:root {
    --bg: #ffffff;
    --bg-soft: #fafafa;
    --fg: #171717;
    --fg-2: #4d4d4d;
    --fg-3: #666666;
    --fg-4: #808080;
    --line: rgba(0, 0, 0, 0.08);
    --line-soft: #ebebeb;
    --ring: rgba(0, 0, 0, 0.08) 0 0 0 1px;
    --card: rgba(0,0,0,0.08) 0 0 0 1px, rgba(0,0,0,0.04) 0 2px 2px, #fafafa 0 0 0 1px;
    --accent: #0072f5;
    --focus: hsla(212, 100%, 48%, 1);
    --err: #c5221f;
    --warn: #9a5b00;
    --info: #0072f5;
    --ok: #0a7a33;
    --note: #666666;
    --chip-err-bg: #fdecea; --chip-err-fg: #a71d1a;
    --chip-warn-bg: #fff4e0; --chip-warn-fg: #8a5200;
    --chip-note-bg: #f1f2f4; --chip-note-fg: #555a62;
    --chip-ok-bg: #e9f6ee;   --chip-ok-fg: #0a6a2c;
    --mono: "Geist Mono Variable", ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
    --sans: "Geist Variable", -apple-system, "Segoe UI", system-ui, "Helvetica Neue", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  }
  [data-theme="dark"] {
    --bg: #0a0a0a;
    --bg-soft: #111112;
    --fg: #f7f8f8;
    --fg-2: #d0d6e0;
    --fg-3: #a0a6b0;
    --fg-4: #6e7681;
    --line: rgba(255, 255, 255, 0.08);
    --line-soft: #23252a;
    --ring: rgba(255,255,255,0.08) 0 0 0 1px;
    --card: rgba(255,255,255,0.08) 0 0 0 1px, rgba(0,0,0,0.3) 0 2px 6px;
    --accent: #5aa8ff;
    --focus: hsla(212, 100%, 62%, 1);
    --err: #ff6b60; --warn: #f5b942; --info: #6cb2ff; --ok: #4cc38a; --note: #a0a6b0;
    --chip-err-bg: #2a1514; --chip-err-fg: #ff8a82;
    --chip-warn-bg: #2a2114; --chip-warn-fg: #f2c66d;
    --chip-note-bg: #1a1c1f; --chip-note-fg: #a0a6b0;
    --chip-ok-bg: #12241a;   --chip-ok-fg: #67d295;
  }
  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --bg: #0a0a0a; --bg-soft: #111112; --fg: #f7f8f8; --fg-2: #d0d6e0; --fg-3: #a0a6b0; --fg-4: #6e7681;
      --line: rgba(255,255,255,0.08); --line-soft: #23252a;
      --ring: rgba(255,255,255,0.08) 0 0 0 1px;
      --card: rgba(255,255,255,0.08) 0 0 0 1px, rgba(0,0,0,0.3) 0 2px 6px;
      --accent: #5aa8ff; --focus: hsla(212,100%,62%,1);
      --err: #ff6b60; --warn: #f5b942; --info: #6cb2ff; --ok: #4cc38a; --note: #a0a6b0;
      --chip-err-bg: #2a1514; --chip-err-fg: #ff8a82;
      --chip-warn-bg: #2a2114; --chip-warn-fg: #f2c66d;
      --chip-note-bg: #1a1c1f; --chip-note-fg: #a0a6b0;
      --chip-ok-bg: #12241a; --chip-ok-fg: #67d295;
    }
  }

  * { box-sizing: border-box; }
  html { -webkit-text-size-adjust: 100%; }
  body {
    margin: 0; background: var(--bg); color: var(--fg);
    font: 400 16px/1.5 var(--sans);
    -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
  }
  a { color: var(--accent); text-decoration: none; }
  a:hover { text-decoration: underline; }
  code, pre, .mono { font-family: var(--mono); font-variant-ligatures: none; }

  .nav {
    position: sticky; top: 0; z-index: 20;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 24px; height: 56px;
    background: color-mix(in srgb, var(--bg) 86%, transparent);
    backdrop-filter: saturate(1.2) blur(10px);
    box-shadow: var(--ring);
  }
  .wordmark { font: 500 15px var(--mono); color: var(--fg); display: flex; align-items: center; gap: 6px; }
  .wordmark .caret { color: var(--accent); }
  .nav-right { display: flex; align-items: center; gap: 4px; }
  .nav a, .nav button { color: var(--fg-3); font: 500 13px var(--sans); }
  .seg { display: flex; border-radius: 8px; box-shadow: var(--ring); overflow: hidden; }
  .seg button {
    border: 0; background: transparent; color: var(--fg-3); cursor: pointer;
    padding: 5px 12px; font: 500 13px var(--sans);
  }
  .seg button + button { box-shadow: var(--ring); }
  .seg button.on { background: var(--fg); color: var(--bg); }

  .wrap { max-width: 860px; margin: 0 auto; padding: 0 24px 96px; }

  .hero { padding: 72px 0 40px; }
  .kicker { margin: 0 0 16px; font: 500 12px var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--fg-4); }
  .hero h1 {
    margin: 0 0 12px; font: 600 44px/1.06 var(--sans); letter-spacing: -0.035em;
    color: var(--fg); max-width: 16ch;
  }
  .hero h1 .prompt { color: var(--accent); font-family: var(--mono); font-weight: 500; }
  .slogan { margin: 0 0 20px; font-size: 19px; line-height: 1.6; color: var(--fg-2); max-width: 52ch; }
  .trust { margin: 0 0 28px; font: 400 13px var(--mono); color: var(--fg-3); }
  .cmd {
    display: inline-flex; align-items: center; gap: 10px; padding: 10px 16px;
    border-radius: 8px; box-shadow: var(--card); background: var(--bg-soft);
    font: 400 14px var(--mono);
  }
  .cmd .copy { color: var(--accent); cursor: pointer; border: 0; background: none; font: 500 13px var(--sans); }
  .cmd .hint { color: var(--fg-4); }

  .tool { margin: 8px 0 24px; padding: 20px; border-radius: 12px; box-shadow: var(--card); background: var(--bg); }
  .tool label { display: block; margin: 0 0 8px; font: 500 14px var(--sans); color: var(--fg); }
  textarea {
    width: 100%; min-height: 148px; resize: vertical; padding: 14px;
    border: 0; border-radius: 8px; box-shadow: var(--ring); background: var(--bg-soft);
    color: var(--fg); font: 400 13.5px/1.6 var(--mono);
  }
  textarea:focus { outline: 2px solid var(--focus); outline-offset: 2px; }
  textarea::placeholder { color: var(--fg-4); }
  .toolbar { display: flex; align-items: center; gap: 12px; margin: 14px 0 0; flex-wrap: wrap; }
  .toolbar label { margin: 0; font: 500 13px var(--sans); color: var(--fg-2); }
  select {
    border: 0; border-radius: 8px; box-shadow: var(--ring); background: var(--bg-soft);
    color: var(--fg); padding: 7px 32px 7px 10px; font: 400 13px var(--sans);
  }
  select:focus { outline: 2px solid var(--focus); outline-offset: 2px; }
  .version-note { font: 400 12px var(--sans); color: var(--fg-4); }
  .actions { display: flex; gap: 8px; margin: 16px 0 0; flex-wrap: wrap; }
  button.primary, button.ghost {
    border-radius: 6px; cursor: pointer; font: 500 14px var(--sans);
    padding: 9px 16px; transition: transform .08s ease, background-color .15s ease;
  }
  button.primary { border: 0; background: var(--fg); color: var(--bg); }
  button.primary:hover { background: var(--fg-2); }
  button.ghost { border: 0; background: transparent; color: var(--fg-2); box-shadow: var(--ring); }
  button.ghost:hover { background: var(--bg-soft); color: var(--fg); }
  button.primary:active, button.ghost:active { transform: scale(.98); }
  button:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
  .status { margin: 12px 0 0; font: 400 13px var(--mono); color: var(--fg-3); }

  .provenance {
    margin: 0 0 16px; padding: 10px 14px; border-radius: 8px;
    background: color-mix(in srgb, var(--warn) 10%, transparent); color: var(--warn);
    font: 400 13px/1.55 var(--sans);
  }

  /* report */
  .summary { display: flex; align-items: center; gap: 8px; margin: 0 0 14px; }
  .chips { display: flex; gap: 6px; flex-wrap: wrap; }
  .chip { padding: 3px 10px; border-radius: 9999px; font: 500 12px var(--mono); }
  .chip.err { background: var(--chip-err-bg); color: var(--chip-err-fg); }
  .chip.warn { background: var(--chip-warn-bg); color: var(--chip-warn-fg); }
  .chip.note { background: var(--chip-note-bg); color: var(--chip-note-fg); }
  .chip.cond, .chip.unk { background: var(--chip-warn-bg); color: var(--chip-warn-fg); }
  .chip.ok { background: var(--chip-ok-bg); color: var(--chip-ok-fg); }
  .meta { display: flex; gap: 16px; flex-wrap: wrap; margin: 0 0 20px; font: 400 12px var(--mono); color: var(--fg-4); }
  .findings-title { font: 600 18px var(--sans); letter-spacing: -0.01em; margin: 0 0 10px; }
  .findings { display: flex; flex-direction: column; gap: 10px; }

  .finding { border-radius: 10px; box-shadow: var(--ring); overflow: hidden; background: var(--bg); }
  .finding-head {
    display: flex; align-items: center; gap: 10px; width: 100%; padding: 14px 16px;
    border: 0; background: transparent; color: var(--fg); cursor: pointer; text-align: left;
  }
  .finding-head:hover { background: var(--bg-soft); }
  .sev-icon { width: 18px; text-align: center; font: 500 15px var(--mono); flex: none; }
  .sev-icon.error { color: var(--err); } .sev-icon.warning { color: var(--warn); }
  .sev-icon.info { color: var(--info); } .sev-icon.note { color: var(--note); }
  .rule-badge {
    flex: none; padding: 1px 7px; border-radius: 5px; font: 500 11px var(--mono);
    box-shadow: var(--ring); color: var(--fg-3);
  }
  .finding-title { flex: 1; margin: 0; font: 500 15px var(--sans); color: var(--fg); }
  .sev-error .finding-title { color: var(--err); }
  .chevron { flex: none; color: var(--fg-4); font: 400 13px var(--mono); transition: transform .2s ease; }
  .finding-head[aria-expanded="true"] .chevron { transform: rotate(180deg); }

  .finding-body { padding: 2px 16px 16px 52px; }
  .finding-body[hidden] { display: none; }
  .symptom { font: 400 14px/1.6 var(--sans); color: var(--fg-2); margin: 0 0 12px; }
  .note-line { font: 400 13px/1.55 var(--sans); color: var(--info); margin: 0 0 8px; }
  .observed { font: 400 13px/1.55 var(--sans); color: var(--fg-2); margin: 0 0 8px; }
  .stale { font: 400 12px var(--sans); color: var(--fg-4); margin: 0 0 8px; }
  .ecosystem { display: inline-block; padding: 4px 10px; border-radius: 6px; box-shadow: var(--ring); font: 400 12.5px var(--mono); color: var(--fg-2); margin: 0 0 12px; }

  .timeline { display: flex; align-items: center; gap: 10px; margin: 0 0 10px; }
  .timeline .spec { flex: none; font: 400 12.5px var(--mono); color: var(--fg); word-break: break-all; max-width: 46%; }
  .track { flex: 1; height: 6px; border-radius: 3px; background: var(--line-soft); overflow: hidden; position: relative; }
  .track.t-never { background: color-mix(in srgb, var(--err) 22%, var(--line-soft)); }
  .track.t-present { background: color-mix(in srgb, var(--ok) 45%, var(--line-soft)); }
  .track.t-removed { background: linear-gradient(90deg, color-mix(in srgb, var(--ok) 45%, var(--line-soft)) 0 62%, color-mix(in srgb, var(--err) 45%, var(--line-soft)) 62% 100%); }
  .tlabel { flex: none; font: 400 12px var(--sans); color: var(--fg-3); max-width: 42%; }

  .steps { margin: 0 0 12px; padding-left: 20px; }
  .steps li { margin: 0 0 6px; font: 400 14px/1.55 var(--sans); color: var(--fg-2); }

  .knownfix { border-radius: 8px; padding: 12px 14px; background: var(--bg-soft); box-shadow: var(--ring); }
  .kf-title { font: 500 12px var(--mono); text-transform: uppercase; letter-spacing: .05em; color: var(--fg-3); margin: 0 0 8px; }
  .kf-fix { font: 400 14px/1.6 var(--sans); color: var(--fg); margin: 0 0 8px; }
  .kf-case { font: 400 12.5px/1.55 var(--sans); color: var(--fg-3); margin: 0 0 4px; }
  .kf-repo { color: var(--fg-2); }
  .kf-url { margin-left: 6px; font: 400 12px var(--mono); }

  .report-actions { display: flex; gap: 8px; margin: 18px 0 0; }
  .all-green-detail { font: 400 14px/1.6 var(--sans); color: var(--fg-2); }
  .privacy { margin: 24px 0 0; font: 400 12.5px/1.55 var(--sans); color: var(--fg-4); }
  .empty, .warn-note { font: 400 14px/1.6 var(--sans); color: var(--fg-3); }
  .warn-note { color: var(--warn); }
  .bare-cmd { display: inline-block; margin: 6px 0 0; padding: 8px 12px; border-radius: 6px; box-shadow: var(--ring); font: 400 13.5px var(--mono); }

  footer { border-top: 1px solid var(--line-soft); padding: 32px 24px 48px; }
  footer .inner { max-width: 860px; margin: 0 auto; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
  footer .fnote { font: 400 13px/1.6 var(--sans); color: var(--fg-4); max-width: 52ch; }
  footer nav { display: flex; gap: 16px; }

  @media (max-width: 640px) {
    .hero { padding-top: 48px; }
    .hero h1 { font-size: 32px; }
    .slogan { font-size: 17px; }
    .finding-body { padding-left: 16px; }
    .timeline { flex-wrap: wrap; }
    .timeline .spec, .tlabel { max-width: 100%; }
  }

  /* loading skeleton — matches the report's rhythm, not a bare spinner */
  .skeleton { display: flex; flex-direction: column; gap: 10px; margin: 0 0 16px; }
  .sk-bar { height: 14px; border-radius: 6px; background: var(--line-soft); position: relative; overflow: hidden; }
  .sk-bar::after {
    content: ''; position: absolute; inset: 0;
    background: linear-gradient(90deg, transparent, color-mix(in srgb, var(--fg) 6%, transparent), transparent);
    animation: shimmer 1.4s infinite;
  }
  .w40 { width: 40%; } .w70 { width: 70%; } .w85 { width: 85%; } .w90 { width: 90%; }
  @keyframes shimmer { from { transform: translateX(-100%); } to { transform: translateX(100%); } }

  /* the plain-text fallback for unrecognized errors */
  pre.report {
    margin: 0; padding: 14px; border-radius: 8px; background: var(--bg-soft);
    box-shadow: var(--ring); overflow: auto; white-space: pre-wrap; word-break: break-word;
    font: 400 13px/1.6 var(--mono);
  }

/* ── error / module topic pages ─────────────────────────────────────────── */
.hero.slim { padding: 56px 0 24px; }
.hero h1 code { font-family: var(--mono); font-size: 0.72em; font-weight: 500; word-break: break-all; }
.errstring { margin: 0 0 14px; }
.errstring code { display: inline-block; padding: 6px 12px; border-radius: 6px; background: var(--bg-soft); box-shadow: var(--ring); color: var(--err); font-size: 14px; }
.lead { margin: 0 0 8px; font: 400 16px/1.65 var(--sans); color: var(--fg-2); max-width: 62ch; }
.e-sec { margin: 28px 0 0; }
.e-sec h2 { margin: 0 0 10px; font: 600 20px/1.3 var(--sans); letter-spacing: -0.01em; }
.e-sec p { margin: 0 0 10px; font: 400 15px/1.7 var(--sans); color: var(--fg-2); max-width: 65ch; }
.mstatus { margin: 0; font: 400 14px/1.6 var(--sans); color: var(--fg-2); }
.qa { margin: 0 0 14px; }
.qa .q { margin: 0 0 4px; font: 500 15px var(--sans); color: var(--fg); }
.qa .a { margin: 0; font: 400 14.5px/1.65 var(--sans); color: var(--fg-2); }
.cta { display: flex; align-items: center; gap: 12px; margin: 18px 0 0; padding: 12px 16px; border-radius: 8px; box-shadow: var(--card); background: var(--bg-soft); font: 400 14px var(--mono); }
.cta code { font-size: 14px; }
.cta a { font: 400 13px var(--sans); }

/* ── reference index (links into /e/* and /m/*) ──────────────────────────── */
.ref { margin: 32px 0 0; padding-top: 24px; border-top: 1px solid var(--line-soft); }
.ref h2 { margin: 0 0 14px; font: 600 18px var(--sans); letter-spacing: -0.01em; }
.ref-group { margin: 0 0 14px; }
.ref-group h3 { margin: 0 0 6px; font: 500 12px var(--mono); text-transform: uppercase; letter-spacing: .05em; color: var(--fg-4); }
.ref ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 6px 18px; }
.ref li a { color: var(--fg-2); font: 400 14px var(--mono); }
.ref li a:hover { color: var(--accent); text-decoration: none; }

/* ── bilingual blocks (CSS dual-language: both in the DOM, one shown) ────── */
html[data-lang="zh"] .en-only { display: none !important; }
html[data-lang="en"] .zh-only { display: none !important; }