:root {
  --color-surface: #efeded;
  --color-surface-alt: #e7e4e4;
  --color-surface-deep: #dcd8d8;
  --color-ink: #4d3d3e;
  --color-ink-soft: #796264;
  --color-ink-muted: #8b7476;
  --color-line: #d2cdce;
  --color-primary: #d02f3c;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #ebd2d4;
  --color-accent: #c2561f;
  --color-accent-ink: #ffffff;
  --color-highlight: #e7d2c8;
  --color-focus: #b14711;
  --color-contrast-surface: #281618;
  --color-contrast-ink: #e7e4e4;
  --color-contrast-line: #524345;
  --color-contrast-accent: #dc6223;
  --overlay-scrim: linear-gradient(180deg, rgba(40, 22, 24, 0.35) 0%, rgba(40, 22, 24, 0.72) 55%, rgba(40, 22, 24, 0.92) 100%);
  --font-heading: "Songti SC", STSong, "Source Han Serif SC", SimSun, serif;
  --font-body: "Songti SC", STSong, "Source Han Serif SC", SimSun, serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 12.2px;
  --text-sm: 15.2px;
  --text-base: 17px;
  --text-lg: 21.2px;
  --text-xl: 26.6px;
  --text-2xl: 33.2px;
  --text-3xl: 41.5px;
  --text-4xl: 51.9px;
  --text-display: clamp(34px, 6.4vw, 82px);
  --text-figure: clamp(28px, 4.6vw, 59px);
  --weight-heading: 606;
  --weight-body: 400;
  --leading-body: 1.86;
  --leading-heading: 1.29;
  --tracking-heading: 0.001em;
  --radius-sm: 1px;
  --radius-md: 1px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1140px;
  --measure: 72ch;
  --gutter: 24px;
  --section-y: 95px;
  --section-y-lg: 133px;
}

/* ==========================================================================
   01 · Reset 与中文基础排版
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 132px;
}
body {
  margin: 0;
  min-height: 100%;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
}
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: inherit;
}
p { margin: 0 0 var(--space-3); }
ul, ol { margin: 0 0 var(--space-3); padding-left: 1.25em; }
li { margin-bottom: var(--space-1); }
img, svg, video { max-width: 100%; height: auto; display: block; }
hr { border: 0; border-top: var(--border-thin) solid var(--color-line); margin: var(--space-4) 0; }
table { border-collapse: collapse; width: 100%; }
button, input { font: inherit; color: inherit; }
summary { cursor: pointer; }

/* 链接：朱红细线下划线渐显 */
a {
  color: var(--color-ink);
  text-decoration: none;
  background-image: linear-gradient(var(--color-primary), var(--color-primary));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 var(--border-thin);
  transition: background-size 220ms ease, color 220ms ease;
}
a:hover, a:focus-visible {
  color: var(--color-focus);
  background-size: 100% var(--border-thin);
}
:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}
:focus:not(:focus-visible) { outline: none; }

/* ==========================================================================
   02 · 跳转链接、容器与工具类
   ========================================================================== */
.skip-link {
  position: absolute;
  left: var(--space-3);
  top: var(--space-1);
  z-index: 200;
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-accent);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  letter-spacing: .12em;
  background-image: none;
  transform: translateY(-220%);
  transition: transform 200ms ease;
}
.skip-link:focus { transform: translateY(0); }

.shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2); }
.stack > * + * { margin-top: var(--space-3); }
.measure { max-width: var(--measure); }
.u-mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.u-soft { color: var(--color-ink-soft); }
.u-center { text-align: center; }

/* ==========================================================================
   03 · 栅格
   ========================================================================== */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* ==========================================================================
   04 · 区块节奏、标题组与错位分隔
   ========================================================================== */
.section { padding-block: var(--section-y); }
.section--major { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section-head { text-align: center; margin-bottom: var(--space-6); }
.section__head { text-align: center; margin-bottom: var(--space-6); }
.section--left .section-head,
.section--left .section__head { text-align: left; }
.section-kicker {
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .28em;
  color: var(--color-ink-soft);
}
.section-title { margin: 0; font-size: var(--text-2xl); }
.section-rule {
  display: block;
  width: 64px;
  height: 3px;
  margin: var(--space-2) auto 0;
  background-image: repeating-linear-gradient(90deg, var(--color-primary) 0 8px, transparent 8px 14px);
}
.section--left .section-rule { margin-inline: 0; }
.rule-offset {
  height: 3px;
  width: min(58%, 640px);
  margin-inline: auto;
  background-image: repeating-linear-gradient(90deg, var(--color-primary) 0 10px, transparent 10px 18px);
}
.rule-offset--start { margin-inline: 0; }

/* 底色分区 */
.band { padding-block: var(--section-y); }
.band--alt { background-color: var(--color-surface-alt); }
.band--deep { background-color: var(--color-surface-deep); }
.band--contrast {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.band--contrast a {
  color: var(--color-contrast-ink);
  background-image: linear-gradient(var(--color-contrast-accent), var(--color-contrast-accent));
}
.band--contrast a:hover,
.band--contrast a:focus-visible { color: var(--color-contrast-accent); }
.band--contrast .section-kicker,
.band--contrast .lede,
.band--contrast .u-soft {
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, var(--color-contrast-surface));
}
.band--contrast .section-rule,
.band--contrast .rule-offset {
  background-image: repeating-linear-gradient(90deg, var(--color-contrast-accent) 0 10px, transparent 10px 18px);
}

/* ==========================================================================
   05 · 头部：导航构成页面上沿边框
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: color-mix(in srgb, var(--color-line) 55%, transparent);
}
.read-progress-bar {
  display: block;
  height: 100%;
  width: 0;
  background-color: var(--color-primary);
  transition: width 140ms linear;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-block: var(--space-2);
}
.brand-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background-image: none;
  color: var(--color-ink);
}
.brand-mark {
  position: relative;
  flex: none;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-sm);
  color: var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1;
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 3px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 45%, transparent);
  pointer-events: none;
}
.brand-text { display: block; }
.brand-name {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.2;
  letter-spacing: .14em;
}
.brand-line {
  display: block;
  font-size: var(--text-xs);
  letter-spacing: .18em;
  color: var(--color-ink-soft);
}
.header-utility {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .06em;
  color: var(--color-ink-soft);
}
.utility-item { display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; }
.utility-dot {
  width: 7px;
  height: 7px;
  border: var(--border-thin) solid var(--color-accent);
  border-radius: var(--radius-sm);
  background-color: var(--color-primary);
}
.utility-sep { width: var(--border-thin); height: 14px; background-color: var(--color-line); }
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  padding: 6px var(--space-2);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: transparent;
  background-image: none;
  font-size: var(--text-sm);
  letter-spacing: .16em;
  cursor: pointer;
  transition: border-color 200ms ease, color 200ms ease, background-color 200ms ease;
}
.nav-toggle:hover { border-color: var(--color-primary); color: var(--color-primary); }
.nav-toggle[aria-expanded="true"] {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
}
.nav-toggle-bars { position: relative; width: 16px; height: 10px; flex: none; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: var(--border-thin);
  background-color: currentColor;
  transition: transform 200ms ease, top 200ms ease, bottom 200ms ease;
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 4px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { bottom: 5px; transform: rotate(-45deg); }
.nav-toggle-label { font-family: var(--font-heading); }
.site-nav {
  border-top: 3px double var(--color-line);
  background-color: var(--color-surface);
}
.nav-inner {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: var(--space-3);
}
.nav-list {
  display: flex;
  align-items: stretch;
  gap: var(--space-6);
  margin: 0;
  padding: 0;
  list-style: none;
}
.nav-list li { margin: 0; }
.nav-list a {
  position: relative;
  display: inline-block;
  padding: var(--space-3) 0;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  letter-spacing: .14em;
  color: var(--color-ink-soft);
  background-image: none;
  transition: color 200ms ease, background-color 200ms ease;
}
.nav-list a:hover,
.nav-list a:focus-visible { color: var(--color-focus); }
.nav-list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background-color: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 200ms ease;
}
.nav-list a:hover::after,
.nav-list a:focus-visible::after { transform: scaleX(1); }
.nav-list a[aria-current="page"] { color: var(--color-ink); }
.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
  background-color: transparent;
  background-image: repeating-linear-gradient(90deg, var(--color-primary) 0 6px, transparent 6px 12px);
}
.nav-note {
  align-self: center;
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .16em;
  color: var(--color-ink-muted);
}
.header-rule {
  height: 3px;
  border-bottom: var(--border-thin) solid var(--color-line);
  background-image: repeating-linear-gradient(90deg, var(--color-primary) 0 12px, transparent 12px 26px);
  background-repeat: repeat-x;
  background-size: 26px 100%;
}

/* ==========================================================================
   06 · 页脚：反色收束
   ========================================================================== */
.site-footer {
  margin-top: var(--section-y);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.site-footer::before {
  content: "";
  display: block;
  height: 3px;
  background-image: repeating-linear-gradient(90deg, var(--color-contrast-accent) 0 12px, transparent 12px 26px);
}
.footer-inner { padding-block: var(--space-8) var(--space-4); }
.footer-top {
  display: grid;
  grid-template-columns: minmax(190px, 1.1fr) repeat(3, minmax(0, .9fr)) minmax(210px, 1.2fr);
  gap: var(--space-4);
}
.footer-top > * + * {
  border-left: 3px double var(--color-contrast-line);
  padding-left: var(--space-3);
}
.footer-brand { min-width: 0; }
.footer-mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: var(--space-2);
  border: var(--border-thin) solid var(--color-contrast-accent);
  border-radius: var(--radius-sm);
  color: var(--color-contrast-accent);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1;
}
.footer-mark::after {
  content: "";
  position: absolute;
  inset: 3px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-accent) 45%, transparent);
  pointer-events: none;
}
.footer-brand-name {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: .14em;
}
.footer-brand-note {
  margin: 0;
  max-width: 30ch;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, var(--color-contrast-surface));
}
.footer-col { min-width: 0; }
.footer-col-title {
  position: relative;
  margin: 0 0 var(--space-2);
  padding-bottom: var(--space-1);
  font-size: var(--text-sm);
  letter-spacing: .2em;
  color: var(--color-contrast-ink);
}
.footer-col-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 2px;
  background-color: var(--color-contrast-accent);
}
.footer-list { margin: 0; padding: 0; list-style: none; }
.footer-list li { margin: 0 0 var(--space-1); }
.footer-list a {
  display: inline-block;
  padding-block: 2px;
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  background-image: linear-gradient(var(--color-contrast-accent), var(--color-contrast-accent));
}
.footer-list a:hover,
.footer-list a:focus-visible { color: var(--color-contrast-accent); }
.footer-contact-line {
  margin: 0 0 var(--space-1);
  font-size: var(--text-sm);
  line-height: 1.7;
}
.footer-contact-key {
  display: block;
  font-size: var(--text-xs);
  letter-spacing: .16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, var(--color-contrast-surface));
}
.footer-contact-value { display: block; }
.footer-contact-value--mono { font-family: var(--font-mono); letter-spacing: .02em; }
.footer-col--contact .btn--copy { margin-top: var(--space-2); }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-6);
  padding-top: var(--space-3);
  border-top: 3px double var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, var(--color-contrast-surface));
}
.footer-legal, .footer-copy { margin: 0; }

/* ==========================================================================
   07 · 按钮与标签
   ========================================================================== */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 10px var(--space-3);
  border: var(--border-thin) solid var(--color-ink-soft);
  border-radius: var(--radius-sm);
  background-color: transparent;
  background-image: none;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  letter-spacing: .14em;
  cursor: pointer;
  transition: border-color 200ms ease, color 200ms ease, background-color 200ms ease;
}
.btn::after {
  content: "";
  position: absolute;
  inset: 3px;
  border: var(--border-thin) solid color-mix(in srgb, currentColor 30%, transparent);
  pointer-events: none;
}
.btn:hover, .btn:focus-visible { border-color: var(--color-primary); color: var(--color-primary); }
.btn--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover, .btn--primary:focus-visible {
  background-color: var(--color-focus);
  border-color: var(--color-focus);
  color: var(--color-primary-ink);
}
.btn--ghost { border-color: var(--color-accent); color: var(--color-accent); }
.btn--ghost:hover, .btn--ghost:focus-visible {
  border-color: var(--color-focus);
  color: var(--color-focus);
  background-color: var(--color-highlight);
}
.btn--copy { font-family: var(--font-mono); letter-spacing: .04em; }
.site-footer .btn--copy { border-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.site-footer .btn--copy:hover,
.site-footer .btn--copy:focus-visible { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }
.btn[data-copy-state="done"] { border-color: var(--color-primary); color: var(--color-primary); }
.site-footer .btn[data-copy-state="done"] { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }

.tag {
  display: inline-block;
  padding: 2px var(--space-1);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .12em;
  color: var(--color-ink-soft);
}
.tag--primary { border-color: var(--color-primary); color: var(--color-primary); background-color: var(--color-primary-soft); }
.tag--accent { border-color: var(--color-accent); color: var(--color-accent); background-color: var(--color-highlight); }
.band--contrast .tag { border-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.band--contrast .tag--primary,
.band--contrast .tag--accent { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); background-color: transparent; }

.link-more { font-size: var(--text-sm); letter-spacing: .14em; color: var(--color-focus); }
.link-more::after { content: " →"; font-family: var(--font-mono); }

/* ==========================================================================
   08 · 卡片、面板、强调段
   ========================================================================== */
.card {
  position: relative;
  padding: var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  transition: border-color 200ms ease;
}
.card::after {
  content: "";
  position: absolute;
  inset: 4px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-line) 65%, transparent);
  pointer-events: none;
  transition: border-color 200ms ease;
}
.card:hover { border-color: var(--color-primary); }
.card:hover::after { border-color: color-mix(in srgb, var(--color-primary) 45%, transparent); }
.band--contrast .card,
.band--alt .card { background-color: var(--color-surface); }
.band--contrast .card { border-color: var(--color-contrast-line); color: var(--color-contrast-ink); background-color: transparent; }

.panel {
  position: relative;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  transition: border-color 200ms ease, box-shadow 200ms ease;
}
.panel + .panel { margin-top: var(--space-2); }
.panel > summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-3);
  list-style: none;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  letter-spacing: .04em;
}
.panel > summary::-webkit-details-marker { display: none; }
.panel > summary::after {
  content: "＋";
  flex: none;
  font-family: var(--font-mono);
  color: var(--color-primary);
}
.panel[open] > summary::after { content: "－"; }
.panel[open] {
  border-color: var(--color-primary);
  border-left-width: var(--border-thick);
}
.panel[open] > summary { background-color: var(--color-surface-alt); }
.panel-body {
  padding: 0 var(--space-3) var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.panel-body p:last-child { margin-bottom: 0; }

.note {
  max-width: 32ch;
  padding-left: var(--space-3);
  border-left: var(--border-thick) solid var(--color-primary);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.callout {
  padding: var(--space-2) 0 var(--space-2) var(--space-3);
  border-left: var(--border-thick) solid var(--color-primary);
}
.callout--tint { padding-right: var(--space-3); background-color: var(--color-highlight); }
.callout p:last-child { margin-bottom: 0; }

/* ==========================================================================
   09 · 参数读数、刻度带与区间条
   ========================================================================== */
.metric { display: flex; flex-direction: column; gap: 4px; }
.metric-value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1.05;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  color: var(--color-ink);
}
.metric-value .metric-unit {
  margin-left: 4px;
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
}
.metric--primary .metric-value { color: var(--color-primary); }
.metric-label {
  font-size: var(--text-sm);
  letter-spacing: .14em;
  color: var(--color-ink-soft);
}
.band--contrast .metric-value { color: var(--color-contrast-ink); }
.band--contrast .metric-label { color: color-mix(in srgb, var(--color-contrast-ink) 66%, var(--color-contrast-surface)); }

.scale-track {
  display: flex;
  align-items: stretch;
  gap: var(--space-2);
  margin: 0;
  padding: var(--space-3) 0 0;
  border-top: var(--border-thin) solid var(--color-line);
  list-style: none;
}
.scale-item {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  padding-top: var(--space-3);
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.scale-item::before {
  content: "";
  position: absolute;
  top: calc(-1 * var(--space-3) - 4px);
  left: 0;
  width: 8px;
  height: 8px;
  border: var(--border-thin) solid var(--color-accent);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
}
.scale-item[data-state="current"] { color: var(--color-ink); }
.scale-item[data-state="current"]::before { background-color: var(--color-primary); }
.band--contrast .scale-track { border-top-color: var(--color-contrast-line); }
.band--contrast .scale-item { color: color-mix(in srgb, var(--color-contrast-ink) 68%, var(--color-contrast-surface)); }
.band--contrast .scale-item::before {
  border-color: var(--color-contrast-accent);
  background-color: var(--color-contrast-surface);
}
.band--contrast .scale-item[data-state="current"] { color: var(--color-contrast-ink); }
.band--contrast .scale-item[data-state="current"]::before { background-color: var(--color-contrast-accent); }

.range-bar {
  position: relative;
  height: 6px;
  background-color: var(--color-surface-deep);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.range-bar > span {
  position: absolute;
  top: 0;
  bottom: 0;
  background-color: var(--color-accent);
}
.band--contrast .range-bar { background-color: var(--color-contrast-line); }

/* ==========================================================================
   10 · 对照表
   ========================================================================== */
.data-table { font-size: var(--text-sm); }
.data-table caption {
  margin-bottom: var(--space-2);
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .18em;
  color: var(--color-ink-soft);
}
.data-table th, .data-table td {
  padding: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  text-align: left;
  vertical-align: top;
}
.data-table thead th {
  background-color: var(--color-surface-deep);
  font-weight: var(--weight-heading);
  letter-spacing: .1em;
}
.data-table tbody tr:hover { background-color: var(--color-surface-alt); }
.data-table .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
}
.band--contrast .data-table th,
.band--contrast .data-table td { border-bottom-color: var(--color-contrast-line); }
.band--contrast .data-table thead th { background-color: color-mix(in srgb, var(--color-contrast-line) 55%, var(--color-contrast-surface)); }
.band--contrast .data-table tbody tr:hover { background-color: color-mix(in srgb, var(--color-contrast-line) 30%, var(--color-contrast-surface)); }

/* ==========================================================================
   11 · 图片容器（叠色 / 反白注记）
   ========================================================================== */
.media-figure { margin: 0 0 var(--space-3); }
.media-frame {
  position: relative;
  overflow: hidden;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-deep);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 5px;
  z-index: 3;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-ink) 14%, transparent);
  pointer-events: none;
}
.media-frame img,
.media-frame .media-placeholder {
  position: relative;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media-frame[data-ratio="21x9"] { aspect-ratio: 21 / 9; }
.media-frame[data-ratio="16x9"] { aspect-ratio: 16 / 9; }
.media-frame[data-ratio="4x3"] { aspect-ratio: 4 / 3; }
.media-frame[data-ratio="1x1"] { aspect-ratio: 1 / 1; }
.media-frame--duotone::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image: linear-gradient(140deg,
    color-mix(in srgb, var(--color-primary) 42%, transparent),
    color-mix(in srgb, var(--color-accent) 30%, transparent));
  pointer-events: none;
}
.media-frame--duotone img {
  filter: grayscale(1) contrast(1.06);
  mix-blend-mode: multiply;
  opacity: .84;
}
.media-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 4;
  margin: 0;
  padding: var(--space-3);
  background-image: var(--overlay-scrim);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.7;
}
.media-caption .u-mono { color: var(--color-contrast-accent); }
.media-placeholder {
  display: grid;
  place-items: center;
  padding: var(--space-6) var(--space-3);
  background-image: repeating-linear-gradient(135deg,
    color-mix(in srgb, var(--color-line) 60%, transparent) 0 1px,
    transparent 1px 14px);
  color: var(--color-ink-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .18em;
  text-align: center;
}
.media-figure figcaption {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.band--contrast .media-frame { border-color: var(--color-contrast-line); background-color: var(--color-contrast-surface); }
.band--contrast .media-figure figcaption { color: color-mix(in srgb, var(--color-contrast-ink) 62%, var(--color-contrast-surface)); }

/* ==========================================================================
   12 · 面包屑、正文栏与封面字号
   ========================================================================== */
.breadcrumb-wrap { border-bottom: 3px double var(--color-line); }
.breadcrumb {
  font-size: var(--text-xs);
  letter-spacing: .12em;
  color: var(--color-ink-soft);
  padding-block: var(--space-2);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
}
.breadcrumb li { margin: 0; }
.breadcrumb li + li::before {
  content: "／";
  margin-inline: var(--space-1);
  color: var(--color-ink-muted);
}
.breadcrumb a { color: var(--color-ink-soft); }
.breadcrumb [aria-current="page"] { color: var(--color-ink); }

.prose { max-width: var(--measure); }
.prose h2 { font-size: var(--text-xl); margin-top: var(--space-6); }
.prose h3 { font-size: var(--text-lg); margin-top: var(--space-4); }
.prose ul li, .prose ol li { margin-bottom: var(--space-1); }
.prose > * + * { margin-top: var(--space-3); }

.lede {
  font-size: var(--text-lg);
  line-height: 1.7;
  color: var(--color-ink-soft);
  max-width: 60ch;
}
.display-title {
  font-size: var(--text-display);
  line-height: 1.08;
  letter-spacing: -0.005em;
  margin: 0;
}

/* ==========================================================================
   13 · 动效（可关闭）
   ========================================================================== */
@keyframes bm-rise {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}
[data-reveal] { opacity: 1; }
[data-reveal].is-revealed { animation: bm-rise 260ms ease both; }

/* ==========================================================================
   14 · 响应式
   ========================================================================== */
@media (max-width: 1024px) {
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 { grid-column: span 6; }
  .footer-top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-top > * + * { border-left: 0; padding-left: 0; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 880px) {
  .nav-toggle { display: inline-flex; }
  .header-inner { flex-wrap: wrap; }
  .header-utility {
    order: 3;
    flex-basis: 100%;
    justify-content: flex-start;
    padding-top: var(--space-1);
    border-top: var(--border-thin) solid var(--color-line);
  }
  .site-nav { display: none; }
  .site-nav[data-open] { display: block; }
  .nav-inner { flex-direction: column; padding-block: var(--space-2); }
  .nav-list { flex-direction: column; gap: 0; }
  .nav-list li + li { border-top: var(--border-thin) dashed var(--color-line); }
  .nav-list a { display: block; padding: var(--space-2) var(--space-2); letter-spacing: .12em; }
  .nav-list a::after { display: none; }
  .nav-list a:hover, .nav-list a:focus-visible { background-color: var(--color-surface-alt); color: var(--color-focus); }
  .nav-list a[aria-current="page"] { color: var(--color-primary); background-color: var(--color-primary-soft); }
  .nav-note { display: none; }
  .header-rule { height: 2px; background-size: 22px 100%; }
  .section { padding-block: var(--space-6); }
  .section--major { padding-block: var(--space-8); }
  .scale-track { flex-direction: column; padding-top: var(--space-2); }
  .scale-item { padding-top: 0; padding-left: var(--space-3); }
  .scale-item::before { top: 6px; left: 0; }
  .footer-inner { padding-block: var(--space-6) var(--space-4); }
}
@media (max-width: 700px) {
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-12 { grid-column: span 12; }
  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-brand { grid-column: auto; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .breadcrumb { font-size: var(--text-xs); }
}

/* ==========================================================================
   15 · 减少动态效果
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  [data-reveal] { opacity: 1; }
  [data-reveal].is-revealed { animation: none; }
  .read-progress-bar { transition: none; }
}