/* ==========================================================================
   /assets/site.css — 新宝5会馆 共享样式
   顺序：变量 → 重置 → 基础排版 → 无障碍 → 按钮/通用组件
        → 头部 → 页脚 → 响应式 → 减少动效
   ========================================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  /* 品牌色盘 */
  --c-crimson: #8C1D2F;
  --c-crimson-deep: #5E1220;
  --c-gold: #D6A64A;
  --c-gold-soft: #F2D9A0;
  --c-turquoise: #2F7F78;
  --c-indigo: #1B2A4A;
  --c-mist: #F7F2E8;
  --c-ink: #231F20;
  --c-glass: rgba(255, 255, 255, 0.14);

  /* 派生墨色与线色 */
  --c-ink-soft: rgba(35, 31, 32, 0.68);
  --c-mist-soft: rgba(247, 242, 232, 0.74);
  --c-line: rgba(35, 31, 32, 0.14);
  --c-line-strong: rgba(35, 31, 32, 0.3);
  --c-line-light: rgba(247, 242, 232, 0.22);

  /* 版式与网格 */
  --shell: 1280px;
  --gutter: clamp(1.25rem, 4vw, 3.5rem);
  --header-h: 76px;
  --radius: 2px;

  /* 字号阶梯 */
  --step--1: 0.84rem;
  --step-0: 1rem;
  --step-1: clamp(1.12rem, 0.6vw + 0.98rem, 1.34rem);
  --step-2: clamp(1.38rem, 1.4vw + 1.02rem, 1.9rem);
  --step-3: clamp(1.85rem, 2.6vw + 1rem, 2.9rem);
  --step-4: clamp(2.3rem, 4vw + 1rem, 4.1rem);
  --step-5: clamp(3.2rem, 8vw, 8.4rem);

  /* 字体 */
  --font-head: "HarmonyOS Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-num: "DIN Alternate", "Barlow Condensed", "Oswald", ui-monospace, "SFMono-Regular", monospace;

  /* 动效与阴影 */
  --ease-out: cubic-bezier(0.22, 0.68, 0.32, 1);
  --shadow-lift: 0 18px 40px -18px rgba(35, 31, 32, 0.38);
  --shadow-panel: 0 28px 70px -30px rgba(27, 42, 74, 0.55);
}

/* ---------- 2. 重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

* { margin: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-ink);
  background-color: var(--c-mist);
  background-image: linear-gradient(180deg, rgba(214, 166, 74, 0.07), rgba(247, 242, 232, 0) 42%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

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

a { color: inherit; }

button { font: inherit; color: inherit; }

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

/* ---------- 3. 焦点与跳转 ---------- */
:focus-visible {
  outline: 2px solid var(--c-gold);
  outline-offset: 3px;
  border-radius: 1px;
}

.site-footer :focus-visible,
.section--dark :focus-visible,
.section--crimson :focus-visible {
  outline-color: var(--c-gold-soft);
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  padding: 0.7em 1.15em;
  background: var(--c-crimson);
  color: var(--c-mist);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lift);
  transform: translateY(-180%);
  transition: transform 0.18s var(--ease-out);
}

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

/* ---------- 4. 容器与分区 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(3rem, 6vw, 6rem); }
.section--tight { padding-block: clamp(1.75rem, 3.4vw, 3.25rem); }

.section--dark {
  background: var(--c-indigo);
  background-image: repeating-linear-gradient(112deg, rgba(214, 166, 74, 0.07) 0 1px, transparent 1px 58px);
  color: var(--c-mist);
}

.section--crimson {
  background: var(--c-crimson);
  color: var(--c-mist);
}

.section--gold {
  background: var(--c-gold-soft);
}

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

.section--dark .rule,
.section--crimson .rule { background: var(--c-line-light); }

/* ---------- 5. 文字模块 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-num);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.24em;
  color: var(--c-crimson);
}

.eyebrow::before {
  content: "";
  display: block;
  width: 28px;
  height: 2px;
  background: var(--c-gold);
}

.section--dark .eyebrow,
.section--crimson .eyebrow { color: var(--c-gold); }

.display {
  font-family: var(--font-head);
  font-size: var(--step-5);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.035em;
  margin-block: 0.32em 0;
}

.lede {
  max-width: 36em;
  font-size: var(--step-1);
  line-height: 1.85;
  color: var(--c-ink-soft);
}

.section--dark .lede,
.section--crimson .lede { color: var(--c-mist-soft); }

.prose { max-width: 68ch; }

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

.prose > h2 {
  font-size: var(--step-3);
  margin-top: 2.1em;
  margin-bottom: 0.5em;
}

.prose > h3 {
  font-size: var(--step-2);
  margin-top: 1.7em;
  margin-bottom: 0.4em;
}

.prose ul,
.prose ol {
  margin-top: 1em;
  padding-left: 1.35em;
}

.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.45em; }

.prose a {
  color: var(--c-turquoise);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

.prose a:hover { color: var(--c-crimson); }

.prose blockquote {
  margin-block: 1.7em;
  padding-left: 1.1em;
  border-left: 3px solid var(--c-gold);
  color: var(--c-ink-soft);
}

.prose code {
  font-family: var(--font-num);
  font-size: 0.92em;
  padding: 0.12em 0.4em;
  border-radius: var(--radius);
  background: rgba(214, 166, 74, 0.2);
}

/* ---------- 6. 面包屑 ---------- */
.breadcrumb { padding-block: 0.9rem; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--step--1);
  color: var(--c-ink-soft);
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--c-gold);
  font-family: var(--font-num);
}

.breadcrumb__link {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.18s var(--ease-out), color 0.18s var(--ease-out);
}

.breadcrumb__link:hover {
  color: var(--c-crimson);
  border-bottom-color: var(--c-gold);
}

.breadcrumb__item[aria-current="page"] {
  color: var(--c-ink);
  font-weight: 600;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.72em 1.4em;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-head);
  font-size: 0.92rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s var(--ease-out), color 0.18s var(--ease-out),
              transform 0.18s var(--ease-out), box-shadow 0.18s var(--ease-out);
}

.btn:hover { transform: translateY(-1px); }

.btn--solid {
  background: var(--c-crimson);
  color: var(--c-mist);
}

.btn--solid:hover { background: var(--c-crimson-deep); }

.btn--gold {
  background: var(--c-gold);
  color: var(--c-ink);
}

.btn--gold:hover { background: var(--c-gold-soft); }

.btn--ghost {
  background: transparent;
  border-color: currentColor;
  color: inherit;
}

.btn--ghost:hover { background: rgba(214, 166, 74, 0.16); }

/* ---------- 8. 卡片与栅格 ---------- */
.grid {
  display: grid;
  gap: clamp(1rem, 2vw, 1.75rem);
}

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

.card {
  position: relative;
  padding: clamp(1.25rem, 2.2vw, 2rem);
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: transform 0.22s var(--ease-out), box-shadow 0.22s var(--ease-out),
              border-color 0.22s var(--ease-out);
}

.card:hover {
  transform: translateY(-3px);
  border-color: rgba(214, 166, 74, 0.65);
  box-shadow: var(--shadow-lift);
}

.card--glass {
  background: var(--c-glass);
  border-color: rgba(247, 242, 232, 0.35);
  color: var(--c-mist);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

.card__title {
  font-family: var(--font-head);
  font-size: var(--step-2);
  font-weight: 800;
  letter-spacing: -0.015em;
}

.card__body {
  margin-top: 0.6rem;
  color: var(--c-ink-soft);
}

.card--glass .card__body { color: var(--c-mist-soft); }

.card__meta {
  margin-top: 0.9rem;
  font-family: var(--font-num);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-turquoise);
}

/* ---------- 9. 图像容器（页面阶段放占位用） ---------- */
.media {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--c-indigo), var(--c-crimson-deep));
}

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

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

.media--placeholder {
  background-image:
    repeating-linear-gradient(115deg, rgba(214, 166, 74, 0.22) 0 1px, transparent 1px 34px),
    linear-gradient(135deg, var(--c-indigo), var(--c-crimson-deep));
}

.media__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(27, 42, 74, 0.08), rgba(27, 42, 74, 0.58));
}

.media__caption {
  margin-top: 0.65rem;
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  color: var(--c-ink-soft);
}

/* ---------- 10. 头部 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 200;
  color: var(--c-mist);
  background-image: linear-gradient(
    180deg,
    rgba(20, 32, 58, 0.86) 0%,
    rgba(20, 32, 58, 0.42) 62%,
    rgba(20, 32, 58, 0) 100%
  );
  border-bottom: 1px solid transparent;
  transition: background-color 0.24s var(--ease-out), color 0.24s var(--ease-out),
              border-color 0.24s var(--ease-out), box-shadow 0.24s var(--ease-out);
}

.site-header.is-stuck {
  background-color: rgba(247, 242, 232, 0.95);
  background-image: none;
  color: var(--c-ink);
  border-bottom-color: var(--c-line);
  box-shadow: 0 12px 30px -22px rgba(35, 31, 32, 0.6);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  backdrop-filter: saturate(140%) blur(12px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2vw, 2.5rem);
  width: 100%;
  max-width: var(--shell);
  min-height: var(--header-h);
  margin-inline: auto;
  padding: 0.55rem var(--gutter);
}

.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--c-crimson), var(--c-gold));
  transition: transform 0.1s linear;
  pointer-events: none;
}

/* 品牌块 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  flex: none;
  margin-right: auto;
  color: inherit;
  text-decoration: none;
}

.brand__glyph {
  position: relative;
  flex: none;
  width: 32px;
  height: 32px;
  border: 1.5px solid currentColor;
  transform: rotate(-6deg);
  transition: transform 0.28s var(--ease-out);
}

.brand:hover .brand__glyph { transform: rotate(-6deg) translateX(2px); }

.brand__glyph::before {
  content: "";
  position: absolute;
  top: -5px;
  bottom: -5px;
  left: 50%;
  width: 1.5px;
  margin-left: -0.75px;
  background: var(--c-gold);
  transform: rotate(16deg);
}

.brand__glyph::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  bottom: 6px;
  height: 5px;
  background: var(--c-gold);
  transform: skewX(-16deg);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand__name {
  font-family: var(--font-head);
  font-size: 1.06rem;
  font-weight: 800;
  letter-spacing: 0.07em;
}

.brand__tag {
  margin-top: 0.28rem;
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--c-gold);
}

/* 导航 */
.nav { display: flex; align-items: center; }

.nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.85rem, 1.6vw, 1.7rem);
}

.nav__item { display: block; }

.nav__link {
  position: relative;
  display: inline-block;
  padding: 0.5rem 0.1rem;
  font-size: 0.94rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: inherit;
  text-decoration: none;
  transition: color 0.18s var(--ease-out);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 2px;
  height: 2px;
  background: var(--c-gold);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.24s var(--ease-out), background-color 0.18s var(--ease-out);
}

.nav__link:hover::after,
.nav__link:focus-visible::after { transform: scaleX(1); }

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

.site-header.is-stuck .nav__link[aria-current="page"] { color: var(--c-crimson); }
.site-header.is-stuck .nav__link[aria-current="page"]::after { background: var(--c-crimson); }

.nav__foot { display: none; }

.nav__cta {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.95rem 1.25rem;
  border-radius: var(--radius);
  background: var(--c-crimson);
  color: var(--c-mist);
  font-family: var(--font-head);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-decoration: none;
}

.nav__cta:hover { background: var(--c-crimson-deep); }

/* 右侧行动区 */
.header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex: none;
}

.header__cta {
  box-shadow: inset 0 0 0 1px rgba(214, 166, 74, 0.55);
  white-space: nowrap;
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid currentColor;
  border-radius: var(--radius);
  background: transparent;
  color: inherit;
  line-height: 1;
  cursor: pointer;
  transition: background-color 0.18s var(--ease-out);
}

.nav-toggle:hover { background: rgba(214, 166, 74, 0.16); }

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 18px;
  height: 13px;
}

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease-out), opacity 0.16s linear;
}

.nav-toggle__label {
  font-family: var(--font-head);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.site-header[data-open] .nav-toggle__bar:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.site-header[data-open] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__bar:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

/* ---------- 11. 页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(2.5rem, 6vw, 5rem);
  padding-top: clamp(2.75rem, 5vw, 4.5rem);
  color: var(--c-mist);
  background-color: var(--c-crimson-deep);
  background-image: linear-gradient(
    158deg,
    rgba(94, 18, 32, 0.97) 0%,
    rgba(94, 18, 32, 0.92) 46%,
    rgba(27, 42, 74, 0.95) 100%
  );
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    108deg,
    rgba(214, 166, 74, 0.1) 0 1px,
    transparent 1px 46px
  );
  opacity: 0.6;
  pointer-events: none;
}

.footer__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.55fr);
  gap: clamp(2rem, 4vw, 4rem) clamp(1.5rem, 4vw, 5rem);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 0 var(--gutter) clamp(2.25rem, 4vw, 3.5rem);
}

.footer__lead { min-width: 0; }

.footer__brand-mark {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-head);
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  line-height: 1.2;
}

.footer__brand-glyph {
  position: relative;
  flex: none;
  width: 26px;
  height: 26px;
  border: 1.5px solid var(--c-gold);
  transform: rotate(-6deg);
}

.footer__brand-glyph::after {
  content: "";
  position: absolute;
  inset: 6px;
  background: var(--c-gold);
}

.footer__summary {
  max-width: 30ch;
  margin-top: 0.95rem;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--c-mist-soft);
}

.footer__cta {
  margin-top: 1.4rem;
  letter-spacing: 0.08em;
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.6rem 1.5rem;
}

.footer__col { min-width: 0; }

.footer__heading {
  margin-bottom: 1rem;
  font-family: var(--font-head);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--c-gold);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.footer__list a {
  display: inline-block;
  padding-bottom: 1px;
  font-size: 0.94rem;
  color: var(--c-mist-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease-out), border-color 0.18s var(--ease-out);
}

.footer__list a:hover,
.footer__list a:focus-visible {
  color: var(--c-mist);
  border-bottom-color: var(--c-gold);
}

.footer__contact {
  grid-column: 1 / -1;
  padding-top: 1.6rem;
  border-top: 1px solid var(--c-line-light);
}

.footer__label {
  margin-bottom: 1rem;
  font-family: var(--font-num);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--c-gold);
}

.footer__contact-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem 1.75rem;
}

.footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
  min-width: 0;
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer__key {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: rgba(247, 242, 232, 0.55);
}

.footer__value {
  color: var(--c-mist);
  overflow-wrap: anywhere;
}

.footer__base {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--c-line-light);
  background: rgba(20, 15, 17, 0.36);
}

.footer__base-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 1.5rem;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 1.1rem var(--gutter);
  font-size: 0.8rem;
  line-height: 1.6;
  color: rgba(247, 242, 232, 0.68);
}

.footer__legal { margin-right: auto; }

.footer__icp {
  font-family: var(--font-num);
  letter-spacing: 0.08em;
}

.footer__note { color: rgba(247, 242, 232, 0.55); }

/* ---------- 12. 滚动辅助组件 ---------- */
[data-reveal] {
  transition: opacity 0.55s var(--ease-out), transform 0.55s var(--ease-out);
}

[data-reveal].is-out {
  opacity: 0;
  transform: translateY(16px);
}

[data-toc] a {
  text-decoration: none;
  transition: color 0.18s var(--ease-out);
}

[data-toc] a:hover { color: var(--c-crimson); }

[data-toc] a[aria-current="true"] {
  color: var(--c-crimson);
  font-weight: 700;
}

.to-top {
  position: fixed;
  right: clamp(1rem, 3vw, 2.25rem);
  bottom: clamp(1rem, 3vw, 2.25rem);
  z-index: 150;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.7rem 0.95rem;
  border: 1px solid rgba(247, 242, 232, 0.45);
  border-radius: var(--radius);
  background: var(--c-indigo);
  color: var(--c-mist);
  font-family: var(--font-head);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  box-shadow: var(--shadow-lift);
  transition: opacity 0.22s var(--ease-out), transform 0.22s var(--ease-out),
              visibility 0.22s, background-color 0.18s var(--ease-out);
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover { background: var(--c-crimson); }

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1024px) {
  .nav-toggle { display: inline-flex; }
  .header__cta { display: none; }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: block;
    max-height: calc(100vh - var(--header-h));
    max-height: calc(100dvh - var(--header-h));
    padding: 1.1rem var(--gutter) 2rem;
    overflow-y: auto;
    background: var(--c-mist);
    color: var(--c-ink);
    border-top: 1px solid var(--c-line);
    border-bottom: 1px solid var(--c-line);
    box-shadow: var(--shadow-panel);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.22s var(--ease-out), transform 0.22s var(--ease-out),
                visibility 0.22s;
  }

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

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav__item + .nav__item { border-top: 1px solid var(--c-line); }

  .nav__link {
    display: block;
    padding: 0.95rem 0.25rem;
    font-size: 1.02rem;
    font-weight: 700;
    letter-spacing: 0.05em;
  }

  .nav__link::after { display: none; }

  .nav__link[aria-current="page"] {
    color: var(--c-crimson);
    padding-left: 0.9rem;
    box-shadow: inset 3px 0 0 var(--c-gold);
  }

  .nav__foot {
    display: block;
    margin-top: 1.15rem;
  }
}

@media (max-width: 900px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 860px) {
  .footer__inner { grid-template-columns: minmax(0, 1fr); }
  .footer__summary { max-width: 46ch; }
  .footer__contact-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 620px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 560px) {
  .brand__tag { display: none; }
  .footer__cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer__contact-list { grid-template-columns: minmax(0, 1fr); }
  .footer__legal { margin-right: 0; width: 100%; }
  .to-top { padding: 0.6rem 0.75rem; }
}

@media (max-width: 380px) {
  .nav-toggle__label { display: none; }
}

/* ---------- 14. 减少动效 ---------- */
@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-out {
    opacity: 1;
    transform: none;
  }
}