/* ============================================================
   乐鱼赛场 /assets/site.css
   共享外壳样式：reset、变量、中文排版、页头、页脚、
   通用按钮、面包屑、正文容器、网格、基础组件
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root{
  --blue:#1357D8;
  --blue-deep:#0F45B0;
  --navy:#0B1730;
  --ink:#16243D;
  --ink-soft:#3A4761;
  --sand:#F3EBDD;
  --sand-deep:#E9DFCB;
  --mist:#E8EEF7;
  --coral:#FF6B4A;
  --coral-deep:#F2542F;
  --teal:#1FAE9A;
  --teal-deep:#0C6E62;
  --line:#C9D4E5;
  --white:#FFFFFF;
  --glass:rgba(255,255,255,.68);

  --header-h:76px;
  --shell:1280px;
  --pad:clamp(20px,4vw,56px);
  --radius:3px;
  --shadow-1:0 18px 40px -24px rgba(11,23,48,.55);
  --focus-ring:#1FAE9A;

  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --ease:cubic-bezier(.22,.61,.36,1);
  --t-fast:160ms;
  --t-mid:240ms;
}

/* ---------- 2. Reset 与基础排版 ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
}
body{
  margin:0;
  font-family:var(--font-sans);
  font-size:clamp(1rem,1.02vw,1.0625rem);
  line-height:1.75;
  color:var(--ink);
  background:var(--sand);
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
body.is-nav-open{overflow:hidden;}
h1,h2,h3,h4,h5{
  margin:0;
  font-weight:800;
  line-height:1.16;
  letter-spacing:-.015em;
  color:var(--ink);
}
p{margin:0;}
ul,ol{margin:0;padding:0;list-style:none;}
figure,blockquote,dl,dd{margin:0;}
img,picture,svg,video{display:block;max-width:100%;height:auto;}
a{color:inherit;}
button{font:inherit;color:inherit;background:none;border:0;}
table{border-collapse:collapse;}
:focus-visible{
  outline:2px solid var(--focus-ring);
  outline-offset:3px;
  border-radius:2px;
}
::selection{background:rgba(19,87,216,.22);color:var(--ink);}

/* 主内容与页头偏移 */
#main-content{
  padding-top:var(--header-h);
  scroll-margin-top:calc(var(--header-h) + 16px);
}
.bleed-top{margin-top:calc(var(--header-h) * -1);}

/* ---------- 3. 工具类 ---------- */
.shell{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--pad);
}
.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.06em;
}
.visually-hidden{
  position:absolute!important;
  width:1px;height:1px;
  margin:-1px;padding:0;
  overflow:hidden;clip:rect(0 0 0 0);
  clip-path:inset(50%);
  white-space:nowrap;border:0;
}
.hairline{
  height:1px;border:0;margin:0;
  background:linear-gradient(90deg,var(--line),rgba(201,212,229,0));
}
.section{padding-block:clamp(48px,7vw,96px);}
.section--tight{padding-block:clamp(32px,4vw,56px);}
.section--navy{background:var(--navy);color:rgba(255,255,255,.82);}
.section--navy h1,.section--navy h2,.section--navy h3,.section--navy h4{color:#fff;}
.section--mist{background:var(--mist);}
.section--white{background:var(--white);}

/* ---------- 4. 页头 ---------- */
.skip-link{
  position:fixed;
  top:10px;left:10px;
  z-index:200;
  padding:10px 18px;
  background:var(--white);
  color:var(--navy);
  font-size:13px;
  font-weight:700;
  text-decoration:none;
  border-radius:var(--radius);
  box-shadow:var(--shadow-1);
  transform:translateY(-200%);
  transition:transform var(--t-fast) var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{transform:none;}

.site-header{
  position:fixed;
  top:0;left:0;right:0;
  z-index:80;
  color:#fff;
  background:linear-gradient(180deg,rgba(11,23,48,.94),rgba(11,23,48,.82));
  -webkit-backdrop-filter:blur(10px) saturate(130%);
  backdrop-filter:blur(10px) saturate(130%);
  border-bottom:1px solid rgba(201,212,229,.14);
  transition:background var(--t-mid) var(--ease),
             box-shadow var(--t-mid) var(--ease),
             border-color var(--t-mid) var(--ease);
}
.site-header[data-state="solid"]{
  background:var(--navy);
  border-bottom-color:rgba(201,212,229,.24);
  box-shadow:0 22px 44px -34px #000;
}
.site-header__inner{
  display:flex;
  align-items:center;
  gap:clamp(12px,2vw,28px);
  min-height:var(--header-h);
}

/* 品牌 */
.brand{
  display:inline-flex;
  align-items:center;
  gap:11px;
  flex:0 0 auto;
  color:#fff;
  text-decoration:none;
}
.brand__mark{
  display:grid;
  place-items:center;
  width:40px;height:40px;
  background:var(--blue);
  color:#fff;
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:700;
  letter-spacing:.06em;
  border-radius:var(--radius);
  box-shadow:inset 0 -3px 0 var(--coral);
  transition:background var(--t-fast) var(--ease);
}
.brand:hover .brand__mark,
.brand:focus-visible .brand__mark{background:var(--blue-deep);}
.brand__text{display:flex;flex-direction:column;line-height:1.1;}
.brand__line{font-size:16px;font-weight:800;letter-spacing:.06em;}
.brand__tag{
  margin-top:4px;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.16em;
  color:rgba(255,255,255,.62);
}

/* 主导航 */
.site-nav{
  flex:1 1 auto;
  display:flex;
  justify-content:flex-end;
  align-items:center;
}
.site-nav__list{
  display:flex;
  align-items:center;
  gap:2px;
  counter-reset:nav;
}
.site-nav__item{display:block;}
.nav-link{
  position:relative;
  display:inline-flex;
  align-items:baseline;
  gap:6px;
  padding:9px 12px;
  font-size:14px;
  font-weight:600;
  letter-spacing:.02em;
  color:rgba(255,255,255,.82);
  text-decoration:none;
  border-radius:2px;
  transition:color var(--t-fast) var(--ease),background var(--t-fast) var(--ease);
}
.nav-link::before{
  counter-increment:nav;
  content:"0" counter(nav);
  font-family:var(--font-mono);
  font-size:9px;
  line-height:1;
  letter-spacing:0;
  color:rgba(255,255,255,.45);
}
.nav-link:hover,
.nav-link:focus-visible{color:#fff;background:rgba(255,255,255,.12);}
.nav-link[aria-current="page"]{color:#fff;}
.nav-link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:12px;right:12px;bottom:3px;
  height:2px;
  background:var(--coral);
}
.nav-link--primary{
  background:var(--blue);
  color:#fff;
  box-shadow:inset 0 -2px 0 rgba(255,255,255,.22);
}
.nav-link--primary::before{color:rgba(255,255,255,.7);}
.nav-link--primary:hover,
.nav-link--primary:focus-visible{background:var(--blue-deep);color:#fff;}
.nav-link--primary[aria-current="page"]::after{background:#fff;}

/* 移动面板底部（桌面隐藏） */
.site-nav__foot{display:none;}
.site-nav__quick{
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.16em;
  color:rgba(255,255,255,.62);
  text-decoration:none;
}
.site-nav__quick:hover{color:#fff;}

/* 右侧工具区 */
.header-utility{
  display:flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
}
.version-tag{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:6px 10px;
  border:1px solid rgba(201,212,229,.34);
  border-radius:999px;
  text-decoration:none;
  color:rgba(255,255,255,.78);
  transition:border-color var(--t-fast) var(--ease),color var(--t-fast) var(--ease);
}
.version-tag:hover,
.version-tag:focus-visible{color:#fff;border-color:rgba(255,255,255,.72);}
.version-tag__dot{
  width:6px;height:6px;
  border-radius:50%;
  background:var(--teal);
  box-shadow:0 0 0 3px rgba(31,174,154,.22);
}
.version-tag__text{font-size:10.5px;letter-spacing:.14em;}
.header-utility__cta{padding:9px 14px;font-size:13px;}

/* 移动菜单按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:9px 12px;
  background:rgba(255,255,255,.10);
  border:1px solid rgba(255,255,255,.3);
  border-radius:2px;
  color:#fff;
  font-size:13px;
  font-weight:700;
  cursor:pointer;
  transition:background var(--t-fast) var(--ease);
}
.nav-toggle:hover{background:rgba(255,255,255,.2);}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:4px;width:16px;}
.nav-toggle__bars span{
  display:block;
  height:2px;
  background:currentColor;
  transition:transform var(--t-fast) var(--ease);
}
.site-header[data-open] .nav-toggle__bars span:first-child{transform:translateY(3px) rotate(45deg);}
.site-header[data-open] .nav-toggle__bars span:last-child{transform:translateY(-3px) rotate(-45deg);}
.nav-toggle__label{letter-spacing:.08em;}

/* 阅读进度轨 */
.scroll-meter{
  position:absolute;
  left:0;right:0;bottom:0;
  height:2px;
  background:rgba(255,255,255,.10);
  overflow:hidden;
}
.scroll-meter__bar{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--blue),var(--coral));
  transition:width 90ms linear;
}

/* ---------- 5. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(56px,8vw,120px);
  background:var(--navy);
  color:rgba(255,255,255,.82);
  font-size:14.5px;
}
.site-footer::before{
  content:"";
  display:block;
  height:5px;
  background:linear-gradient(90deg,
    var(--blue) 0 46%,
    var(--coral) 46% 62%,
    var(--teal) 62% 100%);
}
.footer-top{
  display:grid;
  grid-template-columns:1.5fr repeat(3,minmax(0,1fr));
  gap:clamp(28px,4vw,56px);
  padding-block:clamp(44px,6vw,80px) clamp(24px,3vw,40px);
}
.footer-brand{max-width:34ch;}
.footer-brand__line{
  font-size:20px;
  font-weight:800;
  letter-spacing:.04em;
  color:#fff;
}
.footer-brand__statement{
  margin:14px 0 22px;
  font-size:14.5px;
  line-height:1.8;
  color:rgba(255,255,255,.72);
}
.footer-brand__meta{
  margin-top:20px;
  font-size:10.5px;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:rgba(255,255,255,.48);
}
.footer-col__title{
  display:flex;
  align-items:center;
  gap:10px;
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  letter-spacing:.18em;
  color:rgba(255,255,255,.58);
}
.footer-col__title::before{
  content:"";
  width:18px;height:2px;
  background:var(--coral);
}
.footer-link{
  display:inline-block;
  padding:7px 0;
  color:rgba(255,255,255,.78);
  text-decoration:none;
  font-size:14.5px;
  transition:color var(--t-fast) var(--ease),transform var(--t-fast) var(--ease);
}
.footer-link:hover,
.footer-link:focus-visible{
  color:#fff;
  transform:translateX(3px);
}
.footer-contact{
  padding-block:clamp(24px,3vw,36px);
  border-top:1px solid rgba(201,212,229,.18);
  display:grid;
  gap:16px;
}
.footer-contact__title{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.2em;
  color:rgba(255,255,255,.55);
  font-weight:600;
}
.footer-contact__list{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(16px,3vw,40px);
}
.footer-contact__item{display:grid;gap:6px;}
.footer-contact__key{
  font-size:10px;
  letter-spacing:.2em;
  color:var(--teal);
}
.footer-contact__value{
  font-size:14px;
  line-height:1.7;
  color:#fff;
  overflow-wrap:anywhere;
}
.footer-contact__note{
  max-width:62ch;
  font-size:12.5px;
  line-height:1.75;
  color:rgba(255,255,255,.52);
}
.footer-legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:10px 22px;
  padding-block:20px 26px;
  border-top:1px solid rgba(201,212,229,.18);
  font-size:12.5px;
  color:rgba(255,255,255,.58);
}
.footer-legal__icp{letter-spacing:.1em;}
.footer-legal__links{display:inline-flex;flex-wrap:wrap;gap:8px;margin-left:auto;}
.footer-legal__links a{color:rgba(255,255,255,.72);text-decoration:none;}
.footer-legal__links a:hover,
.footer-legal__links a:focus-visible{color:#fff;text-decoration:underline;text-underline-offset:3px;}

/* 返回顶部 */
.to-top{
  position:fixed;
  right:clamp(14px,3vw,32px);
  bottom:clamp(14px,3vw,32px);
  z-index:70;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:10px 14px;
  background:var(--blue);
  color:#fff;
  border:1px solid rgba(255,255,255,.28);
  border-radius:2px;
  cursor:pointer;
  box-shadow:0 16px 30px -20px rgba(11,23,48,.9);
  opacity:0;
  visibility:hidden;
  transform:translateY(12px);
  transition:opacity var(--t-mid) var(--ease),
             transform var(--t-mid) var(--ease),
             visibility var(--t-mid),
             background var(--t-fast) var(--ease);
}
.to-top[data-visible]{opacity:1;visibility:visible;transform:none;}
.to-top:hover{background:var(--blue-deep);}
.to-top__arrow{font-size:14px;line-height:1;}
.to-top__label{font-size:10.5px;letter-spacing:.18em;}

/* ---------- 6. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:13px 22px;
  font-family:var(--font-sans);
  font-size:14.5px;
  font-weight:700;
  letter-spacing:.02em;
  text-decoration:none;
  border:1px solid transparent;
  border-radius:2px;
  cursor:pointer;
  transition:background var(--t-fast) var(--ease),
             color var(--t-fast) var(--ease),
             border-color var(--t-fast) var(--ease),
             transform var(--t-fast) var(--ease),
             box-shadow var(--t-fast) var(--ease);
}
.btn:hover{transform:translateY(-1px);}
.btn--primary{
  background:var(--blue);
  color:#fff;
  box-shadow:0 16px 30px -22px rgba(19,87,216,.95);
}
.btn--primary:hover{background:var(--blue-deep);}
.btn--accent{
  background:var(--coral);
  color:#fff;
  box-shadow:0 16px 30px -22px rgba(255,107,74,.95);
}
.btn--accent:hover{background:var(--coral-deep);}
.btn--ghost{
  background:transparent;
  color:#fff;
  border-color:rgba(255,255,255,.55);
}
.btn--ghost:hover{background:#fff;color:var(--navy);border-color:#fff;}
.btn--outline{
  background:transparent;
  color:var(--blue);
  border-color:var(--blue);
}
.btn--outline:hover{background:var(--blue);color:#fff;}
.btn--block{width:100%;}

/* ---------- 7. 标签、章节标签、大编号 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.12em;
  text-transform:uppercase;
  border-radius:2px;
  background:var(--mist);
  color:var(--ink);
}
.tag--blue{background:rgba(19,87,216,.12);color:var(--blue-deep);}
.tag--coral{background:rgba(255,107,74,.16);color:#C63A1C;}
.tag--teal{background:rgba(31,174,154,.18);color:var(--teal-deep);}
.tag--solid{background:var(--navy);color:#fff;}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--blue);
}
.eyebrow::before{content:"";width:22px;height:2px;background:currentColor;}
.eyebrow--light{color:var(--teal);}

.chapter-no{
  display:block;
  font-family:var(--font-mono);
  font-size:clamp(2.6rem,6vw,5rem);
  font-weight:700;
  line-height:.9;
  letter-spacing:-.03em;
  color:var(--line);
}
@supports (-webkit-text-stroke:1px #000){
  .chapter-no{color:transparent;-webkit-text-stroke:1.5px var(--line);}
}

/* ---------- 8. 标题组与正文 ---------- */
.section-head{display:grid;gap:14px;max-width:60ch;}
.section-head__title{
  font-size:clamp(1.8rem,3vw,3.2rem);
  line-height:1.1;
  letter-spacing:-.02em;
}
.section-head__lede{
  max-width:34em;
  font-size:1.0625rem;
  line-height:1.8;
  color:var(--ink-soft);
}
.section--navy .section-head__lede{color:rgba(255,255,255,.72);}

.lede{
  max-width:32em;
  font-size:clamp(1.0625rem,1.4vw,1.25rem);
  line-height:1.75;
  color:var(--ink-soft);
}

.prose{
  max-width:34em;
  font-size:clamp(1rem,1.1vw,1.0625rem);
  line-height:1.85;
}
.prose > * + *{margin-top:1.05em;}
.prose h2{font-size:clamp(1.5rem,2.2vw,2rem);margin-top:2em;letter-spacing:-.02em;}
.prose h3{font-size:clamp(1.2rem,1.6vw,1.375rem);margin-top:1.6em;}
.prose ul,.prose ol{padding-left:1.3em;margin:0 0 1em;}
.prose ul{list-style:disc;}
.prose ol{list-style:decimal;}
.prose li + li{margin-top:.4em;}
.prose a{
  color:var(--blue);
  text-decoration:underline;
  text-decoration-thickness:1px;
  text-underline-offset:3px;
}
.prose a:hover{color:var(--coral-deep);}
.prose blockquote{
  margin:1.6em 0;
  padding:14px 18px;
  border-left:3px solid var(--coral);
  background:rgba(232,238,247,.75);
  color:#2B3A55;
}
.prose code{
  font-family:var(--font-mono);
  font-size:.92em;
  background:var(--mist);
  padding:2px 6px;
  border-radius:2px;
}
.prose hr{border:0;border-top:1px solid var(--line);margin:2em 0;}
.section--navy .prose{color:rgba(255,255,255,.8);}
.section--navy .prose a{color:var(--teal);}
.section--navy .prose blockquote{background:rgba(255,255,255,.06);color:rgba(255,255,255,.85);}

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  text-transform:uppercase;
  color:rgba(255,255,255,.72);
}
.breadcrumbs a{color:inherit;text-decoration:none;}
.breadcrumbs a:hover,
.breadcrumbs a:focus-visible{color:#fff;}
.breadcrumbs__item + .breadcrumbs__item::before{
  content:"/";
  margin-right:8px;
  opacity:.5;
}
.breadcrumbs--ink{color:#4A5872;}
.breadcrumbs--ink a:hover,
.breadcrumbs--ink a:focus-visible{color:var(--blue);}

/* ---------- 10. 卡片与表格 ---------- */
.card{
  position:relative;
  padding:clamp(18px,2.2vw,28px);
  background:var(--white);
  border:1px solid var(--line);
  border-radius:var(--radius);
}
.card--glass{
  background:var(--glass);
  border-color:rgba(255,255,255,.55);
  color:var(--ink);
  box-shadow:var(--shadow-1);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
}
.card--navy{
  background:var(--navy);
  border-color:rgba(201,212,229,.2);
  color:rgba(255,255,255,.82);
}
.card--navy h3,.card--navy h4{color:#fff;}

.table-wrap{
  overflow-x:auto;
  background:var(--white);
  border:1px solid var(--line);
  border-radius:var(--radius);
  -webkit-overflow-scrolling:touch;
}
.table{
  width:100%;
  min-width:520px;
  font-size:.9375rem;
}
.table th,.table td{
  padding:12px 14px;
  text-align:left;
  vertical-align:top;
  border-bottom:1px solid var(--line);
}
.table thead th{
  background:var(--mist);
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--navy);
}
.table tbody tr:last-child td{border-bottom:0;}
.table tbody tr:hover{background:rgba(232,238,247,.6);}
.table .is-key{font-weight:700;color:var(--ink);}

/* ---------- 11. 网格与分栏 ---------- */
.grid{display:grid;gap:clamp(16px,2vw,28px);}
.grid--12{grid-template-columns:repeat(12,minmax(0,1fr));}
.span-3,.span-4,.span-5,.span-6,.span-7,.span-8,.span-9,.span-12{grid-column:span 12;}
@media (min-width:901px){
  .span-3{grid-column:span 3;}
  .span-4{grid-column:span 4;}
  .span-5{grid-column:span 5;}
  .span-6{grid-column:span 6;}
  .span-7{grid-column:span 7;}
  .span-8{grid-column:span 8;}
  .span-9{grid-column:span 9;}
}
.split{
  display:grid;
  gap:clamp(20px,3vw,48px);
  grid-template-columns:minmax(0,1fr);
}
@media (min-width:901px){
  .split{grid-template-columns:minmax(0,7fr) minmax(0,5fr);}
  .split--reverse{grid-template-columns:minmax(0,5fr) minmax(0,7fr);}
  .split--mirror{grid-template-columns:repeat(2,minmax(0,1fr));}
}

/* ---------- 12. 响应式图片容器 ---------- */
.media-frame{
  position:relative;
  overflow:hidden;
  isolation:isolate;
  aspect-ratio:16/10;
  border-radius:var(--radius);
  background:
    linear-gradient(135deg,rgba(19,87,216,.18),rgba(31,174,154,.14) 55%,rgba(255,107,74,.16)),
    repeating-linear-gradient(115deg,rgba(11,23,48,.10) 0 2px,transparent 2px 14px),
    var(--mist);
}
.media-frame > img,
.media-frame > picture > img{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
}
.media-frame--wide{aspect-ratio:16/9;}
.media-frame--band{aspect-ratio:24/9;}
.media-frame--tall{aspect-ratio:3/4;}
.media-frame--square{aspect-ratio:1/1;}
.media-frame--tint::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(120deg,rgba(19,87,216,.55),rgba(11,23,48,.12) 58%,rgba(255,107,74,.34));
  mix-blend-mode:multiply;
  pointer-events:none;
}
.media-frame__stamp{
  position:absolute;
  left:14px;bottom:14px;
  z-index:2;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:6px 10px;
  background:rgba(11,23,48,.74);
  color:#fff;
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.16em;
  border-radius:2px;
  -webkit-backdrop-filter:blur(6px);
  backdrop-filter:blur(6px);
}

/* ---------- 13. 显现动效 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(16px);
  transition:opacity 420ms var(--ease),transform 420ms var(--ease);
  will-change:opacity,transform;
}
[data-reveal].is-visible{
  opacity:1;
  transform:none;
  will-change:auto;
}

/* ---------- 14. 响应式 ---------- */
@media (max-width:1180px){
  .nav-link{padding:8px 9px;font-size:13px;}
  .brand__tag{display:none;}
}
@media (max-width:1099px){
  .version-tag{display:none;}
}
@media (max-width:999px){
  :root{--header-h:64px;}
  .header-utility__cta{display:none;}
  .nav-toggle{display:inline-flex;}
  .site-nav{
    position:fixed;
    top:var(--header-h);
    left:0;right:0;
    display:grid;
    align-content:start;
    gap:8px;
    padding:18px var(--pad) 28px;
    max-height:calc(100vh - var(--header-h));
    overflow-y:auto;
    background:var(--navy);
    border-top:1px solid rgba(201,212,229,.16);
    box-shadow:0 30px 50px -30px #000;
    opacity:0;
    visibility:hidden;
    pointer-events:none;
    transform:translateY(-10px);
    transition:opacity 200ms var(--ease),
               transform 200ms var(--ease),
               visibility 200ms linear;
  }
  .site-header[data-open] .site-nav,
  .site-nav[data-open]{
    opacity:1;
    visibility:visible;
    pointer-events:auto;
    transform:none;
  }
  .site-nav__list{
    display:grid;
    gap:0;
    width:100%;
  }
  .nav-link{
    display:flex;
    justify-content:flex-start;
    width:100%;
    padding:15px 4px;
    font-size:16.5px;
    border-bottom:1px solid rgba(201,212,229,.14);
    border-radius:0;
  }
  .nav-link--primary{
    margin-top:6px;
    padding-inline:12px;
    border-bottom:0;
    border-radius:2px;
  }
  .nav-link[aria-current="page"]::after{left:4px;right:auto;width:22px;bottom:8px;}
  .nav-link--primary[aria-current="page"]::after{left:12px;width:22px;}
  .site-nav__foot{
    display:grid;
    gap:14px;
    margin-top:18px;
    padding-top:16px;
    border-top:1px solid rgba(201,212,229,.18);
  }
  .footer-top{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer-brand{grid-column:1 / -1;max-width:none;}
  .footer-contact__list{grid-template-columns:1fr;}
  .footer-legal__links{margin-left:0;width:100%;}
}
@media (max-width:640px){
  body{line-height:1.72;}
  .footer-top{grid-template-columns:1fr;}
  .brand__mark{width:36px;height:36px;font-size:12px;}
  .brand__line{font-size:15px;}
  .to-top{padding:9px 11px;}
  .to-top__label{display:none;}
  .section-head__lede,.lede{max-width:none;}
}
@media (max-width:380px){
  .nav-toggle__label{display:none;}
}

/* ---------- 15. 可访问性与减弱动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1 !important;transform:none !important;}
  .btn:hover,.footer-link:hover,.footer-link:focus-visible{transform:none;}
  .to-top{transition:none;}
}