/* ==========================================================================
   888手机客指南 · 共享样式 /assets/site.css
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body, h1, h2, h3, h4, h5, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button, input { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #08182B;
  --ink-soft: #0D2B31;
  --indigo: #1D1738;
  --wine: #3F1B2A;
  --fog: #EAF2F6;
  --slate: #8FA6B8;
  --cyan: #38E1D0;
  --pulse: #5BFFC8;
  --amber: #F3B64B;
  --orange: #FF8A3D;
  --line: #1D3B52;
  --green: #7FE0A3;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", system-ui, -apple-system, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", system-ui, -apple-system, "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  --maxw: 1440px;
  --gutter: 5vw;
  --gap: 24px;
  --masthead-h: 76px;
  --ease: cubic-bezier(.4, 0, .2, 1);
}

/* ---------- 3. 中文基础排版 ---------- */
body {
  background-color: var(--ink);
  color: var(--fog);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: .02em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 300;
  line-height: 1.15;
  letter-spacing: .06em;
  font-stretch: condensed;
}
h1 { font-size: clamp(38px, 6vw, 96px); }
h2 { font-size: clamp(26px, 3.4vw, 42px); }
h3 { font-size: clamp(19px, 2vw, 24px); font-weight: 400; letter-spacing: .04em; }
p { max-width: 68ch; }
strong { color: var(--fog); font-weight: 600; }

:where(a) { transition: color .2s var(--ease); }
:focus-visible { outline: 2px solid var(--pulse); outline-offset: 3px; }

.mono { font-family: var(--font-mono); font-size: .82em; letter-spacing: .04em; color: var(--amber); }

.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  margin: -1px; padding: 0; overflow: hidden;
  clip-path: inset(50%); white-space: nowrap; border: 0;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-body);
  font-size: 11px; letter-spacing: .18em;
  color: var(--slate);
  text-transform: uppercase;
}
.eyebrow::before { content: ""; width: 18px; height: 1px; background: var(--cyan); }

.lede {
  font-size: 16px; line-height: 1.85;
  color: var(--slate);
  max-width: 68ch;
}

/* ---------- 4. 布局容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section { padding: clamp(48px, 7vw, 104px) 0; }

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

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

/* ---------- 5. 章节色带与章节头 ---------- */
.band {
  display: block;
  height: 8px;
  border: 0;
  background-image: repeating-linear-gradient(90deg, currentColor 0 3px, transparent 3px 14px);
  opacity: .55;
}
.band--teal { color: var(--cyan); background-color: var(--ink-soft); opacity: .9; }
.band--indigo { color: #7A6BD8; background-color: var(--indigo); }
.band--wine { color: #C4698A; background-color: var(--wine); }

.chapter-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 18px;
  padding-bottom: 18px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--line);
}
.chapter-no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--amber);
}
.chapter-title { margin: 0; }
.chapter-lede {
  flex: 1 1 320px;
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate);
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  border: 1px solid var(--line);
  background-color: transparent;
  color: var(--fog);
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: .18em;
  line-height: 1;
  border-radius: 0;
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease), transform .2s var(--ease);
}
.btn::after {
  content: "→";
  font-family: var(--font-mono);
  font-size: 12px;
  transition: transform .2s var(--ease);
}
.btn:hover { border-color: var(--cyan); color: var(--cyan); }
.btn:hover::after { transform: translateX(4px); }

.btn--pulse {
  border-color: var(--pulse);
  color: var(--pulse);
  background-color: rgba(91, 255, 200, .07);
}
.btn--pulse:hover { background-color: rgba(91, 255, 200, .16); color: var(--pulse); }

.btn--ghost { border-color: transparent; padding-left: 0; color: var(--slate); }
.btn--ghost:hover { color: var(--cyan); }

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 22px 0 6px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--slate);
}
.breadcrumb a { color: var(--slate); }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb__sep { color: var(--line); }
.breadcrumb [aria-current="page"] { color: var(--fog); }

/* ---------- 8. 资料卡 ---------- */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  background-color: rgba(13, 43, 49, .45);
  border: 1px solid var(--line);
  border-radius: 0;
  transition: border-color .22s var(--ease), background-color .22s var(--ease), transform .22s var(--ease);
}
.card:hover {
  border-color: rgba(56, 225, 208, .55);
  background-color: rgba(13, 43, 49, .78);
  transform: translateY(-2px);
}
.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--amber);
}
.card__title { margin: 0; font-size: 17px; font-weight: 500; letter-spacing: .04em; line-height: 1.4; }
.card__text { margin: 0; font-size: 14px; line-height: 1.78; color: var(--slate); }

/* ---------- 9. 左侧时间轴索引 ---------- */
.rail {
  position: sticky;
  top: calc(var(--masthead-h) + 20px);
  display: grid;
  border-left: 1px solid var(--line);
  padding-left: 2px;
}
.rail__link {
  position: relative;
  display: grid;
  gap: 2px;
  padding: 10px 0 10px 18px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--slate);
}
.rail__link::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 18px;
  width: 5px;
  height: 5px;
  background-color: var(--line);
  transition: background-color .2s var(--ease), box-shadow .2s var(--ease);
}
.rail__link:hover { color: var(--fog); }
.rail__link[aria-current="true"] { color: var(--fog); }
.rail__link[aria-current="true"]::before {
  background-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(56, 225, 208, .18);
}
.rail__num { font-family: var(--font-mono); font-size: 11px; letter-spacing: .06em; color: rgba(143, 166, 184, .8); }

/* ---------- 10. 折叠面板 ---------- */
.fold { border: 1px solid var(--line); border-top: 0; }
.fold__head {
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px 18px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  letter-spacing: .1em;
  text-align: left;
  transition: background-color .2s var(--ease), color .2s var(--ease);
}
.fold__head:hover { background-color: rgba(13, 43, 49, .7); color: var(--cyan); }
.fold__sign {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
  transition: transform .24s var(--ease);
}
.fold__head[aria-expanded="true"] .fold__sign { transform: rotate(45deg); }
.fold__body { padding: 0 18px 18px; font-size: 14px; line-height: 1.78; color: var(--slate); }
.fold__body[hidden] { display: none; }

/* ---------- 11. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  width: 100%;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line);
  background-image: linear-gradient(155deg, var(--ink-soft) 0%, var(--indigo) 100%);
}
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.9) contrast(1.04);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(234, 242, 246, .07) 0 1px, transparent 1px 44px),
    repeating-linear-gradient(0deg, rgba(234, 242, 246, .07) 0 1px, transparent 1px 44px);
}

/* ---------- 12. 纹理工具 ---------- */
.texture-lattice {
  background-image:
    repeating-linear-gradient(45deg, rgba(234, 242, 246, .05) 0 1px, transparent 1px 16px),
    repeating-linear-gradient(-45deg, rgba(234, 242, 246, .05) 0 1px, transparent 1px 16px);
}

/* ---------- 13. 显现状态（由 JS 写入） ---------- */
[data-reveal="hidden"] { opacity: 0; transform: translateY(14px); }
[data-reveal="in"] {
  opacity: 1;
  transform: none;
  transition: opacity .45s var(--ease), transform .45s var(--ease);
}

/* ==========================================================================
   14. 头部
   ========================================================================== */
.skip-link {
  position: absolute;
  left: var(--gutter);
  top: 8px;
  z-index: 200;
  padding: 10px 16px;
  background-color: var(--pulse);
  color: var(--ink);
  font-size: 12px;
  letter-spacing: .16em;
  transform: translateY(-160%);
  transition: transform .2s var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); outline-offset: 2px; }

.masthead {
  position: sticky;
  top: 0;
  z-index: 120;
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
}
.masthead.is-stuck {
  background-color: rgba(8, 24, 43, .97);
  border-bottom-color: var(--line);
  box-shadow: 0 22px 48px -38px #000;
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background-image: linear-gradient(90deg, var(--cyan), var(--pulse));
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
}

.masthead__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
  min-height: var(--masthead-h);
}

/* 品牌 */
.brand { display: inline-flex; align-items: center; gap: 12px; flex: 0 0 auto; }
.brand__mark {
  position: relative;
  width: 22px;
  height: 22px;
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(56, 225, 208, .07);
}
.brand__mark::before,
.brand__mark::after {
  content: "";
  position: absolute;
  background-color: var(--cyan);
  opacity: .85;
}
.brand__mark::before { left: 50%; top: 0; width: 1px; height: 100%; }
.brand__mark::after { top: 50%; left: 0; height: 1px; width: 100%; }
.brand__name {
  display: block;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 500;
  letter-spacing: .16em;
  line-height: 1.2;
  color: var(--fog);
  white-space: nowrap;
}
.brand__sub {
  display: block;
  margin-top: 3px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 400;
  letter-spacing: .18em;
  color: var(--slate);
}

/* 主导航 */
.masthead__nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  min-width: 0;
}
.nav-list { display: flex; align-items: center; gap: clamp(10px, 1.5vw, 26px); }
.nav-link {
  position: relative;
  display: inline-block;
  padding: 6px 0;
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--slate);
  white-space: nowrap;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background-color: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .28s var(--ease);
}
.nav-link:hover,
.nav-link:focus-visible { color: var(--fog); }
.nav-link:hover::after,
.nav-link:focus-visible::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--fog); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); background-color: var(--pulse); }

/* 右侧工具带 */
.masthead__tools {
  position: relative;
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 检索 */
.search-shell { position: relative; width: clamp(200px, 21vw, 300px); }
.search-shell__label {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.search-input {
  width: 100%;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 0;
  background-color: rgba(234, 242, 246, .04);
  color: var(--fog);
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: .04em;
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
  -webkit-appearance: none;
  appearance: none;
}
.search-input::placeholder { color: rgba(143, 166, 184, .78); letter-spacing: .06em; }
.search-input:hover { border-color: rgba(56, 225, 208, .45); }
.search-input:focus { outline: none; border-color: var(--pulse); background-color: rgba(91, 255, 200, .07); }

.search-shell::before {
  content: "";
  position: absolute;
  inset: -1px;
  border: 1px solid var(--pulse);
  opacity: 0;
  pointer-events: none;
}
.search-shell:not(.is-live)::before { animation: search-pulse 1.6s ease-in-out infinite; }
@keyframes search-pulse {
  0%, 100% { opacity: 0; transform: scale(1); }
  45% { opacity: .5; transform: scale(1.014); }
}

.search-panel {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: min(360px, 86vw);
  padding: 14px;
  background-color: rgba(13, 43, 49, .99);
  border: 1px solid var(--line);
  box-shadow: 0 28px 64px -40px #000;
  display: none;
}
.search-panel[data-open="true"] { display: block; }
.search-panel__hint {
  margin: 0 0 10px;
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--slate);
}
.search-panel__tags { display: flex; flex-wrap: wrap; gap: 8px; }

.tag-chip {
  display: inline-flex;
  align-items: center;
  padding: 5px 11px;
  border: 1px solid var(--line);
  border-radius: 0;
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--slate);
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.tag-chip:hover { color: var(--fog); border-color: rgba(56, 225, 208, .55); }
.tag-chip[aria-pressed="true"] { background-color: var(--cyan); border-color: var(--cyan); color: var(--ink); }

/* 移动检索按钮 */
.search-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--slate);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.search-toggle:hover { color: var(--cyan); border-color: var(--cyan); }

/* 头像 */
.avatar-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 50%;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.avatar-btn:hover { border-color: var(--cyan); box-shadow: 0 0 0 4px rgba(56, 225, 208, .1); }
.avatar-btn[aria-expanded="true"] { border-color: var(--pulse); }
.avatar-btn__glyph { position: relative; width: 20px; height: 20px; }
.avatar-btn__glyph::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 2px;
  width: 7px;
  height: 7px;
  margin-left: -3.5px;
  border-radius: 50%;
  background-color: var(--slate);
  transition: background-color .2s var(--ease);
}
.avatar-btn__glyph::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 11px;
  width: 14px;
  height: 7px;
  margin-left: -7px;
  border-radius: 8px 8px 0 0;
  background-color: var(--slate);
  transition: background-color .2s var(--ease);
}
.avatar-btn:hover .avatar-btn__glyph::before,
.avatar-btn:hover .avatar-btn__glyph::after,
.avatar-btn[aria-expanded="true"] .avatar-btn__glyph::before,
.avatar-btn[aria-expanded="true"] .avatar-btn__glyph::after { background-color: var(--cyan); }
.avatar-btn__dot {
  position: absolute;
  right: -1px;
  bottom: -1px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: var(--green);
  border: 2px solid var(--ink);
}

/* 视图面板 */
.view-panel {
  position: absolute;
  top: calc(100% + 12px);
  right: 0;
  width: 300px;
  padding: 16px;
  background-color: rgba(13, 43, 49, .99);
  border: 1px solid var(--line);
  box-shadow: 0 28px 64px -40px #000;
  display: none;
}
.view-panel[data-open="true"] { display: block; }
.view-panel__title {
  margin: 0 0 12px;
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--slate);
}
.view-switch {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
  overflow: hidden;
}
.view-switch__thumb {
  position: absolute;
  top: 0;
  left: 0;
  width: 50%;
  height: 100%;
  background-color: rgba(56, 225, 208, .16);
  border-right: 1px solid var(--cyan);
  transform: translateX(0);
  transition: transform .32s var(--ease), border-color .32s var(--ease);
}
.view-switch[data-view="mobile"] .view-switch__thumb {
  transform: translateX(100%);
  border-right: 0;
  border-left: 1px solid var(--cyan);
}
.view-switch__opt {
  position: relative;
  z-index: 1;
  padding: 11px 6px;
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--slate);
  transition: color .2s var(--ease);
}
.view-switch__opt[aria-pressed="true"] { color: var(--pulse); }
.view-panel__meta {
  margin: 12px 0 4px;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--slate);
}
.view-panel__note {
  margin: 0;
  font-size: 11px;
  line-height: 1.7;
  color: rgba(143, 166, 184, .8);
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--line);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--fog);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle__bars { display: grid; gap: 4px; width: 16px; }
.nav-toggle__bars span {
  display: block;
  height: 1px;
  background-color: currentColor;
  transition: transform .24s var(--ease), opacity .24s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* ==========================================================================
   15. 页脚
   ========================================================================== */
.footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 96px);
  border-top: 1px solid rgba(143, 166, 184, .35);
  background-color: var(--ink-soft);
  color: var(--fog);
  overflow: hidden;
}
.footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(234, 242, 246, .055) 0 1px, transparent 1px 58px),
    repeating-linear-gradient(0deg, rgba(234, 242, 246, .055) 0 1px, transparent 1px 58px),
    repeating-linear-gradient(45deg, rgba(56, 225, 208, .05) 0 1px, transparent 1px 104px);
  opacity: .9;
}
.footer__inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr) minmax(0, 1.3fr) minmax(0, 1fr);
  gap: clamp(24px, 3vw, 48px);
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(40px, 6vw, 72px) var(--gutter) clamp(28px, 4vw, 48px);
}
.footer__col { min-width: 0; }
.footer__wordmark {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 500;
  letter-spacing: .18em;
  color: var(--fog);
}
.footer__desc {
  margin: 0 0 16px;
  max-width: 34ch;
  font-size: 13px;
  line-height: 1.85;
  color: var(--slate);
}
.footer__stamp {
  margin: 0;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--slate);
}
.footer__title {
  margin: 0 0 16px;
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .2em;
  color: var(--slate);
  line-height: 1.6;
}
.footer__links { display: grid; gap: 11px; }
.footer__links a {
  display: inline-block;
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--fog);
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.footer__links a:hover { color: var(--cyan); border-bottom-color: var(--cyan); }

.footer__contact { display: grid; gap: 11px; font-size: 13px; line-height: 1.7; color: var(--fog); }
.footer__contact li { display: flex; flex-wrap: wrap; gap: 4px 10px; }
.footer__key {
  flex: 0 0 auto;
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--slate);
  padding-top: 3px;
}
.footer__icp { margin: 18px 0 0; font-size: 12px; letter-spacing: .08em; color: var(--slate); }

.footer__base {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 18px var(--gutter) 26px;
  border-top: 1px solid rgba(143, 166, 184, .2);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--slate);
}
.footer__base p { margin: 0; max-width: none; }

/* ==========================================================================
   16. 响应式
   ========================================================================== */
@media (max-width: 1023px) {
  :root { --gap: 18px; }

  .masthead__tools { position: static; }
  .masthead__inner { gap: 12px; }

  .masthead__nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: 8px var(--gutter) 22px;
    background-color: rgba(8, 24, 43, .99);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 32px 64px -44px #000;
  }
  .masthead__nav[data-open="true"] { display: flex; }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav-link {
    display: block;
    padding: 15px 0;
    font-size: 14px;
    border-bottom: 1px solid var(--line);
  }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] { color: var(--pulse); }

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

  .search-shell {
    position: absolute;
    left: var(--gutter);
    right: var(--gutter);
    top: calc(100% + 6px);
    width: auto;
    display: none;
    z-index: 4;
  }
  .search-shell[data-open="true"] { display: block; }
  .search-shell::before { inset: -2px; }
  .search-input { height: 44px; font-size: 14px; }
  .search-panel { left: 0; right: 0; width: auto; top: calc(100% + 8px); }

  .view-panel { left: var(--gutter); right: var(--gutter); width: auto; top: calc(100% + 6px); }

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

  [class*="col-span-"] { grid-column: span 12; }
  .rail { position: static; border-left: 0; padding-left: 0; }
  .rail__link { padding-left: 0; }
  .rail__link::before { display: none; }
}

@media (max-width: 767px) {
  :root { --masthead-h: 64px; --gutter: 18px; }

  body { font-size: 15px; line-height: 1.78; }

  .brand__name { font-size: 14px; letter-spacing: .1em; }
  .brand__sub { display: none; }
  .brand { gap: 9px; }
  .brand__mark { width: 18px; height: 18px; }

  .nav-toggle__text { display: none; }
  .nav-toggle { width: 38px; padding: 0; justify-content: center; }

  .btn { padding: 12px 18px; }

  .footer__inner { grid-template-columns: 1fr; gap: 32px; }
  .footer__desc { max-width: none; }
  .footer__base { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 400px) {
  .avatar-btn { width: 34px; height: 34px; }
  .search-toggle, .nav-toggle { width: 34px; height: 34px; }
}

/* ---------- 17. 动效可访问性 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .search-shell::before { animation: none; opacity: 0; }
  [data-reveal="hidden"] { opacity: 1; transform: none; }
  .card:hover { transform: none; }
}