/* ===== 1. 设计令牌 ===== */
:root{
  --sea-deep:#071A2E;
  --sea:#0B2A4A;
  --coral:#FF6B4A;
  --coral-soft:#FFA98F;
  --ice:#7FC8F8;
  --neon:#3DE0A0;
  --paper:#F4F7FB;
  --mist:#C3D2E3;
  --ink:#0A1017;
  --amber:#FFC24B;
  --line:rgba(195,210,227,.16);
  --line-strong:rgba(195,210,227,.34);
  --rail-w:88px;
  --bar-h:56px;
  --dock-h:60px;
  --radius:8px;
  --font-head:'Noto Serif SC','Source Han Serif SC','Songti SC','SimSun',serif;
  --font-body:'Noto Sans SC','PingFang SC','Hiragino Sans GB','Microsoft YaHei',system-ui,-apple-system,sans-serif;
  --font-num:'JetBrains Mono','SFMono-Regular',ui-monospace,Menlo,Consolas,monospace;
  --scroll-progress:0;
}

/* ===== 2. reset 与基础排版 ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  min-height:100vh;
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  color:var(--mist);
  background-color:var(--sea);
  background-image:
    repeating-linear-gradient(0deg,rgba(244,247,251,.028) 0 1px,rgba(244,247,251,0) 1px 3px),
    repeating-linear-gradient(90deg,rgba(244,247,251,.022) 0 1px,rgba(244,247,251,0) 1px 4px),
    radial-gradient(120% 80% at 6% 0%,rgba(127,200,248,.18) 0%,rgba(127,200,248,0) 58%),
    radial-gradient(90% 60% at 100% 100%,rgba(255,107,74,.13) 0%,rgba(255,107,74,0) 62%),
    linear-gradient(158deg,#0B2A4A 0%,#071A2E 58%,#061424 100%);
  background-attachment:fixed;
  background-repeat:no-repeat;
  background-size:cover;
  overflow-x:hidden;
}
body.nav-open{overflow:hidden}
img,svg,picture{display:block;max-width:100%}
h1,h2,h3,h4,h5{margin:0 0 .6em;font-family:var(--font-head);font-weight:600;letter-spacing:-.01em;line-height:1.28;color:var(--paper)}
p{margin:0 0 1em}
ul,ol{margin:0;padding:0;list-style:none}
a{color:var(--ice);text-decoration:none;transition:color .2s ease,border-color .2s ease}
a:hover{color:var(--coral)}
button{font:inherit;color:inherit;background:none;border:0}
:focus-visible{outline:2px solid var(--coral);outline-offset:3px;border-radius:3px}
::selection{background:rgba(255,107,74,.35);color:#fff}

/* ===== 3. 布局容器与章节 ===== */
.container{width:100%;max-width:1200px;margin:0 auto;padding:0 40px}
.page-main{display:block;min-height:60vh}
@media (min-width:900px){body{padding-left:var(--rail-w)}}
@media (max-width:899px){body{padding-bottom:calc(var(--dock-h) + 10px)}}

.section-block{padding:72px 0;position:relative}
.section-block--paper{background:linear-gradient(180deg,#F4F7FB,#E8EFF8);color:#243446}
.section-block--paper .section-title,
.section-block--paper h2,
.section-block--paper h3{color:var(--ink)}
.section-block--paper .lede,
.section-block--paper p{color:#33465c}
.section-block--paper .section-num{color:#c2421f;border-color:rgba(194,66,31,.45)}
.section-block--paper .divider-line{background:linear-gradient(90deg,rgba(11,42,74,.5),rgba(11,42,74,0))}

.section-head{display:flex;flex-wrap:wrap;align-items:baseline;gap:14px 18px;margin-bottom:26px}
.section-num{
  font-family:var(--font-num);font-size:13px;font-weight:600;letter-spacing:.16em;
  color:var(--coral);border:1px solid rgba(255,107,74,.5);border-radius:3px;padding:3px 9px;
}
.section-title{margin:0;font-size:clamp(26px,3.4vw,40px);color:var(--paper)}
.section-note{margin:0;font-size:13px;letter-spacing:.06em;color:var(--mist)}
.lede{font-size:clamp(16px,1.6vw,18px);line-height:1.85;color:var(--mist);max-width:62ch}
.prose{max-width:72ch}
.prose p{color:var(--mist);line-height:1.85;margin:0 0 1.1em}
.prose h2,.prose h3{color:var(--paper);margin-top:1.6em}
.prose ul,.prose ol{padding-left:1.3em;margin:0 0 1.2em}
.prose ul{list-style:disc}
.prose ol{list-style:decimal}
.prose li{margin-bottom:.5em;line-height:1.8}
.prose strong{color:var(--paper);font-weight:600}
.divider-line{height:1px;border:0;margin:40px 0;background:linear-gradient(90deg,var(--ice),rgba(127,200,248,0));opacity:.55}

.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-split{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
.grid-split--reverse{grid-template-columns:minmax(0,5fr) minmax(0,7fr)}
@media (max-width:900px){
  .grid-2,.grid-3,.grid-split,.grid-split--reverse{grid-template-columns:minmax(0,1fr)}
}

.breadcrumb{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin:0 0 22px;font-size:12px;letter-spacing:.06em;color:var(--mist)}
.breadcrumb__item{display:inline-flex;align-items:center;color:var(--mist)}
.breadcrumb__item a{color:var(--ice)}
.breadcrumb__item a:hover{color:var(--coral)}
.breadcrumb__item + .breadcrumb__item::before{content:"/";margin-right:8px;color:rgba(195,210,227,.4)}

.mono{font-family:var(--font-num);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.num{font-family:var(--font-num);font-variant-numeric:tabular-nums;font-weight:600}

/* ===== 4. 通用组件 ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 22px;border-radius:4px;border:1px solid transparent;
  font-size:14px;font-weight:500;letter-spacing:.06em;line-height:1.2;
  text-decoration:none;cursor:pointer;
  transition:background .2s ease,color .2s ease,border-color .2s ease,transform .2s ease;
}
.btn--primary{background:var(--coral);color:#fff;box-shadow:0 8px 22px -14px rgba(255,107,74,.95)}
.btn--primary:hover{background:var(--coral-soft);color:#131c26;transform:translateY(-1px)}
.btn--ghost{border-color:rgba(127,200,248,.45);background:rgba(127,200,248,.06);color:var(--ice)}
.btn--ghost:hover{border-color:var(--ice);background:rgba(127,200,248,.15);color:var(--paper)}
.btn--quiet{border-color:var(--line);color:var(--mist)}
.btn--quiet:hover{border-color:var(--mist);color:var(--paper)}

.card{
  position:relative;padding:22px 20px;border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(160deg,rgba(11,42,74,.66),rgba(7,26,46,.78));
  transition:border-color .2s ease,transform .2s ease;
}
.card:hover{border-color:var(--line-strong);transform:translateY(-2px)}
.card--anchor{border-color:var(--coral);padding:26px 24px;box-shadow:0 26px 60px -44px rgba(255,107,74,.95)}
.card--anchor::before{content:"";position:absolute;left:-1px;top:18px;bottom:18px;width:3px;border-radius:3px;background:var(--coral)}
.card__title{margin:0 0 8px;font-size:19px;color:var(--paper)}
.card__meta{margin:0;font-family:var(--font-num);font-size:12px;letter-spacing:.1em;color:var(--ice);font-variant-numeric:tabular-nums}
.card__body{margin:10px 0 0;font-size:15px;line-height:1.75;color:var(--mist)}

.data-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));
  gap:1px;background:var(--line);border:1px solid var(--line);border-radius:6px;overflow:hidden;
}
.data-figure{padding:20px 18px;background:rgba(7,26,46,.72)}
.data-figure__value{
  display:block;font-family:var(--font-num);font-weight:700;font-variant-numeric:tabular-nums;
  font-size:clamp(30px,4.6vw,48px);line-height:1.05;color:var(--paper);
}
.data-figure__label{display:block;margin-top:8px;font-size:12px;letter-spacing:.1em;color:var(--mist)}
.data-figure--accent .data-figure__value{color:var(--coral)}

.stat-bar{
  position:relative;display:block;height:8px;border-radius:2px;overflow:hidden;
  background:rgba(127,200,248,.14);transform:skewX(-8deg);
}
.stat-bar__fill{
  display:block;height:100%;width:0;border-radius:2px;
  background:linear-gradient(90deg,var(--ice),var(--neon));
  transition:width .32s ease-out;
}
.stat-bar.is-visible .stat-bar__fill{width:var(--value,0%)}

.table-wrap{
  border:1px solid var(--line);border-radius:var(--radius);overflow-x:auto;
  background:rgba(7,26,46,.6);-webkit-overflow-scrolling:touch;
}
.data-table{width:100%;min-width:560px;border-collapse:collapse;font-size:15px}
.data-table th,.data-table td{padding:13px 16px;text-align:left;border-bottom:1px solid var(--line)}
.data-table thead th{font-size:12px;font-weight:500;letter-spacing:.1em;color:var(--ice);background:rgba(11,42,74,.75)}
.data-table tbody tr{transition:background .2s ease,transform .2s ease}
.data-table tbody tr:hover{background:rgba(127,200,248,.08);transform:translateX(4px)}
.data-table tbody tr:last-child td{border-bottom:0}
.data-table .num{text-align:right;color:var(--paper)}

.tag{
  display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;
  border:1px solid var(--line);font-size:12px;letter-spacing:.08em;color:var(--mist);
}
.tag--live{color:var(--neon);border-color:rgba(61,224,160,.5);background:rgba(61,224,160,.08)}
.tag--muted{color:rgba(195,210,227,.72)}

.media-frame{
  position:relative;border:1px solid var(--line);border-radius:10px;overflow:hidden;
  background:linear-gradient(140deg,rgba(11,42,74,.9),rgba(7,26,46,.96));
  aspect-ratio:4/3;
}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame img,.media-frame svg,.media-frame picture{width:100%;height:100%;object-fit:cover}
.media-frame__caption{
  position:absolute;left:0;right:0;bottom:0;padding:12px 16px;
  font-size:12px;letter-spacing:.06em;color:var(--paper);
  background:linear-gradient(0deg,rgba(4,12,22,.9),rgba(4,12,22,0));
}

.reveal{opacity:1}
html[data-js="on"] .reveal,
html[data-js="on"] [data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .5s ease,transform .5s ease}
html[data-js="on"] .reveal.is-visible,
html[data-js="on"] [data-reveal].is-visible{opacity:1;transform:none}

/* ===== 5. 页头：桌面左轨 ===== */
.skip-link{
  position:fixed;left:12px;top:-70px;z-index:200;
  padding:10px 16px;border-radius:4px;background:var(--coral);color:#fff;
  font-size:14px;letter-spacing:.04em;transition:top .2s ease;
}
.skip-link:focus{top:12px;color:#fff}

.site-header{
  position:fixed;left:0;top:0;bottom:0;width:var(--rail-w);z-index:70;
  display:flex;flex-direction:column;
  background-image:linear-gradient(180deg,rgba(11,42,74,.94) 0%,rgba(7,26,46,.98) 100%);
  border-right:1px solid var(--line);
}
.site-header__rail-top{padding:18px 8px 16px;border-bottom:1px solid var(--line);text-align:center}
.brand{display:block;text-decoration:none;color:var(--paper)}
.brand:hover{color:var(--paper)}
.brand__name{display:block;font-family:var(--font-head);font-size:15px;font-weight:700;letter-spacing:.04em;line-height:1.35;color:var(--paper)}
.brand__tag{display:block;margin-top:8px;font-size:10px;line-height:1.6;letter-spacing:.1em;color:var(--ice);opacity:.8}

.nav-toggle{display:none}

.site-nav{flex:1 1 auto;display:flex;flex-direction:column;gap:12px;padding:20px 8px 14px;overflow-y:auto}
.site-nav__eyebrow{margin:0;text-align:center;font-size:10px;letter-spacing:.16em;color:var(--mist);opacity:.62}
.site-nav__list{display:flex;flex-direction:column;gap:6px}
.site-nav__list a{
  display:flex;flex-direction:column;align-items:center;gap:4px;
  padding:10px 2px;border:1px solid transparent;border-radius:5px;
  color:var(--mist);text-decoration:none;
}
.site-nav__list a:hover{color:var(--paper);border-color:rgba(127,200,248,.28);background:rgba(127,200,248,.07)}
.nav-num{font-family:var(--font-num);font-size:10px;letter-spacing:.06em;font-variant-numeric:tabular-nums;opacity:.7}
.nav-label{font-size:12px;letter-spacing:.08em;line-height:1.25}
.site-nav__list a[aria-current="page"]{
  color:var(--ice);border-color:var(--coral);background:rgba(255,107,74,.1);
}
.site-nav__list a[aria-current="page"] .nav-num{color:var(--coral);opacity:1}
.site-nav__list a[aria-current="page"] .nav-label{color:var(--ice)}

.site-nav__dock{
  margin-top:auto;padding-top:14px;border-top:1px solid var(--line);
  display:flex;flex-direction:column;gap:6px;
}
.dock-link{
  display:block;text-align:center;padding:8px 4px;border-radius:4px;
  border:1px dashed rgba(127,200,248,.26);color:var(--mist);
  font-size:11px;letter-spacing:.06em;line-height:1.3;
}
.dock-link:hover{color:var(--neon);border-color:var(--neon);border-style:solid}

.nav-scrim{display:none}
.mobile-dock{display:none}

.scroll-meter{
  position:fixed;left:var(--rail-w);top:0;width:3px;height:100vh;z-index:68;
  background:rgba(127,200,248,.12);pointer-events:none;
}
.scroll-meter__fill{
  display:block;width:100%;height:100%;transform-origin:top;
  transform:scaleY(var(--scroll-progress,0));
  background:linear-gradient(180deg,var(--coral),var(--amber));
}

/* ===== 6. 页头：移动端顶栏 + 抽屉 + 底部快捷条 ===== */
@media (max-width:899px){
  .site-header{position:static;width:auto;border-right:0;background-image:none;display:block}

  .site-header__rail-top{
    position:fixed;left:0;right:0;top:0;height:var(--bar-h);z-index:62;
    display:flex;align-items:center;padding:0 74px 0 18px;
    background-image:linear-gradient(180deg,rgba(7,26,46,.97),rgba(11,42,74,.86));
    border-bottom:1px solid var(--line);
    -webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);
    transition:transform .32s ease,opacity .32s ease;
  }
  .site-header[data-condensed="true"] .site-header__rail-top{transform:translateY(-100%);opacity:0;pointer-events:none}
  .brand{display:flex;align-items:baseline;gap:10px}
  .brand__name{display:inline;font-size:17px}
  .brand__tag{display:inline;margin:0;font-size:11px;letter-spacing:.06em}

  .nav-toggle{
    position:fixed;top:9px;right:14px;z-index:85;
    display:inline-flex;align-items:center;gap:8px;
    padding:8px 13px 8px 11px;border-radius:999px;cursor:pointer;
    border:1px solid rgba(127,200,248,.42);background:rgba(127,200,248,.1);color:var(--paper);
    font-size:12px;letter-spacing:.1em;
    transition:top .3s ease,bottom .3s ease,background .2s ease,border-color .2s ease;
  }
  .site-header[data-condensed="true"] .nav-toggle{
    top:auto;bottom:calc(var(--dock-h) + 70px);
    background:rgba(255,107,74,.18);border-color:var(--coral);
  }
  .nav-toggle__bars{display:inline-flex;flex-direction:column;gap:3px;width:16px}
  .nav-toggle__bars i{display:block;height:2px;border-radius:2px;background:currentColor;transition:transform .25s ease,opacity .25s ease}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1){transform:translateY(5px) rotate(45deg)}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2){opacity:0}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

  .site-nav{
    position:fixed;top:0;right:0;bottom:0;left:auto;width:min(84vw,330px);z-index:80;
    display:flex;flex-direction:column;gap:16px;padding:74px 20px 28px;overflow-y:auto;
    background-image:linear-gradient(200deg,#0B2A4A 0%,#071A2E 100%);
    border-left:1px solid var(--line);
    transform:translateX(102%);
    transition:transform .32s ease;
  }
  .site-nav[data-open="true"]{transform:translateX(0)}
  .site-nav__eyebrow{text-align:left;font-size:11px;letter-spacing:.18em;padding-bottom:10px;border-bottom:1px solid var(--line)}
  .site-nav__list{gap:8px}
  .site-nav__list a{flex-direction:row;align-items:center;gap:14px;padding:13px 14px;border-radius:6px;font-size:15px}
  .site-nav__list a[aria-current="page"]{border-color:var(--coral);background:rgba(255,107,74,.12)}
  .nav-num{font-size:12px}
  .nav-label{font-size:15px;letter-spacing:.06em}
  .site-nav__dock{margin-top:auto;flex-direction:row;flex-wrap:wrap;gap:8px;padding-top:16px}
  .dock-link{flex:1 1 40%;font-size:11px;padding:9px 6px}

  .nav-scrim{
    display:block;position:fixed;inset:0;z-index:78;
    background:rgba(4,12,22,.66);
    -webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);
    opacity:0;pointer-events:none;transition:opacity .3s ease;
  }
  .site-nav[data-open="true"] + .nav-scrim{opacity:1;pointer-events:auto}

  .mobile-dock{
    position:fixed;left:0;right:0;bottom:0;height:var(--dock-h);z-index:66;
    display:grid;grid-template-columns:repeat(3,1fr);
    background-image:linear-gradient(180deg,rgba(7,26,46,.9),rgba(7,26,46,.99));
    border-top:1px solid var(--line);
    -webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);
  }
  .mobile-dock__item{
    display:flex;align-items:center;justify-content:center;
    color:var(--mist);font-size:13px;letter-spacing:.1em;text-decoration:none;
    border-right:1px solid var(--line);
  }
  .mobile-dock__item:last-child{border-right:0}
  .mobile-dock__item:nth-child(2){color:var(--coral)}
  .mobile-dock__item:hover,.mobile-dock__item:active{color:var(--neon)}

  .scroll-meter{left:0;right:0;top:0;width:auto;height:3px}
  .scroll-meter__fill{transform-origin:left;transform:scaleX(var(--scroll-progress,0));background:linear-gradient(90deg,var(--coral),var(--ice))}
}

/* ===== 7. 页脚 ===== */
.site-footer{
  position:relative;overflow:hidden;
  margin-top:48px;padding:64px 0 0;
  background-image:linear-gradient(180deg,#071A2E 0%,#050F1C 100%);
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";position:absolute;right:-130px;top:-170px;width:380px;height:380px;border-radius:50%;
  border:1px solid rgba(127,200,248,.16);
  box-shadow:0 0 0 46px rgba(127,200,248,.05),0 0 0 92px rgba(127,200,248,.03);
  pointer-events:none;
}
.footer-brand{position:relative;display:flex;flex-direction:column;align-items:flex-start;gap:12px;padding-bottom:38px;border-bottom:1px solid var(--line)}
.footer-brand__name{margin:0;font-family:var(--font-head);font-size:clamp(26px,3.4vw,36px);font-weight:700;color:var(--paper);letter-spacing:.02em}
.footer-brand__line{margin:0;max-width:58ch;font-size:15px;line-height:1.8;color:var(--mist)}
.footer-status{display:inline-flex;align-items:center;gap:8px;margin:0;font-size:12px;letter-spacing:.08em;color:var(--neon)}
.status-dot{width:8px;height:8px;border-radius:50%;background:var(--neon);box-shadow:0 0 0 4px rgba(61,224,160,.16);animation:pulse 2.4s ease-in-out infinite}
@keyframes pulse{0%,100%{box-shadow:0 0 0 4px rgba(61,224,160,.16)}50%{box-shadow:0 0 0 8px rgba(61,224,160,.05)}}
.footer-brand__cta{margin:6px 0 0}

.footer-grid{display:grid;grid-template-columns:1.1fr 1fr 1.5fr;gap:36px;padding:40px 0}
.footer-col__title{margin:0 0 14px;font-family:var(--font-body);font-size:12px;font-weight:500;letter-spacing:.16em;color:var(--ice)}
.footer-links{display:flex;flex-direction:column;gap:10px;font-size:14px;color:var(--mist)}
.footer-links a{color:var(--mist);border-bottom:1px solid transparent;padding-bottom:1px}
.footer-links a:hover{color:var(--paper);border-color:var(--coral)}
.footer-contact li{line-height:1.7;color:var(--mist);word-break:break-word}

.footer-divider{height:1px;background:linear-gradient(90deg,rgba(127,200,248,0),var(--ice),rgba(127,200,248,0));opacity:.55}
.footer-base{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 24px;padding:20px 40px 30px;font-size:13px;color:var(--mist)}
.footer-base p{margin:0}
.footer-base__icp{color:var(--ice)}

.to-top{
  position:fixed;right:28px;bottom:28px;z-index:64;
  display:inline-flex;align-items:center;gap:6px;padding:11px 18px;border-radius:999px;cursor:pointer;
  border:1px solid var(--coral);background:rgba(11,42,74,.92);color:var(--paper);
  font-size:12px;letter-spacing:.1em;
  opacity:0;visibility:hidden;transform:translateY(10px);
  transition:opacity .3s ease,transform .3s ease,visibility .3s ease,background .2s ease;
}
.to-top[data-visible="true"]{opacity:1;visibility:visible;transform:none}
.to-top:hover{background:var(--coral);color:#fff}

/* ===== 8. 平板与手机微调 ===== */
@media (max-width:1024px){
  .container{padding:0 28px}
  .footer-base{padding:20px 28px 30px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:30px}
  .footer-col--contact{grid-column:1 / -1}
}
@media (max-width:640px){
  .container{padding:0 18px}
  .section-block{padding:52px 0}
  .section-head{gap:10px 14px;margin-bottom:20px}
  .footer-base{padding:18px 18px 26px;flex-direction:column;align-items:flex-start}
  .footer-grid{grid-template-columns:1fr;gap:26px}
  .data-table{font-size:14px}
  .to-top{right:14px;bottom:calc(var(--dock-h) + 16px);padding:9px 14px}
}

/* ===== 9. 动效降级与无障碍 ===== */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  html[data-js="on"] .reveal,
  html[data-js="on"] [data-reveal]{opacity:1;transform:none}
  .stat-bar__fill{width:var(--value,0%) !important}
  .to-top{transform:none}
}