/* ============================================================
   ARGX 官网首页 —— 深色主题
   ------------------------------------------------------------
   版式与取值来自 design/prototype/index.html（视觉真源）。
   token 从 ../design/tokens.css 取，本文件不定义任何色值/间距字面量。
   主题：<html data-theme="dark"> 由 tokens.css 提供深色变量。
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0 }
html { scroll-behavior: smooth }
body {
  background: var(--bg-app);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: var(--text-lg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { text-decoration: none; color: inherit }
button { font-family: inherit; background: none; border: none; cursor: pointer; color: inherit }
a:focus-visible, button:focus-visible { outline: none; box-shadow: var(--shadow-focus); border-radius: var(--radius-sm) }

/* ============================================================
   1. 背景层 —— 单点冷调柔光 + 四角收敛 + 88px 网格 + 4.5% 噪点
   全静态：零 rAF、零 canvas、零彩色渐变（配色方案 §6）
   ============================================================ */
.bg {
  position: fixed; inset: 0; z-index: var(--z-base);
  pointer-events: none; overflow: hidden;
  background: var(--bg-app);
}
/* 唯一一处光：顶部中央一束冷调柔光，像顶灯打在墙上 */
.bg-light {
  position: absolute; left: 50%; top: -38%; width: 150%; height: 108%;
  transform: translateX(-50%);
  background:
    radial-gradient(58% 56% at 50% 50%, rgba(228, 232, 238, .115), transparent 72%),
    radial-gradient(34% 34% at 50% 50%, rgba(238, 241, 245, .075), transparent 78%);
}
/* 光锥底部一条极淡的水平切线，给光一个落点 */
.bg-light::after {
  content: ""; position: absolute; left: 50%; bottom: 6%;
  width: min(62vw, 760px); height: 1px; transform: translateX(-50%);
  background: linear-gradient(90deg, transparent,
    rgba(255, 255, 255, .075) 30%, rgba(255, 255, 255, .11) 50%,
    rgba(255, 255, 255, .075) 70%, transparent);
}
/* 88px 细网格，径向 mask 收敛到中心 */
.bg-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, .024) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .024) 1px, transparent 1px);
  background-size: 88px 88px;
  -webkit-mask-image: radial-gradient(ellipse 82% 58% at 50% 28%, #000 6%, transparent 76%);
          mask-image: radial-gradient(ellipse 82% 58% at 50% 28%, #000 6%, transparent 76%);
}
/* 噪点：唯一的「材质」层，把大平面从死板纯色里救出来 */
.bg-noise {
  position: absolute; inset: 0; opacity: .045;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.78' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)'/%3E%3C/svg%3E");
}
/* 四角收敛：压住中心，注意力留在内容上 */
.bg-vignette {
  position: absolute; inset: 0;
  background:
    radial-gradient(128% 104% at 50% 42%, transparent 42%, rgba(0, 0, 0, .52) 100%),
    linear-gradient(180deg, rgba(0, 0, 0, .46) 0%, transparent 20%),
    linear-gradient(0deg, rgba(0, 0, 0, .50) 0%, transparent 24%);
}

/* ============================================================
   2. 开场动画层（首访播放 · 可跳过）
   ------------------------------------------------------------
   三词**永远在页面正中央原位替换**，不位移、不堆叠。
   层内除三词与跳过按钮外**没有任何其他元素**——这是硬要求
   （ARGX-04 §4.3：动画期间文字以外的元素不显示）。
   ============================================================ */
#intro {
  position: fixed; inset: 0; z-index: var(--z-intro);
  background: var(--bg-app);
  display: grid; place-items: center;
  overflow: hidden; cursor: pointer;
  transition: opacity var(--dur-reveal) var(--ease-reveal), visibility var(--dur-reveal);
}
#intro.done { opacity: 0; visibility: hidden; pointer-events: none }

/* 开场期间：页面主体与背景层一并从视觉上移除（避免一闪而过） */
body.intro-open .page-shell { visibility: hidden }
body.intro-open .bg { visibility: hidden }
body.intro-open { overflow: hidden }

.intro-stage {
  position: relative;
  display: grid; place-items: center;
  width: 100%; height: 1.06em;
  font-size: clamp(54px, 9.2vw, 108px);
  line-height: 1.06;
}
.intro-word {
  position: absolute; left: 50%; top: 50%;
  display: flex; align-items: center; justify-content: center;
  line-height: 1.06; white-space: nowrap;
  font-size: inherit; font-weight: 800; letter-spacing: -.045em;
  color: var(--text-primary);
  opacity: 0;
  transform: translate(-50%, -50%) translateY(14px) scale(.985);
  transition: opacity var(--dur-intro-word) var(--ease-reveal),
              transform var(--dur-intro-word) var(--ease-reveal),
              color var(--dur-intro-word) var(--ease-out);
  will-change: opacity, transform;
}
.intro-word.on { opacity: 1; transform: translate(-50%, -50%) translateY(0) scale(1) }
/* 已过的词原地淡出、微微收缩 —— 不位移、不堆叠 */
.intro-word.past { opacity: 0; transform: translate(-50%, -50%) scale(.972); color: #585D65 }

/* 逐字：每个字有自己的延迟，整词不是一块整体推上来 */
.intro-word .ch {
  display: inline-block; opacity: 0;
  transform: translateY(.3em); filter: blur(6px);
  transition: opacity var(--dur-intro-char) var(--ease-reveal),
              transform var(--dur-intro-char) var(--ease-reveal),
              filter var(--dur-intro-char) var(--ease-reveal);
}
.intro-word.on .ch { opacity: 1; transform: translateY(0); filter: blur(0) }

/* 当前词底部扫过的一道光（中性白，不用彩色） */
.intro-word.on::after {
  content: ""; position: absolute; left: 12%; right: 12%; bottom: -.06em; height: 1.5px;
  border-radius: 2px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, .42), transparent);
  transform: scaleX(0); transform-origin: 50% 50%;
  animation: introUnderline 900ms var(--ease-out) 240ms forwards;
}
@keyframes introUnderline {
  0%   { transform: scaleX(0); opacity: 0 }
  40%  { opacity: 1 }
  100% { transform: scaleX(1); opacity: .42 }
}

/* 跳过：开场期间唯一的其他元素 */
.intro-skip {
  position: absolute; bottom: var(--space-12); left: 50%;
  transform: translateX(-50%);
  display: inline-flex; align-items: center; gap: var(--space-2);
  font-size: var(--text-sm); color: var(--text-tertiary);
  padding: var(--space-2) var(--space-4); border-radius: var(--radius-full);
  border: 1px solid transparent;
  transition: color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              background-color var(--dur-fast) var(--ease-out);
}
.intro-skip:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
  background: rgba(255, 255, 255, .04);
}
.intro-skip kbd {
  font-family: var(--font-mono); font-size: var(--text-3xs);
  padding: 1px 5px; border-radius: var(--radius-xs);
  background: rgba(255, 255, 255, .07);
  border: 1px solid var(--border-default);
  color: var(--text-tertiary);
}

/* 首屏内容：由首帧脚本按需展开，避免闪一下再收起 */
.page-shell { position: relative; z-index: 1; visibility: hidden }
body.ready .page-shell { visibility: visible }

/* ============================================================
   3. 顶部导航（透明 → 滚动后吸附 + 毛玻璃）
   ============================================================ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: var(--z-sticky);
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--space-4) var(--space-8);
  border-bottom: 1px solid transparent;
  transition: background-color var(--dur-normal) var(--ease-out),
              backdrop-filter var(--dur-normal) var(--ease-out),
              border-color var(--dur-normal) var(--ease-out);
}
.nav.scrolled {
  background: rgba(10, 11, 13, .70);
  backdrop-filter: blur(22px) saturate(160%);
  -webkit-backdrop-filter: blur(22px) saturate(160%);
  border-bottom-color: var(--border-subtle);
}
.nav-brand { display: flex; align-items: center; gap: var(--space-3) }
.brand-mark {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  border: 1.5px solid var(--text-primary);
  display: grid; place-items: center;
  font-size: var(--text-sm); font-weight: 800;
  transform: rotate(45deg); position: relative;
  transition: transform var(--dur-normal) var(--ease-out);
}
.brand-mark span { transform: rotate(-45deg) }
.brand-mark:hover { transform: rotate(45deg) scale(1.06) }
.nav-word { font-weight: 700; font-size: 17px; letter-spacing: -.01em }
.nav-chip {
  font-size: var(--text-2xs); font-weight: 500; color: var(--text-tertiary);
  padding: 2px 9px; border-radius: var(--radius-full);
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, .03);
}
.nav-center {
  display: flex; align-items: center; gap: var(--space-1);
  position: absolute; left: 50%; transform: translateX(-50%);
}
.nav-link {
  padding: var(--space-2) var(--space-4); border-radius: var(--radius-md);
  color: var(--text-secondary); font-size: var(--text-base); font-weight: 500;
  transition: background-color var(--dur-micro) ease-out, color var(--dur-micro) ease-out;
}
.nav-link:hover { background: rgba(255, 255, 255, .055); color: var(--text-primary) }
.nav-right { display: flex; align-items: center; gap: var(--space-3) }

/* ============================================================
   4. 按钮（深色主题：主/幽灵/亮色三变体）
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
  font-size: var(--text-base); font-weight: 500; line-height: 1;
  white-space: nowrap; border-radius: var(--radius-full);
  transition: background-color var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out);
}
.btn--sm { height: 32px; padding: 0 var(--space-4); font-size: var(--text-sm) }
.btn--md { height: 38px; padding: 0 var(--space-5) }
.btn--lg { height: 46px; padding: 0 var(--space-6); font-size: var(--text-md); gap: var(--space-3) }

.btn--primary {
  background: linear-gradient(180deg, #3B7BF0, #2563EB);
  color: #fff;
  box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, .16);
}
.btn--primary:hover {
  background: linear-gradient(180deg, #4A87F3, #2E6BEE);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md), inset 0 1px 0 rgba(255, 255, 255, .20);
}
.btn--primary:active { transform: translateY(0) }

.btn--ghost {
  background: rgba(255, 255, 255, .045); color: var(--text-primary);
  border: 1px solid var(--border-default);
  box-shadow: var(--inner-top);
}
.btn--ghost:hover {
  background: rgba(255, 255, 255, .085);
  border-color: var(--border-strong);
  transform: translateY(-1px);
}
.btn--ghost:active { transform: translateY(0) }

.btn .arrow { transition: transform var(--dur-fast) var(--ease-out) }
.btn:hover .arrow { transform: translateX(3px) }

/* ============================================================
   5. Hero：左文案 + 规格条 / 右代码卡
   ============================================================ */
.hero {
  min-height: 100vh; display: flex; align-items: center;
  padding: var(--space-32) var(--space-8) var(--space-24);
  max-width: var(--content-max); margin: 0 auto;
}
.hero-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: var(--space-16); align-items: center; width: 100%;
}
.hero-left { max-width: 34rem }

.hero h1 {
  font-size: clamp(40px, 4.6vw, 62px); font-weight: 800;
  line-height: 1.05; letter-spacing: -.035em;
  margin-bottom: var(--space-6);
}
/* 强调：中性亮色 + 一道发丝下划线（不用彩色渐变文字） */
.hero h1 em {
  font-style: normal; color: #FFFFFF;
  background-image: linear-gradient(90deg, rgba(255, 255, 255, .34), rgba(255, 255, 255, .12));
  background-repeat: no-repeat; background-size: 100% 1.5px; background-position: 0 100%;
  padding-bottom: .06em;
}
.hero-body { display: flex; flex-direction: column; gap: var(--space-4); margin-bottom: var(--space-10) }
.hero-lead {
  font-size: 17px; line-height: 1.62;
  color: var(--text-secondary); max-width: 32rem;
}
.hero-lead strong { color: var(--text-primary); font-weight: 500 }
.hero-lead--sub { font-size: var(--text-md) }

.hero-cta { display: flex; flex-direction: column; gap: var(--space-3); margin-bottom: var(--space-8) }
.hero-cta-row { display: flex; gap: var(--space-3); flex-wrap: wrap }

/* 规格条：三项真实参数，发丝线分隔 */
.hero-specs {
  display: flex; align-items: stretch; gap: var(--space-6);
  padding-top: var(--space-6);
  border-top: 1px solid var(--border-subtle);
  max-width: 34rem;
}
.spec { display: flex; flex-direction: column; gap: 3px; min-width: 0 }
.spec-k {
  font-size: 24px; font-weight: 750; letter-spacing: -.03em; line-height: 1.1;
  color: var(--text-primary); font-variant-numeric: tabular-nums;
  display: flex; align-items: baseline; gap: 1px;
}
.spec-k small { font-size: var(--text-sm); font-weight: 600; color: var(--text-tertiary); letter-spacing: 0 }
.spec-v {
  font-size: 11.5px; font-weight: 500; color: var(--text-secondary);
  display: flex; flex-direction: column; gap: 1px;
}
.spec-v small { font-size: 10.5px; font-weight: 400; color: var(--text-tertiary); font-family: var(--font-mono) }
.spec-div { width: 1px; background: var(--border-subtle); flex: none }

/* 右栏：tab 在卡外 + 终端风代码卡 */
.hero-right { display: flex; flex-direction: column; gap: var(--space-3); min-width: 0 }
.code-tabs {
  display: inline-flex; gap: 2px; align-self: flex-start;
  padding: 3px; border-radius: var(--radius-md);
  background: rgba(255, 255, 255, .045);
  border: 1px solid var(--border-default);
  box-shadow: var(--inner-top);
}
.code-tab {
  padding: 6px var(--space-4); border-radius: 7px;
  font-size: var(--text-xs); font-weight: 500; color: var(--text-tertiary);
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.code-tab:hover { color: var(--text-secondary) }
.code-tab.act { background: var(--bg-elevated); color: var(--text-primary); box-shadow: var(--shadow-xs) }

.terminal {
  border-radius: var(--radius-lg); overflow: hidden;
  background: linear-gradient(180deg, #101114, #0C0D0F);
  border: 1px solid var(--border-default);
  box-shadow: var(--shadow-lg), var(--inner-top);
  transition: transform var(--dur-slow) var(--ease-out),
              box-shadow var(--dur-slow) var(--ease-out),
              border-color var(--dur-slow) var(--ease-out);
}
.terminal:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-xl), var(--inner-top);
  transform: translateY(-2px);
}
.terminal-bar {
  display: flex; align-items: center; gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid rgba(255, 255, 255, .055);
  background: rgba(255, 255, 255, .014);
}
.terminal-bar .dots { display: flex; gap: 6px }
.terminal-bar .dots i { width: 10px; height: 10px; border-radius: 50%; display: block }
.terminal-bar .dots i:nth-child(1) { background: #FF5F57 }
.terminal-bar .dots i:nth-child(2) { background: #FEBC2E }
.terminal-bar .dots i:nth-child(3) { background: #28C840 }
.terminal-bar .fname {
  font-family: var(--font-mono); font-size: var(--text-2xs);
  color: var(--text-tertiary); margin-left: auto;
}
.terminal-body { padding: var(--space-5); position: relative }
.term-line {
  display: flex; align-items: flex-start; gap: var(--space-3);
  font-family: var(--font-mono); font-size: var(--text-sm); line-height: 1.85;
}
.term-line + .term-line { margin-top: 2px }
.term-line.gap { margin-top: var(--space-3) }
.term-line .prompt { color: var(--accent-400); flex: none }
.term-line .cmd { color: #D8DCE4 }
.term-line .cmt { color: #4A4F58 }
.term-copy {
  position: absolute; top: var(--space-3); right: var(--space-3);
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px var(--space-3); border-radius: var(--radius-sm);
  font-size: var(--text-2xs); color: var(--text-tertiary);
  background: rgba(255, 255, 255, .05);
  border: 1px solid var(--border-default);
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.terminal:hover .term-copy, .term-copy:focus-visible { opacity: 1 }
.term-copy:hover { color: var(--text-primary) }

/* ============================================================
   6. 通用区块
   ============================================================ */
.section { padding: var(--space-24) var(--space-8); position: relative }
.section--tight { padding-top: 0 }
.section-inner { max-width: var(--content-max); margin: 0 auto }

.reveal {
  opacity: 0; transform: translateY(22px);
  transition: opacity var(--dur-reveal) var(--ease-reveal),
              transform var(--dur-reveal) var(--ease-reveal);
}
.reveal.on { opacity: 1; transform: translateY(0) }

.section-tag {
  display: inline-flex; align-items: center;
  height: 26px; padding: 0 var(--space-3); margin-bottom: var(--space-5);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .05);
  border: 1px solid var(--border-default);
  box-shadow: var(--inner-top);
  font-size: var(--text-2xs); font-weight: 600;
  letter-spacing: .07em; text-transform: uppercase;
  color: var(--text-tertiary);
}
.section h2 {
  font-size: clamp(28px, 3.4vw, 44px); font-weight: 700;
  letter-spacing: -.028em; line-height: 1.14; max-width: 22em;
}
.section h2 .dim { color: var(--text-tertiary) }

/* ---- 能力三卡 ---- */
.cards3 {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5); margin-top: var(--space-12);
}
.fcard {
  position: relative; overflow: hidden;
  padding: var(--space-6); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(255, 255, 255, .042), rgba(255, 255, 255, .012));
  border: 1px solid var(--border-default);
  box-shadow: var(--inner-top);
  transition: transform var(--dur-normal) var(--ease-out),
              border-color var(--dur-normal) var(--ease-out),
              box-shadow var(--dur-normal) var(--ease-out);
}
.fcard::after {
  content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: radial-gradient(420px 200px at 50% 0%, rgba(91, 141, 239, .10), transparent 72%);
  opacity: 0; transition: opacity var(--dur-normal) var(--ease-out);
}
.fcard:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md), var(--inner-top);
}
.fcard:hover::after { opacity: 1 }
.fcard .num {
  font-family: var(--font-mono); font-size: var(--text-2xs); letter-spacing: .08em;
  color: var(--text-tertiary);
  display: flex; align-items: center; gap: var(--space-2);
  margin-bottom: var(--space-5);
}
.fcard .num::after {
  content: ""; flex: 1; height: 1px;
  background: linear-gradient(90deg, var(--border-default), transparent);
}
.fcard .glyph {
  height: 112px; margin-bottom: var(--space-5);
  border-radius: var(--radius-md);
  background: radial-gradient(180px 92px at 50% 100%, rgba(91, 141, 239, .08), transparent 76%), var(--bg-sunken);
  border: 1px solid var(--border-subtle);
  display: grid; place-items: center; overflow: hidden; position: relative;
}
.fcard h3 { font-size: 17px; font-weight: 600; letter-spacing: -.012em; margin-bottom: var(--space-3) }
.fcard p { font-size: var(--text-base); line-height: 1.62; color: var(--text-secondary) }

/* ---- 仓库卡：与 .fcard 共用同一套底，换成「仓库名 + 要点 + 按钮」 ---- */
.rcard { display: flex; flex-direction: column }
.rcard .repo-name {
  font-family: var(--font-mono); font-size: var(--text-lg); font-weight: 600;
  letter-spacing: -.01em; color: var(--text-primary);
  margin-bottom: var(--space-2);
}
.rcard .repo-line { font-size: var(--text-base); line-height: 1.6; color: var(--text-secondary); margin-bottom: var(--space-5) }
.rcard .repo-points {
  list-style: none; margin: 0 0 var(--space-8); padding: 0;
  display: grid; gap: var(--space-2);
}
.rcard .repo-points li {
  position: relative; padding-left: var(--space-4);
  font-size: var(--text-sm); line-height: 1.5; color: var(--text-tertiary);
}
.rcard .repo-points li::before {
  content: ""; position: absolute; left: 3px; top: .62em;
  width: 4px; height: 4px; border-radius: 50%; background: var(--border-strong);
}
.rcard .btn { align-self: flex-start; margin-top: auto }
.repo-foot { margin-top: var(--space-6); text-align: center; font-size: var(--text-sm); color: var(--text-tertiary) }

/* ---- 双入口大按钮 ---- */
.gates { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-5) }
.gate {
  position: relative; overflow: hidden;
  padding: var(--space-10) var(--space-8);
  border-radius: var(--radius-xl);
  background: linear-gradient(180deg, rgba(255, 255, 255, .038), rgba(255, 255, 255, .009));
  border: 1px solid var(--border-default);
  box-shadow: var(--inner-top);
  display: flex; flex-direction: column;
  transition: transform var(--dur-normal) var(--ease-out),
              border-color var(--dur-normal) var(--ease-out),
              box-shadow var(--dur-normal) var(--ease-out);
}
.gate::after {
  content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: radial-gradient(560px 260px at 50% 0%, rgba(91, 141, 239, .15), transparent 72%);
  opacity: 0; transition: opacity var(--dur-normal) var(--ease-out);
}
.gate:hover {
  transform: translateY(-4px);
  border-color: var(--accent-400);
  box-shadow: var(--shadow-lg), var(--inner-top);
}
.gate:hover::after { opacity: 1 }
.gate .g-no {
  font-family: var(--font-mono); font-size: var(--text-2xs);
  letter-spacing: .1em; color: var(--text-tertiary);
  margin-bottom: var(--space-5);
}
.gate h3 { font-size: 26px; font-weight: 700; letter-spacing: -.025em; margin-bottom: var(--space-3) }
.gate .desc {
  font-size: var(--text-md); color: var(--text-secondary);
  line-height: 1.6; margin-bottom: var(--space-8);
}
.gate .btn { align-self: flex-start; margin-top: auto }

/* ============================================================
   7. 页脚
   ============================================================ */
.footer {
  position: relative; z-index: 1;
  padding: var(--space-24) var(--space-8) var(--space-12);
  text-align: center;
  border-top: 1px solid var(--border-subtle);
}
.footer-brand {
  display: inline-flex; align-items: center; gap: var(--space-3);
  font-weight: 700; font-size: var(--text-xl); margin-bottom: var(--space-6);
}
.footer-brand .brand-mark { width: 26px; height: 26px; border-radius: 8px; font-size: var(--text-2xs) }
.footer-links {
  margin-top: var(--space-8);
  display: flex; gap: var(--space-6); justify-content: center; flex-wrap: wrap;
}
.footer-links a { color: var(--text-tertiary); font-size: var(--text-sm); transition: color var(--dur-micro) ease-out }
.footer-links a:hover { color: var(--text-primary) }
.footer-note { margin-top: var(--space-3); font-size: var(--text-xs); color: var(--text-disabled) }

/* ============================================================
   8. prefers-reduced-motion（CSS 全局兜底；JS 那侧还会再判一次）
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
  /* 开场层整层不显示，直接进入页面 */
  #intro { display: none !important }
  body.intro-open { overflow: auto !important }
  body.intro-open .page-shell { visibility: visible !important }
  body.intro-open .bg { visibility: visible !important }
  .intro-word { opacity: 1 !important; transform: translate(-50%, -50%) !important }
  .intro-word .ch { opacity: 1 !important; transform: none !important; filter: none !important }
  .reveal { opacity: 1 !important; transform: none !important }
}

/* ============================================================
   9. 响应式（本阶段只做桌面端；这里只保证不出现横向滚动条）
   ============================================================ */
@media (max-width: 1100px) {
  .hero-grid { grid-template-columns: 1fr; gap: var(--space-12) }
  .hero { min-height: auto; padding-top: var(--space-24) }
  .cards3 { grid-template-columns: 1fr }
}
@media (max-width: 820px) {
  .nav-center { display: none }
  .gates { grid-template-columns: 1fr }
  .hero, .section { padding-left: var(--space-6); padding-right: var(--space-6) }
}
@media (max-width: 640px) {
  .intro-stage { font-size: clamp(46px, 15vw, 72px) }
  .intro-skip { bottom: var(--space-8) }
}
