:root {
  --ink: #171a1f;
  --ink-soft: #3d4654;
  --mute: #6b7380;
  --line: #d7dbe2;
  --line-strong: #b8bfca;
  --paper: #f7f6f2;
  --paper-2: #ffffff;
  --wash: #eef1f5;
  --accent: #1f4e79;
  --accent-soft: #e7eef5;
  --danger: #9b2c2c;
  --warn: #8a5a12;
  --ok: #1f5c45;
  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, "Times New Roman", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, #e6ebf2 0%, transparent 55%),
    linear-gradient(180deg, #e9edf2 0%, #dfe5ec 100%);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  overflow-x: auto;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--ink); }

.frame {
  display: grid;
  grid-template-columns: 232px minmax(0, 1fr);
  gap: 0;
  width: min(1240px, 100%);
  min-width: 980px;
  min-height: 100vh;
  margin: 0 auto;
}

.rail {
  padding: 28px 18px 24px;
  border-right: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.35);
  display: flex;
  flex-direction: column;
  gap: 18px;
  position: sticky;
  top: 0;
  height: 100vh;
}

.rail-code {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 500;
}

.rail-name {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.25;
  margin-top: 6px;
}

.rail-note {
  margin: 0;
  font-size: 12px;
  color: var(--mute);
  line-height: 1.45;
}

.rail-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  overflow-y: auto;
  min-height: 0;
}

.rail-nav .tab {
  appearance: none;
  border: 0;
  background: transparent;
  text-align: left;
  padding: 6px 10px;
  border-radius: 0;
  border-left: 2px solid transparent;
  color: var(--ink-soft);
  font: inherit;
  font-size: 12.5px;
  cursor: pointer;
}

.rail-nav .tab:hover { background: rgba(255,255,255,0.55); color: var(--ink); }
.rail-nav .tab.on {
  border-left-color: var(--accent);
  background: var(--paper-2);
  color: var(--ink);
  font-weight: 600;
}

.rail-foot { margin-top: auto; display: grid; gap: 12px; }
.lang { display: flex; gap: 0; border: 1px solid var(--line); width: fit-content; background: var(--paper-2); }
.lang button {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 5px 10px;
  font: inherit;
  font-size: 12px;
  color: var(--mute);
  cursor: pointer;
  border-right: 1px solid var(--line);
}
.lang button:last-child { border-right: 0; }
.lang button.on { color: var(--ink); background: var(--accent-soft); font-weight: 600; }
.rail-copy { margin: 0; font-size: 11px; color: var(--mute); line-height: 1.4; }

.sheet {
  position: relative;
  padding: 28px 28px 48px;
}

.sheet-edge {
  position: absolute;
  inset: 18px 18px 18px 0;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  box-shadow: 0 1px 0 rgba(255,255,255,0.7) inset, 0 18px 40px rgba(23, 36, 54, 0.08);
  pointer-events: none;
}

.sheet-body {
  position: relative;
  padding: 28px 36px 36px;
  min-height: calc(100vh - 64px);
}

.mast {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-end;
  padding-bottom: 14px;
  border-bottom: 1.5px solid var(--ink);
  margin-bottom: 22px;
}

.mast h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.mast-meta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--mute);
  text-align: right;
  line-height: 1.5;
}

.lead {
  max-width: 62ch;
  color: var(--ink-soft);
  font-size: 14.5px;
  margin: 0 0 20px;
}

.rule {
  margin: 18px 0 0;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink);
  font-size: 15px;
}

.chain {
  display: grid;
  gap: 0;
  margin: 8px 0 0;
  border-top: 1px solid var(--line);
}

.chain-row {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.chain-idx {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
  padding-top: 2px;
}

.chain-row h3 {
  margin: 0 0 4px;
  font-size: 14px;
  font-weight: 600;
}

.chain-row p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 13px;
  max-width: 70ch;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.toolbar label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--mute);
}

.btn, .toolbar select, .form input, .form select {
  font: inherit;
  font-size: 13px;
  border: 1px solid var(--line-strong);
  background: var(--paper-2);
  color: var(--ink);
  padding: 6px 11px;
  border-radius: 0;
}

.btn { cursor: pointer; }
.btn:hover { border-color: var(--ink); }
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 500;
}
.btn.ghost { background: transparent; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.status {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--mute);
  margin-left: auto;
}

.note {
  font-size: 13px;
  color: var(--ink-soft);
  margin: 0 0 14px;
  max-width: 72ch;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0;
  border: 1px solid var(--line);
  margin: 0 0 18px;
  background: var(--paper-2);
}

.metrics > div {
  padding: 10px 12px;
  border-right: 1px solid var(--line);
}
.metrics > div:last-child { border-right: 0; }
.metrics span {
  display: block;
  font-size: 11px;
  color: var(--mute);
  margin-bottom: 4px;
}
.metrics strong {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 500;
}

.metrics.compact {
  grid-template-columns: 1fr;
  margin-top: 10px;
}
.metrics.compact > div { border-right: 0; border-bottom: 1px solid var(--line); }
.metrics.compact > div:last-child { border-bottom: 0; }

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 8px;
}

.block-title {
  margin: 18px 0 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute);
  font-weight: 600;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12.5px;
  background: var(--paper-2);
}

th, td {
  border-bottom: 1px solid var(--line);
  padding: 7px 8px;
  text-align: left;
  vertical-align: top;
}

th {
  font-size: 11px;
  font-weight: 600;
  color: var(--mute);
  background: var(--wash);
  border-bottom-color: var(--line-strong);
}

.wide td { font-size: 12px; }
.mono {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
}

.log {
  margin: 0;
  padding: 10px 12px;
  background: var(--wash);
  border: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11.5px;
  line-height: 1.55;
  white-space: pre-wrap;
  min-height: 72px;
  color: var(--ink-soft);
}

.muted { color: var(--mute); }
.bad { color: var(--danger); font-weight: 600; }

.sev {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.04em;
  font-weight: 500;
}
.sev.HIGH { color: var(--danger); }
.sev.MEDIUM { color: var(--warn); }
.sev.LOW { color: var(--ok); }

.use {
  font-family: var(--mono);
  font-size: 11px;
}
.use.use { color: var(--ok); }
.use.formula { color: var(--accent); }
.use.skip { color: var(--mute); }
.use.avoid { color: var(--danger); }

.plain { margin: 0; padding-left: 18px; color: var(--ink-soft); }
.plain li { margin: 4px 0; }
.links { margin: 16px 0 0; padding: 0; list-style: none; }
.links li { margin: 6px 0; font-family: var(--mono); font-size: 12px; }

.form {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px;
  border: 1px solid var(--line);
  background: var(--paper-2);
}
.form h3 {
  margin: 0 0 4px;
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 600;
}
.form label {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: center;
  font-size: 12px;
  color: var(--mute);
}
.form input, .form select { min-width: 140px; }

.jd-source {
  margin: 0 0 16px;
  padding: 12px 14px;
  border-left: 3px solid var(--ink);
  background: var(--wash);
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.65;
}

.jd-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.9fr);
  gap: 18px;
  align-items: start;
}

.jd-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.jd-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 100%;
  text-align: left;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--paper-2);
  color: inherit;
  cursor: pointer;
  font: inherit;
}
.jd-item strong {
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
}
.jd-item span {
  font-size: 12px;
  color: var(--mute);
  line-height: 1.45;
}
.jd-item.on {
  border-color: var(--ink);
  background: #fff;
  box-shadow: inset 3px 0 0 var(--ink);
}

.ai-panel {
  position: sticky;
  top: 12px;
  padding: 12px;
  border: 1px solid var(--line);
  background: var(--paper-2);
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 220px;
}
.ai-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
}
.ai-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute);
}
.ai-head .status.on { color: var(--ok); }
.ai-head .status.off { color: var(--danger); }
.ai-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.ai-out {
  margin: 0;
  flex: 1;
  min-height: 160px;
  max-height: 480px;
  overflow: auto;
  padding: 10px 12px;
  background: var(--wash);
  border: 1px solid var(--line);
  font-family: var(--serif);
  font-size: 13px;
  line-height: 1.55;
  white-space: pre-wrap;
  color: var(--ink-soft);
}
.ai-out.bad {
  color: var(--danger);
  font-family: var(--mono);
  font-size: 12px;
}

.desk-note {
  margin: 0;
  font-size: 11.5px;
  line-height: 1.45;
  color: var(--mute);
}

.oss-blurb {
  margin-top: 4px;
  font-size: 12px;
  line-height: 1.45;
  color: var(--ink-soft);
  font-weight: 400;
}

button.linkish {
  border: 0;
  padding: 0;
  background: none;
  color: var(--accent);
  font: inherit;
  font-family: var(--mono);
  font-size: 12px;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.demo-path {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 8px 0 16px;
}
.demo-step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 12px;
  text-align: left;
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--paper-2);
  color: inherit;
  cursor: pointer;
  font: inherit;
}
.demo-step h3 {
  margin: 0 0 4px;
  font-family: var(--serif);
  font-size: 15px;
}
.demo-step p { margin: 0; color: var(--ink-soft); font-size: 13px; }
.demo-step:hover { border-color: var(--ink); }

.row-flag td { background: #f8efef; }

.toolbar .status.on { color: var(--ok); }
.toolbar .status.off { color: var(--danger); font-weight: 600; }

@media print {
  body { background: #fff; }
  .rail, .sheet-edge, .toolbar, .ai-panel { display: none !important; }
  .frame {
    display: block;
    width: 100%;
    min-width: 0;
    margin: 0;
  }
  .sheet { box-shadow: none; }
}

@media (max-width: 900px) {
  .split, .jd-grid { grid-template-columns: 1fr; }
  .ai-panel { position: static; }
  .metrics { grid-template-columns: repeat(2, 1fr); }
  .metrics > div:nth-child(odd) { border-right: 1px solid var(--line); }
  .mast { flex-direction: column; align-items: flex-start; }
  .mast-meta { text-align: left; }
}