@charset "UTF-8";
/* ==========================================================================
 SIO超级智能优化实验室 — 站点样式表
   Standard: W3C CSS Snapshot / WCAG 2.2 AA / Core Web Vitals
   Design tokens first. No external font or script requests.
   ========================================================================== */

/* ---------- 1. Design tokens ---------- */
:root {
  /* Ink & surfaces (light theme) */
  --ink: #0C1524;
  --ink-2: #24344C;
  --ink-3: #4C5D75;
  --muted: #5A6B82;
  --line: #DDE4EE;
  --line-2: #ECF0F6;
  --paper: #FFFFFF;
  --canvas: #F7F9FC;
  --canvas-2: #EFF3F9;

  /* Brand */
  --brand: #0E2A4F;
  --brand-600: #163F6E;
  --brand-500: #1D5490;
  --accent: #0B7285;
  --accent-2: #0F8A9E;
  --accent-soft: #E7F3F5;
  --accent-line: #B9DCE1;

  /* Support */
  --warn-soft: #FBF4E6;
  --warn-line: #E8D5AE;
  --warn-ink: #7A5A12;

  /* Type */
  --sans: "Inter", "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui,
    -apple-system, sans-serif;
  --mono: "SFMono-Regular", "JetBrains Mono", "Cascadia Mono", Consolas,
    "Liberation Mono", Menlo, monospace;
  --serif: "Iowan Old Style",GEOrgia, "Times New Roman", "Songti SC", SimSun,
    serif;

  /* Rhythm */
  --shell: 1180px;
  --gutter: clamp(20px, 4vw, 48px);
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 18px;
  --s-5: 22px;
  --s-6: 30px;
  --s-7: 42px;
  --s-8: 60px;
  --s-9: clamp(40px, 4.4vw, 64px);

  --radius: 3px;
  --radius-lg: 6px;
  --shadow-1: 0 1px 2px rgba(12, 21, 36, 0.04), 0 8px 24px rgba(12, 21, 36, 0.05);
  --shadow-2: 0 2px 4px rgba(12, 21, 36, 0.05), 0 18px 44px rgba(12, 21, 36, 0.09);
  --ring: 0 0 0 3px rgba(11, 114, 133, 0.28);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  font-feature-settings: "kern" 1;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1,
h2,
h3,
h4,
p,
figure,
blockquote,
dl,
dd {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
}

a {
  color: var(--brand-500);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

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

/* ---------- 3. Utilities ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--brand);
  color: #fff;
  font-size: 14px;
  text-decoration: none;
  border-radius: var(--radius);
  transition: top 0.2s var(--ease);
}

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

.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;
}

.mono {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.num {
  font-family: var(--serif);
  font-variant-numeric: lining-nums tabular-nums;
}

/* ---------- 4. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(1.6) blur(12px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: var(--s-5);
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--ink);
  margin-right: auto;
}

.brand .mark {
  width: 40px;
  height: 40px;
  color: var(--brand);
  flex: none;
  object-fit: contain;
}

/* 徽标为白底位图，multiply 让白底融进浅色背景，避免出现方块 */
.brand img.mark {
  mix-blend-mode: multiply;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-sub {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-transform: uppercase;
  margin-top: 5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav a {
  position: relative;
  display: inline-block;
  padding: 9px 13px;
  font-size: 14.5px;
  color: var(--ink-2);
  text-decoration: none;
  border-radius: var(--radius);
  transition: color 0.18s var(--ease), background 0.18s var(--ease);
}

.nav a:hover {
  color: var(--brand);
  background: var(--canvas);
}

.nav a[aria-current="page"] {
  color: var(--brand);
  font-weight: 600;
}

.nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 2px;
  height: 2px;
  background: var(--accent);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 0 16px;
  background: var(--brand);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background 0.18s var(--ease), transform 0.18s var(--ease);
}

.header-cta:hover {
  background: var(--brand-600);
  color: #fff;
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  position: relative;
  display: block;
  width: 17px;
  height: 1.5px;
  background: var(--ink);
  transition: transform 0.2s var(--ease), background 0.2s var(--ease);
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 17px;
  height: 1.5px;
  background: var(--ink);
  transition: transform 0.2s var(--ease);
}

.nav-toggle span::before {
  top: -5.5px;
}

.nav-toggle span::after {
  top: 5.5px;
}

.nav-toggle[aria-expanded="true"] span {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] span::before {
  transform: translateY(5.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span::after {
  transform: translateY(-5.5px) rotate(-45deg);
}

/* ---------- 5. Type scale ---------- */
h1,
.h1 {
  font-size: clamp(27px, 3.6vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.022em;
  font-weight: 700;
}

h2,
.h2 {
  font-size: clamp(21px, 2.4vw, 30px);
  line-height: 1.26;
  letter-spacing: -0.015em;
  font-weight: 700;
}

h3,
.h3 {
  font-size: clamp(16.5px, 1.35vw, 19px);
  line-height: 1.4;
  font-weight: 650;
  letter-spacing: -0.005em;
}

.lede {
  font-size: clamp(15.5px, 1.2vw, 17px);
  line-height: 1.72;
  color: var(--ink-3);
}

.small {
  font-size: 13.5px;
  color: var(--muted);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--s-4);
}

.eyebrow .idx {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 20px;
  padding: 0 5px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  color: var(--accent);
  border-radius: 2px;
  font-size: 10.5px;
  letter-spacing: 0.04em;
}

.eyebrow::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
  max-width: 96px;
}

/* ---------- 6. Sections ---------- */
.section {
  padding-block: var(--s-9);
}

.section--tight {
  padding-block: clamp(30px, 3.6vw, 48px);
}

.section--canvas {
  background: var(--canvas);
  border-block: 1px solid var(--line);
}

.sec-head {
  max-width: 760px;
  margin-bottom: var(--s-7);
}

.sec-head .lede {
  margin-top: var(--s-3);
}

.rule {
  height: 1px;
  background: var(--line);
  border: 0;
  margin: 0;
}

/* ---------- 7. Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(180deg, #ffffff 0%, #fbfcfe 55%, #f6f9fc 100%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(14, 42, 79, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(14, 42, 79, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(120% 90% at 78% 8%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(120% 90% at 78% 8%, #000 0%, transparent 72%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
  padding-block: clamp(34px, 4.4vw, 60px);
}

.hero h1 {
  margin-bottom: var(--s-5);
}

.hero h1 .hl {
  color: var(--accent);
}

.hero .lede {
  max-width: 34em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: var(--s-6);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 46px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease),
    color 0.18s var(--ease), transform 0.18s var(--ease);
}

.btn--primary {
  background: var(--brand);
  color: #fff;
}

.btn--primary:hover {
  background: var(--brand-600);
  color: #fff;
  transform: translateY(-1px);
}

.btn--ghost {
  background: #fff;
  color: var(--brand);
  border-color: var(--line);
}

.btn--ghost:hover {
  border-color: var(--brand-500);
  color: var(--brand-600);
  background: var(--canvas);
}

.btn svg {
  width: 15px;
  height: 15px;
}

/* Standard record card */
.record {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-1);
  overflow: hidden;
}

.record-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 18px;
  background: var(--canvas);
  border-bottom: 1px solid var(--line);
}

.record-top .t {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--warn-ink);
  background: var(--warn-soft);
  border: 1px solid var(--warn-line);
  border-radius: 2px;
  white-space: nowrap;
}

.badge::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #C08A1E;
}

.record dl {
  margin: 0;
}

.record .row {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 14px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--line-2);
  font-size: 13.5px;
}

.record .row:last-child {
  border-bottom: 0;
}

.record dt {
  color: var(--muted);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  padding-top: 1px;
}

.record dd {
  color: var(--ink-2);
  font-weight: 550;
}

.record dd .mono {
  font-size: 12.5px;
  color: var(--brand);
}

.record-foot {
  padding: 11px 18px;
  border-top: 1px solid var(--line);
  background: var(--canvas);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 8. Fact strip ---------- */
.facts {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  background: #fff;
}

.fact {
  padding: 26px clamp(14px, 2vw, 28px);
  border-right: 1px solid var(--line-2);
}

.fact:last-child {
  border-right: 0;
}

.fact .n {
  font-family: var(--serif);
  font-size: clamp(28px, 3.4vw, 40px);
  line-height: 1;
  color: var(--brand);
  letter-spacing: -0.02em;
}

.fact .n small {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  margin-left: 4px;
  letter-spacing: 0;
}

.fact .k {
  margin-top: 9px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-2);
}

.fact .d {
  margin-top: 2px;
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- 9. Page header (inner pages) ---------- */
.page-head {
  position: relative;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #fff 0%, #f7fafc 100%);
  padding-block: clamp(26px, 3vw, 40px) clamp(22px, 2.4vw, 30px);
}

.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--muted);
  margin-bottom: var(--s-4);
}

.crumbs a {
  color: var(--ink-3);
  text-decoration: none;
}

.crumbs a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.crumbs span[aria-current] {
  color: var(--ink-2);
  font-weight: 600;
}

.crumbs .sep {
  color: var(--line);
}

.page-head h1 {
  font-size: clamp(25px, 3.1vw, 36px);
  max-width: 22em;
}

.page-head .lede {
  margin-top: var(--s-4);
  max-width: 44em;
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: var(--s-4);
  padding-top: var(--s-3);
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-transform: uppercase;
}

/* ---------- 10. Grid & cards ---------- */
.grid {
  display: grid;
  gap: var(--s-4);
}

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

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

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: clamp(18px, 1.9vw, 24px);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease),
    transform 0.2s var(--ease);
}

.card:hover {
  border-color: #C3D2E4;
  box-shadow: var(--shadow-1);
  transform: translateY(-2px);
}

.card .tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  padding: 2px 8px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  border-radius: 2px;
  margin-bottom: var(--s-3);
}

.card h3 {
  margin-bottom: 10px;
}

.card p {
  color: var(--ink-3);
  font-size: 14.5px;
  line-height: 1.72;
}

.card p + p {
  margin-top: 10px;
}

.card .foot {
  margin-top: auto;
  padding-top: var(--s-4);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

a.card {
  color: inherit;
  text-decoration: none;
}

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

a.card p {
  color: var(--ink-3);
}

.card--flat {
  background: var(--canvas);
}

.card--flat:hover {
  transform: none;
  box-shadow: none;
}

/* numbered list inside cards */
.deflist {
  list-style: none;
  margin-top: var(--s-4);
}

.deflist li {
  position: relative;
  padding-left: 20px;
  font-size: 13.8px;
  color: var(--ink-3);
  line-height: 1.75;
}

.deflist li + li {
  margin-top: 9px;
}

.deflist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 7px;
  height: 7px;
  border: 1px solid var(--accent);
  border-radius: 1px;
}

/* ---------- 11. Timeline (three eras) ---------- */
.eras {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
}

.era {
  position: relative;
  padding: var(--s-6) clamp(16px, 2.2vw, 30px) var(--s-6) 0;
  border-right: 1px solid var(--line-2);
}

.era:last-child {
  border-right: 0;
}

.era .v {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--serif);
  font-size: 40px;
  line-height: 1;
  color: #7C8DA6;
  letter-spacing: -0.03em;
}

.era.is-now .v {
  color: var(--accent);
}

.era .v span {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
}

.era h3 {
  margin-top: var(--s-4);
}

.era .k {
  margin-top: var(--s-3);
  font-size: 10.5px;
  font-family: var(--mono);
  letter-spacing: 0.1em;
  color: var(--muted);
  text-transform: uppercase;
}

.era p {
  margin-top: 6px;
  font-size: 14px;
  color: var(--ink-3);
  line-height: 1.72;
}

.era.is-now::before {
  content: "";
  position: absolute;
  left: 0;
  top: -1px;
  width: calc(100% - clamp(16px, 2.2vw, 30px));
  height: 2px;
  background: var(--accent);
}

/* ---------- 12. Quote / callout ---------- */
.callout {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: var(--s-5);
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--canvas);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.callout .glyph {
  font-family: var(--serif);
  font-size: 44px;
  line-height: 0.9;
  color: var(--accent-line);
}

.callout p {
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.76;
  color: var(--ink-2);
}

.callout p + p {
  margin-top: 10px;
}

.callout strong {
  color: var(--brand);
}

.callout--plain {
  grid-template-columns: minmax(0, 1fr);
  border-left: 1px solid var(--line);
  border-top: 2px solid var(--brand);
  border-radius: 0 0 var(--radius) var(--radius);
}

/* ---------- 13. Tables ---------- */
.table-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

table.data {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 14px;
}

table.data--wide {
  min-width: 880px;
}

table.data--wide thead th:nth-child(2),
table.data--wide tbody td:nth-child(2) {
  width: 22%;
  color: var(--ink-2);
}

table.data--wide thead th:nth-child(3),
table.data--wide tbody td:nth-child(3) {
  width: 27%;
}

table.data--wide thead th:nth-child(4),
table.data--wide tbody td:nth-child(4) {
  width: 33%;
}

table.data--wide th,
table.data--wide td {
  padding-left: 14px;
  padding-right: 14px;
}

table.data caption {
  caption-side: top;
  text-align: left;
  padding: 11px 16px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
  background: var(--canvas);
}

table.data th,
table.data td {
  padding: 11px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-2);
  line-height: 1.62;
}

table.data thead th {
  background: var(--canvas);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: 0.06em;
  color: var(--ink-2);
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}

table.data tbody th {
  font-weight: 600;
  color: var(--brand);
  font-size: 13.5px;
  white-space: nowrap;
  background: #FCFDFE;
}

table.data tbody tr:last-child th,
table.data tbody tr:last-child td {
  border-bottom: 0;
}

table.data tbody tr:hover td,
table.data tbody tr:hover th {
  background: #FAFCFD;
}

table.data td.is-SIO{
  color: var(--ink);
  background: #F7FBFC;
}

table.data .em {
  color: var(--brand);
  font-weight: 600;
}

/* 四列表格在窄屏改为堆叠卡片，避免横滚漏看SIO列 */
@media (max-width: 720px) {
  .table-wrap--wide {
    border: 0;
    border-radius: 0;
    background: transparent;
    overflow-x: visible;
  }

  table.data--wide,
  table.data--wide tbody,
  table.data--wide tbody tr,
  table.data--wide tbody th,
  table.data--wide tbody td {
    display: block;
    width: 100%;
    box-sizing: border-box;
  }

  table.data--wide {
    min-width: 0;
  }

  table.data--wide caption {
    display: block;
    width: 100%;
    box-sizing: border-box;
    padding: 0 0 12px;
    border-bottom: 0;
    background: transparent;
    line-height: 1.7;
  }

  table.data--wide thead {
    display: none;
  }

  table.data--wide tbody tr {
    margin-bottom: 12px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: #fff;
    overflow: hidden;
  }

  table.data--wide tbody th {
    padding: 11px 16px;
    background: var(--canvas);
    border-bottom: 1px solid var(--line-2);
    white-space: normal;
    font-size: 13.5px;
  }

  table.data--wide tbody td,
  table.data--wide tbody td:nth-child(2),
  table.data--wide tbody td:nth-child(3),
  table.data--wide tbody td:nth-child(4) {
    display: flex;
    gap: 10px;
    width: 100%;
    padding: 11px 16px;
    font-size: 13px;
    border-bottom: 1px solid var(--line-2);
  }

  table.data--wide tbody td::before {
    flex: 0 0 40px;
    padding-top: 2px;
    font-family: var(--mono);
    font-size: 10.5px;
    letter-spacing: 0.06em;
    color: var(--muted);
  }

  table.data--wide tbody td:nth-child(2)::before {
    content: "SEO";
  }

  table.data--wide tbody td:nth-child(3)::before {
    content: "GEO";
  }

  table.data--wide tbody td:nth-child(4)::before {
    content: "SIO";
    color: var(--accent);
  }

  table.data--wide tbody tr:last-child {
    margin-bottom: 0;
  }

  table.data--wide tbody tr th:last-child,
  table.data--wide tbody tr td:last-child {
    border-bottom: 0;
  }
}

/* ---------- 14. Metric cards ---------- */
.metric {
  padding: clamp(20px, 2.4vw, 28px);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.metric .id {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.metric h3 {
  margin-top: 10px;
  font-size: 17px;
}

.metric .body {
  margin-top: 10px;
  font-size: 13.8px;
  color: var(--ink-3);
  line-height: 1.72;
}

.metric .kv {
  display: flex;
  gap: 10px;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 12.5px;
  color: var(--muted);
}

.metric .kv b {
  color: var(--ink-2);
  font-weight: 600;
  white-space: nowrap;
}

/* weight bar */
.weights {
  list-style: none;
  margin-top: var(--s-4);
}

.weights li + li {
  margin-top: 12px;
}

.weights .lbl {
  display: flex;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--ink-2);
  margin-bottom: 5px;
}

.weights .lbl span:last-child {
  font-family: var(--mono);
  color: var(--brand);
}

.weights .bar {
  height: 4px;
  background: var(--line-2);
  border-radius: 2px;
  overflow: hidden;
}

.weights .bar i {
  display: block;
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
}

/* ---------- 15. Roadmap / steps ---------- */
.steps {
  list-style: none;
  border-top: 1px solid var(--line);
}

.step {
  display: grid;
  grid-template-columns: 128px 30px minmax(0, 1fr) 168px;
  gap: var(--s-4);
  align-items: start;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-2);
}

.step .when {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--accent);
  padding-top: 4px;
}

.step .dot {
  position: relative;
  display: flex;
  justify-content: center;
  padding-top: 9px;
}

.step .dot i {
  width: 9px;
  height: 9px;
  background: #fff;
  border: 2px solid var(--accent);
  border-radius: 50%;
  z-index: 1;
}

.step .dot::before {
  content: "";
  position: absolute;
  top: 18px;
  bottom: -34px;
  width: 1px;
  background: var(--line);
}

.step:last-child .dot::before {
  display: none;
}

.step h3 {
  font-size: 16.5px;
}

.step h3 em {
  font-style: normal;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-left: 8px;
  vertical-align: 2px;
}

.step p {
  margin-top: 7px;
  font-size: 13.8px;
  color: var(--ink-3);
  line-height: 1.72;
}

.step .out {
  font-size: 12.5px;
  color: var(--muted);
  border-left: 2px solid var(--accent-line);
  padding-left: 12px;
  line-height: 1.7;
}

.step .out b {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 3px;
  text-transform: uppercase;
  font-weight: 500;
}

/* ---------- 15b. 首页新闻速览 ---------- */
.newslist {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.newslist li {
  display: grid;
  grid-template-columns: 104px minmax(0, 1fr) auto;
  gap: var(--s-4);
  align-items: baseline;
  padding: 17px 0;
  border-bottom: 1px solid var(--line-2);
}

.newslist .n-date {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.newslist .n-title {
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.55;
}

.newslist .n-title a {
  color: var(--ink);
  text-decoration: none;
}

.newslist .n-title a:hover {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.newslist .n-tag {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.09em;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 12px;
  white-space: nowrap;
}

@media (max-width: 720px) {
  .newslist li {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
    padding: 15px 0;
  }

  .newslist .n-tag {
    justify-self: start;
  }
}

/* ---------- 16. FAQ ---------- */
.faq {
  border-top: 1px solid var(--line);
}

.faq details {
  border-bottom: 1px solid var(--line-2);
}

.faq summary {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 20px 4px;
  cursor: pointer;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  list-style: none;
  transition: color 0.18s var(--ease);
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::before {
  content: "Q";
  flex: none;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  border-radius: 2px;
  width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}

.faq summary:hover {
  color: var(--brand-500);
}

.faq summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mono);
  font-weight: 400;
  color: var(--muted);
  transition: transform 0.2s var(--ease);
}

.faq details[open] summary::after {
  content: "-";
}

.faq .a {
  padding: 0 4px 18px 40px;
  font-size: 14.5px;
  color: var(--ink-3);
  line-height: 1.76;
  max-width: 62em;
}

.faq .a p + p {
  margin-top: 9px;
}

/* ---------- 17. Panel CTA ---------- */
.panel {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: clamp(22px, 3.2vw, 44px);
  align-items: center;
  padding: clamp(24px, 3.2vw, 40px);
  background:
    radial-gradient(120% 140% at 100% 0%, #E8F1F8 0%, transparent 60%),
    var(--canvas-2);
  border: 1px solid #D3DFEE;
  border-radius: var(--radius-lg);
}

.panel h2 {
  max-width: 18em;
}

.panel .lede {
  margin-top: var(--s-4);
}

.panel-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 18. Self-check widget ---------- */
.checker {
  padding: clamp(22px, 3vw, 34px);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-1);
}

.checker fieldset {
  border: 0;
  padding: 0;
  margin: 0 0 var(--s-5);
}

.checker .qs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 clamp(28px, 4vw, 56px);
}

@media (max-width: 900px) {
  .checker .qs {
    grid-template-columns: minmax(0, 1fr);
  }
}

.checker legend {
  display: flex;
  gap: 10px;
  padding: 0;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 10px;
  line-height: 1.6;
}

.checker legend .qn {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  padding-top: 3px;
}

.scale {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.scale label {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 6px 10px;
  font-size: 13px;
  color: var(--ink-3);
  background: var(--canvas);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  text-align: center;
  transition: all 0.16s var(--ease);
}

.scale label:hover {
  border-color: var(--accent-line);
  background: var(--accent-soft);
}

.scale input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.scale input:focus-visible + span {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.scale input:checked + span {
  color: var(--brand);
  font-weight: 600;
}

.scale label:has(input:checked) {
  background: var(--accent-soft);
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}

.checker-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  padding-top: var(--s-4);
  border-top: 1px solid var(--line-2);
}

.result {
  margin-top: var(--s-5);
  padding: var(--s-5);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  background: var(--canvas);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.result[hidden] {
  display: none;
}

.result .score {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--serif);
  font-size: 46px;
  line-height: 1;
  color: var(--brand);
}

.result .score small {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
  font-weight: 500;
}

.result .tier {
  margin-top: 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.result .advice {
  margin-top: 8px;
  font-size: 14px;
  color: var(--ink-3);
  line-height: 1.72;
}

.result .meter {
  margin-top: var(--s-4);
  height: 6px;
  background: var(--line-2);
  border-radius: 3px;
  overflow: hidden;
}

.result .meter i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--brand-500));
  transition: width 0.8s var(--ease);
}

/* ---------- 19. Footer ---------- */
.site-footer {
  background: var(--canvas);
  border-top: 1px solid var(--line);
  padding-block: var(--s-8) var(--s-4);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) repeat(3, minmax(0, 1fr));
  gap: clamp(24px, 3.5vw, 48px);
}

.footer-brand .brand {
  margin-bottom: var(--s-4);
}

.footer-brand p {
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.85;
  max-width: 30em;
}

.footer-col h4 {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: var(--s-4);
  font-weight: 500;
}

.footer-col ul {
  list-style: none;
}

.footer-col li + li {
  margin-top: 9px;
}

.footer-col a {
  font-size: 13.5px;
  color: var(--ink-3);
  text-decoration: none;
  transition: color 0.16s var(--ease);
}

.footer-col a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--s-7);
  padding-top: var(--s-5);
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--muted);
}

.footer-base .std {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
}

/* ---------- 页脚链接列：移动端折叠手风琴 ----------
   桌面端（≥721px）始终展开；移动端（≤720px）默认折叠，点按 summary 展开。
   原生 <details> 实现，无 JS 也能折叠；下方媒体查询负责桌面端强制展开。 */
.footer-col .f-col-sum {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: var(--s-4);
  cursor: pointer;
  list-style: none;                 /* 去掉原生三角，改用自定义箭头 */
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 500;
  -webkit-tap-highlight-color: transparent;
}

/* 兼容 WebKit / Firefox 的原生标记 */
.footer-col .f-col-sum::-webkit-details-marker { display: none; }
.footer-col .f-col-sum::marker { content: ""; }

.footer-col .f-col-sum:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
  border-radius: 2px;
}

.footer-col .f-col-title { flex: 1 1 auto; }

.footer-col .f-col-caret {
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: translateY(-2px) rotate(45deg);   /* 向下箭头（▽） */
  transition: transform 0.2s ease;
  opacity: 0.65;
}

.footer-col[open] .f-col-caret {
  transform: translateY(1px) rotate(-135deg);   /* 展开时向上（△） */
}

/* 移动端（≤720px）：闭合时隐藏链接列表，实现默认折叠；展开后原生显示 */
.footer-col:not([open]) > ul {
  display: none;
}

/* 桌面端（≥721px）：强制始终展开、隐藏箭头、标题不可点；!important 兼顾无 JS 场景 */
@media (min-width: 721px) {
  .footer-col > ul { display: block !important; }
  .footer-col .f-col-caret { display: none; }
  .footer-col .f-col-sum {
    cursor: default;
    pointer-events: none;
  }
  .footer-col .f-col-sum:focus-visible { outline: none; }
}

@media (prefers-reduced-motion: reduce) {
  .footer-col .f-col-caret { transition: none; }
}

/* ---------- 20. Reveal animation ----------
   仅在脚本生效时隐藏内容：无 JS / 抓取器 / 打印均保持完全可见 */
.reveal {
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.js-reveal .reveal {
  opacity: 0;
  transform: translateY(14px);
}

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

/* ---------- 21. Responsive ---------- */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s-6);
  }

  .record {
    max-width: 560px;
  }

  .nav {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .header-cta {
    display: none;
  }

  .nav.is-open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px var(--gutter) 18px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-1);
  }

  .nav.is-open a {
    padding: 13px 4px;
    border-bottom: 1px solid var(--line-2);
    border-radius: 0;
  }

  .nav.is-open a[aria-current="page"]::after {
    display: none;
  }

  .nav.is-open a[aria-current="page"] {
    color: var(--accent);
  }

  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .step {
    grid-template-columns: 108px 24px minmax(0, 1fr);
  }

  .step .out {
    grid-column: 3;
  }
}

@media (max-width: 780px) {
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: minmax(0, 1fr);
  }

  .eras {
    grid-template-columns: minmax(0, 1fr);
  }

  .era {
    padding: var(--s-5) 0;
    border-right: 0;
    border-bottom: 1px solid var(--line-2);
  }

  .era:last-child {
    border-bottom: 0;
  }

  .era.is-now::before {
    width: 48px;
  }

  .facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .fact {
    border-bottom: 1px solid var(--line-2);
  }

  .fact:nth-child(2n) {
    border-right: 0;
  }

  .panel {
    grid-template-columns: minmax(0, 1fr);
  }

  .step {
    grid-template-columns: 1fr;
    gap: 8px;
    padding-block: var(--s-5);
  }

  .step .dot {
    display: none;
  }

  .step .when {
    padding-top: 0;
  }

  .step .out {
    grid-column: auto;
    margin-top: 6px;
  }

  .callout {
    grid-template-columns: minmax(0, 1fr);
  }

  .callout .glyph {
    display: none;
  }

  .scale {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-brand {
    padding-bottom: var(--s-5);
    border-bottom: 1px solid var(--line);
  }
}

@media (max-width: 480px) {
  .facts {
    grid-template-columns: minmax(0, 1fr);
  }

  .fact {
    border-right: 0;
  }

  .hero-actions .btn,
  .panel-actions .btn {
    flex: 1 1 100%;
  }
}

/* ---------- 22. Motion & print ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

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

/* ---------- 23. Long-form (whitepaper) ---------- */
.chapters {
  border-top: 1px solid var(--line);
}

.chapter {
  display: grid;
  grid-template-columns: 132px minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 40px);
  padding-block: clamp(26px, 3.2vw, 40px);
  border-bottom: 1px solid var(--line-2);
}

.chapter .ch-no {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent);
  padding-top: 1px;
  white-space: nowrap;
}

.chapter .ch-no span {
  display: block;
  font-size: 10px;
  color: var(--muted);
  letter-spacing: 0.08em;
  margin-top: 5px;
}

.chapter h2 {
  font-size: clamp(19px, 1.9vw, 25px);
  margin-bottom: 14px;
}

.chapter p {
  font-size: 14.6px;
  color: var(--ink-3);
  line-height: 1.78;
  max-width: 62em;
}

.chapter p + p {
  margin-top: 10px;
}

.chapter blockquote {
  margin: 16px 0 0;
  padding: 14px 18px;
  background: var(--canvas);
  border-left: 2px solid var(--accent);
  font-size: 14px;
  line-height: 1.76;
  color: var(--ink-2);
  max-width: 60em;
}

.chapter blockquote cite {
  display: block;
  margin-top: 8px;
  font-style: normal;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.chapter ul.deflist {
  max-width: 60em;
}

/* Table of contents */
.toc {
  columns: 2;
  column-gap: clamp(24px, 4vw, 56px);
  list-style: none;
  border-top: 1px solid var(--line);
}

.toc li {
  break-inside: avoid;
  border-bottom: 1px solid var(--line-2);
}

.toc a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 13px 2px;
  color: var(--ink-2);
  text-decoration: none;
  font-size: 14.5px;
  transition: color 0.16s var(--ease), padding-left 0.16s var(--ease);
}

.toc a:hover {
  color: var(--accent);
  padding-left: 6px;
}

.toc .n {
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--muted);
  letter-spacing: 0.06em;
  flex: none;
  width: 42px;
}

/* Note line — 表格下方的单行口径补充 */
.note-line {
  margin-top: var(--s-4);
  max-width: 60em;
  padding: 13px 18px 13px 16px;
  background: var(--paper);
  border-left: 2px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-2);
}

.note-line--full {
  max-width: none;
}

.note-line strong {
  color: var(--brand);
  font-weight: 600;
}

/* Sub heading — 板块内的二级说明标题 */
.sub-h {
  margin: var(--s-6) 0 var(--s-4);
  font-size: clamp(16px, 1.7vw, 19px);
  font-weight: 650;
  letter-spacing: -0.01em;
  line-height: 1.45;
  color: var(--ink);
}

/* Layers —SEO/GEO/SIO三层对照 */
.layers {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.layer {
  display: flex;
  flex-direction: column;
  padding: 22px 20px 18px;
  background: var(--paper);
}

.layer.is-SIO{
  background: #FAFDFE;
}

.layer-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-2);
}

.layer-head .abbr {
  font-family: var(--mono);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--brand);
}

.layer.is-SIO.layer-head .abbr {
  color: var(--accent);
}

.layer-head .full {
  font-size: 12px;
  color: var(--muted);
}

.layer dl {
  margin: 14px 0 0;
  display: grid;
  gap: 9px;
}

.layer dl > div {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 10px;
}

.layer dt {
  padding-top: 2px;
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.layer dd {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.62;
  color: var(--ink-2);
}

.layer-line {
  margin-top: auto;
  padding-top: 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--brand);
}

.layer.is-SIO.layer-line {
  color: var(--accent);
}

.layers-flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--muted);
}

.layers-flow .ar {
  font-family: var(--mono);
  color: var(--accent);
}

.layers-flow b {
  color: var(--brand);
  font-weight: 600;
}

/* Era outcome line */
.era .out {
  margin-top: 10px;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink-3);
}

.era.is-now .out {
  color: var(--accent);
}

@media (max-width: 860px) {
  .layers {
    grid-template-columns: 1fr;
  }

  .layer-line {
    margin-top: 14px;
  }
}

.cite {
  margin: 0;
  padding: 18px 20px;
  background: var(--canvas);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.85;
  color: var(--ink-2);
  white-space: pre-wrap;
  word-break: break-word;
  overflow-x: auto;
}

.cite + .cite {
  margin-top: 12px;
}

.cite-label {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 8px;
}

/* Abstract */
.abstract {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
  gap: clamp(24px, 4vw, 56px);
  padding: clamp(24px, 3.4vw, 44px);
  background: #fff;
  border: 1px solid var(--line);
  border-top: 3px solid var(--brand);
  border-radius: 0 0 var(--radius) var(--radius);
}

.abstract p {
  font-size: 15px;
  line-height: 1.95;
  color: var(--ink-2);
}

.abstract p + p {
  margin-top: 12px;
}

.abstract dl {
  border-left: 1px solid var(--line-2);
  padding-left: clamp(16px, 2.4vw, 32px);
}

.abstract .row {
  padding: 9px 0;
  border-bottom: 1px dashed var(--line-2);
  font-size: 13px;
}

.abstract .row:last-child {
  border-bottom: 0;
}

.abstract dt {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 3px;
}

.abstract dd {
  color: var(--ink-2);
  font-weight: 550;
}

@media (max-width: 780px) {
  .chapter {
    grid-template-columns: minmax(0, 1fr);
    gap: 10px;
  }

  .chapter .ch-no {
    padding-top: 0;
  }

  .toc {
    columns: 1;
  }

  .abstract {
    grid-template-columns: minmax(0, 1fr);
  }

  .abstract dl {
    border-left: 0;
    border-top: 1px solid var(--line-2);
    padding-left: 0;
    padding-top: 14px;
  }
}

@media print {
  .site-header,
  .site-footer,
  .hero-actions,
  .panel-actions,
  .nav-toggle,
  .checker-actions {
    display: none !important;
  }

  body {
    font-size: 11pt;
    color: #000;
  }

  .section {
    padding-block: 12pt;
    break-inside: avoid;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 8pt;
    color: #555;
  }

  .card,
  .metric,
  .record {
    box-shadow: none;
    border-color: #bbb;
  }

  .reveal {
    opacity: 1 !important;
    transform: none !important;
  }
}

/* ==========================================================================
   SIO 概念短片 — overview.html
   约束：不自动播放、preload=none、poster 先行；不引入任何第三方播放器
   ========================================================================== */
.sio-figure {
  margin: 0;
}

.sio-video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  background: var(--brand);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 32px rgba(14, 42, 79, 0.12);
}

.sio-video:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.sio-video-cap {
  margin: var(--s-3) 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.sio-video-cap strong {
  color: var(--ink-2);
  font-weight: 600;
}

.video-transcript {
  margin-top: var(--s-4);
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--paper);
}

.video-transcript > summary {
  padding: 12px 0;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  color: var(--brand);
  list-style-position: inside;
}

.video-transcript > summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.video-transcript[open] > summary {
  border-bottom: 1px solid var(--line);
}

.video-transcript ol {
  margin: 0;
  padding: 14px 0 16px 22px;
}

.video-transcript li {
  margin: 6px 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-2);
}

.sio-tc {
  margin-right: 8px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
}

@media (max-width: 720px) {
  .video-transcript { padding: 0 14px; }
  .video-transcript li { font-size: 13.5px; }
  .sio-tc { display: block; margin-right: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .sio-video { box-shadow: none; }
}

/* 概念短片：自定义封面按钮（避免 preload=none 时原生控件显示加载转圈） */
.sio-video-frame {
  position: relative;
}

.sio-play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 76px;
  height: 76px;
  padding: 0;
  border: 2px solid rgba(255, 255, 255, 0.92);
  border-radius: 50%;
  background: rgba(14, 42, 79, 0.82);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.22);
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease;
}

.sio-play[hidden] { display: none; }

.sio-play::before {
  content: "";
  width: 0;
  height: 0;
  margin-left: 5px;
  border-left: 20px solid #fff;
  border-top: 12px solid transparent;
  border-bottom: 12px solid transparent;
}

.sio-play:hover {
  background: rgba(11, 114, 133, 0.92);
  transform: translate(-50%, -50%) scale(1.06);
}

.sio-play:focus-visible {
  outline: 3px solid #fff;
  outline-offset: 3px;
}

@media (max-width: 720px) {
  .sio-play { width: 60px; height: 60px; }
  .sio-play::before {
    border-left-width: 16px;
    border-top-width: 10px;
    border-bottom-width: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .sio-play { transition: none; }
  .sio-play:hover { transform: translate(-50%, -50%); }
}