/* ==========================================================================
   新2投注指南 · 共享样式 /assets/site.css
   夜间控制台 + 纵向长卷：玻璃层与实色内容层并置
   ========================================================================== */

:root{
  /* 色彩 */
  --deep:#0B1026;
  --chapter:#141C3F;
  --edge:#2A3560;
  --mist:#8C9AC0;
  --text:#E6EBF7;
  --text-soft:#C6D0E8;
  --cyan:#5FE3DE;
  --amber:#FFC46B;
  --teal:#1F4E4A;
  --violet:#3B2A5A;
  --wine:#7A2E45;
  --glass:rgba(20,28,63,.58);
  --glass-line:rgba(140,154,192,.24);

  /* 字体 */
  --font-head:'Archivo Narrow','HarmonyOS Sans SC Condensed','Source Han Sans SC','Noto Sans SC',system-ui,sans-serif;
  --font-body:'PingFang SC','Hiragino Sans GB','Noto Sans SC',system-ui,-apple-system,'Segoe UI',sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Noto Sans Mono',monospace;

  /* 骨架 */
  --wrap:1240px;
  --gutter:clamp(1.15rem,4vw,3rem);
  --header-h:74px;
  --radius:14px;
  --radius-sm:10px;
  --ease:cubic-bezier(.22,1,.36,1);
}

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  font-family:var(--font-body);
  font-size:17px;
  font-weight:400;
  line-height:1.85;
  color:var(--text);
  background-color:var(--deep);
  background-image:
    radial-gradient(1100px 520px at 78% -12%, rgba(95,227,222,.10), transparent 62%),
    radial-gradient(900px 520px at -8% 16%, rgba(59,42,90,.42), transparent 62%),
    linear-gradient(rgba(42,53,96,.26) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42,53,96,.26) 1px, transparent 1px);
  background-size:auto,auto,92px 92px,92px 92px;
  background-repeat:no-repeat,no-repeat,repeat,repeat;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
body[data-nav-open]{overflow:hidden}
img,svg,video{max-width:100%;display:block;height:auto}
ul,ol{margin:0;padding:0;list-style:none}
button{font:inherit}
table{border-collapse:collapse;width:100%}

/* ---------- 排版 ---------- */
h1,h2,h3,h4{
  font-family:var(--font-head);
  font-weight:800;
  letter-spacing:-.01em;
  line-height:1.18;
  margin:0 0 .6em;
  color:#F4F7FF;
}
h1{font-size:clamp(2.4rem,6vw,4.6rem)}
h2{font-size:clamp(1.6rem,3vw,2.4rem)}
h3{font-size:1.25rem;font-weight:700;line-height:1.35}
h4{font-size:1rem;font-weight:700;letter-spacing:0}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}
a{color:var(--cyan);text-decoration:none;transition:color .18s var(--ease)}
a:hover{color:#9df3ef}
strong{font-weight:700;color:#F4F7FF}
.mono{font-family:var(--font-mono);letter-spacing:.04em}
.muted{color:var(--mist)}
.lede{font-size:clamp(1rem,1.6vw,1.15rem);line-height:1.8;color:var(--text-soft);max-width:64ch}
.eyebrow{
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--cyan);
  margin:0 0 .55rem;
}
.index-num{
  font-family:var(--font-mono);
  font-size:.8rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--mist);
  white-space:nowrap;
}
.rule{height:1px;border:0;margin:0;background:var(--edge)}
.divider{height:1px;border:0;margin:clamp(2rem,5vw,3rem) 0;background:linear-gradient(90deg,var(--edge),rgba(42,53,96,0))}

/* ---------- 聚焦 ---------- */
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px;border-radius:4px}

/* ---------- 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:.6rem;
  left:-9999px;
  z-index:200;
  padding:.65rem 1.1rem;
  border-radius:999px;
  background:var(--cyan);
  color:#04141A;
  font-weight:700;
  font-size:.86rem;
}
.skip-link:focus{left:var(--gutter);color:#04141A}

/* ---------- 布局骨架 ---------- */
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
main{padding-top:var(--header-h);display:block}
.section{position:relative;padding:clamp(3.5rem,8vw,6.5rem) 0}
.section--tight{padding:clamp(2rem,4vw,3rem) 0}
.section--teal{background:linear-gradient(180deg, rgba(31,78,74,.55), rgba(11,16,38,0) 72%)}
.section--violet{background:linear-gradient(180deg, rgba(59,42,90,.55), rgba(11,16,38,0) 72%)}
.section--wine{border-top:1px solid var(--wine);border-bottom:1px solid var(--wine)}
.section__head{
  display:flex;
  align-items:flex-end;
  justify-content:space-between;
  gap:1rem 1.5rem;
  flex-wrap:wrap;
  border-bottom:1px solid var(--edge);
  padding-bottom:.9rem;
  margin-bottom:clamp(1.5rem,3.5vw,2.4rem);
}
.section__head--plain{border-bottom:0;padding-bottom:0;margin-bottom:1rem}
.section__title{margin:0;font-size:clamp(1.35rem,2.4vw,1.9rem)}
.section__head p{margin:.2rem 0 0;color:var(--mist);font-size:.9rem;max-width:56ch}

.page-hero{
  margin-top:calc(var(--header-h) * -1);
  padding:calc(var(--header-h) + clamp(2.4rem,7vw,4.6rem)) 0 clamp(2rem,5vw,3.2rem);
  position:relative;
}
.page-hero__inner{display:grid;gap:clamp(1.2rem,3vw,2rem)}
.page-hero__meta{
  display:flex;flex-wrap:wrap;gap:.5rem 1.4rem;align-items:center;
  font-family:var(--font-mono);font-size:.76rem;letter-spacing:.1em;color:var(--mist);
}
.breadcrumbs{margin:0 0 clamp(1rem,2.5vw,1.6rem)}
.breadcrumbs__list{display:flex;flex-wrap:wrap;gap:.5rem;font-family:var(--font-mono);font-size:.74rem;letter-spacing:.08em;color:var(--mist)}
.breadcrumbs__list li+li::before{content:"/";margin-right:.5rem;color:var(--edge)}
.breadcrumbs a{color:var(--mist)}
.breadcrumbs a:hover{color:var(--cyan)}
.breadcrumbs [aria-current="page"]{color:var(--text)}

/* 非对称双栏 */
.split{
  display:grid;
  grid-template-columns:minmax(230px,300px) minmax(0,1fr);
  gap:clamp(1.4rem,4vw,3.2rem);
  align-items:start;
}
.split--wide-aside{grid-template-columns:minmax(260px,340px) minmax(0,1fr)}
.split__aside{min-width:0}
.split__main{min-width:0}
.sticky-aside{position:sticky;top:calc(var(--header-h) + 1.2rem)}

/* 网格 */
.grid{display:grid;gap:clamp(1rem,2.5vw,1.6rem)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}

/* ---------- 表面 ---------- */
.glass{
  background:var(--glass);
  border:1px solid var(--glass-line);
  border-radius:var(--radius);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
}
.card{
  background:var(--chapter);
  border:1px solid var(--edge);
  border-radius:var(--radius);
  padding:clamp(1.1rem,2.4vw,1.6rem);
  transition:border-color .22s var(--ease),transform .22s var(--ease),background-color .22s var(--ease);
}
.card:hover{border-color:rgba(95,227,222,.55);transform:translateY(-2px)}
.card__head{display:flex;align-items:center;justify-content:space-between;gap:.8rem;margin-bottom:.7rem;flex-wrap:wrap}
.card__title{margin:0;font-size:1.08rem}
.panel{
  background:var(--chapter);
  border:1px solid var(--edge);
  border-left:3px solid var(--wine);
  border-radius:var(--radius-sm);
  padding:1.05rem 1.2rem;
}
.panel p{margin:0;color:var(--text-soft);font-size:.95rem}
.panel--cyan{border-left-color:var(--cyan)}
.panel--amber{border-left-color:var(--amber)}
.panel--teal{border-left-color:var(--teal)}

.tag{
  display:inline-block;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  padding:.2rem .6rem;
  border-radius:999px;
  border:1px solid var(--edge);
  color:var(--mist);
  white-space:nowrap;
}
.tag--live{border-color:rgba(95,227,222,.7);color:var(--cyan)}
.tag--note{border-color:rgba(255,196,107,.7);color:var(--amber)}
.status{
  display:inline-flex;align-items:center;gap:.5rem;
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.06em;color:var(--mist);
}
.status::before{
  content:"";width:7px;height:7px;border-radius:50%;
  background:var(--cyan);box-shadow:0 0 0 3px rgba(95,227,222,.16);
}
.status--amber::before{background:var(--amber);box-shadow:0 0 0 3px rgba(255,196,107,.16)}
.status--wine::before{background:#C4638A;box-shadow:0 0 0 3px rgba(122,46,69,.35)}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.45rem;
  padding:.6rem 1.1rem;
  border-radius:999px;
  border:1px solid var(--edge);
  background:rgba(20,28,63,.72);
  color:var(--text);
  font-family:var(--font-body);
  font-size:.86rem;
  font-weight:500;
  line-height:1.4;
  text-decoration:none;
  cursor:pointer;
  transition:border-color .2s var(--ease),background-color .2s var(--ease),color .2s var(--ease),box-shadow .2s var(--ease);
}
.btn:hover{border-color:var(--cyan);color:var(--cyan)}
.btn--accent{background:var(--cyan);border-color:var(--cyan);color:#04141A;font-weight:700}
.btn--accent:hover{background:#8FF0EC;border-color:#8FF0EC;color:#04141A;box-shadow:0 0 0 4px rgba(95,227,222,.18)}
.btn--ghost{background:transparent}
.btn--line{border-color:rgba(255,196,107,.75);color:var(--amber)}
.btn--line:hover{border-color:var(--amber);color:#FFD79A;box-shadow:0 0 0 4px rgba(255,196,107,.14)}
.btn--block{width:100%}
.cta-row{display:flex;flex-wrap:wrap;gap:.7rem;align-items:center;margin-top:1.2rem}

/* ---------- 图片容器基础规则 ---------- */
.media{display:block;min-width:0}
.media__frame{
  position:relative;
  aspect-ratio:16/10;
  border:1px solid var(--edge);
  border-radius:var(--radius);
  overflow:hidden;
  background:
    linear-gradient(140deg, rgba(20,28,63,.96), rgba(11,16,38,.96)),
    repeating-linear-gradient(90deg, rgba(42,53,96,.4) 0 1px, transparent 1px 46px);
  display:grid;
  place-items:center;
}
.media__frame::after{
  content:"";
  position:absolute;inset:0;
  background:radial-gradient(420px 220px at 70% 8%, rgba(95,227,222,.12), transparent 65%);
  pointer-events:none;
}
.media__frame img{width:100%;height:100%;object-fit:cover}
.media__hint{
  position:relative;
  z-index:1;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--mist);
  text-align:center;
  padding:1rem;
}
.media__caption{
  display:block;
  margin-top:.6rem;
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.04em;
  color:var(--mist);
}
.media--device .media__frame{aspect-ratio:4/3;border-radius:18px}
.media--map .media__frame{aspect-ratio:1/1;border-radius:50%}
.media--layers .media__frame{aspect-ratio:3/2}

/* ---------- 标签页（版本对照） ---------- */
.tabs{
  display:inline-flex;gap:4px;padding:4px;
  border:1px solid var(--edge);
  border-radius:999px;
  background:rgba(20,28,63,.75);
  flex-wrap:wrap;
}
.tab{
  border:0;background:transparent;color:var(--mist);
  font-family:var(--font-mono);font-size:.76rem;letter-spacing:.1em;text-transform:uppercase;
  padding:.5rem 1rem;border-radius:999px;cursor:pointer;
  transition:background-color .2s var(--ease),color .2s var(--ease);
}
.tab:hover{color:var(--text)}
.tab[aria-selected="true"]{background:var(--cyan);color:#04141A}
.tabpanel{padding-top:1.2rem}
.tabpanel[hidden]{display:none}

/* ---------- 目录 ---------- */
.toc{padding:1rem 1.1rem}
.toc__title{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.18em;text-transform:uppercase;color:var(--mist);margin:0 0 .7rem}
.toc__list{display:grid;gap:.15rem}
.toc__link{
  display:block;
  padding:.5rem .7rem;
  border-left:2px solid transparent;
  border-radius:0 8px 8px 0;
  color:var(--text-soft);
  font-size:.9rem;
  line-height:1.5;
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.toc__link:hover{background:rgba(42,53,96,.45);color:var(--text)}
.toc__link[aria-current="true"],
[data-spy] a[aria-current="true"]{
  border-left-color:var(--cyan);
  color:var(--cyan);
  background:rgba(95,227,222,.08);
}

/* ---------- 折叠问答 ---------- */
.faq__item{
  background:var(--chapter);
  border:1px solid var(--edge);
  border-radius:var(--radius-sm);
  margin-bottom:.7rem;
  overflow:hidden;
}
.faq__item summary{
  cursor:pointer;
  list-style:none;
  padding:1rem 1.15rem;
  font-weight:500;
  color:var(--text);
  display:flex;align-items:center;justify-content:space-between;gap:1rem;
}
.faq__item summary::-webkit-details-marker{display:none}
.faq__item summary::after{
  content:"+";
  font-family:var(--font-mono);
  color:var(--mist);
  flex:none;
}
.faq__item[open] summary{color:var(--cyan)}
.faq__item[open] summary::after{content:"–";color:var(--cyan)}
.faq__body{padding:0 1.15rem 1.1rem;color:var(--text-soft);font-size:.95rem}
.faq__body p{margin:0 0 .6em}

/* ---------- 清单 ---------- */
.checklist{display:grid;gap:.5rem}
.checklist__item{
  display:flex;gap:.75rem;align-items:flex-start;
  padding:.8rem 1rem;
  border:1px solid var(--edge);
  border-radius:var(--radius-sm);
  background:rgba(20,28,63,.6);
  font-size:.95rem;
  line-height:1.7;
  transition:border-color .2s var(--ease),background-color .2s var(--ease);
}
.checklist__item:hover{border-color:rgba(140,154,192,.55)}
.checklist__item input[type="checkbox"]{
  margin:.45rem 0 0;
  width:16px;height:16px;flex:none;
  accent-color:var(--cyan);
  cursor:pointer;
}
.checklist__item.is-done{border-color:rgba(95,227,222,.4);background:rgba(95,227,222,.07)}
.checklist__item.is-done .checklist__text{color:var(--mist);text-decoration:line-through;text-decoration-color:rgba(140,154,192,.6)}
.checklist__progress{font-family:var(--font-mono);font-size:.74rem;letter-spacing:.1em;color:var(--amber)}

/* ---------- 显现动效 ---------- */
.js-ready .reveal{opacity:0;transform:translateY(12px)}
.reveal{
  transition:opacity .32s var(--ease),transform .32s var(--ease);
}
.reveal.is-visible{opacity:1;transform:none}

/* ==========================================================================
   头部
   ========================================================================== */
.site-header{
  position:fixed;
  top:0;left:0;right:0;
  z-index:60;
  background:transparent;
  border-bottom:1px solid transparent;
  transition:background-color .2s var(--ease),border-color .2s var(--ease),box-shadow .2s var(--ease);
}
.site-header[data-scrolled="true"]{
  background:rgba(11,16,38,.9);
  border-bottom-color:var(--edge);
  -webkit-backdrop-filter:blur(16px) saturate(150%);
  backdrop-filter:blur(16px) saturate(150%);
  box-shadow:0 12px 34px rgba(4,8,20,.45);
}
.site-header__inner{
  width:100%;
  max-width:var(--wrap);
  margin-inline:auto;
  padding-inline:var(--gutter);
  min-height:var(--header-h);
  display:flex;
  align-items:center;
  gap:clamp(.8rem,2vw,2rem);
}
.brand{display:flex;flex-direction:column;justify-content:center;gap:.1rem;min-width:0}
.brand__mark{
  display:flex;
  flex-direction:column;
  gap:.05rem;
  text-decoration:none;
  color:var(--text);
}
.brand__mark:hover{color:var(--text)}
.brand__name{
  font-family:var(--font-head);
  font-weight:800;
  font-size:1.06rem;
  letter-spacing:.01em;
  line-height:1.2;
  color:#F4F7FF;
}
.brand__line{
  font-size:.7rem;
  letter-spacing:.06em;
  color:var(--mist);
  line-height:1.3;
}
.brand__meta{
  display:none;
  font-size:.66rem;
  letter-spacing:.1em;
  color:var(--mist);
}

/* 导航 */
.site-nav{margin-inline:auto;min-width:0}
.site-nav__list{display:flex;align-items:center;gap:.1rem}
.site-nav__link{
  position:relative;
  display:block;
  padding:.55rem .78rem;
  border-radius:8px;
  font-size:.9rem;
  color:var(--text-soft);
  white-space:nowrap;
  transition:color .18s var(--ease),background-color .18s var(--ease);
}
.site-nav__link:hover{color:var(--text);background:rgba(42,53,96,.5)}
.site-nav__link::after{
  content:"";
  position:absolute;
  left:.78rem;right:.78rem;bottom:.28rem;
  height:2px;
  background:var(--cyan);
  transform:scaleX(0);
  transform-origin:0 50%;
  transition:transform .22s var(--ease);
}
.site-nav__link:hover::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]{color:var(--cyan)}
.site-nav__link[aria-current="page"]::after{transform:scaleX(1)}

.header-actions{display:flex;align-items:center;gap:.55rem;flex:none}
.header-cta{padding:.5rem .95rem;font-size:.82rem;white-space:nowrap}

/* 移动按钮 */
.nav-toggle{
  display:none;
  align-items:center;gap:.5rem;
  padding:.5rem .8rem;
  border:1px solid var(--edge);
  border-radius:999px;
  background:rgba(20,28,63,.75);
  color:var(--text);
  cursor:pointer;
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle__bars{position:relative;width:16px;height:10px;flex:none}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";position:absolute;left:0;right:0;height:1.5px;border-radius:2px;
  background:currentColor;
  transition:transform .22s var(--ease),top .22s var(--ease);
}
.nav-toggle__bars::before{top:0}
.nav-toggle__bars::after{top:8px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(4px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-4px) rotate(-45deg)}
.nav-toggle__label{font-size:.78rem;letter-spacing:.06em}

/* 阅读进度 */
.header-progress{
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:2px;
  overflow:hidden;
  background:transparent;
}
.header-progress__bar{
  display:block;
  height:100%;
  width:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--amber));
  transition:transform .1s linear;
}

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer{
  margin-top:clamp(4rem,10vw,8rem);
  padding:clamp(2.6rem,6vw,4.4rem) 0 1.4rem;
  border-top:1px solid var(--edge);
  background:linear-gradient(180deg, rgba(20,28,63,.92), rgba(8,12,30,1));
  color:var(--text);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1.35fr 1fr;
  gap:clamp(1.6rem,4vw,2.6rem);
}
.footer-col{min-width:0}
.footer-col__title{
  margin:0 0 .85rem;
  font-size:.7rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--mist);
  font-weight:400;
}
.footer-brand__name{
  font-family:var(--font-head);
  font-weight:800;
  font-size:1.24rem;
  line-height:1.3;
  margin:0 0 .5rem;
  color:#F4F7FF;
}
.footer-brand__desc{font-size:.92rem;color:var(--text-soft);margin:0 0 .8rem;max-width:34ch}
.footer-brand__meta{font-size:.72rem;color:var(--mist);margin:0}
.footer-nav__list{display:grid;gap:.35rem}
.footer-nav__link{color:var(--text-soft);font-size:.92rem}
.footer-nav__link:hover{color:var(--cyan)}
.footer-contact__list{display:grid;gap:.55rem;margin:0 0 .9rem}
.contact-line{display:flex;gap:.6rem;align-items:baseline;flex-wrap:wrap;font-size:.9rem}
.contact-line__key{
  flex:none;
  font-size:.68rem;
  letter-spacing:.14em;
  color:var(--mist);
  min-width:2.4em;
}
.contact-line__val{color:var(--text-soft);word-break:break-word}
.footer-note{font-size:.78rem;color:var(--mist);margin:0;max-width:32ch}
.footer-legal__list{display:grid;gap:.35rem;margin:0 0 .8rem}
.footer-legal__link{color:var(--text-soft);font-size:.92rem}
.footer-legal__link:hover{color:var(--cyan)}
.footer-legal__icp{font-size:.72rem;color:var(--mist);margin:0}
.footer-bottom{
  margin-top:clamp(2rem,5vw,3rem);
  padding-top:1.1rem;
  border-top:1px solid var(--edge);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem 1.5rem;
  flex-wrap:wrap;
}
.footer-bottom__copy{margin:0;font-size:.74rem;color:var(--mist)}
.footer-bottom__actions{display:flex;align-items:center;gap:.8rem;flex-wrap:wrap}
.footer-local{
  font-size:.78rem;
  color:var(--mist);
  border-bottom:1px solid rgba(140,154,192,.4);
  padding-bottom:1px;
}
.footer-local:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.footer-top{
  padding:.42rem .9rem;
  border:1px solid var(--edge);
  border-radius:999px;
  background:rgba(20,28,63,.8);
  color:var(--text-soft);
  font-size:.78rem;
  cursor:pointer;
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.footer-top:hover{border-color:var(--cyan);color:var(--cyan)}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (min-width:1080px){
  .brand__meta{display:block}
}

@media (max-width:1080px){
  .grid--4{grid-template-columns:repeat(2,minmax(0,1fr))}
}

@media (max-width:980px){
  .split,
  .split--wide-aside{grid-template-columns:minmax(0,1fr)}
  .sticky-aside{position:static;top:auto}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:1fr 1fr}
}

@media (max-width:900px){
  :root{--header-h:66px}
  html{font-size:16.5px}
  .site-header{background:rgba(11,16,38,.9);border-bottom-color:var(--edge);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px)}
  .nav-toggle{display:inline-flex}
  .site-header__inner{gap:.7rem}
  .brand__line{font-size:.66rem}
  .site-nav{
    position:fixed;
    top:var(--header-h);
    left:0;right:0;
    margin:0;
    padding:.6rem var(--gutter) 1.4rem;
    background:rgba(11,16,38,.98);
    border-bottom:1px solid var(--edge);
    -webkit-backdrop-filter:blur(18px);
    backdrop-filter:blur(18px);
    max-height:calc(100vh - var(--header-h));
    overflow-y:auto;
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    pointer-events:none;
    transition:opacity .22s var(--ease),transform .22s var(--ease),visibility .22s var(--ease);
  }
  .site-nav[data-open="true"]{opacity:1;visibility:visible;transform:translateY(0);pointer-events:auto}
  .site-nav__list{flex-direction:column;align-items:stretch;gap:0}
  .site-nav__link{
    padding:.9rem .4rem;
    border-bottom:1px solid rgba(42,53,96,.6);
    border-radius:0;
    font-size:.98rem;
    color:var(--text);
  }
  .site-nav__link::after{display:none}
  .site-nav__item:last-child .site-nav__link{border-bottom:0}
  .site-nav__link[aria-current="page"]{color:var(--cyan)}
  .header-cta{padding:.45rem .8rem;font-size:.78rem}
}

@media (max-width:760px){
  body{font-size:16px}
  .grid--2,.grid--3,.grid--4{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:1.8rem}
  .section{padding:clamp(2.6rem,9vw,4rem) 0}
  .footer-bottom{flex-direction:column;align-items:flex-start}
}

@media (max-width:520px){
  .brand__line{display:none}
  .nav-toggle__label{display:none}
  .nav-toggle{padding:.5rem .7rem}
}

/* ==========================================================================
   动效降级
   ========================================================================== */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .js-ready .reveal{opacity:1;transform:none}
  .card:hover{transform:none}
  .header-progress__bar{transition:none}
}