/* ============================================================
   /assets/site.css — 盛世LL 共享外壳
   reset · 变量 · 中文排版 · 头部 · 页脚 · 通用组件 · 网格
   ============================================================ */

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body,
h1, h2, h3, h4, p,
figure, blockquote,
dl, dd, ol, ul {
  margin: 0;
}

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

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

button, input, select, textarea { font: inherit; color: inherit; }

html { scroll-behavior: smooth; }

/* ---------- 变量 ---------- */
:root {
  /* 色板 */
  --night: #150B26;
  --deep: #211238;
  --magenta: #FF2E88;
  --cyan: #22E0D6;
  --gold: #F5C36B;
  --moss: #4F7A5B;
  --clay: #B4593C;
  --paper: #F4EFE7;
  --ash: #B9B2C7;
  --glass: rgba(244, 239, 231, 0.08);
  --ink: #2A2434;
  --ink-soft: #5A5169;
  --line: rgba(185, 178, 199, 0.2);
  --hair: rgba(244, 239, 231, 0.1);

  /* 字体 */
  --font-display: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", "Cascadia Mono", Consolas, monospace;

  /* 尺度 */
  --header-h: 74px;
  --shell: 1280px;
  --gutter: clamp(18px, 4vw, 56px);
  --radius-s: 14px;
  --radius-l: 28px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 基础排版 ---------- */
body {
  background-color: var(--night);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  padding-top: var(--header-offset, var(--header-h));
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-variant-numeric: tabular-nums;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.015em;
}

p { max-width: 72ch; }

a { color: var(--cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }

strong { font-weight: 700; color: var(--paper); }

::selection { background: var(--magenta); color: #1A0A14; }

/* ---------- 焦点态 ---------- */
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

.section--read a:focus-visible,
.section--read button:focus-visible {
  outline-color: #8C1F52;
}

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

/* ---------- 通用文字 ---------- */
.display {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(44px, 8vw, 150px);
  line-height: 0.94;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-shadow:
    0 0 34px rgba(255, 46, 136, 0.30),
    0 0 96px rgba(34, 224, 214, 0.12);
  max-width: 18ch;
}

.lede {
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.75;
  color: var(--ash);
  max-width: 62ch;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

.label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.75;
}

.prose > * + * { margin-top: 1.05em; }

.prose h2 {
  font-size: clamp(24px, 3vw, 34px);
  margin-top: 1.8em;
}

.prose h3 {
  font-size: clamp(19px, 2.2vw, 24px);
  margin-top: 1.6em;
}

.prose a { color: var(--cyan); }

.section--read .prose a { color: #0F6F6A; }

/* ---------- 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 14px;
  top: -120px;
  z-index: 200;
  padding: 11px 20px;
  border-radius: var(--radius-s);
  background: var(--cyan);
  color: #06201E;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: top 180ms var(--ease);
}

.skip-link:focus {
  top: 14px;
}

/* ============================================================
   头部
   ============================================================ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 90;
  background-image: linear-gradient(
    180deg,
    rgba(21, 11, 38, 0.92) 0%,
    rgba(21, 11, 38, 0.42) 58%,
    rgba(21, 11, 38, 0) 100%
  );
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition:
    background-color 220ms var(--ease),
    border-color 220ms var(--ease),
    backdrop-filter 220ms var(--ease);
}

.site-header[data-scrolled="true"] {
  background-image: none;
  background-color: rgba(21, 11, 38, 0.94);
  border-bottom-color: rgba(34, 224, 214, 0.18);
  backdrop-filter: saturate(150%) blur(16px);
  -webkit-backdrop-filter: saturate(150%) blur(16px);
  box-shadow: 0 18px 40px -32px rgba(0, 0, 0, 0.95);
}

.header-shell {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 24px);
  min-height: var(--header-h);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: 0 0 auto;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  display: inline-flex;
  align-items: flex-end;
  gap: 3px;
  height: 22px;
}

.brand-mark-bar {
  display: block;
  width: 4px;
  border-radius: 3px;
}

.brand-mark-bar:nth-child(1) {
  height: 22px;
  background: var(--magenta);
  box-shadow: 0 0 12px rgba(255, 46, 136, 0.85);
}

.brand-mark-bar:nth-child(2) {
  height: 13px;
  background: var(--cyan);
  box-shadow: 0 0 12px rgba(34, 224, 214, 0.75);
}

.brand-mark-bar:nth-child(3) {
  height: 18px;
  background: var(--gold);
  box-shadow: 0 0 12px rgba(245, 195, 107, 0.65);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  line-height: 1.14;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--paper);
  text-shadow: 0 0 20px rgba(255, 46, 136, 0.55);
}

.brand-line {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ash);
  white-space: nowrap;
}

/* 主导航 */
.site-nav {
  position: relative;
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-list a {
  position: relative;
  display: block;
  padding: 9px 14px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ash);
  text-decoration: none;
  transition:
    color 170ms var(--ease),
    background-color 170ms var(--ease);
}

.nav-list a:hover {
  color: var(--paper);
  background-color: rgba(244, 239, 231, 0.07);
}

.nav-list a[aria-current="page"] {
  color: var(--paper);
  background-color: rgba(255, 46, 136, 0.15);
  box-shadow: inset 0 0 0 1px rgba(255, 46, 136, 0.35);
}

.nav-rail {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--magenta), var(--cyan));
  box-shadow: 0 0 10px rgba(255, 46, 136, 0.7);
  opacity: 0;
  pointer-events: none;
}

.nav-rail.is-ready {
  opacity: 1;
  transition: left 220ms var(--ease), width 220ms var(--ease);
}

/* 右侧短入口 */
.header-utility {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

.util-link {
  display: inline-flex;
  align-items: center;
  padding: 9px 15px;
  border-radius: 999px;
  border: 1px solid rgba(34, 224, 214, 0.38);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--cyan);
  text-decoration: none;
  white-space: nowrap;
  transition:
    background-color 170ms var(--ease),
    color 170ms var(--ease),
    border-color 170ms var(--ease),
    transform 170ms var(--ease);
}

.util-link:hover {
  background-color: rgba(34, 224, 214, 0.14);
  color: var(--paper);
  transform: translateY(-1px);
}

.util-link--accent {
  background-color: var(--magenta);
  border-color: var(--magenta);
  color: #1A0A14;
  box-shadow: 0 12px 30px -16px rgba(255, 46, 136, 0.9);
}

.util-link--accent:hover {
  background-color: #ff4d9b;
  border-color: #ff4d9b;
  color: #1A0A14;
}

/* 移动端开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 13px;
  border-radius: 12px;
  border: 1px solid rgba(185, 178, 199, 0.28);
  background-color: rgba(244, 239, 231, 0.05);
  color: var(--paper);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: border-color 170ms var(--ease), background-color 170ms var(--ease);
}

.nav-toggle:hover {
  border-color: rgba(34, 224, 214, 0.6);
  background-color: rgba(34, 224, 214, 0.1);
}

.nav-toggle-bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle-bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 180ms var(--ease);
}

.site-header[data-open="true"] .nav-toggle-bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}

.site-header[data-open="true"] .nav-toggle-bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

/* 阅读进度 */
.header-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
}

.header-progress span {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--magenta), var(--cyan) 58%, var(--gold));
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  background-color: var(--night);
  background-image:
    radial-gradient(90% 70% at 8% 0%, rgba(255, 46, 136, 0.16), transparent 62%),
    radial-gradient(80% 64% at 94% 8%, rgba(34, 224, 214, 0.13), transparent 60%);
  border-top: 1px solid rgba(34, 224, 214, 0.18);
  color: var(--ash);
  padding-block: clamp(42px, 6vw, 78px) 0;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) 2fr;
  gap: clamp(30px, 5vw, 76px);
  align-items: start;
}

.footer-brand {
  display: grid;
  gap: 14px;
  align-content: start;
}

.footer-wordmark {
  font-family: var(--font-display);
  font-size: clamp(44px, 7vw, 96px);
  font-weight: 900;
  line-height: 0.92;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-shadow: 0 0 44px rgba(255, 46, 136, 0.4);
}

.footer-tagline {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ash);
  max-width: 26ch;
}

.footer-rail {
  display: block;
  width: min(240px, 70%);
  height: 3px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--magenta), var(--cyan) 52%, var(--gold) 78%, transparent);
}

.footer-contact {
  display: grid;
  gap: 7px;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(185, 178, 199, 0.92);
  word-break: break-word;
}

.footer-contact span { max-width: 34ch; }

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 42px);
}

.footer-col-title {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 16px;
}

.footer-links {
  display: grid;
  gap: 11px;
}

.footer-links a {
  font-size: 15px;
  color: var(--ash);
  text-decoration: none;
  transition: color 170ms var(--ease), padding-left 170ms var(--ease);
}

.footer-links a:hover {
  color: var(--cyan);
  padding-left: 4px;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  margin-top: clamp(34px, 5vw, 60px);
  padding-block: 20px 30px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: rgba(185, 178, 199, 0.85);
}

.footer-copy { margin: 0; }

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
}

.footer-icp { font-variant-numeric: tabular-nums; }

.footer-note { color: rgba(185, 178, 199, 0.7); }

/* ============================================================
   通用组件
   ============================================================ */

/* 区块节奏 */
.section {
  position: relative;
  padding-block: clamp(48px, 8vw, 112px);
}

.section--night { background-color: var(--night); }

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

.section--read {
  background-color: var(--paper);
  color: var(--ink);
}

.section--read .section-title { color: var(--ink); }

.section--read .lede,
.section--read .section-note,
.section--read .card-body { color: var(--ink-soft); }

.section--read .eyebrow { color: #A3175C; }

.section--read .section-num { color: #8C1F52; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 16px 30px;
  margin-bottom: clamp(24px, 4vw, 48px);
}

.section-num {
  font-family: var(--font-mono);
  font-weight: 200;
  font-size: clamp(20px, 3vw, 28px);
  letter-spacing: 0.28em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  flex: 0 0 auto;
}

.section-title {
  flex: 1 1 300px;
  font-size: clamp(28px, 4.6vw, 56px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.section-note {
  flex: 1 1 240px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ash);
  max-width: 46ch;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 25px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: none;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-decoration: none;
  cursor: pointer;
  transition:
    transform 180ms var(--ease),
    background-color 180ms var(--ease),
    border-color 180ms var(--ease),
    color 180ms var(--ease);
}

.btn--primary {
  background-color: var(--magenta);
  color: #1A0A14;
  box-shadow: 0 16px 36px -18px rgba(255, 46, 136, 0.95);
}

.btn--primary:hover {
  background-color: #ff4d9b;
  transform: translateY(-2px);
}

.btn--ghost {
  border-color: rgba(34, 224, 214, 0.42);
  color: var(--cyan);
}

.btn--ghost:hover {
  background-color: rgba(34, 224, 214, 0.12);
  color: var(--paper);
  transform: translateY(-2px);
}

.btn--quiet {
  border-color: rgba(185, 178, 199, 0.28);
  color: var(--ash);
}

.btn--quiet:hover {
  border-color: rgba(244, 239, 231, 0.55);
  color: var(--paper);
  transform: translateY(-2px);
}

.section--read .btn--ghost {
  border-color: rgba(140, 31, 82, 0.4);
  color: #8C1F52;
}

.section--read .btn--ghost:hover {
  background-color: rgba(140, 31, 82, 0.1);
  color: #6E1640;
}

/* 标签 */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid var(--hair);
  background-color: var(--glass);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--paper);
  white-space: nowrap;
}

.chip--cyan {
  background-color: rgba(34, 224, 214, 0.14);
  border-color: rgba(34, 224, 214, 0.4);
  color: var(--cyan);
}

.chip--gold {
  background-color: rgba(245, 195, 107, 0.16);
  border-color: rgba(245, 195, 107, 0.42);
  color: var(--gold);
}

.chip--magenta {
  background-color: rgba(255, 46, 136, 0.16);
  border-color: rgba(255, 46, 136, 0.44);
  color: #FF7FB6;
}

.chip--clay {
  background-color: rgba(180, 89, 60, 0.24);
  border-color: rgba(180, 89, 60, 0.55);
  color: #E9A184;
}

.chip--moss {
  background-color: rgba(79, 122, 91, 0.26);
  border-color: rgba(79, 122, 91, 0.6);
  color: #9BC7A6;
}

/* 数字徽章 */
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 27px;
  height: 24px;
  padding: 0 9px;
  border-radius: 8px;
  background-color: var(--gold);
  color: #2A1B02;
  font-size: 12px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.badge--ring {
  background-color: transparent;
  border: 1px solid rgba(245, 195, 107, 0.55);
  color: var(--gold);
}

/* 卡片 */
.card {
  position: relative;
  border-radius: var(--radius-l);
  border: 1px solid var(--line);
  background-color: var(--deep);
  padding: clamp(20px, 3vw, 34px);
  transition:
    transform 190ms var(--ease),
    border-color 190ms var(--ease),
    background-color 190ms var(--ease),
    box-shadow 190ms var(--ease);
}

.card:hover,
.card:focus-within {
  transform: translateY(-4px);
  border-color: rgba(34, 224, 214, 0.55);
  box-shadow: 0 28px 54px -38px rgba(34, 224, 214, 0.85);
}

.card--glass {
  background-color: var(--glass);
  border-color: rgba(244, 239, 231, 0.14);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.card--solid {
  background-color: var(--paper);
  border-color: rgba(42, 36, 52, 0.12);
  color: var(--ink);
}

.card--sm { border-radius: var(--radius-s); }

.card-title {
  font-size: clamp(19px, 2.4vw, 25px);
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: -0.012em;
  margin-bottom: 10px;
}

.card-body {
  font-size: 15px;
  line-height: 1.72;
  color: var(--ash);
}

.card-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 20px;
}

/* 网格 */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(14px, 2vw, 26px);
}

.col-3 { grid-column: span 3; }
.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; }

/* 轨道块 */
.rail-block { position: relative; }

.rail-scroller {
  display: flex;
  gap: clamp(12px, 1.8vw, 20px);
  overflow-x: auto;
  scroll-snap-type: x proximity;
  padding-bottom: 12px;
  scrollbar-width: thin;
  scrollbar-color: rgba(34, 224, 214, 0.4) transparent;
}

.rail-scroller::-webkit-scrollbar { height: 6px; }
.rail-scroller::-webkit-scrollbar-track { background: transparent; }
.rail-scroller::-webkit-scrollbar-thumb {
  background: rgba(34, 224, 214, 0.35);
  border-radius: 6px;
}

.rail-item {
  flex: 0 0 min(286px, 78vw);
  scroll-snap-align: start;
}

/* 索引列表 */
.index-list {
  border-top: 1px solid var(--line);
}

.index-list li {
  border-bottom: 1px solid var(--line);
}

.index-list a {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: baseline;
  gap: 16px;
  padding: 18px 10px;
  color: var(--paper);
  text-decoration: none;
  transition:
    background-color 180ms var(--ease),
    padding-left 180ms var(--ease),
    color 180ms var(--ease);
}

.index-list a:hover {
  background-color: rgba(244, 239, 231, 0.05);
  padding-left: 18px;
  color: var(--cyan);
}

.index-num {
  font-family: var(--font-mono);
  font-weight: 200;
  font-size: 20px;
  letter-spacing: 0.2em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

/* 图片容器 */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-l);
  border: 1px solid var(--hair);
  aspect-ratio: 16 / 9;
  background-color: var(--deep);
  background-image:
    radial-gradient(120% 92% at 18% 0%, rgba(255, 46, 136, 0.24), transparent 60%),
    radial-gradient(102% 84% at 86% 100%, rgba(34, 224, 214, 0.2), transparent 62%);
}

.media-frame__img,
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

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

/* 面包屑 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 20px;
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--ash);
}

.breadcrumb li {
  display: flex;
  align-items: center;
}

.breadcrumb li + li::before {
  content: "/";
  margin: 0 10px;
  color: rgba(185, 178, 199, 0.45);
}

.breadcrumb a {
  color: var(--ash);
  text-decoration: none;
  transition: color 160ms var(--ease);
}

.breadcrumb a:hover { color: var(--cyan); }

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

.section--read .breadcrumb { color: var(--ink-soft); }
.section--read .breadcrumb a { color: var(--ink-soft); }
.section--read .breadcrumb a:hover { color: #8C1F52; }
.section--read .breadcrumb [aria-current="page"] { color: var(--ink); }

/* 淡入 */
html.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
}

html.js-ready [data-reveal].is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 380ms var(--ease), transform 380ms var(--ease);
}

html.js-ready [data-reveal][data-delay="1"].is-visible { transition-delay: 70ms; }
html.js-ready [data-reveal][data-delay="2"].is-visible { transition-delay: 140ms; }
html.js-ready [data-reveal][data-delay="3"].is-visible { transition-delay: 210ms; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1180px) {
  .brand-line { display: none; }
}

@media (max-width: 1024px) {
  .col-3, .col-4, .col-5 { grid-column: span 6; }
  .col-6, .col-7, .col-8 { grid-column: span 12; }
}

@media (max-width: 900px) {
  :root { --header-h: 64px; }

  .header-shell {
    gap: 10px;
  }

  .header-utility { margin-left: auto; }

  .util-link {
    padding: 8px 13px;
    font-size: 12px;
  }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    margin-left: 0;
    padding: 10px var(--gutter) 20px;
    background-color: rgba(21, 11, 38, 0.98);
    border-bottom: 1px solid rgba(34, 224, 214, 0.22);
    box-shadow: 0 34px 60px -34px rgba(0, 0, 0, 0.95);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition:
      opacity 180ms var(--ease),
      transform 180ms var(--ease),
      visibility 180ms;
  }

  .site-header[data-open="true"] .site-nav {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .nav-list a {
    padding: 13px 15px;
    font-size: 15px;
    border-radius: var(--radius-s);
  }

  .nav-list a[aria-current="page"] {
    box-shadow: inset 3px 0 0 var(--magenta);
    background-color: rgba(255, 46, 136, 0.16);
  }

  .nav-rail { display: none; }

  .footer-top {
    grid-template-columns: 1fr;
  }

  .footer-cols {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }
}

@media (max-width: 640px) {
  body { font-size: 16px; }

  .stack-grid > * { grid-column: span 12; }

  .section-num { letter-spacing: 0.2em; }

  .brand-name { font-size: 18px; }

  .nav-toggle-label { display: none; }

  .util-link {
    padding: 7px 11px;
    font-size: 11.5px;
    letter-spacing: 0.02em;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .index-list a { grid-template-columns: auto 1fr; }
}

/* ============================================================
   动效偏好
   ============================================================ */
@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;
    transition-delay: 0ms !important;
  }

  html.js-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .card:hover,
  .card:focus-within,
  .btn:hover,
  .util-link:hover,
  .footer-links a:hover {
    transform: none;
  }
}