/* ==========================================================================
   365 平台 · 共享站点样式  /assets/site.css
   档案库隐喻 / 非对称编辑部版式 / 双产品线色彩分区
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 104px;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd, ul, ol {
  margin: 0;
}

ul, ol { padding: 0; list-style: none; }

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

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

button { background: none; border: 0; padding: 0; cursor: pointer; }

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

table { border-collapse: collapse; width: 100%; }

/* ---------------------------------------------------------------
   2. 设计令牌
   --------------------------------------------------------------- */
:root {
  --c-navy: #0E1B33;
  --c-ink: #060B14;
  --c-silver: #C7CDD6;
  --c-paper: #F2F4F7;
  --c-copper: #C4672C;
  --c-copper-lit: #E3A768;
  --c-copper-deep: #B4571F;
  --c-ice: #4FA8CE;
  --c-ice-lit: #8FD8EA;
  --c-mint: #63CDAA;
  --c-cyan: #2EE0C8;
  --c-numeral: #7A8699;

  --c-link: #1B5E7E;
  --c-link-hover: #0B2C3D;

  --grad-copper: linear-gradient(120deg, #E3A768 0%, #B4571F 100%);
  --grad-ice: linear-gradient(120deg, #8FD8EA 0%, #4FA8CE 100%);

  --ff-display: 'Oswald', 'Archivo Narrow', 'Noto Sans SC', sans-serif;
  --ff-serif: 'Noto Serif SC', 'Source Han Serif SC', Georgia, 'Songti SC', serif;
  --ff-body: 'Inter', 'Noto Sans SC', system-ui, -apple-system, 'PingFang SC', sans-serif;
  --ff-mono: 'JetBrains Mono', 'Roboto Mono', ui-monospace, 'Courier New', monospace;

  --w-max: 1440px;
  --gutter: clamp(20px, 4.6vw, 72px);
  --header-h: 88px;
  --header-h-sm: 64px;

  --ease: cubic-bezier(.22, .61, .36, 1);

  --line: rgba(14, 27, 51, .12);
  --line-dark: rgba(199, 205, 214, .16);
  --line-darker: rgba(199, 205, 214, .08);
}

/* ---------------------------------------------------------------
   3. 基础排版
   --------------------------------------------------------------- */
body {
  background: var(--c-paper);
  color: var(--c-navy);
  font-family: var(--ff-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--ff-display);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -.005em;
  color: var(--c-navy);
}

h1 { font-size: clamp(34px, 5.2vw, 64px); }
h2 { font-size: clamp(26px, 3.4vw, 44px); }
h3 { font-size: clamp(20px, 2.2vw, 32px); }
h4 { font-size: clamp(17px, 1.5vw, 21px); }

.serif-display {
  font-family: var(--ff-serif);
  font-weight: 700;
  letter-spacing: .01em;
}

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

strong { font-weight: 600; }

a {
  color: var(--c-link);
  transition: color .2s var(--ease);
}
a:hover { color: var(--c-link-hover); }

::selection {
  background: rgba(46, 224, 200, .3);
  color: var(--c-ink);
}

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

/* ---------------------------------------------------------------
   4. 布局容器与网格
   --------------------------------------------------------------- */
.wrap {
  width: min(100%, var(--w-max));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap-narrow {
  width: min(100%, 46em);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid { display: grid; gap: 24px; }
.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)); }

/* ---------------------------------------------------------------
   5. 通用元件
   --------------------------------------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-numeral);
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.numeral-bar {
  display: inline-block;
  padding: 4px 10px 4px 9px;
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: .08em;
  line-height: 1.5;
  color: var(--c-navy);
  background: rgba(199, 205, 214, .42);
  border-left: 3px solid var(--c-copper);
  white-space: nowrap;
}
.numeral-bar--ice { border-left-color: var(--c-ice); }
.numeral-bar--mint { border-left-color: var(--c-mint); }

.card-num {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 8px;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--c-numeral);
  background: rgba(199, 205, 214, .28);
}

.line-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  vertical-align: middle;
  flex: none;
}
.line-dot--kitchen { background: var(--c-copper); }
.line-dot--clean { background: var(--c-ice); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 24px;
  font-family: var(--ff-display);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 3px;
  cursor: pointer;
  transition: background .24s var(--ease), color .24s var(--ease),
              border-color .24s var(--ease), transform .24s var(--ease);
}
.btn-primary {
  background: var(--c-copper);
  color: #fff;
  border-color: var(--c-copper);
}
.btn-primary:hover {
  background: var(--grad-copper);
  border-color: transparent;
  color: var(--c-ink);
  transform: translateY(-2px);
}
.btn-ghost {
  background: transparent;
  color: var(--c-navy);
  border-color: rgba(14, 27, 51, .28);
}
.btn-ghost:hover {
  background: var(--c-navy);
  border-color: var(--c-navy);
  color: var(--c-paper);
}

/* 章节头：大标题 + 窄栏注释 */
.section-head {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: 18px 48px;
  align-items: end;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}
.section-head h2 { margin: 0; }
.section-note {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--c-numeral);
  max-width: 26em;
}

/* 面包屑 */
.breadcrumb {
  font-family: var(--ff-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--c-numeral);
  padding-block: 18px 0;
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 0;
}
.breadcrumb li { display: inline-flex; align-items: center; }
.breadcrumb li + li::before {
  content: "/";
  margin: 0 10px;
  color: rgba(122, 134, 153, .55);
}
.breadcrumb a { color: inherit; }
.breadcrumb a:hover { color: var(--c-link); text-decoration: underline; text-underline-offset: 3px; }
.breadcrumb [aria-current="page"] { color: var(--c-navy); }

/* 长文阅读区 */
.prose {
  max-width: 42em;
  font-size: 17px;
  line-height: 1.78;
}
.prose p { margin-bottom: 1.4em; }
.prose h2 { margin: 2.2em 0 .7em; }
.prose h3 { margin: 1.8em 0 .6em; }
.prose ul,
.prose ol { margin: 0 0 1.4em; padding-left: 1.3em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li { margin-bottom: .5em; }
.prose blockquote {
  margin: 1.6em 0;
  padding: 2px 0 2px 20px;
  border-left: 3px solid var(--c-copper);
  font-family: var(--ff-serif);
  font-size: 19px;
  color: #253koš;
  color: #253550;
}

/* 档案卡 */
.archive-card {
  position: relative;
  padding: 22px 22px 26px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 2px;
  box-shadow: 0 1px 0 rgba(14, 27, 51, .04);
  transition: transform .3s var(--ease), border-color .3s var(--ease),
              box-shadow .3s var(--ease);
}
.archive-card::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 24px;
  height: 24px;
  background: linear-gradient(45deg, transparent 50%, rgba(14, 27, 51, .07) 50%);
  pointer-events: none;
}
.archive-card:hover {
  transform: translateY(-3px);
  border-color: rgba(79, 168, 206, .42);
  box-shadow: 0 16px 34px -22px rgba(14, 27, 51, .5);
}
.archive-card--kitchen { border-top: 3px solid var(--c-copper); }
.archive-card--clean { border-top: 3px solid var(--c-ice); }

/* 图片容器基础规则 */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border-radius: 3px;
  background: linear-gradient(145deg, #13243F 0%, #0A1526 100%);
}
.media-frame::before {
  content: "";
  display: block;
  padding-top: var(--ratio, 62.5%);
}
.media-frame > img,
.media-frame > picture,
.media-frame > svg,
.media-frame > .media-placeholder {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { --ratio: 42%; }
.media-frame--square { --ratio: 100%; }
.media-frame--portrait { --ratio: 124%; }

.media-placeholder {
  display: grid;
  place-items: center;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: rgba(199, 205, 214, .5);
  text-align: center;
  padding: 12px;
  background-image: repeating-linear-gradient(
    135deg,
    rgba(199, 205, 214, .05) 0 8px,
    transparent 8px 16px
  );
}
.media-placeholder--copper {
  background-image: repeating-linear-gradient(
    135deg,
    rgba(196, 103, 44, .14) 0 8px,
    transparent 8px 16px
  );
  color: rgba(227, 167, 104, .72);
}

/* 滚动显现 */
.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .55s var(--ease), transform .55s var(--ease);
  will-change: opacity, transform;
}
.js-ready [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* 目录跟随高亮 */
[data-toc] a.is-active {
  color: var(--c-navy);
  border-color: var(--c-copper);
}

/* ---------------------------------------------------------------
   6. 页头
   --------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--c-navy);
  color: var(--c-paper);
  border-bottom: 1px solid var(--line-dark);
  isolation: isolate;
}

.skip-link {
  position: absolute;
  top: -80px;
  left: 16px;
  z-index: 999;
  padding: 11px 20px;
  background: var(--c-cyan);
  color: var(--c-ink);
  font-family: var(--ff-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  border-radius: 0 0 6px 6px;
  transition: top .22s var(--ease);
}
.skip-link:focus { top: 0; }

.header-inner {
  width: min(100%, var(--w-max));
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  transition: min-height .28s var(--ease);
}
.site-header.is-compact .header-inner { min-height: var(--header-h-sm); }

/* 品牌署名 */
.brand-signature {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
  text-decoration: none;
  color: inherit;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  flex: none;
  font-family: var(--ff-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--c-ink);
  background: var(--grad-copper);
  border-radius: 4px 14px 4px 14px;
  transition: border-radius .35s var(--ease);
}
.brand-signature:hover .brand-mark { border-radius: 14px 4px 14px 4px; }

.brand-text { display: block; min-width: 0; }
.brand-name {
  display: block;
  font-family: var(--ff-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .05em;
  line-height: 1.2;
  color: var(--c-paper);
  white-space: nowrap;
}
.brand-sub {
  display: block;
  margin-top: 3px;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--c-numeral);
  white-space: nowrap;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 9px 15px;
  color: var(--c-paper);
  background: transparent;
  border: 1px solid rgba(199, 205, 214, .3);
  border-radius: 999px;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .16em;
  transition: border-color .22s var(--ease), color .22s var(--ease);
}
.nav-toggle:hover { border-color: var(--c-cyan); color: var(--c-cyan); }
.nav-toggle-bars { display: grid; gap: 4px; width: 16px; flex: none; }
.nav-toggle-bars span {
  display: block;
  height: 1.5px;
  background: currentColor;
  border-radius: 2px;
  transition: transform .26s var(--ease), opacity .2s var(--ease);
}
.site-header[data-open="true"] .nav-toggle-bars span:nth-child(1) {
  transform: translateY(5.5px) rotate(45deg);
}
.site-header[data-open="true"] .nav-toggle-bars span:nth-child(2) { opacity: 0; }
.site-header[data-open="true"] .nav-toggle-bars span:nth-child(3) {
  transform: translateY(-5.5px) rotate(-45deg);
}
.nav-toggle-label { white-space: nowrap; }

/* 主导航 */
.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 2.2vw, 34px);
}
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(14px, 1.7vw, 28px);
}
.nav-link {
  position: relative;
  display: inline-block;
  padding: 6px 1px;
  font-size: 14px;
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--c-silver);
  white-space: nowrap;
  transition: color .2s var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .3s var(--ease);
}
.nav-link:hover { color: var(--c-cyan); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--c-paper); }
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--c-copper-lit);
  height: 2px;
}

/* 铜金描边主按钮 */
.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  font-family: var(--ff-display);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  white-space: nowrap;
  color: var(--c-copper-lit);
  background: linear-gradient(120deg, rgba(227, 167, 104, .14), rgba(180, 87, 31, .14));
  border: 1px solid var(--c-copper);
  border-radius: 999px;
  transition: background .26s var(--ease), color .26s var(--ease),
              border-color .26s var(--ease);
}
.btn-cta:hover {
  background: var(--grad-copper);
  border-color: transparent;
  color: var(--c-ink);
}

/* 阅读进度条 */
.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(199, 205, 214, .12);
  pointer-events: none;
  z-index: 1;
}
.scroll-meter-fill {
  display: block;
  width: 0;
  height: 100%;
  background: var(--grad-copper);
}

/* ---------------------------------------------------------------
   7. 页脚
   --------------------------------------------------------------- */
.site-footer {
  position: relative;
  background: var(--c-ink);
  color: var(--c-silver);
  border-top: 1px solid var(--line-dark);
}

.footer-top {
  width: min(100%, var(--w-max));
  margin-inline: auto;
  padding: clamp(46px, 6vw, 84px) var(--gutter) clamp(26px, 3.2vw, 44px);
  display: grid;
  grid-template-columns: minmax(0, 250px) minmax(0, 1fr);
  gap: 40px 60px;
}

.footer-sign-name {
  font-family: var(--ff-display);
  font-size: clamp(24px, 2.4vw, 30px);
  font-weight: 600;
  letter-spacing: .05em;
  line-height: 1.1;
  color: var(--c-paper);
}
.footer-sign-sub {
  margin-top: 10px;
  font-size: 13.5px;
  letter-spacing: .05em;
  color: var(--c-ice-lit);
}
.footer-sign-mono {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-darker);
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--c-numeral);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 32px 24px;
}

.footer-col-title {
  margin: 0 0 14px;
  font-family: var(--ff-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--c-silver);
}
.footer-col-title a {
  color: inherit;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}
.footer-col-title a:hover {
  color: var(--c-cyan);
  border-bottom-color: var(--c-cyan);
}

.footer-col-line {
  margin: 0 0 7px;
  font-size: 13px;
  line-height: 1.68;
  color: #98A4B6;
}
.footer-mono {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: .01em;
  color: #A9B5C6;
  word-break: break-word;
}

/* 年份刻度线 */
.footer-ruler {
  width: min(100%, var(--w-max));
  margin-inline: auto;
  padding: 0 var(--gutter);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2px;
  min-height: 46px;
}
.ruler-tick {
  position: relative;
  padding-top: 20px;
  font-family: var(--ff-mono);
  font-size: 10px;
  letter-spacing: .04em;
  color: rgba(122, 134, 153, .72);
  transition: color .3s var(--ease), opacity .45s var(--ease),
              transform .45s var(--ease);
}
.ruler-tick::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  width: 1px;
  height: 9px;
  background: rgba(199, 205, 214, .26);
  transform: translateX(-50%);
  transition: height .3s var(--ease), background .3s var(--ease);
}
.footer-ruler.js-ready .ruler-tick {
  opacity: 0;
  transform: translateY(8px);
}
.footer-ruler.js-ready .ruler-tick.is-visible {
  opacity: 1;
  transform: none;
}
.ruler-tick.is-current { color: var(--c-cyan); }
.ruler-tick.is-current::before {
  height: 15px;
  background: var(--c-cyan);
  box-shadow: 0 0 0 3px rgba(46, 224, 200, .14);
}

.footer-base {
  width: min(100%, var(--w-max));
  margin-inline: auto;
  padding: 22px var(--gutter) clamp(26px, 3vw, 38px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 36px;
  border-top: 1px solid var(--line-darker);
}

.footer-legal {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--c-numeral);
}
.footer-legal a {
  color: #A9B5C6;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(199, 205, 214, .3);
}
.footer-legal a:hover { color: var(--c-cyan); }

.footer-copy {
  margin: 0;
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: rgba(122, 134, 153, .85);
}

.footer-anchors {
  display: flex;
  align-items: baseline;
  gap: 18px;
}
.anchor-num {
  font-family: var(--ff-display);
  font-size: clamp(34px, 3.6vw, 46px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--c-paper);
}
.anchor-range {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-numeral);
}

/* ---------------------------------------------------------------
   8. 返回顶部
   --------------------------------------------------------------- */
.to-top {
  position: fixed;
  right: clamp(16px, 3vw, 34px);
  bottom: clamp(16px, 3vw, 34px);
  z-index: 150;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  border: 1px solid rgba(46, 224, 200, .5);
  background: rgba(6, 11, 20, .88);
  color: var(--c-cyan);
  font-family: var(--ff-mono);
  font-size: 15px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .3s var(--ease), transform .3s var(--ease),
              visibility .3s var(--ease), border-color .24s var(--ease);
}
.to-top.is-on {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.to-top:hover { border-color: var(--c-cyan); background: rgba(46, 224, 200, .12); }

/* ---------------------------------------------------------------
   9. 响应式
   --------------------------------------------------------------- */
@media (max-width: 1180px) {
  .brand-name { font-size: 14px; }
  .nav-link { font-size: 13.5px; }
}

@media (max-width: 980px) {
  :root { --header-h: 72px; }

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

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 3;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px var(--gutter) 28px;
    background: var(--c-ink);
    border-bottom: 1px solid var(--line-dark);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }
  .site-header[data-open="true"] .site-nav {
    display: flex;
    animation: navDrop .28s var(--ease) both;
  }
  @keyframes navDrop {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: none; }
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding-bottom: 16px;
  }
  .nav-list li { border-bottom: 1px solid var(--line-darker); }
  .nav-link {
    display: block;
    padding: 15px 2px;
    font-size: 16px;
    color: var(--c-silver);
  }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] {
    color: var(--c-cyan);
    padding-left: 14px;
    box-shadow: inset 3px 0 0 var(--c-copper-lit);
  }
  .nav-link[aria-current="page"]::after { display: none; }

  .btn-cta { align-self: flex-start; margin-top: 20px; padding: 12px 26px; }

  .footer-top { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .footer-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }

  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 84px; }
  body { font-size: 16px; }

  .brand-name { white-space: normal; font-size: 13px; letter-spacing: .03em; }
  .brand-sub { font-size: 10px; letter-spacing: .1em; }
  .brand-mark { width: 38px; height: 38px; font-size: 14px; }

  .section-head { grid-template-columns: minmax(0, 1fr); gap: 12px; }
  .section-note { max-width: none; }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px 20px; }
  .footer-base { flex-direction: column; align-items: flex-start; gap: 14px; }
  .footer-anchors { gap: 14px; }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: minmax(0, 1fr); }

  .ruler-tick { font-size: 9px; }
  .ruler-tick:nth-child(even) { display: none; }
}

@media (max-width: 480px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .anchor-num { font-size: 34px; }
  .nav-toggle-label { display: none; }
}

/* ---------------------------------------------------------------
   10. 动效降级
   --------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

  .js-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .footer-ruler.js-ready .ruler-tick {
    opacity: 1;
    transform: none;
  }
  .scroll-meter-fill { transition: none !important; }
}