/* ============================================================
   量策档案 QuantFile — paper, ink, vermilion
   System fonts only. No external requests.
   ============================================================ */

:root {
  color-scheme: light;
  --paper: #f3f0e7;
  --surface: #faf8f1;
  --surface-2: #ece8dc;
  --ink: #141412;
  --ink-2: #4f4d45;
  --muted: #6b685e;
  --rule: #d6d1c2;
  --rule-strong: #141412;
  --accent: #b23a2f;
  --accent-ink: #ffffff;
  --up: #b23a2f;
  --down: #1f6b52;
  --warn: #8a6100;
  --chart-strategy: #b23a2f;
  --chart-bench: #1f6feb;
  --chart-grid: #ded9ca;
  --heat-pos: #b23a2f;
  --heat-neg: #2f6b5e;
  --focus: #141412;
  --bw: 2px;
  --shadow: 6px 6px 0 var(--ink);
  --container: 1200px;
  --gutter: clamp(20px, 5vw, 56px);
  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", "Source Han Serif SC", "SimSun", serif;
  --sans: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --mono: "SFMono-Regular", "Cascadia Mono", "JetBrains Mono", Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #121210;
    --surface: #1a1a17;
    --surface-2: #23231f;
    --ink: #edeae0;
    --ink-2: #bdb8aa;
    --muted: #a6a296;
    --rule: #34332d;
    --rule-strong: #edeae0;
    --accent: #e4675b;
    --accent-ink: #1a1a17;
    --up: #e4675b;
    --down: #56a98a;
    --warn: #d9a23a;
    --chart-strategy: #e4675b;
    --chart-bench: #4a8fe0;
    --chart-grid: #2c2c27;
    --heat-pos: #e4675b;
    --heat-neg: #56a98a;
    --focus: #edeae0;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #121210;
  --surface: #1a1a17;
  --surface-2: #23231f;
  --ink: #edeae0;
  --ink-2: #bdb8aa;
  --muted: #a6a296;
  --rule: #34332d;
  --rule-strong: #edeae0;
  --accent: #e4675b;
  --accent-ink: #1a1a17;
  --up: #e4675b;
  --down: #56a98a;
  --warn: #d9a23a;
  --chart-strategy: #e4675b;
  --chart-bench: #4a8fe0;
  --chart-grid: #2c2c27;
  --heat-pos: #e4675b;
  --heat-neg: #56a98a;
  --focus: #edeae0;
}

*,
*::before,
*::after { box-sizing: border-box; }

[hidden] { display: none !important; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  font-feature-settings: "tnum" 1;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { max-width: 100%; }

a {
  color: var(--ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover { color: var(--accent); }

::selection {
  background: var(--accent);
  color: var(--accent-ink);
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

button, input, select { font: inherit; color: inherit; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 100;
  background: var(--ink);
  color: var(--paper);
  padding: 10px 16px;
  font-family: var(--mono);
  font-size: 12px;
}

.skip-link:focus { top: 12px; }

/* ---------- shell ---------- */

.wrap {
  width: min(100% - (var(--gutter) * 2), var(--container));
  margin-inline: auto;
}

.mono {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .09em;
  text-transform: uppercase;
  font-variant-numeric: tabular-nums;
}

.muted { color: var(--muted); }

.rule { border: 0; border-top: 1px solid var(--rule); margin: 0; }

/* ---------- nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--paper);
  border-bottom: var(--bw) solid var(--rule-strong);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 64px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  white-space: nowrap;
}

.brand-mark {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  border: 1.5px solid var(--ink);
  padding: 3px 6px;
  line-height: 1;
}

.brand-name {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .02em;
}

.brand-en {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .14em;
  color: var(--muted);
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-left: auto;
}

.nav-links a {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
  text-decoration: none;
  color: var(--ink-2);
  padding: 6px 0;
  border-bottom: 2px solid transparent;
}

.nav-links a:hover { color: var(--ink); border-bottom-color: var(--ink); }

.nav-links a[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.theme-toggle {
  appearance: none;
  background: transparent;
  border: 1.5px solid var(--rule-strong);
  width: 34px; height: 34px;
  display: grid;
  place-items: center;
  cursor: pointer;
  padding: 0;
  flex: none;
}

.theme-toggle:hover { background: var(--surface-2); }

.theme-toggle svg { width: 16px; height: 16px; }

.nav-menu-btn {
  display: none;
  margin-left: auto;
  appearance: none;
  background: transparent;
  border: 1.5px solid var(--rule-strong);
  width: 38px; height: 34px;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 12px;
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
    position: absolute;
    left: 0; right: 0;
    top: 64px;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--paper);
    border-bottom: var(--bw) solid var(--rule-strong);
    padding: 8px var(--gutter) 16px;
  }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--rule); font-size: 13px; }
  .nav-links a[aria-current="page"] { border-bottom-color: var(--accent); }
  .nav-menu-btn { display: block; margin-left: auto; }
  .theme-toggle { margin-left: 8px; }
}

/* ---------- hero ---------- */

.hero {
  position: relative;
  border-bottom: var(--bw) solid var(--rule-strong);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--ink) 7%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--ink) 7%, transparent) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, #000 55%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 0%, #000 55%, transparent 100%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(28px, 5vw, 64px);
  padding-block: clamp(56px, 9vw, 104px) clamp(48px, 7vw, 84px);
  align-items: end;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-2);
  margin: 0 0 22px;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--accent);
  flex: none;
}

.display {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(42px, 7.2vw, 92px);
  line-height: 1.02;
  letter-spacing: -.025em;
  margin: 0 0 24px;
  text-wrap: balance;
}

.display em {
  font-style: normal;
  color: var(--accent);
  position: relative;
}

.lede {
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.75;
  color: var(--ink-2);
  max-width: 34em;
  margin: 0 0 30px;
}

.actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 22px;
  border: var(--bw) solid var(--rule-strong);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
  text-decoration: none;
  box-shadow: 4px 4px 0 var(--accent);
  transition: transform .16s ease, box-shadow .16s ease;
}

.btn:hover {
  color: var(--paper);
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--accent);
}

.btn-outline {
  background: transparent;
  color: var(--ink);
  box-shadow: none;
  border-color: var(--rule-strong);
}

.btn-outline:hover {
  color: var(--ink);
  background: var(--surface);
  box-shadow: 4px 4px 0 var(--ink);
}

.hero-figure {
  margin: 0;
  border: var(--bw) solid var(--rule-strong);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-figure svg { display: block; width: 100%; height: auto; }

.hero-figure figcaption {
  border-top: 1px solid var(--rule);
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .06em;
  color: var(--muted);
  text-transform: uppercase;
}

.fact-strip {
  border-top: 1px solid var(--rule);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.fact {
  padding: 18px 20px;
  border-left: 1px solid var(--rule);
}

.fact:first-child { border-left: 0; padding-left: 0; }

.fact dt {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 2px;
}

.fact dd {
  margin: 0;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 650;
}

@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; align-items: start; }
  .hero-figure { max-width: 620px; }
  .fact-strip { grid-template-columns: repeat(2, 1fr); }
  .fact:nth-child(3) { border-left: 0; padding-left: 0; border-top: 1px solid var(--rule); }
  .fact:nth-child(4) { border-top: 1px solid var(--rule); }
}

/* ---------- sections ---------- */

.section { padding-block: clamp(56px, 8vw, 96px); border-bottom: 1px solid var(--rule); }

.section:last-of-type { border-bottom: 0; }

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: clamp(20px, 4vw, 56px);
  align-items: start;
  margin-bottom: 40px;
}

.section-index {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--accent);
  margin: 0 0 10px;
  text-transform: uppercase;
}

.section-title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(30px, 4.2vw, 50px);
  line-height: 1.08;
  letter-spacing: -.02em;
  margin: 0;
  text-wrap: balance;
}

.section-intro {
  color: var(--ink-2);
  font-size: 16px;
  max-width: 46em;
  margin: 0;
}

.section-intro + .section-intro { margin-top: 12px; }

.section-head-side { max-width: 52em; }

.link-arrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
  text-transform: uppercase;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 2px;
  white-space: nowrap;
}

.link-arrow:hover { border-bottom-color: var(--accent); }

@media (max-width: 860px) {
  .section-head { grid-template-columns: 1fr; gap: 18px; }
}

/* ---------- cards ---------- */

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

@media (max-width: 960px) {
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: var(--bw) solid var(--rule-strong);
  padding: 22px;
  min-height: 100%;
  transition: transform .16s ease, box-shadow .16s ease;
}

@media (hover: hover) {
  .card:hover { transform: translate(-2px, -2px); box-shadow: var(--shadow); }
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}

.card-id {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--muted);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--rule-strong);
  padding: 2px 7px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .07em;
  text-transform: uppercase;
  white-space: nowrap;
}

.badge-accent { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

.badge-soft { background: var(--surface-2); }

/* 策略卡上的成本口径标签：成本差异会让跨策略收益不可直接比较，所以显式标出来 */
.chip-cost {
  display: inline-flex;
  align-items: center;
  border: 1px dashed var(--rule-strong);
  padding: 1px 6px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: .06em;
  color: var(--muted);
  white-space: nowrap;
  cursor: help;
}

.card h3 {
  font-family: var(--serif);
  font-size: 24px;
  line-height: 1.22;
  letter-spacing: -.01em;
  margin: 0 0 8px;
}

.card h3 a { text-decoration: none; }

.card h3 a:hover { color: var(--accent); }

.card .thesis {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--ink-2);
  margin: 0 0 18px;
  flex: 1;
}

.card .spark {
  display: block;
  width: 100%;
  height: 54px;
  margin: 0 0 14px;
  border-bottom: 1px solid var(--rule);
}

.card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-top: 1px solid var(--rule);
  padding-top: 12px;
  margin-top: auto;
}

.card-foot .mono { color: var(--muted); font-size: 9.5px; }

.tags { display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; list-style: none; }

.tag {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .04em;
  color: var(--ink-2);
  border: 1px solid var(--rule);
  padding: 1px 6px;
}

.metrics-inline {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin: 0 0 16px;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.metrics-inline > div {
  padding: 9px 8px 8px 0;
  border-left: 1px solid var(--rule);
}

.metrics-inline > div:first-child { border-left: 0; padding-left: 0; }
.metrics-inline > div:not(:first-child) { padding-left: 10px; }

.metrics-inline dt {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--muted);
}

.metrics-inline dd {
  margin: 1px 0 0;
  font-size: 17px;
  font-weight: 650;
  letter-spacing: -.01em;
  font-variant-numeric: tabular-nums;
}

/* evidence / notes */

.note-box {
  border-left: 3px solid var(--accent);
  background: var(--surface);
  padding: 16px 18px;
  font-size: 13.5px;
  color: var(--ink-2);
}

.note-box strong { color: var(--ink); }

.evidence-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: var(--bw) solid var(--rule-strong);
  background: var(--surface);
}

.evidence-cell {
  padding: 20px;
  border-left: 1px solid var(--rule);
}

.evidence-cell:first-child { border-left: 0; }

.evidence-cell .n {
  font-family: var(--serif);
  font-size: 38px;
  line-height: 1;
  letter-spacing: -.02em;
  display: block;
  margin-bottom: 6px;
}

.evidence-cell p { margin: 0; font-size: 12.5px; line-height: 1.55; color: var(--ink-2); }

@media (max-width: 860px) {
  .evidence-row { grid-template-columns: repeat(2, 1fr); }
  .evidence-cell:nth-child(3) { border-left: 0; border-top: 1px solid var(--rule); }
  .evidence-cell:nth-child(4) { border-top: 1px solid var(--rule); }
}

@media (max-width: 480px) {
  .evidence-row { grid-template-columns: 1fr; }
  .evidence-cell { border-left: 0; border-top: 1px solid var(--rule); }
  .evidence-cell:first-child { border-top: 0; }
}

/* ---------- filter bar ---------- */

.filter-bar {
  position: sticky;
  top: 64px;
  z-index: 30;
  background: var(--paper);
  border-top: 1px solid var(--rule);
  border-bottom: var(--bw) solid var(--rule-strong);
  padding-block: 12px;
}

.filter-inner {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.chips { display: flex; gap: 6px; flex-wrap: wrap; }

.chip {
  appearance: none;
  border: 1.5px solid var(--rule-strong);
  background: transparent;
  padding: 7px 12px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .05em;
  cursor: pointer;
  white-space: nowrap;
}

.chip:hover { background: var(--surface-2); }

/* 资源页的分组跳转用的是 <a>，不能继承按钮的默认外观 */
a.chip { display: inline-flex; align-items: center; color: var(--ink); text-decoration: none; }
a.chip:hover { background: var(--ink); color: var(--paper); }

.chip[aria-pressed="true"] {
  background: var(--ink);
  color: var(--paper);
}

.search {
  flex: 1 1 200px;
  min-width: 160px;
  max-width: 320px;
  border: 1.5px solid var(--rule-strong);
  background: var(--surface);
  padding: 8px 12px;
  font-size: 13px;
}

.search::placeholder { color: var(--muted); }

.filter-count {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--muted);
  white-space: nowrap;
}

@media (max-width: 720px) {
  .filter-bar { top: 64px; }
  .filter-bar .chips { overflow-x: auto; padding-bottom: 2px; flex-wrap: nowrap; width: 100%; }
  .search { max-width: none; }
}

/* ---------- results / charts ---------- */

.panel {
  border: var(--bw) solid var(--rule-strong);
  background: var(--surface);
}

.panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--rule);
  padding: 14px 18px;
}

.panel-title {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .09em;
  text-transform: uppercase;
  margin: 0;
}

.panel-body { padding: 18px; }

.select {
  appearance: none;
  border: 1.5px solid var(--rule-strong);
  background: var(--surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%23141412'/%3E%3C/svg%3E") no-repeat right 10px center;
  padding: 7px 30px 7px 10px;
  font-family: var(--mono);
  font-size: 11px;
}

:root[data-theme="dark"] .select,
:root:not([data-theme="light"]) .select { color-scheme: dark; }

.seg {
  display: inline-flex;
  border: 1.5px solid var(--rule-strong);
}

.seg button {
  appearance: none;
  background: transparent;
  border: 0;
  border-left: 1px solid var(--rule);
  padding: 6px 10px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .05em;
  cursor: pointer;
}

.seg button:first-child { border-left: 0; }

.seg button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }

.metric-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  border-bottom: 1px solid var(--rule);
}

.metric-cell {
  padding: 16px 18px;
  border-left: 1px solid var(--rule);
}

.metric-cell:first-child { border-left: 0; }

.metric-cell dt {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}

.metric-cell dd {
  margin: 0;
  font-size: clamp(22px, 2.6vw, 32px);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.metric-cell .sub {
  display: block;
  margin-top: 4px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .03em;
  color: var(--muted);
  text-transform: none;
}

.metric-cell .delta {
  display: block;
  margin-top: 3px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .03em;
  font-variant-numeric: tabular-nums;
}
.metric-cell .delta.pos { color: var(--up); }
.metric-cell .delta.neg { color: var(--down); }

@media (max-width: 860px) {
  .metric-grid { grid-template-columns: repeat(2, 1fr); }
  .metric-cell:nth-child(3) { border-left: 0; border-top: 1px solid var(--rule); }
  .metric-cell:nth-child(4), .metric-cell:nth-child(5) { border-top: 1px solid var(--rule); }
  .metric-cell:nth-child(5) { grid-column: span 2; border-left: 0; }
}

.chart-wrap { position: relative; }

.chart-svg { display: block; width: 100%; height: auto; overflow: visible; }

.chart-svg text {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .02em;
  fill: var(--muted);
}

.chart-svg .grid-line { stroke: var(--chart-grid); stroke-width: 1; }
.chart-svg .axis-line { stroke: var(--ink); stroke-width: 1.5; }
.chart-svg .series-strategy { fill: none; stroke: var(--chart-strategy); stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.chart-svg .series-bench { fill: none; stroke: var(--chart-bench); stroke-width: 1.6; stroke-linejoin: round; stroke-linecap: round; }
.chart-svg .area-dd { fill: var(--chart-strategy); opacity: .12; }
.chart-svg .crosshair { stroke: var(--ink); stroke-width: 1; stroke-dasharray: 2 2; opacity: 0; }
.chart-svg .end-dot { stroke: var(--surface); stroke-width: 2; }
.chart-svg .hit { fill: transparent; cursor: crosshair; }

.chart-tooltip {
  position: absolute;
  pointer-events: none;
  background: var(--ink);
  color: var(--paper);
  border: 1px solid var(--rule-strong);
  padding: 8px 10px;
  font-family: var(--mono);
  font-size: 10.5px;
  line-height: 1.55;
  white-space: nowrap;
  opacity: 0;
  transform: translate(-50%, -110%);
  transition: opacity .12s ease;
  z-index: 5;
  font-variant-numeric: tabular-nums;
}

.chart-tooltip.is-on { opacity: 1; }

.chart-tooltip .k { color: color-mix(in srgb, var(--paper) 62%, transparent); margin-right: 8px; }

.legend {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin: 0 0 12px;
  padding: 0;
  list-style: none;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-2);
}

.legend li { display: inline-flex; align-items: center; gap: 7px; }

.swatch { width: 16px; height: 3px; display: inline-block; }

.chart-note {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .02em;
  color: var(--muted);
  margin: 12px 0 0;
  line-height: 1.6;
}

.table-toggle {
  appearance: none;
  background: transparent;
  border: 1.5px solid var(--rule-strong);
  padding: 6px 10px;
  font-family: var(--mono);
  font-size: 10px;
  cursor: pointer;
}

.table-toggle:hover { background: var(--surface-2); }

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.data-table caption {
  text-align: left;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .06em;
  color: var(--muted);
  padding: 0 0 8px;
  text-transform: uppercase;
}

.data-table th, .data-table td {
  border-bottom: 1px solid var(--rule);
  padding: 7px 8px;
  text-align: right;
  white-space: nowrap;
}

.data-table th:first-child, .data-table td:first-child { text-align: left; }

.data-table thead th {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
  border-bottom: 1.5px solid var(--ink);
}

.data-table td.pos { color: var(--up); }
.data-table td.neg { color: var(--down); }

/* heatmap */

.heatmap { display: grid; grid-template-columns: 46px repeat(12, minmax(0, 1fr)); gap: 2px; min-width: 560px; }

.hm-label {
  font-family: var(--mono);
  font-size: 9px;
  color: var(--muted);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 4px;
  font-variant-numeric: tabular-nums;
}

.hm-month { text-align: center; justify-content: center; padding: 0 0 4px; }

.hm-cell {
  position: relative;
  aspect-ratio: 1.55;
  background: color-mix(in srgb, var(--hm, var(--surface)) var(--hm-pct, 0%), var(--surface));
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 9px;
  font-variant-numeric: tabular-nums;
  border: 1px solid transparent;
}

.hm-cell:hover { border-color: var(--ink); }

/* 数据未覆盖的月份：留白 + 虚线框，读作「无数据」而不是「0%」 */
.hm-cell-missing {
  background: var(--surface);
  border-color: var(--rule);
  border-style: dashed;
  color: var(--muted);
}

.hm-scale {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 9px;
  color: var(--muted);
  margin-top: 12px;
}

.hm-gradient {
  width: 120px;
  height: 10px;
  background: linear-gradient(to right, var(--heat-neg), var(--surface), var(--heat-pos));
  border: 1px solid var(--rule);
}

.heatmap-scroll { overflow-x: auto; padding-bottom: 4px; }

/* ---------- strategy detail ---------- */

.detail-grid {
  display: grid;
  grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
  gap: 32px;
  align-items: start;
}

.detail-rail { position: sticky; top: 88px; }

@media (max-width: 960px) {
  .detail-grid { grid-template-columns: 1fr; }
  /* 窄屏下把「关键指标」提到正文之前：读者先看到数字，再往下读规则 */
  .detail-rail { position: static; display: contents; }
  .rail-metrics { order: -1; margin-bottom: 24px; }
}

.prose { max-width: 72ch; }

.prose h2 {
  font-family: var(--serif);
  font-size: 28px;
  line-height: 1.2;
  margin: 40px 0 12px;
  letter-spacing: -.01em;
}

.prose h3 {
  font-family: var(--sans);
  font-size: 16px;
  margin: 26px 0 8px;
}

.prose p { margin: 0 0 14px; color: var(--ink-2); }

.prose ul, .prose ol { margin: 0 0 16px; padding-left: 22px; color: var(--ink-2); }

.prose li { margin-bottom: 6px; }

.prose code {
  font-family: var(--mono);
  font-size: .88em;
  background: var(--surface-2);
  padding: 1px 5px;
}

.prose .callout {
  border: 1.5px solid var(--rule-strong);
  background: var(--surface);
  padding: 16px 18px;
  margin: 20px 0;
}

.prose .callout strong { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: .08em; text-transform: uppercase; margin-bottom: 6px; }

.kv {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 16px;
  margin: 0;
  font-size: 13px;
}

.kv dt { font-family: var(--mono); font-size: 10px; letter-spacing: .05em; color: var(--muted); text-transform: uppercase; align-self: center; }
.kv dd { margin: 0; }

.code-block {
  border: 1.5px solid var(--rule-strong);
  background: var(--surface);
  padding: 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 11.5px;
  line-height: 1.7;
  white-space: pre;
}

.page-head {
  padding-block: clamp(40px, 6vw, 64px) 32px;
  border-bottom: var(--bw) solid var(--rule-strong);
}

.breadcrumb {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .07em;
  color: var(--muted);
  margin: 0 0 16px;
  text-transform: uppercase;
}

.breadcrumb a { color: var(--muted); }

.page-title {
  font-family: var(--serif);
  font-size: clamp(34px, 5.4vw, 64px);
  line-height: 1.06;
  letter-spacing: -.025em;
  margin: 0 0 14px;
  text-wrap: balance;
}

.page-sub {
  font-size: 16px;
  color: var(--ink-2);
  max-width: 52em;
  margin: 0;
}

/* ---------- steps / paths ---------- */

.path-card {
  border: var(--bw) solid var(--rule-strong);
  background: var(--surface);
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.path-card h3 {
  font-family: var(--serif);
  font-size: 26px;
  margin: 0 0 4px;
}

.path-meta {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .06em;
  color: var(--accent);
  text-transform: uppercase;
  margin: 0 0 14px;
}

.path-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.path-steps li {
  counter-increment: step;
  position: relative;
  padding: 10px 0 10px 30px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  color: var(--ink-2);
}

.path-steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 11px;
  font-family: var(--mono);
  font-size: 9px;
  color: var(--muted);
}

/* ---------- timeline ---------- */

.timeline { border-top: 2px solid var(--ink); margin: 0; padding: 0; list-style: none; }

.timeline li {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 20px;
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
}

.timeline time {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .05em;
  color: var(--accent);
}

.timeline h3 { font-size: 16px; margin: 0 0 4px; }

.timeline p { margin: 0; font-size: 13.5px; color: var(--ink-2); max-width: 62ch; }

.timeline a { font-family: var(--mono); font-size: 10px; }

@media (max-width: 640px) {
  .timeline li { grid-template-columns: 1fr; gap: 6px; }
}

/* ---------- footer ---------- */

.site-footer {
  border-top: var(--bw) solid var(--rule-strong);
  background: var(--surface);
  margin-top: 0;
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: 32px;
  padding-block: 40px;
}

.footer-brand .brand-name { font-size: 22px; }

.footer-brand p { font-size: 12.5px; color: var(--muted); max-width: 34em; margin: 12px 0 0; }

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.footer-links h4 {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .09em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 10px;
}

.footer-links ul { list-style: none; margin: 0; padding: 0; }

.footer-links li { margin: 0 0 6px; }

.footer-links a { font-size: 12.5px; text-decoration: none; color: var(--ink-2); }

.footer-links a:hover { color: var(--accent); }

.footer-disclaimer {
  border-top: 1px solid var(--rule);
  padding-block: 18px;
  font-size: 11px;
  line-height: 1.7;
  color: var(--muted);
}

.footer-bottom {
  border-top: 1px solid var(--rule);
  padding-block: 14px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .05em;
  color: var(--muted);
  text-transform: uppercase;
}

@media (max-width: 760px) {
  .footer-main { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: repeat(2, 1fr); }
}

/* ---------- reveal (progressive) ---------- */

html.js .reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .45s ease, transform .45s ease;
}

html.js .reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html.js .reveal { opacity: 1; transform: none; transition: none; }
}

/* hero line draw */
.hero-line {
  stroke-dasharray: 1200;
  stroke-dashoffset: 1200;
  animation: draw 1.4s .15s ease-out forwards;
}

.hero-line-bench {
  stroke-dasharray: 1200;
  stroke-dashoffset: 1200;
  animation: draw 1.4s .35s ease-out forwards;
}

@keyframes draw { to { stroke-dashoffset: 0; } }

@media (prefers-reduced-motion: reduce) {
  .hero-line, .hero-line-bench { animation: none; stroke-dashoffset: 0; }
}

/* utilities */
.mt-24 { margin-top: 24px; }
.mt-40 { margin-top: 40px; }
.mb-0 { margin-bottom: 0; }
.stack-16 > * + * { margin-top: 16px; }
.center { text-align: center; }
.nowrap { white-space: nowrap; }

.disclaimer-inline {
  font-size: 12px;
  color: var(--muted);
  border-top: 1px solid var(--rule);
  padding-top: 14px;
  margin-top: 24px;
}

/* print */
@media print {
  .nav, .filter-bar, .theme-toggle, .site-footer .footer-links { display: none; }
  body { background: #fff; color: #000; }
  .card, .panel { box-shadow: none; }
}