/* ============================================================
   如影如风 Shadowind — 官网样式表
   设计取向：Apple 式极简、留白优先、层级清晰、动效克制
   - 深色为默认主题，浅色随系统偏好自动切换
   - 全部颜色走 CSS 变量，便于统一调整
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root{
  color-scheme:dark light;

  --bg:#000;
  --bg-elev:#0a0a0c;
  --bg-soft:#0d0d10;
  --surface:rgba(255,255,255,.045);
  --surface-hover:rgba(255,255,255,.078);
  --border:rgba(255,255,255,.09);
  --border-strong:rgba(255,255,255,.17);

  --text:#f5f5f7;
  --text-secondary:rgba(245,245,247,.72);
  --text-tertiary:rgba(245,245,247,.45);
  --text-quaternary:rgba(245,245,247,.28);

  --accent:#0a84ff;
  --accent-hover:#3a9bff;
  --accent-soft:rgba(10,132,255,.16);
  --accent-2:#5e5ce6;
  --accent-3:#30d158;
  --accent-4:#ff9f0a;
  --accent-5:#ff375f;

  --grad-brand:linear-gradient(120deg,#0a84ff 0%,#5e5ce6 48%,#bf5af2 100%);
  --grad-text:linear-gradient(180deg,#fff 0%,rgba(255,255,255,.70) 100%);
  --grad-card:linear-gradient(160deg,rgba(255,255,255,.06) 0%,rgba(255,255,255,.015) 100%);

  /* 8pt 间距系统 */
  --s1:8px;  --s2:16px; --s3:24px; --s4:32px;
  --s5:48px; --s6:64px; --s7:88px; --s8:120px; --s9:160px;

  --radius-xs:8px;
  --radius-s:12px;
  --radius-m:20px;
  --radius-l:28px;
  --radius-xl:36px;

  --shadow-s:0 1px 2px rgba(0,0,0,.30);
  --shadow-m:0 8px 30px rgba(0,0,0,.42);
  --shadow-l:0 30px 80px rgba(0,0,0,.55);
  --shadow-glow:0 0 60px rgba(10,132,255,.28);

  --ease:cubic-bezier(.22,.61,.36,1);
  --ease-out:cubic-bezier(.16,1,.3,1);

  --maxw:1140px;
  --maxw-narrow:720px;
  --nav-h:52px;
}

@media (prefers-color-scheme:light){
  :root{
    --bg:#fff;
    --bg-elev:#f5f5f7;
    --bg-soft:#fafafa;
    --surface:rgba(0,0,0,.028);
    --surface-hover:rgba(0,0,0,.052);
    --border:rgba(0,0,0,.08);
    --border-strong:rgba(0,0,0,.15);

    --text:#1d1d1f;
    --text-secondary:rgba(29,29,31,.72);
    --text-tertiary:rgba(29,29,31,.48);
    --text-quaternary:rgba(29,29,31,.30);

    --grad-text:linear-gradient(180deg,#1d1d1f 0%,rgba(29,29,31,.72) 100%);
    --grad-card:linear-gradient(160deg,rgba(0,0,0,.035) 0%,rgba(0,0,0,.01) 100%);

    --shadow-m:0 8px 30px rgba(0,0,0,.10);
    --shadow-l:0 30px 70px rgba(0,0,0,.14);
    --shadow-glow:0 0 60px rgba(10,132,255,.18);
  }
}

/* ---------- 基础重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--nav-h) + 16px);
}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","SF Pro Display",
    "Helvetica Neue","PingFang SC","Hiragino Sans GB","Microsoft YaHei",
    "Source Han Sans SC",system-ui,sans-serif;
  font-size:17px;
  line-height:1.6;
  letter-spacing:-0.011em;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}
img,svg{display:block;max-width:100%}
a{color:var(--accent);text-decoration:none}
h1,h2,h3,h4{margin:0;font-weight:600;letter-spacing:-0.022em;line-height:1.08}
p{margin:0}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px}
::selection{background:var(--accent-soft)}
hr{border:0;border-top:1px solid var(--border);margin:0}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

.skip-link{
  position:absolute;top:-100px;left:16px;z-index:999;
  background:var(--accent);color:#fff;
  padding:12px 20px;border-radius:0 0 12px 12px;
  font-weight:600;transition:top .2s var(--ease);
}
.skip-link:focus{top:0;text-decoration:none}

/* ---------- 布局 ---------- */
.wrap{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:22px}
.wrap--narrow{max-width:var(--maxw-narrow)}
.section{padding-block:var(--s8)}
.section--tight{padding-block:var(--s7)}
.section--soft{background:var(--bg-soft)}

/* ---------- 导航 ---------- */
.nav{
  position:fixed;inset:0 0 auto 0;
  height:var(--nav-h);
  z-index:100;
  background:color-mix(in srgb,var(--bg) 72%,transparent);
  backdrop-filter:saturate(180%) blur(20px);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid transparent;
  transition:border-color .3s var(--ease),background .3s var(--ease);
}
.nav.is-scrolled{border-bottom-color:var(--border)}
.nav__inner{
  max-width:var(--maxw);margin-inline:auto;
  height:100%;padding-inline:22px;
  display:flex;align-items:center;gap:var(--s4);
}
.brand{
  display:inline-flex;align-items:center;gap:9px;
  color:var(--text);font-weight:600;font-size:19px;
  letter-spacing:-0.02em;flex-shrink:0;
}
.brand:hover{text-decoration:none;opacity:.82}
.brand__mark{
  width:26px;height:26px;border-radius:8px;
  background:var(--grad-brand);
  display:grid;place-items:center;
  box-shadow:0 2px 10px rgba(10,132,255,.4);
}
.brand__mark svg{width:15px;height:15px}
.brand__en{font-size:12px;font-weight:500;letter-spacing:.04em;color:var(--text-tertiary)}

.nav__links{display:flex;align-items:center;gap:2px;margin-left:auto}
.nav__links a{
  color:var(--text-secondary);font-size:13.5px;
  padding:7px 13px;border-radius:9px;
  transition:color .2s var(--ease),background .2s var(--ease);
}
.nav__links a:hover{color:var(--text);background:var(--surface);text-decoration:none}
.nav__links a[aria-current="page"]{color:var(--text)}

.nav__toggle{
  display:none;position:relative;margin-left:auto;
  width:40px;height:40px;
  border:0;background:transparent;cursor:pointer;
  border-radius:10px;padding:0;color:var(--text);
}
.nav__toggle:hover{background:var(--surface)}
.nav__toggle span{
  position:absolute;left:50%;top:50%;
  width:17px;height:1.5px;
  background:currentColor;border-radius:2px;
  transition:transform .32s var(--ease-out),opacity .18s var(--ease);
}
.nav__toggle span:nth-child(1){transform:translate(-50%,calc(-50% - 5px))}
.nav__toggle span:nth-child(2){transform:translate(-50%,-50%)}
.nav__toggle span:nth-child(3){transform:translate(-50%,calc(-50% + 5px))}
.nav__toggle[aria-expanded="true"] span:nth-child(1){transform:translate(-50%,-50%) rotate(45deg)}
.nav__toggle[aria-expanded="true"] span:nth-child(2){opacity:0;transform:translate(-50%,-50%) scaleX(.3)}
.nav__toggle[aria-expanded="true"] span:nth-child(3){transform:translate(-50%,-50%) rotate(-45deg)}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;
  height:46px;padding-inline:26px;
  border-radius:980px;
  font-size:16px;font-weight:500;letter-spacing:-0.01em;
  border:1px solid transparent;cursor:pointer;
  transition:transform .22s var(--ease-out),background .22s var(--ease),
             border-color .22s var(--ease),opacity .22s var(--ease),box-shadow .22s var(--ease);
  white-space:nowrap;
}
.btn:hover{text-decoration:none}
.btn:active{transform:scale(.97)}
.btn--primary{background:var(--accent);color:#fff;box-shadow:0 4px 18px rgba(10,132,255,.34)}
.btn--primary:hover{background:var(--accent-hover);box-shadow:0 6px 24px rgba(10,132,255,.44)}
.btn--ghost{background:transparent;color:var(--text);border-color:var(--border-strong)}
.btn--ghost:hover{background:var(--surface);border-color:var(--text-tertiary)}
.btn--sm{height:38px;padding-inline:20px;font-size:14.5px}
.btn--link{
  height:auto;padding:0;border-radius:0;
  color:var(--accent);font-weight:500;
}
.btn--link::after{content:"›";margin-left:2px;display:inline-block;transition:transform .22s var(--ease)}
.btn--link:hover{text-decoration:none}
.btn--link:hover::after{transform:translateX(4px)}

/* ---------- Hero ---------- */
.hero{
  position:relative;
  padding-top:calc(var(--nav-h) + var(--s7));
  padding-bottom:var(--s6);
  text-align:center;
  overflow:hidden;
}
.hero__glow{
  position:absolute;top:-42%;left:50%;
  width:min(1100px,150vw);aspect-ratio:1;
  transform:translateX(-50%);
  background:
    radial-gradient(circle at 50% 50%,rgba(10,132,255,.30) 0%,transparent 58%),
    radial-gradient(circle at 30% 40%,rgba(94,92,230,.26) 0%,transparent 52%),
    radial-gradient(circle at 70% 55%,rgba(191,90,242,.22) 0%,transparent 52%);
  filter:blur(38px);pointer-events:none;
  animation:glowFloat 18s ease-in-out infinite alternate;
}
@keyframes glowFloat{
  from{transform:translateX(-50%) scale(1) rotate(0deg)}
  to{transform:translateX(-50%) scale(1.12) rotate(8deg)}
}
.hero__grid{
  position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.028) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.028) 1px,transparent 1px);
  background-size:64px 64px;
  mask-image:radial-gradient(ellipse 60% 46% at 50% 42%,#000 12%,transparent 74%);
  -webkit-mask-image:radial-gradient(ellipse 60% 46% at 50% 42%,#000 12%,transparent 74%);
  pointer-events:none;
}
@media (prefers-color-scheme:light){
  .hero__grid{
    background-image:
      linear-gradient(rgba(0,0,0,.035) 1px,transparent 1px),
      linear-gradient(90deg,rgba(0,0,0,.035) 1px,transparent 1px);
  }
}
.hero__inner{position:relative;z-index:2}

/* 粒子场画布：铺满首屏，位于光晕之上、正文之下 */
.hero__particles{
  position:absolute;inset:0;
  width:100%;height:100%;
  display:block;
  pointer-events:none;      /* 不挡正文交互；指针位置由 window 监听获取 */
  z-index:1;
}

.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  padding:6px 15px 6px 11px;
  border:1px solid var(--border-strong);
  border-radius:980px;
  background:var(--surface);
  backdrop-filter:blur(12px);
  font-size:12.5px;font-weight:500;
  color:var(--text-secondary);letter-spacing:.01em;
  margin-bottom:var(--s3);
}
.eyebrow__dot{
  width:6px;height:6px;border-radius:50%;
  background:var(--accent-3);
  box-shadow:0 0 0 3px rgba(48,209,88,.2);
  animation:pulse 2.4s ease-in-out infinite;
}
@keyframes pulse{
  0%,100%{opacity:1;transform:scale(1)}
  50%{opacity:.55;transform:scale(.86)}
}

.hero h1{
  font-size:clamp(2.5rem,7.6vw,5.2rem);
  line-height:1.03;letter-spacing:-0.035em;font-weight:600;
  background:var(--grad-text);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
  margin-bottom:var(--s2);
}
.hero h1 .accent{
  background:var(--grad-brand);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
}
.hero__en{
  font-size:clamp(11px,2.6vw,13px);font-weight:500;
  letter-spacing:.34em;text-transform:uppercase;
  color:var(--text-tertiary);
  margin-bottom:var(--s3);padding-left:.34em;
}
.hero__sub{
  max-width:620px;margin:0 auto var(--s5);
  font-size:clamp(16px,2.4vw,20px);
  line-height:1.55;color:var(--text-secondary);letter-spacing:-0.01em;
}
.hero__actions{display:flex;gap:var(--s2);justify-content:center;flex-wrap:wrap}
.hero__note{margin-top:var(--s3);font-size:12.5px;color:var(--text-tertiary)}

/* 入场动画 */
.reveal{opacity:0;transform:translateY(22px);animation:revealUp .9s var(--ease-out) forwards}
@keyframes revealUp{to{opacity:1;transform:none}}
.d1{animation-delay:.05s}.d2{animation-delay:.14s}.d3{animation-delay:.23s}
.d4{animation-delay:.32s}.d5{animation-delay:.41s}.d6{animation-delay:.5s}

.on-scroll{opacity:0;transform:translateY(28px);transition:opacity .8s var(--ease-out),transform .8s var(--ease-out)}
.on-scroll.in{opacity:1;transform:none}

/* ---------- 区块标题 ---------- */
.head{max-width:680px;margin-bottom:var(--s6)}
.head--center{margin-inline:auto;text-align:center}
.head__tag{
  display:block;font-size:13px;font-weight:600;
  letter-spacing:.1em;text-transform:uppercase;
  color:var(--accent);margin-bottom:var(--s2);
}
.head h2{
  font-size:clamp(1.9rem,4.6vw,3.2rem);
  line-height:1.08;letter-spacing:-0.028em;
  margin-bottom:var(--s2);
}
.head p{
  font-size:clamp(16px,2.2vw,19px);
  line-height:1.55;color:var(--text-secondary);letter-spacing:-0.01em;
}

/* ---------- 统计条 ---------- */
.stats{
  display:grid;grid-template-columns:repeat(4,1fr);
  gap:1px;background:var(--border);
  border:1px solid var(--border);border-radius:var(--radius-m);
  overflow:hidden;
}
.stat{background:var(--bg);padding:var(--s4) var(--s3);text-align:center}
.stat__num{
  font-size:clamp(1.7rem,4vw,2.5rem);font-weight:600;
  letter-spacing:-0.03em;line-height:1;
  background:var(--grad-brand);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
  margin-bottom:8px;
}
.stat__label{font-size:13px;color:var(--text-secondary);letter-spacing:.01em}
.stat__en{font-size:11px;color:var(--text-quaternary);letter-spacing:.08em;text-transform:uppercase;margin-top:3px}

/* ---------- 卡片网格 ---------- */
.grid{display:grid;gap:var(--s3)}
.grid--2{grid-template-columns:repeat(2,1fr)}
.grid--3{grid-template-columns:repeat(3,1fr)}
.grid--4{grid-template-columns:repeat(4,1fr)}

.card{
  position:relative;
  padding:var(--s4);
  border:1px solid var(--border);
  border-radius:var(--radius-m);
  background:var(--grad-card);
  overflow:hidden;
  transition:border-color .3s var(--ease),transform .3s var(--ease-out);
}
.card::before{
  content:"";position:absolute;inset:0;
  background:radial-gradient(420px circle at var(--mx,50%) var(--my,50%),
    rgba(10,132,255,.10),transparent 68%);
  opacity:0;transition:opacity .4s var(--ease);pointer-events:none;
}
.card:hover{border-color:var(--border-strong);transform:translateY(-3px)}
.card:hover::before{opacity:1}

.card__icon{
  width:44px;height:44px;border-radius:13px;
  display:grid;place-items:center;
  background:var(--accent-soft);
  color:var(--accent);
  margin-bottom:var(--s2);
}
.card__icon svg{width:22px;height:22px}
.card h3{font-size:18px;letter-spacing:-0.02em;margin-bottom:8px}
.card p{font-size:14.5px;line-height:1.6;color:var(--text-secondary)}
.card__meta{
  margin-top:var(--s2);padding-top:var(--s2);
  border-top:1px solid var(--border);
  font-size:12px;color:var(--text-tertiary);
  display:flex;gap:8px;flex-wrap:wrap;align-items:center;
}

/* 生态卡片：小标签 */
.chip{
  display:inline-flex;align-items:center;
  font-size:11px;font-weight:500;letter-spacing:.02em;
  padding:3px 9px;border-radius:980px;
  background:var(--surface);border:1px solid var(--border);
  color:var(--text-secondary);
}
.chip--live{background:rgba(48,209,88,.12);border-color:rgba(48,209,88,.3);color:#5ee07a}
.chip--build{background:rgba(255,159,10,.12);border-color:rgba(255,159,10,.3);color:#ffb340}
.chip--plan{background:rgba(255,255,255,.06);color:var(--text-tertiary)}
@media (prefers-color-scheme:light){
  .chip--live{color:#1a8a35}
  .chip--build{color:#b26a00}
}

/* ---------- 特色大卡（左右分栏） ---------- */
.feature{
  display:grid;grid-template-columns:1fr 1fr;
  gap:var(--s6);align-items:center;
}
.feature--reverse .feature__media{order:-1}
.feature__body h3{font-size:clamp(1.5rem,3.2vw,2.2rem);letter-spacing:-0.026em;margin-bottom:var(--s2)}
.feature__body p{font-size:16.5px;line-height:1.6;color:var(--text-secondary);margin-bottom:var(--s3)}
.feature__list{list-style:none;padding:0;margin:0;display:grid;gap:12px}
.feature__list li{
  display:flex;gap:11px;align-items:flex-start;
  font-size:15px;color:var(--text-secondary);line-height:1.5;
}
.feature__list svg{width:18px;height:18px;flex-shrink:0;margin-top:3px;color:var(--accent-3)}

.feature__media{
  border-radius:var(--radius-l);
  border:1px solid var(--border);
  background:var(--bg-elev);
  padding:var(--s4);
  box-shadow:var(--shadow-m);
}

/* ---------- 产品视觉（CSS 绘制的界面示意） ---------- */
.mock{
  border-radius:var(--radius-m);
  border:1px solid var(--border);
  background:linear-gradient(180deg,rgba(255,255,255,.05),rgba(255,255,255,.01));
  overflow:hidden;
}
.mock__bar{
  display:flex;align-items:center;gap:7px;
  padding:12px 16px;
  border-bottom:1px solid var(--border);
  background:rgba(255,255,255,.025);
}
.mock__dot{width:10px;height:10px;border-radius:50%;background:var(--border-strong)}
.mock__dot:nth-child(1){background:#ff5f57}
.mock__dot:nth-child(2){background:#febc2e}
.mock__dot:nth-child(3){background:#28c840}
.mock__title{
  margin-left:auto;font-size:11.5px;color:var(--text-tertiary);
  letter-spacing:.02em;
}
.mock__body{padding:var(--s3);display:grid;gap:12px}

.mock__row{
  display:flex;align-items:center;gap:12px;
  padding:12px 14px;border-radius:12px;
  border:1px solid var(--border);
  background:rgba(255,255,255,.02);
}
.mock__avatar{
  width:34px;height:34px;border-radius:10px;flex-shrink:0;
  display:grid;place-items:center;
  font-size:13px;font-weight:600;color:#fff;
}
.mock__lines{flex:1;min-width:0}
.mock__line{height:8px;border-radius:4px;background:var(--border);}
.mock__line + .mock__line{margin-top:7px}
.mock__line--w70{width:70%}
.mock__line--w45{width:45%}
.mock__line--w55{width:55%}
.mock__badge{
  font-size:10.5px;padding:3px 8px;border-radius:980px;
  background:var(--surface);border:1px solid var(--border);
  color:var(--text-tertiary);flex-shrink:0;
}

/* 无障碍：尊重减少动效偏好 */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .on-scroll{opacity:1;transform:none}
  .reveal{opacity:1;transform:none}
}

/* ---------- 时间线（路线图） ---------- */
.timeline{display:grid;gap:0;position:relative}
.phase{
  display:grid;grid-template-columns:auto 1fr;
  gap:var(--s3);
  padding-bottom:var(--s5);
  position:relative;
}
.phase:last-child{padding-bottom:0}
.phase__rail{display:flex;flex-direction:column;align-items:center;width:44px}
.phase__dot{
  width:44px;height:44px;border-radius:50%;
  display:grid;place-items:center;
  font-size:14px;font-weight:600;
  border:1px solid var(--border-strong);
  background:var(--bg-elev);
  color:var(--text-secondary);
  flex-shrink:0;
}
.phase--now .phase__dot{
  background:var(--grad-brand);color:#fff;border-color:transparent;
  box-shadow:var(--shadow-glow);
}
.phase__line{flex:1;width:1px;background:var(--border);margin-top:10px}
.phase:last-child .phase__line{display:none}
.phase__body{padding-top:6px;padding-bottom:4px}
.phase__body h3{font-size:19px;letter-spacing:-0.02em;margin-bottom:6px}
.phase__body > p{font-size:15px;color:var(--text-secondary);line-height:1.55;margin-bottom:14px}
.phase__items{display:flex;flex-wrap:wrap;gap:8px}

/* ---------- FAQ（原生 details） ---------- */
.faq{display:grid;gap:0;border-top:1px solid var(--border)}
.faq details{border-bottom:1px solid var(--border)}
.faq summary{
  cursor:pointer;list-style:none;
  padding:var(--s3) 0;
  display:flex;align-items:center;gap:var(--s2);
  font-size:17px;font-weight:500;letter-spacing:-0.015em;
  color:var(--text);
  transition:color .2s var(--ease);
}
.faq summary::-webkit-details-marker{display:none}
.faq summary:hover{color:var(--accent)}
.faq summary::after{
  content:"";margin-left:auto;flex-shrink:0;
  width:11px;height:11px;
  border-right:1.6px solid currentColor;
  border-bottom:1.6px solid currentColor;
  transform:rotate(45deg) translateY(-2px);
  transition:transform .3s var(--ease-out);
  opacity:.6;
}
.faq details[open] summary::after{transform:rotate(-135deg) translateY(-2px)}
.faq__answer{
  padding-bottom:var(--s3);
  font-size:15.5px;line-height:1.68;
  color:var(--text-secondary);
  max-width:76ch;
}

/* ---------- CTA ---------- */
.cta{
  position:relative;overflow:hidden;
  border-radius:var(--radius-xl);
  border:1px solid var(--border);
  padding:var(--s7) var(--s5);
  text-align:center;
  background:
    radial-gradient(ellipse 70% 120% at 50% 0%,rgba(10,132,255,.13),transparent 62%),
    var(--bg-elev);
}
.cta h2{
  font-size:clamp(1.9rem,4.4vw,2.9rem);
  letter-spacing:-0.028em;margin-bottom:var(--s2);
}
.cta p{
  max-width:520px;margin:0 auto var(--s4);
  font-size:17px;color:var(--text-secondary);
}
.cta__actions{display:flex;gap:var(--s2);justify-content:center;flex-wrap:wrap}

/* ---------- 页脚 ---------- */
.footer{
  border-top:1px solid var(--border);
  padding-block:var(--s6) var(--s4);
  font-size:13.5px;
  color:var(--text-tertiary);
}
.footer__grid{
  display:grid;grid-template-columns:1.6fr repeat(3,1fr);
  gap:var(--s5);
  margin-bottom:var(--s5);
}
.footer__brand{max-width:280px}
.footer__brand .brand{margin-bottom:var(--s2)}
.footer__brand p{font-size:13.5px;line-height:1.6;color:var(--text-tertiary)}
.footer h4{
  font-size:12px;font-weight:600;letter-spacing:.09em;
  text-transform:uppercase;color:var(--text-secondary);
  margin-bottom:var(--s2);
}
.footer ul{list-style:none;padding:0;margin:0;display:grid;gap:11px}
.footer ul a{color:var(--text-tertiary);font-size:13.5px}
.footer ul a:hover{color:var(--text);text-decoration:none}
.footer__bottom{
  display:flex;justify-content:space-between;gap:var(--s3);
  flex-wrap:wrap;align-items:center;
  padding-top:var(--s4);border-top:1px solid var(--border);
  font-size:12.5px;color:var(--text-quaternary);
}
.footer__bottom a{color:var(--text-tertiary)}
.footer__bottom a:hover{color:var(--text);text-decoration:none}

/* ---------- 内容页（隐私/条款） ---------- */
.doc{padding-top:calc(var(--nav-h) + var(--s6));padding-bottom:var(--s7)}
.doc__head{margin-bottom:var(--s5);padding-bottom:var(--s4);border-bottom:1px solid var(--border)}
.doc__head h1{font-size:clamp(2rem,5vw,3rem);letter-spacing:-0.03em;margin-bottom:var(--s2)}
.doc__meta{font-size:13.5px;color:var(--text-tertiary)}
.doc h2{
  font-size:1.35rem;letter-spacing:-0.02em;
  margin-top:var(--s5);margin-bottom:var(--s2);
}
.doc h3{font-size:1.05rem;margin-top:var(--s3);margin-bottom:10px;color:var(--text)}
.doc p,.doc li{font-size:15.5px;line-height:1.75;color:var(--text-secondary)}
.doc p + p{margin-top:var(--s2)}
.doc ul,.doc ol{padding-left:1.3em;margin:var(--s2) 0;display:grid;gap:9px}
.doc a{text-decoration:underline;text-underline-offset:2px}
.doc__toc{
  padding:var(--s3);border:1px solid var(--border);border-radius:var(--radius-m);
  background:var(--surface);margin-bottom:var(--s5);
}
.doc__toc h4{font-size:12px;letter-spacing:.09em;text-transform:uppercase;color:var(--text-tertiary);margin-bottom:12px}
.doc__toc ol{margin:0;padding-left:1.2em;gap:7px}
.doc__toc a{color:var(--text-secondary);text-decoration:none;font-size:14px}
.doc__toc a:hover{color:var(--accent)}

/* ---------- 响应式 ---------- */
@media (max-width:900px){
  .grid--4{grid-template-columns:repeat(2,1fr)}
  .grid--3{grid-template-columns:repeat(2,1fr)}
  .feature{grid-template-columns:1fr;gap:var(--s4)}
  .feature--reverse .feature__media{order:0}
  .footer__grid{grid-template-columns:1fr 1fr;gap:var(--s4)}
  .footer__brand{grid-column:1 / -1;max-width:none}
}

@media (max-width:820px){
  .nav__toggle{display:block}
  .nav__links{
    position:fixed;inset:var(--nav-h) 0 auto 0;
    flex-direction:column;align-items:stretch;gap:0;
    background:var(--bg);
    border-bottom:1px solid var(--border);
    box-shadow:var(--shadow-m);
    padding:var(--s2) 22px var(--s3);
    transform:translateY(-14px);opacity:0;visibility:hidden;
    transition:transform .34s var(--ease-out),opacity .26s var(--ease),visibility .26s;
    max-height:calc(100dvh - var(--nav-h));overflow-y:auto;
  }
  .nav__links.is-open{transform:none;opacity:1;visibility:visible}
  .nav__links a{
    font-size:16px;padding:14px 4px;border-radius:10px;
    border-bottom:1px solid var(--border);
  }
  .nav__links a:last-child{border-bottom:0}
  .nav__links a:hover{background:transparent;color:var(--accent)}
}

@media (max-width:640px){
  :root{--s8:88px;--s7:64px;--s6:48px}
  .wrap{padding-inline:18px}
  .nav__inner{padding-inline:18px}
  .stats{grid-template-columns:repeat(2,1fr)}
  .grid--2,.grid--3,.grid--4{grid-template-columns:1fr}
  .footer__grid{grid-template-columns:1fr 1fr}
  .cta{padding:var(--s5) var(--s3);border-radius:var(--radius-l)}
  .card{padding:var(--s3)}
  .feature__media{padding:var(--s3)}
}

/* 打印：去掉装饰，保留内容 */
@media print{
  .nav,.cta,.footer__bottom,.hero__glow,.hero__grid{display:none}
  body{background:#fff;color:#000}
  .section{padding-block:24px}
}