/* ============================================================
   layout.css — 顶栏 / 区块 / 页脚
   全直角、细线分隔、大留白。
   ============================================================ */

.container {
  width: 100%;
  max-width: var(--w-page);
  margin: 0 auto;
  padding: 0 var(--s7);
}

.container--doc {
  max-width: var(--w-doc);
}

/* ---------- 顶栏 ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 249, 245, 0.88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(160%) blur(12px);
}

/* 深色首屏上的顶栏：嵌在出血区里，透明反白，不吸顶
   （吸顶会在滚过深色区后压在浅色内容上） */
.site-header--onDark {
  position: static;
  background: transparent;
  border-bottom-color: rgba(255, 255, 255, 0.14);
  backdrop-filter: none;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s5);
  height: 78px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-family: var(--font-serif);
  font-size: 1.125rem;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.brand:hover {
  color: var(--ink);
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  background: var(--brand);
  color: #fff;
}

.brand__mark .icon {
  width: 17px;
  height: 17px;
  stroke-width: 1.5;
}

.site-header--onDark .brand,
.site-header--onDark .brand:hover {
  color: #fff;
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--s7);
}

.nav__link {
  position: relative;
  padding: 4px 0;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.28s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.nav__link:hover {
  color: var(--brand);
}

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

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

.site-header--onDark .nav__link {
  color: rgba(255, 255, 255, 0.72);
}

.site-header--onDark .nav__link:hover,
.site-header--onDark .nav__link[aria-current="page"] {
  color: #fff;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 1px solid var(--line-2);
  border-radius: 0;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}

.site-header--onDark .nav-toggle {
  border-color: rgba(255, 255, 255, 0.3);
  color: #fff;
}

/* ---------- 区块 ---------- */

.section {
  padding: var(--s-sec) 0;
}

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

.section--surface {
  background: var(--surface);
}

.section__head {
  max-width: 36em;
  margin-bottom: var(--s8);
}

.section__head p:last-child {
  margin-bottom: 0;
}

/* 标题与说明左右分栏，编辑版式常用 */
.section__head--split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s8);
  max-width: none;
  align-items: end;
}

.section__head--split h2 {
  margin-bottom: 0;
}

.section__head--split p {
  margin-bottom: 0;
  padding-bottom: 6px;
}

/* ---------- 页脚 ---------- */

.site-footer {
  padding: var(--s8) 0 var(--s5);
  background: var(--ink);
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.8125rem;
}

.site-footer__top {
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr;
  gap: var(--s7);
  padding-bottom: var(--s8);
}

.site-footer .brand {
  margin-bottom: var(--s5);
  color: #fff;
}

.site-footer .brand:hover {
  color: #fff;
}

.site-footer h4 {
  margin: 0 0 var(--s5);
  font-family: var(--font-sans);
  font-size: 0.625rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.45);
}

.site-footer p {
  margin: 0;
  max-width: 24em;
  font-size: 0.8125rem;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.5);
}

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

/* 页脚主体信息：每页都展示，备案核验以此为准 */
.site-footer ul.site-footer__contact {
  margin-top: var(--s5);
  max-width: 26em;
  font-size: 0.8125rem;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.5);
}

.site-footer__contact li {
  margin-bottom: var(--s2);
}

.site-footer__contact strong {
  font-weight: 400;
  color: rgba(255, 255, 255, 0.38);
}

.site-footer li {
  margin-bottom: 11px;
}

.site-footer a {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.62);
}

.site-footer a:hover {
  color: #fff;
}

.beian {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s2) var(--s5);
  padding-top: var(--s5);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.38);
}

.beian a {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.38);
}

.beian a:hover {
  color: rgba(255, 255, 255, 0.85);
}

.beian__gongan img {
  display: inline-block;
  width: 16px;
  height: 16px;
  vertical-align: middle;
  margin-right: 3px;
}

@media (max-width: 1000px) {
  .container {
    padding: 0 var(--s5);
  }
  .section__head--split {
    grid-template-columns: 1fr;
    gap: var(--s5);
    align-items: start;
  }
  .section__head--split p {
    padding-bottom: 0;
  }
}

@media (max-width: 900px) {
  .site-footer__top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 720px) {
  .container {
    padding: 0 var(--s4);
  }

  .site-header__inner {
    height: 64px;
  }

  .section__head {
    margin-bottom: var(--s7);
  }

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

  .nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 64px;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0 var(--s4);
    background: var(--paper);
    border-bottom: 1px solid var(--line);
  }

  .nav[hidden] {
    display: none;
  }

  .nav__link {
    padding: var(--s4) 0;
    border-bottom: 1px solid var(--line);
    font-size: 0.8125rem;
    color: var(--ink-2);
  }

  .nav__link:last-child {
    border-bottom: 0;
  }

  .nav__link::after {
    display: none;
  }

  .site-footer__top {
    grid-template-columns: 1fr;
    gap: var(--s6);
  }
}