/* =========================================================
   利国际中心 · 中文主页发布平台
   共享样式 / assets/site.css
   ========================================================= */

/* ---------- 1. 基础重置 ---------- */
*,
*::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, figure, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

/* ---------- 2. 设计变量 ---------- */
:root {
  --indigo: #16355C;
  --indigo-deep: #0E2440;
  --indigo-mid: #2B4E7C;
  --gold: #C9962B;
  --gold-light: #E8C878;
  --cinnabar: #C0392B;
  --cool: #F5F7FA;
  --paper: #FFFFFF;
  --ink: #1F2933;
  --gray: #6B7A8F;
  --jade: #2E7D6F;

  --line: rgba(31, 41, 51, .14);
  --line-strong: rgba(31, 41, 51, .3);
  --line-invert: rgba(255, 255, 255, .16);
  --line-invert-strong: rgba(255, 255, 255, .36);

  --shell: 1240px;
  --gutter: 24px;
  --ease: cubic-bezier(.22, 1, .36, 1);

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

body {
  background: var(--cool);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--gold); outline-offset: 3px; }

::selection { background: var(--gold-light); color: var(--indigo-deep); }

/* ---------- 3. 布局容器 ---------- */
.shell {
  width: min(100% - 40px, var(--shell));
  margin-inline: auto;
}

@media (min-width: 768px) {
  .shell { width: min(100% - 64px, var(--shell)); }
}

.page-main { display: block; }

.section {
  position: relative;
  padding: clamp(48px, 6vw, 88px) 0;
}

.section--paper {
  background: var(--paper);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section--deep {
  background: var(--indigo-deep);
  color: #E7ECF2;
}

.section__head {
  display: grid;
  gap: 14px;
  max-width: 62ch;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.section__head--wide { max-width: none; }

.stack { display: grid; gap: 18px; }
.stack--tight { gap: 10px; }

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

.prose { max-width: 40em; font-size: 17px; line-height: 1.85; color: #333F4C; }

/* ---------- 4. 排版 ---------- */
.display {
  font-size: clamp(40px, 6.4vw, 96px);
  line-height: 1.02;
  font-weight: 900;
  letter-spacing: -.02em;
}

.h1 { font-size: clamp(30px, 4.4vw, 64px); line-height: 1.1; font-weight: 900; letter-spacing: -.015em; }
.h2 { font-size: clamp(24px, 3vw, 44px); line-height: 1.18; font-weight: 900; letter-spacing: -.01em; }
.h3 { font-size: clamp(19px, 1.9vw, 32px); line-height: 1.32; font-weight: 800; }
.h4 { font-size: clamp(17px, 1.4vw, 21px); line-height: 1.4; font-weight: 700; }

.lead {
  font-size: clamp(16px, 1.35vw, 20px);
  line-height: 1.78;
  color: #333F4C;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--indigo-mid);
}

.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--gold);
  transform: rotate(45deg);
}

.section--deep .eyebrow { color: var(--gold-light); }

/* ---------- 5. 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: 1px solid transparent;
  background: var(--indigo);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: background .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}

.btn:hover { background: var(--indigo-mid); }

.btn--gold { background: var(--gold); border-color: var(--gold); color: #20180A; }
.btn--gold:hover { background: var(--gold-light); border-color: var(--gold-light); color: #20180A; }

.btn--ghost { background: transparent; border-color: var(--line-strong); color: var(--ink); }
.btn--ghost:hover { background: var(--cool); border-color: var(--indigo); color: var(--indigo); }

.btn--light { background: transparent; border-color: var(--line-invert-strong); color: #fff; }
.btn--light:hover { background: rgba(255, 255, 255, .12); border-color: var(--gold-light); }

.btn--sm { padding: 8px 14px; font-size: 13px; }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid var(--line-strong);
  background: transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink);
}

.tag--gold { background: rgba(201, 150, 43, .14); border-color: rgba(201, 150, 43, .55); color: #7A5A12; }
.tag--jade { background: rgba(46, 125, 111, .12); border-color: rgba(46, 125, 111, .45); color: #22604F; }
.tag--cinnabar { background: rgba(192, 57, 43, .12); border-color: rgba(192, 57, 43, .45); color: #8E2A20; }
.tag--invert { border-color: var(--line-invert-strong); color: #D7DEE8; }

/* ---------- 6. 底纹 ---------- */
.pattern-weave {
  background-image:
    repeating-linear-gradient(45deg, rgba(201, 150, 43, .07) 0 1px, transparent 1px 14px),
    repeating-linear-gradient(-45deg, rgba(201, 150, 43, .07) 0 1px, transparent 1px 14px);
}

.pattern-drum {
  background-image: repeating-radial-gradient(circle at center,
    rgba(201, 150, 43, .16) 0 1px,
    transparent 1px 40px);
}

/* ---------- 7. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: -70px;
  transform: translateX(-50%);
  z-index: 200;
  padding: 10px 18px;
  background: var(--gold);
  color: #20180A;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transition: top .2s var(--ease);
}

.skip-link:focus { top: 8px; }

/* ---------- 8. 站点头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--indigo);
  color: #fff;
  border-bottom: 1px solid rgba(255, 255, 255, .16);
}

.header-strip {
  max-height: 80px;
  overflow: hidden;
  background: var(--indigo-deep);
  border-bottom: 1px solid rgba(255, 255, 255, .12);
  transition: max-height .3s var(--ease), opacity .24s var(--ease);
}

.header-strip__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 6px 20px;
  padding: 9px 0;
  font-size: 13px;
}

.header-strip__note {
  display: flex;
  align-items: center;
  gap: 9px;
  color: #E4E9F0;
}

.pulse-dot {
  flex: none;
  width: 7px;
  height: 7px;
  background: var(--gold);
  transform: rotate(45deg);
  box-shadow: 0 0 0 3px rgba(201, 150, 43, .18);
}

.header-strip__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: #9FB0C4;
}

.site-header[data-compact] .header-strip {
  max-height: 0;
  opacity: 0;
  border-bottom-color: transparent;
}

/* 刊头 */
.masthead {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 20px;
  padding: 20px 0 16px;
  transition: padding .3s var(--ease);
}

.site-header[data-compact] .masthead { padding: 10px 0 8px; }

.masthead__side {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: #9FB0C4;
}

.masthead__side--right { justify-content: flex-end; }

.masthead__rule {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 255, 255, .3), transparent);
  transition: opacity .3s var(--ease);
}

.masthead__side--right .masthead__rule {
  background: linear-gradient(270deg, rgba(255, 255, 255, .3), transparent);
}

.site-header[data-compact] .masthead__rule { opacity: 0; }

.masthead__brand { justify-self: center; }

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  color: #fff;
  text-decoration: none;
}

.brand__mark {
  flex: none;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border: 1px solid var(--gold);
  background: rgba(201, 150, 43, .1);
  color: var(--gold-light);
  font-size: 22px;
  font-weight: 900;
  transition: background .16s var(--ease), color .16s var(--ease);
}

.brand:hover .brand__mark { background: var(--gold); color: var(--indigo-deep); }

.brand__text { display: grid; gap: 3px; }

.brand__name {
  font-size: clamp(22px, 2.3vw, 34px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: .05em;
}

.brand__tagline {
  font-size: 12px;
  letter-spacing: .1em;
  color: #9FB0C4;
}

/* 导航 */
.site-nav {
  position: relative;
  border-top: 1px solid rgba(255, 255, 255, .14);
  background: linear-gradient(180deg, rgba(14, 36, 64, .5), rgba(14, 36, 64, .9));
}

.site-nav__bar {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 16px;
  min-height: 54px;
}

.site-nav__label {
  grid-column: 1;
  justify-self: start;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: #9FB0C4;
}

.site-nav__label::before {
  content: "";
  width: 6px;
  height: 6px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}

.site-nav__list {
  grid-column: 2;
  justify-self: center;
  display: flex;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  display: block;
  padding: 16px 13px;
  color: rgba(255, 255, 255, .8);
  font-size: 15px;
  letter-spacing: .03em;
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color .16s var(--ease), background .16s var(--ease), border-color .16s var(--ease);
}

.site-nav__link:hover {
  color: #fff;
  background: rgba(255, 255, 255, .07);
  border-bottom-color: var(--gold-light);
}

.site-nav__link[aria-current="page"] {
  color: #fff;
  background: rgba(201, 150, 43, .12);
  border-bottom-color: var(--gold);
}

.site-nav__cta { grid-column: 3; justify-self: end; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  background: transparent;
  border: 1px solid var(--line-invert-strong);
  color: #fff;
  font-size: 14px;
  letter-spacing: .08em;
  cursor: pointer;
}

.nav-toggle:hover { border-color: var(--gold-light); }

.nav-toggle__bars { display: grid; gap: 3px; width: 18px; }

.nav-toggle__bars i {
  display: block;
  height: 1.5px;
  background: currentColor;
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}

.site-nav[data-open] .nav-toggle__bars i:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.site-nav[data-open] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.site-nav[data-open] .nav-toggle__bars i:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

/* ---------- 9. 站点页脚 ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  background: var(--indigo-deep);
  color: #D7DEE8;
  border-top: 3px solid var(--gold);
  --muted: #8FA0B4;
}

.footer-rings {
  position: absolute;
  top: -140px;
  right: -140px;
  width: 460px;
  height: 460px;
  border-radius: 50%;
  background-image: repeating-radial-gradient(circle at center,
    rgba(201, 150, 43, .16) 0 1px,
    transparent 1px 32px);
  opacity: .6;
  pointer-events: none;
}

.footer-main {
  position: relative;
  z-index: 1;
  padding: clamp(40px, 5vw, 60px) 0 36px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.5fr;
  gap: 36px;
}

.footer-col__title {
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-invert);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gold-light);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  color: #fff;
  text-decoration: none;
}

.footer-brand__mark {
  flex: none;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--gold);
  background: rgba(201, 150, 43, .1);
  color: var(--gold-light);
  font-size: 18px;
  font-weight: 900;
}

.footer-brand__name {
  font-size: 22px;
  font-weight: 900;
  letter-spacing: .04em;
}

.footer-brand__summary {
  max-width: 34ch;
  font-size: 15px;
  line-height: 1.75;
  color: #AFBCCC;
}

.footer-brand__meta {
  margin-top: 16px;
  font-size: 12px;
  color: var(--muted);
}

.footer-list { display: grid; gap: 10px; }

.footer-list__link {
  display: inline-block;
  color: #D7DEE8;
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.footer-list__link:hover {
  color: #fff;
  border-bottom-color: var(--gold);
}

.footer-contact { display: grid; gap: 4px; }

.contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
  padding: 9px 0;
  border-bottom: 1px dashed rgba(255, 255, 255, .13);
  font-size: 15px;
}

.contact-row__key {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--gold-light);
}

.contact-row__val {
  min-width: 0;
  color: #D7DEE8;
  word-break: break-word;
}

.copy-btn {
  flex: none;
  margin-left: auto;
  padding: 3px 10px;
  background: transparent;
  border: 1px solid var(--line-invert-strong);
  color: #D7DEE8;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  cursor: pointer;
  transition: background .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}

.copy-btn:hover { border-color: var(--gold); color: #fff; background: rgba(201, 150, 43, .16); }
.copy-btn.is-copied { background: var(--gold); border-color: var(--gold); color: #20180A; }

.footer-note {
  margin-top: 14px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.footer-legal {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line-invert);
}

.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding: 20px 0 26px;
  font-size: 13px;
  color: var(--muted);
}

.footer-legal__icp {
  font-family: var(--font-mono);
  letter-spacing: .06em;
}

/* ---------- 10. 面包屑 ---------- */
.crumbs {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 14px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--gray);
}

.crumbs__item { display: flex; align-items: center; gap: 8px; }
.crumbs__item + .crumbs__item::before { content: "/"; color: var(--line-strong); }

.crumbs__link { color: var(--gray); text-decoration: none; }
.crumbs__link:hover { color: var(--indigo); text-decoration: underline; }
.crumbs__current { color: var(--ink); font-weight: 600; }

/* ---------- 11. 分屏与网格 ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(0, 38fr) minmax(0, 62fr);
  background: var(--paper);
  border: 1px solid var(--line);
}

.split__aside {
  padding: clamp(28px, 3.4vw, 52px);
  background: var(--indigo-deep);
  color: #E7ECF2;
  border-right: 1px solid var(--line);
}

.split__main { padding: clamp(28px, 3.4vw, 52px); }

.grid { display: grid; gap: var(--gutter); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* ---------- 12. 卡片与标签组 ---------- */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px;
  background: var(--paper);
  border: 1px solid var(--line);
  transition: border-color .16s var(--ease), box-shadow .16s var(--ease);
}

.card:hover { border-color: var(--gold); }

.card__index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--gold);
}

.card__title { font-size: 20px; font-weight: 800; line-height: 1.35; }

.card__text { font-size: 15px; line-height: 1.75; color: #3B4753; }

.card__foot {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gray);
}

/* ---------- 13. 图片容器 ---------- */
.media {
  display: block;
  background: var(--paper);
  border: 1px solid var(--line);
}

.media__frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, rgba(22, 53, 92, .12), rgba(201, 150, 43, .12));
}

.media__frame--pattern {
  background-image:
    repeating-linear-gradient(45deg, rgba(22, 53, 92, .09) 0 1px, transparent 1px 16px),
    repeating-linear-gradient(-45deg, rgba(22, 53, 92, .09) 0 1px, transparent 1px 16px);
}

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

.media--4x3 .media__frame { aspect-ratio: 4 / 3; }
.media--1x1 .media__frame { aspect-ratio: 1 / 1; }
.media--tall .media__frame { aspect-ratio: 3 / 4; }

.media__caption {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--gray);
}

/* ---------- 14. 筛选 ---------- */
.filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.filter__btn {
  padding: 8px 14px;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  color: var(--ink);
  font-size: 14px;
  letter-spacing: .02em;
  cursor: pointer;
  transition: background .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}

.filter__btn:hover { border-color: var(--gold); color: var(--indigo); }

.filter__btn[aria-pressed="true"] {
  background: var(--indigo);
  border-color: var(--indigo);
  color: #fff;
}

.filter__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--gray);
}

[data-filter-item].is-hidden { display: none; }

@keyframes filterIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

[data-filter-item].is-enter { animation: filterIn .22s var(--ease) both; }

/* ---------- 15. 折叠面板 ---------- */
.accordion { border-top: 1px solid var(--line); }

.accordion__item { border-bottom: 1px solid var(--line); }

.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 20px 4px;
  background: none;
  border: 0;
  text-align: left;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  cursor: pointer;
  transition: color .16s var(--ease);
}

.accordion__trigger:hover { color: var(--indigo-mid); }

.accordion__icon {
  position: relative;
  flex: none;
  width: 22px;
  height: 22px;
  border: 1px solid var(--line-strong);
}

.accordion__icon::before,
.accordion__icon::after {
  content: "";
  position: absolute;
  left: 5px;
  right: 5px;
  top: 50%;
  height: 1px;
  background: var(--ink);
  transform: translateY(-50%);
}

.accordion__icon::after {
  transform: translateY(-50%) rotate(90deg);
  transition: transform .18s var(--ease);
}

.accordion__trigger[aria-expanded="true"] .accordion__icon::after { transform: translateY(-50%) rotate(0deg); }
.accordion__trigger[aria-expanded="true"] .accordion__icon { border-color: var(--gold); }

.accordion__panel {
  padding: 0 4px 22px;
  font-size: 16px;
  line-height: 1.85;
  color: #3B4753;
}

.accordion__panel[hidden] { display: none; }

/* ---------- 16. 侧边索引 ---------- */
.rail {
  position: sticky;
  top: 132px;
  padding: 20px 0;
}

.rail__title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gray);
}

.rail__list { display: grid; }

.rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 0 9px 14px;
  border-left: 2px solid var(--line);
  color: var(--gray);
  font-size: 14px;
  line-height: 1.6;
  text-decoration: none;
  transition: color .16s var(--ease), border-color .16s var(--ease), background .16s var(--ease);
}

.rail__link:hover { color: var(--indigo); border-left-color: var(--indigo-mid); }

.rail__link.is-active,
.rail__link[aria-current="true"] {
  color: var(--indigo);
  font-weight: 700;
  border-left-color: var(--gold);
  background: rgba(201, 150, 43, .08);
}

.rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gold);
}

/* ---------- 17. 进度与返回顶部 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 130;
  height: 3px;
  pointer-events: none;
  background: transparent;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--gold), var(--gold-light));
  transition: width .1s linear;
}

.to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 120;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  background: var(--paper);
  border: 1px solid var(--indigo);
  color: var(--indigo);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .2s var(--ease), transform .2s var(--ease), background .16s var(--ease), color .16s var(--ease);
}

.to-top.is-visible { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--indigo); color: #fff; }

/* ---------- 18. 显现动效 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

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

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1023px) {
  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-7, .col-8, .col-5, .col-6, .col-12 { grid-column: span 6; }
  .col-4 { grid-column: span 3; }

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

  .split { grid-template-columns: 1fr; }
  .split__aside { border-right: 0; border-bottom: 1px solid var(--line); }

  .rail { position: static; top: auto; }

  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-col--brand { grid-column: span 2; }
}

@media (max-width: 900px) {
  .site-nav__bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px 12px;
    padding: 10px 0;
    min-height: 0;
  }

  .nav-toggle { display: inline-flex; order: 1; }
  .site-nav__label { display: none; }
  .site-nav__cta { order: 2; margin-left: auto; }

  .site-nav__list {
    order: 3;
    flex: 1 0 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height .3s var(--ease), opacity .2s var(--ease);
  }

  .site-nav[data-open] .site-nav__list {
    max-height: 460px;
    opacity: 1;
  }

  .site-nav__link {
    padding: 14px 6px;
    border-bottom: 1px solid rgba(255, 255, 255, .12);
    border-left: 2px solid transparent;
  }

  .site-nav__link[aria-current="page"] {
    border-bottom-color: rgba(255, 255, 255, .12);
    border-left-color: var(--gold);
  }

  .masthead__side { display: none; }
  .masthead { grid-template-columns: 1fr; }
  .masthead__brand { justify-self: center; }
}

@media (max-width: 699px) {
  body { font-size: 15.5px; }

  .grid--2, .grid--3 { grid-template-columns: 1fr; }
  .grid--12 { grid-template-columns: 1fr; }
  .grid--12 > * { grid-column: 1 / -1; }

  .header-strip__meta { display: none; }
  .brand__mark { width: 40px; height: 40px; font-size: 19px; }
  .brand__tagline { font-size: 11px; }
  .brand { gap: 10px; }

  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-col--brand { grid-column: auto; }

  .footer-legal__inner { justify-content: flex-start; }

  .to-top { right: 14px; bottom: 16px; width: 42px; height: 42px; }

  .filter__count { margin-left: 0; width: 100%; }
}

/* ---------- 20. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

  .js [data-reveal] { opacity: 1; transform: none; }
  .scroll-progress__bar { transition: none; }
}