/* ============================================================
   壹号官网 · 共享站点样式 /assets/site.css
   设计基调：可追溯版本档案室 · 墨蓝底 + 铜橙 / 琥珀点线
   ============================================================ */

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

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

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

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

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

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

a { color: inherit; }

[hidden] { display: none !important; }

:where([id]) { scroll-margin-top: 96px; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink-900: #081725;
  --ink-800: #061320;
  --ink-700: #102B42;
  --steel: #4A6073;
  --mist: #D9E2E8;
  --paper: #F5F1E8;
  --copper: #A9532F;
  --amber: #D7A64A;
  --wine: #6E3445;
  --build: #15453F;
  --interactive: #274C5E;

  --line: rgba(217, 226, 232, .16);
  --line-strong: rgba(217, 226, 232, .3);
  --line-amber: rgba(215, 166, 74, .42);

  --gutter: clamp(1.05rem, 3.6vw, 3rem);
  --w-max: 1240px;
  --radius: 18px;
  --radius-sm: 10px;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--ink-900);
  background-image:
    radial-gradient(90% 60% at 88% -8%, rgba(169, 83, 47, .16), transparent 62%),
    radial-gradient(80% 60% at 4% 4%, rgba(21, 69, 63, .22), transparent 58%);
  background-repeat: no-repeat;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: clamp(1rem, .96rem + .17vw, 1.0625rem);
  line-height: 1.82;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .06em;
  font-stretch: 88%;
  text-wrap: balance;
}

h1 { font-size: clamp(2rem, 4.6vw, 3.4rem); letter-spacing: .05em; }
h2 { font-size: clamp(1.5rem, 2.8vw, 2.35rem); }
h3 { font-size: clamp(1.12rem, 1.7vw, 1.42rem); letter-spacing: .05em; }

p { text-wrap: pretty; }

::selection { background: var(--amber); color: var(--ink-900); }

/* ---------- 4. 焦点与可达性 ---------- */
:where(a, button, [tabindex]):focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  top: .55rem;
  left: .55rem;
  z-index: 200;
  padding: .62rem 1.1rem;
  border-radius: 999px;
  background: var(--amber);
  color: var(--ink-900);
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .1em;
  text-decoration: none;
  transform: translateY(-220%);
  transition: transform .2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

/* ---------- 5. 布局工具 ---------- */
.wrap {
  width: min(100% - 2 * var(--gutter), var(--w-max));
  margin-inline: auto;
}

.band {
  padding-block: clamp(2.6rem, 6vw, 5.4rem);
}

.band--paper { background: var(--paper); color: #0E1F2E; }
.band--mist { background: var(--mist); color: #0B1F31; }
.band--build { background: var(--build); color: var(--paper); }
.band--wine { background: var(--wine); color: var(--paper); }
.band--harbor { background: var(--ink-700); color: var(--paper); }

.band--paper .archive-note,
.band--mist .archive-note {
  color: rgba(14, 31, 46, .82);
  border-left-color: var(--copper);
}

/* ---------- 6. 文字零件 ---------- */
.mono {
  font-family: var(--font-mono);
  letter-spacing: .08em;
  font-variant-numeric: tabular-nums;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--amber);
}

.eyebrow::before {
  content: "";
  width: 40px;
  height: 1px;
  background: currentColor;
  opacity: .72;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .26rem .7rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: transparent;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  line-height: 1.6;
}

.chip--copper { border-color: rgba(169, 83, 47, .62); color: #E8B69D; }
.chip--amber { border-color: var(--line-amber); color: var(--amber); }

.archive-note {
  padding: .15rem 0 .15rem 1rem;
  border-left: 2px solid var(--amber);
  font-size: .92rem;
  line-height: 1.8;
  color: rgba(217, 226, 232, .8);
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .74rem 1.2rem;
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--copper);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: .92rem;
  letter-spacing: .07em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .2s ease, box-shadow .24s ease, background-color .2s ease, border-color .2s ease, color .2s ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 30px -20px rgba(169, 83, 47, .95);
}

.btn:active { transform: translateY(0); }

.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--paper);
}

.btn--ghost:hover {
  border-color: var(--amber);
  color: var(--amber);
  box-shadow: none;
}

.btn--amber {
  background: var(--amber);
  color: var(--ink-900);
}

.btn--amber:hover {
  box-shadow: 0 16px 30px -20px rgba(215, 166, 74, .95);
}

/* ---------- 8. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  color: var(--paper);
  background-color: rgba(8, 23, 37, .62);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(14px) saturate(1.12);
  backdrop-filter: blur(14px) saturate(1.12);
  transition: background-color .28s ease, border-color .28s ease, box-shadow .28s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background-image: repeating-linear-gradient(90deg, rgba(215, 166, 74, .55) 0 1px, transparent 1px 46px);
  opacity: .55;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}

.site-header[data-stuck="true"] {
  background-color: rgba(8, 23, 37, .97);
  border-bottom-color: rgba(217, 226, 232, .2);
  box-shadow: 0 22px 44px -32px rgba(0, 0, 0, .95);
}

.header-bar {
  width: min(100% - 2 * var(--gutter), var(--w-max));
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: clamp(.6rem, 1.8vw, 1.6rem);
  min-height: 76px;
  padding-block: .5rem;
}

/* 品牌锁定 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: .72rem;
  flex: 0 0 auto;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line-amber);
  border-radius: 13px;
  background: linear-gradient(150deg, rgba(169, 83, 47, .34), rgba(21, 69, 63, .34));
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .06em;
  transition: border-color .22s ease, color .22s ease;
}

.brand:hover .brand-mark {
  border-color: var(--amber);
  color: var(--paper);
}

.brand-text {
  display: inline-flex;
  flex-direction: column;
  gap: .1rem;
  line-height: 1.16;
}

.brand-eyebrow {
  font-family: var(--font-mono);
  font-size: .6rem;
  letter-spacing: .2em;
  color: rgba(217, 226, 232, .6);
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: .17em;
  color: var(--paper);
}

/* 主导航 */
.site-nav {
  margin-inline-start: clamp(.8rem, 3.4vw, 3.2rem);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(.35rem, 1.3vw, 1.4rem);
  counter-reset: nav;
}

.nav-list li { counter-increment: nav; }

.nav-list a {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .42rem;
  padding: .55rem .12rem;
  color: rgba(245, 241, 232, .78);
  font-size: .9rem;
  letter-spacing: .04em;
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s ease;
}

.nav-list a::before {
  content: counter(nav, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .06em;
  color: var(--steel);
  transition: color .2s ease;
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: .16rem;
  height: 1px;
  background: var(--copper);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .24s ease;
}

.nav-list a:hover { color: var(--paper); }
.nav-list a:hover::after { transform: scaleX(1); }

.nav-list a[aria-current="page"] {
  color: var(--amber);
}

.nav-list a[aria-current="page"]::before {
  color: var(--amber);
}

.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--amber);
}

/* 页头工具区 */
.header-tools {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-inline-start: auto;
  flex: 0 0 auto;
}

.index-toggle {
  display: none;
  align-items: center;
  gap: .4rem;
  padding: .44rem .95rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--paper);
  font-size: .82rem;
  letter-spacing: .1em;
  cursor: pointer;
  transition: border-color .2s ease, color .2s ease, background-color .2s ease;
}

.index-toggle:hover,
.index-toggle[aria-expanded="true"] {
  border-color: var(--amber);
  color: var(--amber);
  background: rgba(215, 166, 74, .08);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .5rem .9rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--paper);
  font-size: .8rem;
  letter-spacing: .12em;
  cursor: pointer;
  transition: border-color .2s ease, color .2s ease;
}

.nav-toggle:hover,
.site-header[data-open] .nav-toggle {
  border-color: var(--amber);
  color: var(--amber);
}

.nav-toggle__bars {
  display: inline-grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .24s ease, opacity .2s ease;
}

.site-header[data-open] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(5.5px) rotate(45deg);
}

.site-header[data-open] .nav-toggle__bars span:nth-child(2) {
  opacity: 0;
}

.site-header[data-open] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5.5px) rotate(-45deg);
}

.nav-toggle__text { line-height: 1; }

/* 目录面板 */
.index-panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--ink-800);
  border-bottom: 1px solid var(--line-amber);
  box-shadow: 0 46px 76px -44px rgba(0, 0, 0, .96);
}

.index-panel__inner {
  width: min(100% - 2 * var(--gutter), var(--w-max));
  margin-inline: auto;
  padding: clamp(1.1rem, 2.4vw, 2rem) 0 clamp(1.3rem, 2.8vw, 2.2rem);
}

.index-panel__title {
  margin-bottom: 1rem;
  font-size: .7rem;
  letter-spacing: .26em;
  text-transform: uppercase;
  color: var(--amber);
}

.index-list {
  display: grid;
  gap: .3rem;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.index-list a {
  display: flex;
  align-items: baseline;
  gap: .7rem;
  padding: .62rem .2rem;
  border-bottom: 1px solid rgba(217, 226, 232, .09);
  color: rgba(245, 241, 232, .84);
  font-size: .92rem;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.index-list a:hover {
  color: var(--amber);
  border-bottom-color: var(--line-amber);
}

.index-list__num {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .06em;
  color: var(--steel);
}

/* ---------- 9. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(3rem, 7vw, 6rem);
  padding-block: clamp(2.6rem, 5.4vw, 4.6rem) 1.4rem;
  color: var(--paper);
  background-color: var(--ink-800);
  background-image:
    radial-gradient(120% 90% at 10% 0%, rgba(21, 69, 63, .36), transparent 58%),
    radial-gradient(95% 80% at 92% 8%, rgba(169, 83, 47, .24), transparent 62%);
  background-repeat: no-repeat;
  border-top: 1px solid var(--line-amber);
}

.footer-seam {
  position: absolute;
  inset: 0 0 auto 0;
  height: 9px;
  background-image: repeating-linear-gradient(90deg, rgba(215, 166, 74, .5) 0 1px, transparent 1px 44px);
  opacity: .5;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 14%, #000 86%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 14%, #000 86%, transparent);
}

.footer-inner {
  width: min(100% - 2 * var(--gutter), var(--w-max));
  margin-inline: auto;
}

.footer-grid {
  display: grid;
  gap: clamp(1.8rem, 4vw, 3.4rem);
  grid-template-columns: 1.45fr 1fr 1.15fr;
}

.footer-brandline {
  max-width: 26ch;
  margin-bottom: .9rem;
  font-family: var(--font-display);
  font-size: clamp(1.08rem, 1.9vw, 1.4rem);
  font-weight: 700;
  line-height: 1.55;
  letter-spacing: .04em;
  color: var(--paper);
}

.footer-note {
  max-width: 34ch;
  font-size: .9rem;
  line-height: 1.85;
  color: rgba(217, 226, 232, .7);
}

.footer-heading {
  margin-bottom: .9rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--amber);
}

.footer-links {
  display: grid;
  gap: .5rem;
}

.footer-links a {
  display: inline-block;
  padding-bottom: 1px;
  border-bottom: 1px solid transparent;
  color: rgba(245, 241, 232, .76);
  font-size: .93rem;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--line-amber);
}

.footer-contact {
  display: grid;
  gap: .5rem;
  margin-top: 1.15rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.footer-contact__line {
  display: grid;
  grid-template-columns: 3.4em minmax(0, 1fr);
  gap: .6rem;
  font-size: .84rem;
  line-height: 1.72;
  color: rgba(217, 226, 232, .78);
  word-break: break-word;
}

.footer-contact__key {
  padding-top: .2em;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .14em;
  color: var(--amber);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .5rem 1.6rem;
  margin-top: clamp(1.9rem, 4vw, 3rem);
  padding-top: 1.05rem;
  border-top: 1px solid rgba(217, 226, 232, .12);
}

.footer-bottom__meta {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .06em;
  color: rgba(217, 226, 232, .58);
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  padding-block: .9rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .1em;
  color: rgba(217, 226, 232, .62);
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--steel);
}

.breadcrumb a {
  text-decoration: none;
  color: inherit;
  transition: color .2s ease;
}

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

/* ---------- 11. 长文 ---------- */
.prose {
  max-width: 38rem;
  font-size: clamp(1rem, .97rem + .12vw, 1.06rem);
  line-height: 1.9;
}

.prose p { margin-bottom: 1.15em; }
.prose p:last-child { margin-bottom: 0; }

.prose h2 {
  margin: 2.2em 0 .7em;
  font-size: clamp(1.3rem, 2.1vw, 1.8rem);
}

.prose h3 {
  margin: 1.8em 0 .55em;
}

.prose ul,
.prose ol {
  margin: 0 0 1.2em;
  padding-left: 1.3em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose li { margin-bottom: .45em; }

.prose a {
  color: var(--copper);
  text-decoration: underline;
  text-underline-offset: .2em;
}

.prose strong { color: var(--amber); }

.band--paper .prose a,
.band--mist .prose a { color: var(--copper); }

.band--paper .prose strong,
.band--mist .prose strong { color: #7A3A1F; }

/* ---------- 12. 图片容器基础 ---------- */
.media {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--ink-700);
  background-image:
    linear-gradient(150deg, rgba(16, 43, 66, .95), rgba(8, 23, 37, .95) 58%, rgba(21, 69, 63, .9)),
    repeating-linear-gradient(45deg, rgba(217, 226, 232, .06) 0 1px, transparent 1px 16px);
  background-blend-mode: normal, screen;
}

.media::after {
  content: "";
  position: absolute;
  inset: auto -20% -55% auto;
  width: 60%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(215, 166, 74, .22), transparent 68%);
  pointer-events: none;
}

.media > img,
.media > svg {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--wide { aspect-ratio: 16 / 9; }
.media--portrait { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

.media__tag {
  position: absolute;
  z-index: 2;
  top: .85rem;
  left: .85rem;
  padding: .22rem .6rem;
  border: 1px solid var(--line-amber);
  border-radius: 999px;
  background: rgba(8, 23, 37, .78);
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .12em;
}

.media__caption {
  position: absolute;
  z-index: 2;
  right: .9rem;
  bottom: .7rem;
  left: .9rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  color: rgba(245, 241, 232, .72);
}

/* ---------- 13. 章节目录跟随 ---------- */
.toc-link {
  display: block;
  padding: .42rem .2rem .42rem .9rem;
  border-left: 1px solid var(--line);
  color: rgba(245, 241, 232, .7);
  font-size: .86rem;
  line-height: 1.6;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease, padding-left .2s ease;
}

.toc-link:hover { color: var(--paper); }

.toc-link.is-active,
.toc-link[aria-current="location"] {
  padding-left: 1.15rem;
  border-left-color: var(--amber);
  color: var(--amber);
}

.band--paper .toc-link,
.band--mist .toc-link {
  color: rgba(14, 31, 46, .7);
  border-left-color: rgba(14, 31, 46, .18);
}

.band--paper .toc-link.is-active,
.band--mist .toc-link.is-active {
  color: var(--copper);
  border-left-color: var(--copper);
}

/* ---------- 14. 渐显与返回顶部 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .48s ease, transform .48s ease;
}

html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

.to-top {
  position: fixed;
  right: clamp(.85rem, 2.6vw, 2rem);
  bottom: clamp(.9rem, 3vw, 2.1rem);
  z-index: 70;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border: 1px solid var(--line-amber);
  border-radius: 50%;
  background: rgba(6, 19, 32, .92);
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: opacity .24s ease, transform .24s ease, visibility .24s ease, background-color .2s ease;
}

.to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover {
  background: var(--interactive);
  color: var(--paper);
}

/* ---------- 15. 响应式 ---------- */
@media (min-width: 1080px) {
  .index-toggle { display: inline-flex; }
}

@media (max-width: 1180px) {
  .nav-list a::before { display: none; }
  .nav-list a { font-size: .85rem; }
}

@media (max-width: 960px) {
  .header-bar {
    min-height: 64px;
    gap: .6rem;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
    border-radius: 11px;
    font-size: .68rem;
  }

  .brand-eyebrow { display: none; }
  .brand-name { font-size: .96rem; letter-spacing: .14em; }

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

  .index-toggle { display: none; }
  .index-panel { display: none; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    max-height: calc(100dvh - 66px);
    overflow-y: auto;
    margin-inline-start: 0;
    padding: .5rem var(--gutter) 1.5rem;
    background: #0A1C2C;
    border-bottom: 1px solid var(--line-amber);
    box-shadow: 0 34px 64px -36px rgba(0, 0, 0, .96);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-10px);
    transition: opacity .24s ease, transform .24s ease, visibility .24s;
  }

  .site-header[data-open] .site-nav {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-list {
    display: block;
    gap: 0;
  }

  .nav-list li + li {
    border-top: 1px solid rgba(217, 226, 232, .1);
  }

  .nav-list a {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
    padding: .95rem 0;
    font-size: 1rem;
    white-space: normal;
  }

  .nav-list a::before { display: inline; }
  .nav-list a::after { display: none; }

  .nav-list a[aria-current="page"] {
    padding-left: .6rem;
    box-shadow: inset 2px 0 0 var(--amber);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 620px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.7rem;
  }

  .footer-brand { grid-column: auto; }

  .footer-bottom {
    justify-content: flex-start;
    gap: .35rem 1.2rem;
  }

  .footer-bottom__meta { font-size: .72rem; }

  .to-top {
    width: 42px;
    height: 42px;
  }

  .btn { width: 100%; }
}

/* ---------- 16. 减弱动效 ---------- */
@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;
  }

  html.js [data-reveal] {
    opacity: 1;
    transform: none;
  }
}