/* ==========================================================================
   加拿大主页 · /assets/site.css
   共享层：reset / tokens / 中文排版 / 共享头部与页脚 / 通用组件
   ========================================================================== */

/* ---------- 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, li, dl, dt, dd,
figure, figcaption, blockquote, fieldset, legend {
  margin: 0;
}

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

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

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

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

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

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

/* ---------- 2. Tokens ---------- */
:root {
  --paper: #F6F0E3;
  --snow: #FFFFFF;
  --ink: #14201C;
  --maple: #C4342A;
  --maple-soft: #E8776A;
  --fir: #10493A;
  --fir-soft: #2F7A61;
  --glacier: #3E7FA6;
  --glacier-soft: #A9CDE0;
  --gold: #D9A03C;
  --graphite: #3B4440;
  --line: #C9C3B4;

  --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", "SFMono-Regular", ui-monospace, Menlo, Consolas, "Courier New", monospace;

  --step-13: 13px;
  --step-15: 15px;
  --step-17: 17px;
  --step-21: 21px;
  --step-28: 28px;
  --step-40: 40px;
  --step-56: 56px;
  --step-72: 72px;

  --shell: 1200px;
  --gutter: clamp(18px, 4vw, 44px);
  --radius: 4px;
  --border: 1px solid var(--line);

  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --dur: 200ms;
}

/* ---------- 3. 中文排版基底 ---------- */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: var(--paper);
  background-image:
    linear-gradient(rgba(201, 195, 180, 0.26) 1px, transparent 1px),
    linear-gradient(90deg, rgba(201, 195, 180, 0.26) 1px, transparent 1px);
  background-size: 88px 88px;
  background-position: center top;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--step-17);
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.01em;
}

p { text-wrap: pretty; }

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

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

/* ---------- 4. Skip link ---------- */
.skip-link {
  position: fixed;
  top: -72px;
  left: 16px;
  z-index: 300;
  padding: 10px 20px;
  background: var(--maple);
  color: var(--snow);
  font-size: var(--step-15);
  font-weight: 700;
  border-radius: 0 0 var(--radius) var(--radius);
  transition: top var(--dur) var(--ease);
}

.skip-link:focus {
  top: 0;
}

/* ---------- 5. 共享头部（居中刊头） ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--fir);
  color: var(--snow);
  box-shadow: 0 10px 26px rgba(16, 73, 58, 0.16);
}

.scroll-meter {
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: rgba(246, 240, 227, 0.16);
  overflow: hidden;
}

.scroll-meter__fill {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--maple), var(--gold));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 120ms linear;
}

.site-header__band {
  padding: 22px 0 18px;
}

.site-header__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
}

.site-header__left {
  display: flex;
  align-items: center;
  gap: 12px;
  justify-content: flex-start;
  min-width: 0;
}

.site-header__right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
}

.coord {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.06em;
  color: rgba(246, 240, 227, 0.62);
  white-space: nowrap;
}

/* 报头 */
.masthead {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
}

.masthead__brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 4px 8px;
  border-radius: var(--radius);
}

.masthead__mark {
  width: 26px;
  height: 26px;
  flex: none;
  background: var(--maple);
  clip-path: polygon(50% 0%, 62% 33%, 100% 27%, 73% 55%, 88% 100%, 50% 75%, 12% 100%, 27% 55%, 0% 27%, 38% 33%);
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.masthead__brand:hover .masthead__mark {
  background: var(--gold);
  transform: rotate(-8deg);
}

.masthead__words {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  line-height: 1.05;
}

.masthead__zh {
  font-size: var(--step-28);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.masthead__en {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--gold);
}

.masthead__tagline {
  font-size: var(--step-13);
  letter-spacing: 0.18em;
  color: rgba(246, 240, 227, 0.7);
}

/* 小屏查询入口 */
.query-entry {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 15px;
  border: 1px solid rgba(246, 240, 227, 0.36);
  border-radius: 999px;
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--snow);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
    color var(--dur) var(--ease);
}

.query-entry:hover {
  background: var(--maple);
  border-color: var(--maple);
}

.query-entry__icon {
  font-size: var(--step-15);
  line-height: 1;
}

.query-entry__text { white-space: nowrap; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid rgba(246, 240, 227, 0.34);
  border-radius: var(--radius);
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.nav-toggle:hover { background: rgba(246, 240, 227, 0.1); }

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
}

.nav-toggle__bars i {
  display: block;
  width: 16px;
  height: 2px;
  background: var(--snow);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-toggle__text { white-space: nowrap; }

/* 栏目索引带 */
.site-nav {
  border-top: 1px solid rgba(246, 240, 227, 0.18);
  background: rgba(20, 32, 28, 0.16);
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: stretch;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-nav__item {
  display: flex;
  align-items: stretch;
}

.site-nav__item + .site-nav__item {
  border-left: 1px solid rgba(246, 240, 227, 0.18);
}

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 15px 22px;
  font-size: var(--step-15);
  font-weight: 700;
  color: rgba(246, 240, 227, 0.86);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 7px;
  height: 2px;
  background: linear-gradient(90deg, var(--maple), var(--maple-soft));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}

.site-nav__link:hover {
  background: rgba(246, 240, 227, 0.08);
  color: var(--snow);
}

.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] { color: var(--snow); }

.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--gold);
}

/* ---------- 6. 共享页脚 ---------- */
.site-footer {
  margin-top: auto;
  background: var(--ink);
  color: rgba(246, 240, 227, 0.86);
}

.site-footer .legend-title { color: var(--gold); }

.site-footer__top {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr;
  gap: clamp(20px, 3vw, 48px);
  padding-block: clamp(38px, 5vw, 66px) clamp(26px, 3.4vw, 40px);
  border-bottom: 1px solid rgba(246, 240, 227, 0.16);
}

.site-footer__brand { min-width: 0; }

.site-footer__name {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: var(--step-21);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.site-footer__mark {
  width: 18px;
  height: 18px;
  flex: none;
  background: var(--maple);
  clip-path: polygon(50% 0%, 62% 33%, 100% 27%, 73% 55%, 88% 100%, 50% 75%, 12% 100%, 27% 55%, 0% 27%, 38% 33%);
}

.site-footer__lead {
  margin-top: 14px;
  max-width: 46ch;
  font-size: var(--step-15);
  line-height: 1.75;
  color: rgba(246, 240, 227, 0.72);
}

.site-footer__col { min-width: 0; }

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: 12px;
}

.footer-links__a {
  display: inline-block;
  padding: 5px 0;
  font-size: var(--step-15);
  color: rgba(246, 240, 227, 0.8);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.footer-links__a:hover {
  color: var(--paper);
  border-bottom-color: var(--maple-soft);
}

.site-footer__query {
  background: linear-gradient(180deg, rgba(47, 122, 97, 0.42), rgba(47, 122, 97, 0.14));
  border-bottom: 1px solid rgba(246, 240, 227, 0.16);
}

.site-footer__query-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 44px);
  align-items: center;
  padding-block: clamp(24px, 3.2vw, 34px);
}

.query-panel { min-width: 0; }

.query-panel__text {
  max-width: 54ch;
  margin: 10px 0 16px;
  font-size: var(--step-15);
  color: rgba(246, 240, 227, 0.78);
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-left: 22px;
  border-left: 1px solid rgba(246, 240, 227, 0.22);
}

.contact-list__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 4px 16px;
}

.contact-list__row dt {
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.contact-list__row dd {
  font-family: var(--font-mono);
  font-size: var(--step-15);
  letter-spacing: 0.02em;
  color: var(--paper);
  word-break: break-all;
}

.site-footer__base {
  background: rgba(0, 0, 0, 0.22);
}

.site-footer__base-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 16px;
  font-size: var(--step-13);
  color: rgba(246, 240, 227, 0.62);
}

.site-footer__legal {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  color: rgba(246, 240, 227, 0.72);
}

.site-footer__addr {
  flex: 1 1 260px;
  min-width: 0;
}

.site-footer__copy {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ---------- 7. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-size: var(--step-15);
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.btn--primary {
  background: var(--maple);
  color: var(--snow);
}

.btn--primary:hover { background: var(--maple-soft); }

.btn--ghost {
  background: var(--snow);
  border-color: var(--line);
  color: var(--ink);
}

.btn--ghost:hover {
  border-color: var(--maple);
  color: var(--maple);
}

/* ---------- 8. 面包屑与页面标题区 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--graphite);
}

.crumbs a {
  color: var(--glacier);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.crumbs a:hover { border-bottom-color: var(--glacier); }

.crumbs__sep { color: var(--line); }

.page-head {
  padding: clamp(30px, 5vw, 60px) 0 clamp(22px, 3vw, 32px);
  border-bottom: var(--border);
}

.eyebrow {
  display: inline-block;
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--maple);
}

.page-title {
  margin-top: 12px;
  font-size: clamp(28px, 4.6vw, 56px);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-lede {
  max-width: 64ch;
  margin-top: 16px;
  font-size: var(--step-17);
  color: var(--graphite);
}

/* ---------- 9. 正文容器 ---------- */
.prose {
  max-width: 68ch;
  font-size: var(--step-17);
  line-height: 1.75;
}

.prose p + p { margin-top: 1em; }

.prose h2 {
  margin: 2em 0 0.6em;
  font-size: var(--step-28);
  font-weight: 800;
}

.prose h3 {
  margin: 1.6em 0 0.5em;
  font-size: var(--step-21);
  font-weight: 800;
}

.prose ul,
.prose ol {
  margin: 1em 0;
  padding-left: 1.3em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose li + li { margin-top: 0.4em; }

.prose a {
  color: var(--glacier);
  border-bottom: 1px solid var(--glacier-soft);
  transition: border-color var(--dur) var(--ease);
}

.prose a:hover { border-bottom-color: var(--glacier); }

.prose code {
  padding: 1px 5px;
  background: var(--snow);
  border: 1px solid var(--line);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.94em;
}

.prose blockquote {
  margin: 1.4em 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--maple);
  color: var(--graphite);
}

/* ---------- 10. 栅格与章节 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.2vw, 28px);
}

.main-col { grid-column: 2 / span 7; }

.side-col { grid-column: 10 / span 3; }

.section { padding: clamp(30px, 4.6vw, 60px) 0; }

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

/* ---------- 11. 内容块 ---------- */
.card {
  padding: clamp(16px, 2.2vw, 26px);
  background: var(--snow);
  border: var(--border);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.card:hover {
  border-color: var(--maple);
  box-shadow: 0 8px 22px rgba(20, 32, 28, 0.08);
}

.index-block {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px 18px;
  background: var(--snow);
  border: var(--border);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.index-block:hover {
  border-color: var(--maple);
  transform: translateY(-2px);
}

.index-block__num {
  font-family: var(--font-mono);
  font-size: var(--step-13);
  letter-spacing: 0.06em;
  color: var(--maple);
}

.index-block__title {
  font-size: var(--step-17);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.index-block__meta {
  font-size: var(--step-13);
  color: var(--graphite);
}

.chapter-block {
  padding: clamp(20px, 3vw, 38px);
  background: var(--snow);
  border: var(--border);
  border-radius: var(--radius);
}

.visual-block {
  position: relative;
  overflow: hidden;
  background: var(--snow);
  border: var(--border);
  border-radius: var(--radius);
}

.legend-block {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  padding: 12px 16px;
  background: rgba(169, 205, 224, 0.16);
  border: var(--border);
  border-radius: var(--radius);
}

.legend-block__item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: var(--step-13);
  letter-spacing: 0.04em;
  color: var(--graphite);
}

.legend-block__swatch {
  width: 10px;
  height: 10px;
  flex: none;
  border-radius: 2px;
  background: var(--fir-soft);
}

.legend-block__swatch--maple { background: var(--maple); }
.legend-block__swatch--gold { background: var(--gold); }
.legend-block__swatch--glacier { background: var(--glacier); }

/* ---------- 12. 标签与图例文字 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 11px;
  background: var(--snow);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--graphite);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.tag--accent {
  border-color: var(--maple);
  color: var(--maple);
}

.tag--accent:hover,
.tag--accent[aria-pressed="true"] {
  background: var(--maple);
  color: var(--snow);
}

.tag--fir {
  background: var(--fir-soft);
  border-color: var(--fir-soft);
  color: var(--snow);
}

.tag--gold {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.legend-title {
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fir-soft);
}

/* ---------- 13. 坐标轴目录 ---------- */
.axis-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 18px;
  border-left: 1px solid var(--line);
}

.axis-list__link {
  display: block;
  margin-left: -19px;
  padding: 7px 10px 7px 18px;
  border-left: 2px solid transparent;
  font-size: var(--step-15);
  color: var(--graphite);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background var(--dur) var(--ease);
}

.axis-list__link:hover {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.7);
}

.axis-list__link[aria-current="true"] {
  color: var(--maple);
  border-left-color: var(--maple);
  font-weight: 700;
}

/* ---------- 14. 图片容器基础规则 ---------- */
.media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: linear-gradient(135deg, var(--glacier-soft), #e7e1d3);
  border: var(--border);
  border-radius: var(--radius);
}

.media img,
.media svg,
.media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 4 / 5; }
.media--square { aspect-ratio: 1 / 1; }

.media__caption {
  margin-top: 10px;
  font-size: var(--step-13);
  color: var(--graphite);
}

.media__label {
  position: absolute;
  left: 12px;
  bottom: 12px;
  padding: 4px 9px;
  background: rgba(20, 32, 28, 0.78);
  color: var(--snow);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

/* ---------- 15. 玻璃层与数据块 ---------- */
.glass {
  background: rgba(169, 205, 224, 0.18);
  border: 1px solid rgba(201, 195, 180, 0.7);
  border-radius: var(--radius);
  backdrop-filter: blur(8px);
  transition: background var(--dur) var(--ease);
}

.glass:hover { background: rgba(169, 205, 224, 0.3); }

.stat { display: flex; flex-direction: column; gap: 2px; }

.stat__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--fir);
}

.stat__label {
  font-size: var(--step-13);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--graphite);
}

/* ---------- 16. 显现协议 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 420ms var(--ease), transform 420ms var(--ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1000px) {
  .main-col,
  .side-col { grid-column: 1 / -1; }

  .site-footer__top {
    grid-template-columns: 1fr 1fr;
  }

  .site-footer__brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .coord { display: none; }

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

  .site-header__band { padding: 14px 0 12px; }

  .site-header__inner {
    grid-template-columns: auto 1fr auto;
    gap: 10px;
  }

  .masthead { gap: 3px; }

  .masthead__brand { gap: 8px; padding: 2px 4px; }

  .masthead__mark { width: 20px; height: 20px; }

  .masthead__zh { font-size: var(--step-21); }

  .masthead__en { font-size: 10px; letter-spacing: 0.24em; }

  .masthead__tagline { display: none; }

  .query-entry { padding: 9px 11px; }

  .query-entry__text { display: none; }

  .query-entry__icon { font-size: var(--step-17); }

  .site-nav__list {
    flex-direction: column;
    padding-block: 6px 14px;
  }

  .site-nav__item + .site-nav__item {
    border-left: 0;
    border-top: 1px solid rgba(246, 240, 227, 0.14);
  }

  .site-nav__link {
    width: 100%;
    padding: 14px 0;
    font-size: var(--step-17);
    justify-content: flex-start;
  }

  .site-nav__link::after {
    left: 0;
    right: auto;
    bottom: 10px;
    width: 34px;
  }

  .site-nav {
    display: none;
    max-height: calc(100vh - 120px);
    overflow-y: auto;
  }

  .site-nav[data-open] {
    display: block;
    animation: nav-drop 220ms var(--ease);
  }

  .site-footer__query-inner { grid-template-columns: 1fr; }

  .contact-list {
    padding-left: 0;
    padding-top: 18px;
    border-left: 0;
    border-top: 1px solid rgba(246, 240, 227, 0.22);
  }
}

@media (max-width: 640px) {
  body { font-size: var(--step-17); }

  .site-footer__top { grid-template-columns: 1fr; }

  .site-footer__base-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .btn { width: 100%; justify-content: center; }
}

@media (min-width: 901px) {
  .site-nav { display: block; }
}

@keyframes nav-drop {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 18. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

  [data-reveal],
  [data-reveal].is-visible {
    opacity: 1;
    transform: none;
  }

  .index-block:hover { transform: none; }
}