:root {
  --bg: #0b0f14;
  --bg-2: #101820;
  --panel: #141c26;
  --panel-2: #1a2430;
  --border: #243041;
  --text: #e8eef5;
  --muted: #8b9aab;
  --accent: #f0a34a;
  --accent-dim: rgba(240, 163, 74, 0.14);
  --ok: #3ecf8e;
  --ok-dim: rgba(62, 207, 142, 0.12);
  --warn: #f0a34a;
  --warn-dim: rgba(240, 163, 74, 0.12);
  --danger: #f07178;
  --danger-dim: rgba(240, 113, 120, 0.12);
  --info: #5b9fd4;
  --info-dim: rgba(91, 159, 212, 0.12);
  --font: "IBM Plex Sans", "Noto Sans SC", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --max: 920px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(240, 163, 74, 0.08), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(91, 159, 212, 0.07), transparent 50%),
    var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
}
a { color: var(--info); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.25rem 1.1rem 3.5rem;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}
.brand {
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: -0.02em;
}
.brand span { color: var(--accent); }
.top-meta {
  font-size: 0.75rem;
  color: var(--muted);
  font-family: var(--mono);
}

.hero {
  margin-bottom: 1.5rem;
}
.hero h1 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.55rem, 4vw, 2.05rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
}
.hero .lede {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  max-width: 42rem;
}

.pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 1rem 0 0;
}
.pill {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.28rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--muted);
}
.pill.warn { background: var(--warn-dim); color: var(--warn); border-color: transparent; }
.pill.danger { background: var(--danger-dim); color: var(--danger); border-color: transparent; }
.pill.ok { background: var(--ok-dim); color: var(--ok); border-color: transparent; }
.pill.info { background: var(--info-dim); color: var(--info); border-color: transparent; }

.stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.65rem;
  margin: 1.15rem 0 1.35rem;
}
.stat {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.85rem 0.9rem;
}
.stat strong {
  display: block;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.2rem;
}
.stat span { font-size: 0.72rem; color: var(--muted); }
.stat.warn strong { color: var(--warn); }
.stat.danger strong { color: var(--danger); }
.stat.info strong { color: var(--info); }

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 1.25rem;
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 0.55rem 0;
  background: linear-gradient(180deg, var(--bg) 70%, transparent);
}
.nav a {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--muted);
  padding: 0.35rem 0.55rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--panel);
  text-decoration: none;
}
.nav a:hover,
.nav a.active {
  color: var(--text);
  border-color: var(--accent);
  background: var(--accent-dim);
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.15rem 1rem 1.2rem;
  margin-bottom: 1rem;
}
.panel > h2 {
  margin: 0 0 0.85rem;
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: -0.015em;
}
.panel h3 {
  margin: 1.05rem 0 0.5rem;
  font-size: 0.92rem;
  font-weight: 650;
}
.note { margin: 0.35rem 0 0.7rem; font-size: 0.84rem; color: var(--muted); }

.callout {
  border-radius: 10px;
  padding: 0.85rem 0.95rem;
  margin: 0.75rem 0;
  border: 1px solid var(--border);
  background: var(--panel-2);
}
.callout.warn { background: var(--warn-dim); border-color: transparent; }
.callout.danger { background: var(--danger-dim); border-color: transparent; }
.callout.ok { background: var(--ok-dim); border-color: transparent; }
.callout.info { background: var(--info-dim); border-color: transparent; }
.callout .ctitle {
  margin: 0 0 0.35rem;
  font-size: 0.88rem;
  font-weight: 700;
}
.callout p { margin: 0; font-size: 0.86rem; }
.callout ul { margin: 0.25rem 0 0; padding-left: 1.1rem; font-size: 0.86rem; }

.table-scroll { overflow-x: auto; margin: 0.4rem 0 0.6rem; -webkit-overflow-scrolling: touch; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  min-width: 560px;
}
th, td {
  text-align: left;
  padding: 0.55rem 0.6rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.74rem;
  white-space: nowrap;
}
td.num, th.num { font-family: var(--mono); white-space: nowrap; }
.neg { color: var(--danger); }
.pos { color: var(--ok); }

.timeline {
  list-style: none;
  margin: 0.5rem 0 0;
  padding: 0;
  border-left: 2px solid var(--border);
}
.timeline li {
  position: relative;
  padding: 0 0 1rem 1.1rem;
  margin-left: 0.15rem;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: -0.42rem;
  top: 0.35rem;
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}
.timeline .t-time {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent);
  margin-bottom: 0.15rem;
}
.timeline .t-body { font-size: 0.86rem; }

.verdict {
  display: grid;
  gap: 0.65rem;
}
.verdict-row {
  display: grid;
  grid-template-columns: 7.5rem 1fr;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  background: var(--panel-2);
  border-radius: 8px;
  font-size: 0.86rem;
}
.verdict-row strong {
  font-size: 0.78rem;
  color: var(--muted);
  font-weight: 600;
}

.sources { font-size: 0.84rem; }
.sources ol { margin: 0.4rem 0 0; padding-left: 1.2rem; }
.sources li { margin-bottom: 0.35rem; }

.footer {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--muted);
}

.theme-btn {
  font: inherit;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.35rem 0.55rem;
  cursor: pointer;
}
.theme-btn:hover { color: var(--text); }

.calc {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.85rem 0.95rem;
  margin: 0.5rem 0 0.85rem;
}
.calc-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}
.calc-row-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}
.calc-row-5 {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}
.calc label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--muted);
}
.calc input,
.calc select {
  font: inherit;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.6rem;
}
.calc-assump { margin: 0.65rem 0 0; }

.formula-details {
  padding: 0;
  overflow: hidden;
}
.formula-details summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.85rem 0.95rem;
  cursor: pointer;
  list-style: none;
}
.formula-details summary::-webkit-details-marker { display: none; }
.formula-details .summary-hint {
  font-size: 0.75rem;
  color: var(--muted);
}
.formula-details[open] .summary-hint::before { content: "已展开"; }
.formula-details:not([open]) .summary-hint::before { content: "点击展开"; }
.formula-details[open] .summary-hint {
  color: var(--info);
}
.formula-details .formula-body {
  padding: 0 0.95rem 0.9rem;
}

.formula-steps {
  margin: 0.35rem 0 0.65rem;
  padding-left: 1.2rem;
  font-size: 0.86rem;
}
.formula-steps li { margin-bottom: 0.28rem; }
.formula-eq {
  margin: 0.4rem 0 0.55rem;
  font-size: 0.82rem;
}
.formula-eq code {
  display: block;
  font-family: var(--mono);
  font-size: 0.78rem;
  line-height: 1.45;
  padding: 0.55rem 0.65rem;
  border-radius: 8px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  white-space: pre-wrap;
  word-break: break-word;
}
#formulaExample {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.5;
}

.return-cards {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.55rem;
  margin: 0.75rem 0;
}
.return-cards article {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.75rem 0.8rem;
}
.return-cards strong {
  display: block;
  font-size: 0.72rem;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 0.3rem;
}
.return-cards p {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  font-family: var(--mono);
  letter-spacing: -0.02em;
}
.return-cards p span {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.72rem;
  font-weight: 500;
  font-family: var(--font);
  color: var(--muted);
}

body.light {
  --bg: #f4f6f8;
  --bg-2: #eef1f4;
  --panel: #ffffff;
  --panel-2: #f0f3f6;
  --border: #d5dde6;
  --text: #15202b;
  --muted: #5c6b7a;
  --accent: #c47a1a;
  --accent-dim: rgba(196, 122, 26, 0.12);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(196, 122, 26, 0.08), transparent 55%),
    var(--bg);
}

@media (max-width: 720px) {
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .verdict-row { grid-template-columns: 1fr; gap: 0.25rem; }
  table { min-width: 480px; }
  .calc-row { grid-template-columns: 1fr; }
  .calc-row-4 { grid-template-columns: 1fr; }
  .calc-row-5 { grid-template-columns: 1fr; }
  .return-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}