:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1b1f24;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #2563eb;
  --accent-soft: #e8efff;
  --ok: #16a34a;
  --ok-soft: #e7f6ec;
  --bad: #dc2626;
  --bad-soft: #fdecec;
  --mid: #d97706;
  --shadow: 0 1px 2px rgba(0, 0, 0, .05);
  --radius: 12px;
  --safe-b: env(safe-area-inset-bottom, 0px);
  --safe-t: env(safe-area-inset-top, 0px);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --card: #1e2127;
    --text: #e6e8eb;
    --muted: #9aa1ab;
    --line: #2e333b;
    --accent: #6b9bff;
    --accent-soft: #1f2b45;
    --ok: #4ade80;
    --ok-soft: #173224;
    --bad: #f87171;
    --bad-soft: #3a1d1d;
    --mid: #fbbf24;
    --shadow: none;
  }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; }
h1 { font-size: 20px; margin: 0; }
h2 { font-size: 15px; margin: 0 0 10px; display: flex; align-items: center; gap: 8px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.err { color: var(--bad); }
.center { padding: 40vh 16px 0; text-align: center; }
.row { display: flex; gap: 8px; align-items: center; }

/* ---------- 布局 ---------- */
.page { max-width: 760px; margin: 0 auto; padding: 16px 16px calc(96px + var(--safe-b)); }
.page section { margin: 22px 0; }
.bar {
  position: sticky; top: 0; z-index: 10; display: flex; align-items: center; gap: 8px;
  padding: calc(8px + var(--safe-t)) 8px 8px; background: var(--bg); border-bottom: 1px solid var(--line);
}
.bar h1 { flex: 1; font-size: 17px; text-align: center; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bar-right { min-width: 40px; display: flex; justify-content: flex-end; }
.bar-btn {
  min-width: 40px; height: 40px; display: inline-flex; align-items: center; justify-content: center;
  font-size: 24px; border: 0; background: none; border-radius: 10px; cursor: pointer;
}
.bar-btn.flagged { color: var(--mid); }
.footer-bar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 10px 16px calc(10px + var(--safe-b)); background: var(--card); border-top: 1px solid var(--line);
}
.footer-bar.nav .btn { flex: 1; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 44px; padding: 0 18px;
  border-radius: 10px; border: 1px solid var(--line); background: var(--card); cursor: pointer; font-weight: 500;
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.ghost { background: transparent; }
.btn.ok { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); flex: 1; }
.btn.bad { background: var(--bad-soft); border-color: var(--bad); color: var(--bad); flex: 1; }
.btn.block { display: flex; width: 100%; }
.btn:disabled, .btn.disabled { opacity: .4; pointer-events: none; }
.bad-text { color: var(--bad); }
.link { border: 0; background: none; color: var(--accent); padding: 0; cursor: pointer; font-weight: 400; font-size: 13px; }

/* ---------- 登录 ---------- */
.login { max-width: 340px; margin: 0 auto; padding: 18vh 16px 0; text-align: center; }
.login form { display: grid; gap: 12px; margin-top: 28px; }
.logo {
  width: 72px; height: 72px; margin: 0 auto 12px; border-radius: 18px; background: var(--accent); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 24px; letter-spacing: 1px;
}
input[type=password], input:not([type]), .field input {
  width: 100%; min-height: 46px; padding: 0 14px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--card); color: var(--text); font: inherit;
}
.field { display: grid; gap: 6px; margin-bottom: 12px; font-size: 13px; color: var(--muted); }

/* ---------- 首页 ---------- */
.home-head { display: flex; justify-content: space-between; align-items: center; padding-top: var(--safe-t); margin-bottom: 16px; }
.kpis { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 16px; }
.kpis div { background: var(--card); border-radius: var(--radius); padding: 12px 8px; text-align: center; box-shadow: var(--shadow); }
.kpis b { display: block; font-size: 22px; font-variant-numeric: tabular-nums; }
.kpis b small { font-size: 13px; color: var(--muted); font-weight: 400; }
.kpis span { font-size: 12px; color: var(--muted); }
.card { display: block; background: var(--card); border-radius: var(--radius); padding: 16px; margin-bottom: 10px; box-shadow: var(--shadow); }
.card.big { display: flex; align-items: center; gap: 14px; }
.card.big b { display: block; font-size: 16px; }
.card.big span:not(.ico) { font-size: 13px; color: var(--muted); }
.ico { width: 42px; height: 42px; flex: none; border-radius: 12px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-size: 20px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.grid2 .card { margin: 0; }
.card.resume, .card.mock { display: flex; justify-content: space-between; align-items: center; gap: 10px; border: 1px solid var(--accent); }
.card.mock { border-color: transparent; }

/* ---------- 选题 ---------- */
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  min-height: 38px; padding: 0 14px; border-radius: 19px; border: 1px solid var(--line); background: var(--card);
  cursor: pointer; display: inline-flex; align-items: center; gap: 6px; font-size: 14px;
}
.chip small { font-size: 11px; color: var(--muted); }
.chip.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.chip.on small { color: rgba(255, 255, 255, .8); }
.chip.empty:not(.on) { opacity: .5; }
.check { display: flex; gap: 8px; align-items: center; font-size: 14px; margin-top: 8px; }
.check input { width: 18px; height: 18px; }

/* ---------- 答题 ---------- */
.quiz-bar { justify-content: space-between; }
.progress { border: 0; background: var(--accent-soft); color: var(--accent); border-radius: 16px; padding: 4px 14px; font-weight: 600; cursor: pointer; }
.progress small { font-weight: 400; opacity: .8; }
.timer { font-variant-numeric: tabular-nums; color: var(--muted); min-width: 60px; text-align: center; }
.timer.low { color: var(--bad); font-weight: 600; }
.pbar { height: 3px; background: var(--line); }
.pbar i { display: block; height: 100%; background: var(--accent); transition: width .2s; }
.qtag { display: flex; gap: 6px; margin-bottom: 12px; flex-wrap: wrap; }
.qtag span { font-size: 12px; padding: 2px 8px; border-radius: 6px; background: var(--card); color: var(--muted); border: 1px solid var(--line); }
.stem { font-size: 16.5px; margin-bottom: 16px; }
.options { display: grid; gap: 10px; margin-bottom: 18px; }
.opt {
  display: flex; gap: 12px; align-items: flex-start; text-align: left; width: 100%; padding: 12px 14px;
  border-radius: var(--radius); border: 1.5px solid var(--line); background: var(--card); cursor: pointer; line-height: 1.5;
}
.opt:disabled { cursor: default; }
.opt-l {
  flex: none; width: 28px; height: 28px; border-radius: 50%; border: 1.5px solid var(--line);
  display: grid; place-items: center; font-weight: 600; font-size: 14px;
}
.opt-t { flex: 1; padding-top: 2px; }
.opt.picked { border-color: var(--accent); background: var(--accent-soft); }
.opt.picked .opt-l { background: var(--accent); border-color: var(--accent); color: #fff; }
.opt.right { border-color: var(--ok); background: var(--ok-soft); }
.opt.right .opt-l { background: var(--ok); border-color: var(--ok); color: #fff; }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.opt.wrong .opt-l { background: var(--bad); border-color: var(--bad); color: #fff; }
.case { background: var(--card); border-radius: var(--radius); padding: 10px 14px; margin-bottom: 14px; border-left: 3px solid var(--accent); }
.case summary { font-weight: 600; font-size: 14px; cursor: pointer; }
.case .md { max-height: 45vh; overflow-y: auto; margin-top: 8px; font-size: 15px; }
.self-mark { margin: 14px 0; }

.sheet { position: fixed; inset: 0; z-index: 20; background: rgba(0, 0, 0, .4); display: flex; align-items: flex-end; }
.sheet[hidden] { display: none; }
.sheet-panel { background: var(--card); width: 100%; max-height: 75vh; overflow: auto; border-radius: 16px 16px 0 0; padding: 12px 16px calc(16px + var(--safe-b)); }
.sheet-head { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.sheet-head b { flex: 1; }
.sheet-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(44px, 1fr)); gap: 8px; margin-bottom: 14px; }
.sheet-grid button { height: 44px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); cursor: pointer; position: relative; }
.sheet-grid .done { background: var(--accent-soft); border-color: var(--accent); }
.sheet-grid .ok { background: var(--ok-soft); border-color: var(--ok); }
.sheet-grid .bad { background: var(--bad-soft); border-color: var(--bad); }
.sheet-grid .cur { outline: 2px solid var(--accent); outline-offset: 1px; }
.sheet-grid .flag::after { content: '★'; position: absolute; top: -2px; right: 2px; font-size: 11px; color: var(--mid); }

/* ---------- 解释 ---------- */
.explain { margin-top: 8px; }
.verdict { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 6px; padding: 12px 14px; border-radius: var(--radius); font-weight: 600; }
.verdict span { font-weight: 400; font-size: 14px; }
.verdict.ok { background: var(--ok-soft); color: var(--ok); }
.verdict.bad { background: var(--bad-soft); color: var(--bad); }
.verdict span { color: var(--text); }
.qmeta { margin: 8px 2px 12px; }
.sec { background: var(--card); border-radius: var(--radius); margin-bottom: 10px; box-shadow: var(--shadow); }
.sec > summary, .sec details > summary { padding: 12px 14px; font-weight: 600; cursor: pointer; font-size: 15px; }
.sec .md { padding: 0 14px 12px; }
.sec.ai { background: transparent; box-shadow: none; }
.sec.ai details { background: var(--card); border-radius: var(--radius); border: 1px solid var(--accent); }
.sec.ai .link { margin: 0 14px 12px; }
.ai-wait { padding: 14px; text-align: center; background: var(--card); border-radius: var(--radius); animation: pulse 1.6s infinite; }
@keyframes pulse { 50% { opacity: .5; } }

.md { overflow-wrap: anywhere; }
.md p { margin: 0 0 10px; }
.md > :last-child { margin-bottom: 0; }
.md h3, .md h4 { font-size: 15px; margin: 16px 0 8px; }
.md ul, .md ol { padding-left: 22px; margin: 0 0 10px; }
.md blockquote { margin: 0 0 10px; padding: 8px 12px; border-left: 3px solid var(--line); color: var(--muted); background: var(--bg); border-radius: 0 8px 8px 0; }
.md code { font-size: .9em; padding: 1px 5px; border-radius: 4px; background: var(--bg); }
.md table { border-collapse: collapse; margin: 0 0 12px; font-size: 14px; display: block; overflow-x: auto; max-width: 100%; width: max-content; }
.md th, .md td { border: 1px solid var(--line); padding: 6px 8px; text-align: left; vertical-align: top; min-width: 3.5em; max-width: 15em; overflow-wrap: normal; word-break: normal; }
.md th { background: var(--bg); }
.md .katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
.md img { max-width: 100%; }

/* ---------- 列表 / 统计 ---------- */
.score { display: flex; align-items: center; gap: 18px; }
.ring {
  --p: 0; width: 84px; height: 84px; border-radius: 50%; flex: none; display: grid; place-items: center;
  background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--line) 0);
}
.ring b { width: 68px; height: 68px; border-radius: 50%; background: var(--card); display: grid; place-items: center; font-size: 20px; }
.barrow { display: grid; grid-template-columns: 7.5em 1fr 5.5em; align-items: center; gap: 10px; margin-bottom: 10px; font-size: 14px; }
.bl { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bb { height: 8px; background: var(--line); border-radius: 4px; overflow: hidden; }
.bb i { display: block; height: 100%; border-radius: 4px; }
.bv { text-align: right; font-variant-numeric: tabular-nums; line-height: 1.2; }
.bv small { display: block; font-size: 11px; color: var(--muted); }
.ok { --c: var(--ok); } .mid { --c: var(--mid); } .bad { --c: var(--bad); }
.bb i.ok, .bb i.mid, .bb i.bad { background: var(--c); }
.seg { margin-left: auto; display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.seg button { border: 0; background: var(--card); padding: 4px 10px; font-size: 13px; font-weight: 400; cursor: pointer; }
.seg button.on { background: var(--accent); color: #fff; }
.qlist { display: grid; gap: 6px; }
.qitem { display: flex; gap: 10px; align-items: center; background: var(--card); padding: 10px 12px; border-radius: 10px; box-shadow: var(--shadow); }
.qi-n { color: var(--muted); font-size: 13px; min-width: 1.6em; }
.qi-t { flex: 1; font-size: 14px; overflow: hidden; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.qi-t small { display: block; color: var(--muted); font-size: 12px; }
.mark { flex: none; width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; font-size: 12px; color: #fff; background: var(--c); }
.sc { flex: none; min-width: 48px; text-align: center; font-weight: 600; color: var(--c); font-variant-numeric: tabular-nums; }
.hist { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; }
.trend { width: 100%; height: 90px; display: block; }
.trend .line { fill: none; stroke: var(--accent); stroke-width: 2; vector-effect: non-scaling-stroke; }
.trend .dot { fill: var(--accent); }
.trend .ref { stroke: var(--muted); stroke-dasharray: 4 4; stroke-width: 1; vector-effect: non-scaling-stroke; opacity: .6; }

.toast {
  position: fixed; left: 50%; bottom: calc(90px + var(--safe-b)); transform: translateX(-50%); z-index: 50;
  background: rgba(20, 22, 26, .92); color: #fff; padding: 10px 16px; border-radius: 10px; font-size: 14px; max-width: 86vw;
}