/* ============================================================
   壹号官网 共享样式 /assets/site.css
   颜色：红土 / 孔雀绿 / 铜金 / 纸米 / 扫描青
   ============================================================ */

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

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

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

ul, ol { padding: 0; }

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

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

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

a { color: inherit; }

[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  --clay: #A6401F;
  --clay-deep: #6B2412;
  --clay-soft: #F0D8CB;
  --jade: #0E6B5C;
  --jade-deep: #094A40;
  --jade-soft: #CFE6DF;
  --brass: #C2893C;
  --brass-soft: #EFD9AE;
  --mist: #6C7076;
  --ink: #17181A;
  --paper: #F7F2E9;
  --paper-lift: #FCF8F1;
  --scan: #7FD1C1;

  --line-brass: rgba(194, 137, 60, .45);
  --line-soft: rgba(108, 112, 118, .22);

  --font-display: "HarmonyOS Sans SC Condensed", "Noto Sans SC Condensed", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --fs-h1: clamp(2rem, 4.4vw, 3.5rem);
  --fs-h2: clamp(1.5rem, 2.6vw, 2.125rem);
  --fs-h3: clamp(1.125rem, 1.6vw, 1.375rem);
  --fs-body: 1rem;
  --fs-note: 0.8125rem;
  --fs-index: clamp(3.25rem, 8vw, 6rem);

  --shell: 1440px;
  --gutter: clamp(16px, 3vw, 32px);
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.75;
  letter-spacing: .01em;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

main, #main-content { flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  color: var(--ink);
}

h1 { font-size: var(--fs-h1); line-height: 1.1; }
h2 { font-size: var(--fs-h2); line-height: 1.24; }
h3 { font-size: var(--fs-h3); line-height: 1.36; }

p { text-wrap: pretty; }

::selection {
  background: var(--clay-soft);
  color: var(--clay-deep);
}

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

.site-footer :focus-visible { outline-color: var(--scan); }

/* ---------- 4. 通用容器与排版件 ---------- */
.wrap {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.prose { max-width: 66ch; }

.prose > * + * { margin-top: 1.1em; }

.prose h2 {
  margin-top: 2.2em;
  padding-top: .6em;
  border-top: 1px solid var(--line-brass);
}

.prose h3 { margin-top: 1.8em; }

.prose ul, .prose ol { padding-left: 1.35em; }
.prose li + li { margin-top: .4em; }

.prose a {
  color: var(--jade);
  text-decoration: none;
  border-bottom: 1px solid rgba(14, 107, 92, .35);
  transition: color .2s ease, border-color .2s ease;
}

.prose a:hover {
  color: var(--jade-deep);
  border-bottom-color: var(--brass);
}

.prose blockquote {
  margin: 1.6em 0;
  padding: .9em 1.2em;
  border-left: 3px solid var(--jade);
  background: var(--jade-soft);
  color: var(--jade-deep);
}

.lede {
  font-size: clamp(1.05rem, 1.5vw, 1.22rem);
  line-height: 1.7;
  color: #34373b;
  max-width: 52ch;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .7em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--clay);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--brass);
}

.index-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-index);
  line-height: .9;
  letter-spacing: -.04em;
  color: rgba(166, 64, 31, .16);
  user-select: none;
}

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

.rule--jade { background: linear-gradient(90deg, var(--jade), transparent); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .5rem 1.4rem;
  padding-bottom: .9rem;
  border-bottom: 1px solid var(--line-brass);
  margin-bottom: clamp(24px, 3.4vw, 44px);
}

.section-head__no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--jade);
}

.section-head__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-h2);
  letter-spacing: -.02em;
  line-height: 1.2;
}

.section-head__note {
  margin-left: auto;
  max-width: 32ch;
  font-size: var(--fs-note);
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 5. 面包屑 ---------- */
.breadcrumb {
  padding-top: clamp(18px, 3vw, 30px);
  padding-bottom: clamp(10px, 1.6vw, 18px);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: .55em;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}

.breadcrumb__list li {
  display: flex;
  align-items: center;
  gap: .55em;
}

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

.breadcrumb__list a {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.breadcrumb__list a:hover {
  color: var(--clay);
  border-bottom-color: var(--brass);
}

/* ---------- 6. 网格 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 32px);
}

.col-rail { grid-column: 1 / span 2; }
.col-main { grid-column: 3 / span 7; }
.col-side { grid-column: 10 / span 3; }
.col-full { grid-column: 1 / -1; }

@media (max-width: 1024px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-rail, .col-main, .col-side, .col-full { grid-column: 1 / -1; }
}

/* ---------- 7. 按钮 / 标签 / 卡片 ---------- */
.btn {
  --btn-bg: var(--clay);
  --btn-fg: var(--paper);
  --btn-line: var(--clay-deep);
  --btn-shadow: rgba(194, 137, 60, .55);
  display: inline-flex;
  align-items: center;
  gap: .5em;
  padding: .78em 1.35em;
  border: 1px solid var(--btn-line);
  border-radius: 2px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: .02em;
  text-decoration: none;
  box-shadow: 3px 3px 0 var(--btn-shadow);
  transition: transform .2s ease, box-shadow .2s ease, background-color .2s ease, color .2s ease, border-color .2s ease;
}

.btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 5px 5px 0 var(--btn-shadow);
}

.btn:active {
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0 var(--btn-shadow);
}

.btn--clay {
  --btn-bg: var(--clay);
  --btn-fg: var(--paper);
  --btn-line: var(--clay-deep);
  --btn-shadow: rgba(107, 36, 18, .32);
}

.btn--jade {
  --btn-bg: var(--jade);
  --btn-fg: var(--paper);
  --btn-line: var(--jade-deep);
  --btn-shadow: rgba(14, 107, 92, .3);
}

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--clay-deep);
  --btn-line: var(--brass);
  --btn-shadow: rgba(194, 137, 60, .38);
}

.btn--ghost:hover {
  background: var(--brass-soft);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .45em;
  padding: .34em .7em;
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--paper-lift);
  color: var(--clay-deep);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  line-height: 1.5;
}

.tag--jade {
  border-color: rgba(14, 107, 92, .4);
  background: var(--jade-soft);
  color: var(--jade-deep);
}

.tag--brass {
  border-color: var(--brass);
  background: var(--brass-soft);
  color: #5A3D10;
}

.tag--solid {
  border-color: var(--clay-deep);
  background: var(--clay);
  color: var(--paper);
}

.card {
  padding: clamp(18px, 2.4vw, 30px);
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--paper-lift);
  box-shadow: 4px 4px 0 rgba(194, 137, 60, .16);
  transition: border-color .2s ease, box-shadow .2s ease;
}

.card:hover {
  border-color: var(--brass);
  box-shadow: 6px 6px 0 rgba(194, 137, 60, .24);
}

.card--jade {
  background: var(--jade-soft);
  border-color: rgba(14, 107, 92, .35);
  box-shadow: 4px 4px 0 rgba(14, 107, 92, .14);
}

.card--clay {
  background: var(--clay-soft);
  border-color: rgba(166, 64, 31, .3);
  box-shadow: 4px 4px 0 rgba(166, 64, 31, .16);
}

.aside-note {
  padding-left: 1rem;
  border-left: 2px solid var(--brass);
  font-size: var(--fs-note);
  line-height: 1.75;
  color: #4B4E53;
}

/* ---------- 8. 表格 / 折叠 ---------- */
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
}

.table caption {
  caption-side: top;
  text-align: left;
  padding-bottom: .7rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist);
}

.table th,
.table td {
  padding: .75rem .9rem;
  border-bottom: 1px solid var(--line-soft);
  text-align: left;
  vertical-align: top;
}

.table thead th {
  background: var(--jade-soft);
  color: var(--jade-deep);
  border-bottom: 1px solid rgba(14, 107, 92, .3);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  font-weight: 700;
}

.table tbody tr { transition: background-color .2s ease; }
.table tbody tr:hover { background: var(--clay-soft); }
.table tbody tr:hover td { border-bottom-color: var(--brass); }

.fold {
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--paper-lift);
  transition: border-color .2s ease;
}

.fold + .fold { margin-top: .6rem; }

.fold:hover { border-color: var(--brass); }

.fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.2rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  letter-spacing: -.01em;
  cursor: pointer;
  list-style: none;
}

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

.fold > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--brass);
}

.fold[open] > summary::after { content: "–"; }

.fold__body {
  padding: 0 1.2rem 1.2rem;
  font-size: 15px;
  line-height: 1.75;
  color: #3B3E43;
}

/* ---------- 9. 媒体容器（页面阶段放图） ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--clay-soft);
}

.media__inner {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 16 / 10;
  background:
    linear-gradient(135deg, rgba(166, 64, 31, .16), rgba(14, 107, 92, .14) 55%, rgba(194, 137, 60, .2));
}

.media__inner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media__inner::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 8px;
  width: 18px;
  height: 18px;
  border-top: 1px solid var(--brass);
  border-left: 1px solid var(--brass);
  pointer-events: none;
}

.media__placeholder {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: rgba(107, 36, 18, .62);
  text-align: center;
  padding: 0 1rem;
}

.media__caption {
  display: block;
  padding: .7rem .9rem;
  border-top: 1px solid var(--line-brass);
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.media--wide .media__inner { aspect-ratio: 21 / 9; }
.media--tall .media__inner { aspect-ratio: 3 / 4; }
.media--square .media__inner { aspect-ratio: 1 / 1; }

.media--scan .media__inner::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(180deg, rgba(127, 209, 193, .18) 0 1px, transparent 1px 5px);
}

/* ---------- 10. 页头 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -70px;
  z-index: 200;
  padding: .6em 1em;
  border-radius: 2px;
  background: var(--ink);
  color: var(--paper);
  font-size: 13px;
  text-decoration: none;
  transition: top .2s ease;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--paper);
  border-bottom: 1px solid var(--brass);
  box-shadow: 0 1px 0 rgba(107, 36, 18, .06);
}

.header-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  display: block;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--clay), var(--scan));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .12s linear;
}

.header-inner {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 14px var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px clamp(16px, 2.4vw, 36px);
  transition: padding .2s ease;
}

.site-header[data-scrolled] .header-inner { padding-block: 8px; }

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  line-height: 1;
  text-decoration: none;
}

.brand__mark {
  display: inline-flex;
  align-items: baseline;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.4vw, 26px);
  letter-spacing: -.02em;
  color: var(--ink);
}

.brand__mark em {
  font-style: normal;
  color: var(--clay);
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
  text-transform: uppercase;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.2vw, 16px);
}

.old-archive {
  padding: .45em .7em;
  border: 1px solid rgba(14, 107, 92, .35);
  border-radius: 2px;
  background: var(--jade-soft);
  color: var(--jade-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}

.old-archive:hover {
  background: var(--jade);
  border-color: var(--jade-deep);
  color: var(--paper);
}

/* 站内检索 */
.site-search {
  position: relative;
  display: flex;
  align-items: center;
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--paper-lift);
  transition: border-color .2s ease, box-shadow .2s ease;
}

.site-search:focus-within {
  border-color: var(--jade);
  box-shadow: 0 0 0 3px rgba(127, 209, 193, .35);
}

.site-search__label {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.site-search__input {
  width: clamp(118px, 13vw, 190px);
  padding: .5em .7em;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 13px;
  outline: none;
}

.site-search__input::placeholder { color: var(--mist); }

.site-search__go {
  padding: .5em .8em;
  border-left: 1px solid var(--line-brass);
  background: transparent;
  color: var(--clay-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  transition: background-color .2s ease, color .2s ease;
}

.site-search__go:hover {
  background: var(--brass-soft);
  color: var(--clay-deep);
}

.site-search__panel {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 90;
  width: min(360px, 86vw);
  max-height: min(60vh, 420px);
  overflow: auto;
  padding: .7rem;
  border: 1px solid var(--brass);
  border-radius: 2px;
  background: var(--paper);
  box-shadow: 6px 6px 0 rgba(194, 137, 60, .22);
}

.site-search__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-search__list a {
  display: block;
  padding: .55em .7em;
  border-left: 2px solid transparent;
  color: var(--ink);
  font-size: 13.5px;
  line-height: 1.5;
  text-decoration: none;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}

.site-search__list a:hover,
.site-search__list a:focus-visible {
  background: var(--clay-soft);
  border-left-color: var(--clay);
  color: var(--clay-deep);
}

.site-search__empty {
  margin: 0;
  padding: .6em .7em;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* 版本切换抽屉 */
.version-drawer { position: relative; }

.version-drawer__toggle {
  display: inline-flex;
  align-items: center;
  gap: .6em;
  padding: .5em .8em;
  border: 1px solid var(--brass);
  border-radius: 2px;
  background: var(--paper-lift);
  color: var(--clay-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  white-space: nowrap;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}

.version-drawer__toggle:hover { background: var(--brass-soft); }

.version-drawer__toggle[aria-expanded="true"] {
  background: var(--clay);
  border-color: var(--clay-deep);
  color: var(--paper);
}

.version-drawer__value {
  font-weight: 700;
  color: var(--jade);
}

.version-drawer__toggle[aria-expanded="true"] .version-drawer__value { color: var(--brass-soft); }

.version-drawer__panel {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 90;
  width: min(330px, 88vw);
  padding: 1rem;
  border: 1px solid var(--brass);
  border-radius: 2px;
  background: var(--paper);
  background-image: linear-gradient(180deg, rgba(127, 209, 193, .14), transparent 36%);
  box-shadow: 8px 8px 0 rgba(107, 36, 18, .16);
}

.version-drawer__hint {
  margin-bottom: .8rem;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

.version-drawer__cta {
  width: 100%;
  justify-content: center;
  margin-top: .9rem;
}

.version-axis {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
}

.version-axis__item {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: .8rem;
  align-items: baseline;
  padding: .6rem 0;
  border-bottom: 1px dashed rgba(194, 137, 60, .45);
  transition: background-color .2s ease;
}

.version-axis__item:last-child { border-bottom: 0; }

.version-axis__item:hover { background: rgba(239, 217, 174, .38); }

.version-axis__key {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  color: var(--clay);
}

.version-axis__text {
  font-size: 13px;
  line-height: 1.6;
  color: #494C50;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: .55em;
  padding: .5em .8em;
  border: 1px solid var(--line-brass);
  border-radius: 2px;
  background: var(--paper-lift);
  color: var(--clay-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}

.nav-toggle:hover { background: var(--brass-soft); }

.nav-toggle[aria-expanded="true"] {
  background: var(--clay);
  border-color: var(--clay-deep);
  color: var(--paper);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.5px;
  background: currentColor;
  transition: transform .2s ease, top .2s ease, bottom .2s 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: 4px;
  transform: rotate(-45deg);
}

/* 主导航 */
.site-nav {
  border-top: 1px solid var(--line-brass);
  background: var(--paper);
}

.site-nav__list {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 0 var(--gutter);
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 clamp(16px, 2.6vw, 40px);
}

.site-nav__list li { position: relative; }

.site-nav__list a {
  position: relative;
  display: inline-block;
  padding: 12px 0;
  color: var(--ink);
  font-size: 14px;
  letter-spacing: .06em;
  text-decoration: none;
  transition: color .2s ease;
}

.site-nav__list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 8px;
  height: 1.5px;
  background: var(--clay);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s ease, background-color .2s ease;
}

.site-nav__list a:hover { color: var(--clay-deep); }
.site-nav__list a:hover::after { transform: scaleX(1); }

.site-nav__list a[aria-current="page"] {
  color: var(--jade-deep);
  font-weight: 700;
}

.site-nav__list a[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--jade);
}

/* ---------- 11. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 120px);
  background: var(--clay-deep);
  color: var(--paper);
}

.footer-scan {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: block;
  height: 3px;
  background: linear-gradient(90deg, rgba(127, 209, 193, 0), var(--scan) 28%, var(--scan) 72%, rgba(127, 209, 193, 0));
  box-shadow: 0 0 12px rgba(127, 209, 193, .5);
}

.footer-inner {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(44px, 7vw, 88px) var(--gutter) clamp(28px, 4vw, 52px);
  display: grid;
  grid-template-columns: minmax(240px, 1.5fr) repeat(2, minmax(130px, .8fr)) minmax(220px, 1.2fr);
  gap: clamp(24px, 3.4vw, 56px);
  align-items: start;
}

.brand--inverse .brand__mark { color: var(--paper); }
.brand--inverse .brand__mark em { color: var(--brass-soft); }
.brand--inverse .brand__tag { color: rgba(247, 242, 233, .62); }

.footer-brand__line {
  max-width: 34ch;
  margin-top: 1rem;
  font-size: 13.5px;
  line-height: 1.85;
  color: rgba(247, 242, 233, .78);
}

.footer-brand__meta {
  margin-top: .7rem;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--brass-soft);
}

.footer-col__title {
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--brass-soft);
}

.footer-nav {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .55rem;
}

.footer-nav a {
  display: inline-block;
  border-bottom: 1px solid transparent;
  color: rgba(247, 242, 233, .86);
  font-size: 13.5px;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.footer-nav a:hover {
  color: var(--brass-soft);
  border-bottom-color: var(--brass);
}

.footer-contact {
  margin: 0;
  display: grid;
  gap: .85rem;
}

.footer-contact__item { display: grid; gap: .2rem; }

.footer-contact__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--brass-soft);
}

.footer-contact__value {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(247, 242, 233, .9);
  word-break: break-word;
}

.footer-base {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(16px, 2vw, 22px) var(--gutter) clamp(28px, 3.4vw, 42px);
  border-top: 1px solid rgba(239, 217, 174, .28);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.6rem;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: rgba(247, 242, 233, .7);
}

/* ---------- 12. 响应式 ---------- */
@media (max-width: 1080px) {
  .old-archive { display: none; }
  .site-search__input { width: clamp(110px, 16vw, 150px); }
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .header-inner {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
  }

  .brand { flex: 1 1 auto; }

  .header-tools {
    flex: 0 1 auto;
    gap: 8px;
  }

  .site-search {
    order: 9;
    flex: 1 1 100%;
  }

  .site-search__input { width: 100%; }

  .site-search__panel {
    right: auto;
    left: 0;
    width: 100%;
  }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    border-top: 1px solid var(--brass);
    border-bottom: 1px solid var(--brass);
    background: var(--paper);
    box-shadow: 0 14px 24px rgba(107, 36, 18, .12);
  }

  .site-nav[data-open] { display: block; }

  .site-nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 0;
    padding-block: 6px;
  }

  .site-nav__list li { border-bottom: 1px dashed var(--line-brass); }
  .site-nav__list li:last-child { border-bottom: 0; }

  .site-nav__list a {
    display: block;
    padding: 14px 0;
    font-size: 16px;
  }

  .site-nav__list a::after { display: none; }

  .site-nav__list a[aria-current="page"] { color: var(--clay); }

  .site-nav__list a[aria-current="page"]::before {
    content: "▍";
    margin-right: .5em;
    font-size: 12px;
    color: var(--brass);
  }
}

@media (max-width: 720px) {
  .section-head__note {
    margin-left: 0;
    max-width: none;
  }

  .version-drawer__panel {
    right: auto;
    left: 0;
    width: min(330px, calc(100vw - 32px));
  }
}

@media (max-width: 600px) {
  .footer-inner { grid-template-columns: 1fr; }
  .footer-base { justify-content: flex-start; }
}

/* ---------- 13. 无障碍与动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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