; gap: 8px; justify-content: flex-end; }

.toast {
  position: fixed; left: 50%; bottom: 34px; transform: translateX(-50%) translateY(20px);
  background: #17203a; color: #fff; padding: 10px 18px; border-radius: 10px;
  font-size: 13.5px; z-index: 300; opacity: 0; pointer-events: none; transition: .25s;
  box-shadow: var(--shadow-lg); max-width: 88vw; text-align: center;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* 收藏星 */
.star { width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center; color: var(--border-strong); transition: .15s; }
.star:hover { background: var(--bg-soft); color: var(--warn); }
.star.on { color: var(--warn); }
.star svg { width: 17px; height: 17px; }

.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* ===================== 响应式 ===================== */
@media (max-width: 1024px) {
  .g4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .g3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 860px) {
  .hamburger { display: flex; }
  .sidebar {
    position: fixed; left: 0; top: var(--header-h); z-index: 90;
    transform: translateX(-100%); transition: transform .26s ease;
    box-shadow: var(--shadow-lg); width: 250px;
  }
  .sidebar.open { transform: none; }
  .backdrop {
    position: fixed; inset: var(--header-h) 0 0; background: rgba(15, 23, 42, .4);
    z-index: 80; display: none;
  }
  .backdrop.open { display: block; }
  .main { padding: 16px 14px 70px; }
  .search { max-width: none; }
  .brand-txt span { display: none; }
}

@media (max-width: 640px) {
  body { font-size: 14.5px; }
  .g2, .g3, .g4 { grid-template-columns: 1fr; }
  .grid { gap: 12px; }
  .page-head h1 { font-size: 19px; }
  .card-head { padding: 12px 14px; }
  .card-pad { padding: 14px; }
  .q-body { padding: 8px 13px 13px; }
  .q-head { padding: 11px 13px 0; }
  .q-actions { padding: 0 13px 12px; }
  .q-stem { font-size: 14.5px; }
  .stat-card .sc-val { font-size: 23px; }
  .bar-row .br-name { width: 92px; font-size: 12.5px; }
  .bar-row .br-val { width: 50px; font-size: 12px; }
  .rh-score { font-size: 42px; }
  .rh-metrics { gap: 18px; }
  .row-item { padding: 12px 13px; flex-wrap: wrap; }
  .row-item .ri-ops { width: 100%; justify-content: flex-end; }
  .practice-bar { padding: 9px 11px; gap: 9px; }
  .filter-line .fl-label { width: 100%; }
  .header { padding: 0 11px; gap: 8px; }
  .qnav { grid-template-columns: repeat(auto-fill, minmax(30px, 1fr)); }
  .qnav button { height: 30px; font-size: 12px; }
  .pager button { min-width: 31px; height: 31px; padding: 0 7px; font-size: 12.5px; }
}

@media (max-width: 400px) {
  .brand-txt b { font-size: 13.5px; }
  .quick-grid { grid-template-columns: 1fr; }
}