/* =========================================================
   BET亚洲 · 数字航站楼 Site Kit / assets/site.css
   1 reset · 2 变量 · 3 基础排版 · 4 布局 · 5 通用组件
   6 页头 · 7 页脚 · 8 响应式 · 9 动效降级
   ========================================================= */

/* ---------- 1 reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote,fieldset{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}

/* ---------- 2 变量 ---------- */
:root{
  --deep:#071A2B;
  --navy:#0E2A47;
  --ink:#04101C;
  --cyan:#2FE6D6;
  --teal:#00BFA6;
  --coral:#FF6B4A;
  --mist:#F4F8FB;
  --steel:#8FA3B8;
  --steel-2:#B8C7D9;
  --violet:#6C5CE7;
  --amber:#FFC857;

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

  --line:rgba(143,163,184,.28);
  --line-soft:rgba(143,163,184,.16);
  --line-cyan:rgba(47,230,214,.42);
  --shell:1280px;
  --pad:clamp(1rem,3.2vw,2.5rem);
  --ease:cubic-bezier(.2,.7,.3,1);
}

/* ---------- 3 基础排版 ---------- */
body{
  min-height:100vh;
  color:var(--mist);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  background:
    radial-gradient(1100px 520px at 88% -12%,rgba(47,230,214,.10),transparent 62%),
    radial-gradient(820px 460px at -5% 2%,rgba(108,92,231,.12),transparent 58%),
    linear-gradient(180deg,#04101C 0%,#071A2B 34%,#0E2A47 100%);
}
::selection{background:var(--cyan);color:var(--ink)}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px;border-radius:2px}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:800;line-height:1.14;letter-spacing:-.01em;color:var(--mist)}
p{max-width:72ch}

/* ---------- 4 布局 ---------- */
.shell{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--pad);
}
.page-main{padding-block:clamp(2rem,4.5vw,3.5rem)}
.section + .section{margin-top:clamp(2rem,5vw,3.5rem)}
.grid{display:grid;gap:clamp(1rem,2.4vw,1.75rem)}
.grid--2{display:grid;gap:clamp(1rem,2.4vw,1.75rem);grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{display:grid;gap:clamp(1rem,2.4vw,1.75rem);grid-template-columns:repeat(3,minmax(0,1fr))}
.split{display:grid;gap:clamp(1.25rem,3vw,2.75rem);grid-template-columns:minmax(0,4fr) minmax(0,7fr)}

/* ---------- 5 通用组件 ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:.55rem;
  font-family:var(--font-mono);font-size:.74rem;font-weight:500;
  letter-spacing:.22em;line-height:1.4;color:var(--cyan);
}
.eyebrow::before{content:"";width:22px;height:1px;background:var(--cyan);opacity:.7}
.section-title{
  margin-top:.55rem;
  font-size:clamp(1.6rem,3.4vw,2.6rem);
  line-height:1.1;
}
.lede{max-width:64ch;margin-top:.9rem;color:var(--steel-2);font-size:clamp(1rem,1.3vw,1.125rem);line-height:1.8}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.55rem;
  padding:.72rem 1.25rem;
  font-family:var(--font-body);font-size:.95rem;font-weight:600;line-height:1.2;
  color:var(--ink);background:linear-gradient(100deg,var(--cyan),var(--teal));
  border:1px solid transparent;border-radius:2px;
  transition:transform .18s var(--ease),filter .18s var(--ease),background-color .18s var(--ease);
}
.btn:hover{transform:translateY(-1px);filter:brightness(1.08)}
.btn:active{transform:none}
.btn--ghost{background:transparent;color:var(--mist);border-color:var(--line-cyan)}
.btn--ghost:hover{background:rgba(47,230,214,.12);color:var(--mist);filter:none}
.btn--coral{background:linear-gradient(100deg,var(--coral),#FF8A63);color:#200A04;border-color:transparent}

.panel{
  position:relative;
  padding:clamp(1rem,2.2vw,1.6rem);
  background:linear-gradient(160deg,rgba(14,42,71,.92),rgba(7,26,43,.94));
  border:1px solid var(--line);
  border-radius:2px;
}
.panel--cut{clip-path:polygon(0 0,calc(100% - 22px) 0,100% 22px,100% 100%,22px 100%,0 calc(100% - 22px))}

.media{
  position:relative;overflow:hidden;
  background:linear-gradient(135deg,var(--navy),var(--deep) 58%,#0A2340);
  border:1px solid var(--line);
  border-radius:2px;
}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:
    linear-gradient(rgba(47,230,214,.14) 1px,transparent 1px),
    linear-gradient(90deg,rgba(47,230,214,.14) 1px,transparent 1px);
  background-size:34px 34px;
  -webkit-mask-image:linear-gradient(120deg,#000 10%,transparent 78%);
  mask-image:linear-gradient(120deg,#000 10%,transparent 78%);
}
.media__img{display:block;width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--square{aspect-ratio:1/1}

.crumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:.5rem;
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.1em;line-height:1.4;
  color:var(--steel);
}
.crumbs a{color:var(--steel-2);transition:color .16s var(--ease)}
.crumbs a:hover{color:var(--cyan)}
.crumbs__sep{color:rgba(143,163,184,.5)}

.prose{max-width:74ch;color:var(--steel-2);font-size:1.02rem;line-height:1.85}
.prose h2{margin-top:2rem;font-size:clamp(1.3rem,2.2vw,1.7rem);color:var(--mist)}
.prose h3{margin-top:1.5rem;font-size:1.15rem;color:var(--mist)}
.prose p{margin-top:.9rem}
.prose ul,.prose ol{margin-top:.9rem;padding-left:1.35rem;list-style:disc}
.prose ol{list-style:decimal}
.prose li{margin-top:.4rem}
.prose a{color:var(--cyan);text-decoration:underline;text-underline-offset:3px}
.prose strong{color:var(--mist);font-weight:600}

.tabs{display:flex;flex-wrap:wrap;gap:.45rem;padding-bottom:.7rem;margin-bottom:1.3rem;border-bottom:1px solid var(--line-soft)}
.tabs__btn{
  padding:.55rem 1rem;border:1px solid var(--line);border-radius:2px;
  font-size:.9rem;font-weight:600;line-height:1.2;color:var(--steel-2);
  transition:color .16s var(--ease),border-color .16s var(--ease),background-color .16s var(--ease);
}
.tabs__btn:hover{color:var(--mist);border-color:var(--line-cyan)}
.tabs__btn[aria-selected="true"]{color:var(--cyan);background:rgba(47,230,214,.14);border-color:var(--line-cyan)}
.tab-panel{animation:panel-in .22s var(--ease)}
.tab-panel[hidden]{display:none}

@keyframes panel-in{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
@keyframes drawer-in{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:none}}

/* ---------- 6 页头 ---------- */
.skip-link{
  position:absolute;left:1rem;top:-120px;z-index:200;
  padding:.6rem 1rem;background:var(--cyan);color:var(--ink);
  font-weight:700;font-size:.9rem;line-height:1.2;border-radius:2px;
  transition:top .18s var(--ease);
}
.skip-link:focus{top:.7rem}

.site-header{
  position:sticky;top:0;z-index:90;
  background:linear-gradient(180deg,#04101C 0%,#071A2B 58%,#0E2A47 100%);
  border-bottom:1px solid var(--line-soft);
  box-shadow:0 14px 34px -26px rgba(0,0,0,.95);
}

.header-rail{background:rgba(4,16,28,.6);border-bottom:1px solid var(--line-soft)}
.header-rail__inner{display:flex;align-items:center;gap:1rem;min-height:32px}
.rail__tag{
  display:inline-flex;align-items:center;gap:.5rem;flex:0 0 auto;
  font-family:var(--font-mono);font-size:.66rem;letter-spacing:.2em;line-height:1.4;
  color:var(--cyan);
}
.rail__dot{width:6px;height:6px;flex:0 0 auto;background:var(--cyan);box-shadow:0 0 0 3px rgba(47,230,214,.16)}
.rail__list{
  display:flex;align-items:center;gap:.95rem;flex:1 1 auto;min-width:0;
  overflow-x:auto;scrollbar-width:none;
}
.rail__list::-webkit-scrollbar{display:none}
.rail__link{
  display:inline-flex;align-items:baseline;gap:.35rem;white-space:nowrap;
  font-size:.72rem;line-height:1.4;color:var(--steel);
  transition:color .16s var(--ease);
}
.rail__num{font-family:var(--font-mono);font-size:.66rem;letter-spacing:.1em;color:rgba(47,230,214,.72)}
.rail__link:hover{color:var(--mist)}
.rail__link[aria-current="page"]{color:var(--cyan)}
.rail__link[aria-current="page"] .rail__num{color:var(--cyan)}
.rail__status{
  flex:0 0 auto;font-family:var(--font-mono);font-size:.66rem;
  letter-spacing:.18em;line-height:1.4;color:var(--steel);
}

.header-main__inner{
  display:flex;flex-wrap:wrap;align-items:center;
  gap:clamp(.6rem,1.6vw,1.5rem);
  min-height:76px;padding-block:.7rem;
  transition:min-height .24s var(--ease);
}
.site-header.is-scrolled .header-main__inner{min-height:62px}

.brand-slab{flex:0 0 auto;display:flex;align-items:center}
.brand{display:inline-flex;align-items:center;gap:.65rem;color:var(--mist)}
.brand__mark{font-family:var(--font-mono);font-size:1.15rem;line-height:1;letter-spacing:.08em;color:var(--cyan)}
.brand__text{display:block}
.brand__name{
  display:block;font-family:var(--font-display);font-weight:800;
  font-size:1.35rem;line-height:1.1;letter-spacing:.01em;
}
.brand__claim{
  display:block;margin-top:.22rem;
  font-size:.7rem;line-height:1.4;letter-spacing:.16em;color:var(--steel);
  transition:opacity .2s var(--ease);
}
.site-header.is-scrolled .brand__claim{opacity:0}

.header-divider{
  flex:0 0 auto;position:relative;width:28px;height:46px;
}
.header-divider::before{
  content:"";position:absolute;top:0;bottom:0;left:50%;
  border-left:1px solid var(--line-cyan);
  transform:skewX(-14deg);transform-origin:top center;
}
.header-divider::after{
  content:"";position:absolute;top:6px;bottom:6px;left:calc(50% - 8px);width:16px;
  background:repeating-linear-gradient(180deg,rgba(143,163,184,.55) 0 1px,transparent 1px 6px);
  transform:skewX(-14deg);
}

.primary-nav{flex:1 1 auto;min-width:0}
.primary-nav__list{display:flex;align-items:center;justify-content:flex-end;gap:.2rem}
.primary-nav__item{display:block}
.primary-nav__link{
  display:grid;gap:.12rem;
  padding:.42rem .68rem;
  border:1px solid transparent;border-radius:2px;
  transition:color .16s var(--ease),background-color .16s var(--ease),border-color .16s var(--ease);
}
.primary-nav__num{
  font-family:var(--font-mono);font-size:.63rem;font-weight:500;
  letter-spacing:.18em;line-height:1.3;color:var(--steel);
  transition:color .16s var(--ease);
}
.primary-nav__label{font-size:.88rem;font-weight:500;line-height:1.3;color:var(--steel-2)}
.primary-nav__link:hover{background:rgba(47,230,214,.08);border-color:var(--line-cyan)}
.primary-nav__link:hover .primary-nav__label{color:var(--mist)}
.primary-nav__link:hover .primary-nav__num{color:var(--cyan)}
.primary-nav__link[aria-current="page"]{
  background:linear-gradient(100deg,var(--cyan),var(--teal));
  border-color:transparent;
}
.primary-nav__link[aria-current="page"] .primary-nav__label{color:var(--ink);font-weight:700}
.primary-nav__link[aria-current="page"] .primary-nav__num{color:rgba(4,16,28,.72)}
.primary-nav__foot{display:none}
.primary-nav__note{
  margin-top:.85rem;padding-left:.7rem;
  border-left:2px solid var(--coral);
  font-size:.8rem;line-height:1.7;color:var(--steel-2);
}

.header-cta{
  flex:0 0 auto;
  display:inline-flex;align-items:center;justify-content:center;
  padding:.62rem 1.05rem;
  background:linear-gradient(100deg,var(--cyan),var(--teal));
  color:var(--ink);font-size:.86rem;font-weight:700;letter-spacing:.04em;line-height:1.2;
  transform:skewX(-8deg);
  transition:transform .18s var(--ease),filter .18s var(--ease);
}
.header-cta:hover{transform:skewX(-8deg) translateY(-1px);filter:brightness(1.08)}
.header-cta__label{display:inline-block;transform:skewX(8deg)}

.nav-toggle{
  display:none;flex:0 0 auto;
  width:44px;height:44px;align-items:center;justify-content:center;
  background:rgba(47,230,214,.08);
  border:1px solid var(--line-cyan);border-radius:2px;color:var(--mist);
  transition:background-color .16s var(--ease);
}
.nav-toggle:hover{background:rgba(47,230,214,.16)}
.nav-toggle__bars{display:grid;gap:5px;width:20px}
.nav-toggle__bars i{
  display:block;height:2px;width:100%;background:currentColor;
  transition:transform .2s var(--ease),opacity .2s var(--ease);
}
.site-header[data-open] .nav-toggle__bars i:nth-child(1){transform:translateY(7px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bars i:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle__bars i:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.scroll-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;pointer-events:none;background:transparent}
.scroll-progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--cyan),var(--teal) 58%,var(--coral));
  transition:width .1s linear;
}

/* ---------- 7 页脚 ---------- */
.site-footer{
  margin-top:clamp(2.5rem,6vw,4.5rem);
  background:var(--ink);
  color:var(--steel-2);
  border-top:1px solid var(--line-cyan);
}
.footer-chapters{
  background:linear-gradient(90deg,rgba(14,42,71,.92),rgba(4,16,28,.96) 62%);
  border-bottom:1px solid var(--line-soft);
}
.footer-chapters__inner{
  display:flex;flex-wrap:wrap;gap:.4rem 1.4rem;
  padding-block:.7rem;
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;line-height:1.4;
  color:var(--steel);
}
.footer-chapters__item{display:inline-flex;align-items:baseline;gap:.4rem;white-space:nowrap}
.footer-chapters__num{color:var(--cyan);font-size:.68rem}

.footer-shell{
  display:grid;
  grid-template-columns:1.5fr .8fr .8fr .7fr 1.3fr;
  gap:clamp(1.25rem,3vw,2.5rem);
  padding-block:clamp(2rem,4vw,3.25rem);
}
.footer-brand__link{
  display:inline-block;
  font-family:var(--font-display);font-size:1.45rem;font-weight:800;line-height:1.1;
  color:var(--mist);letter-spacing:.01em;
}
.footer-brand__claim{
  margin-top:.4rem;
  font-family:var(--font-mono);font-size:.7rem;letter-spacing:.18em;line-height:1.5;color:var(--cyan);
}
.footer-brand__note{margin-top:.9rem;font-size:.86rem;line-height:1.8;color:var(--steel-2)}
.footer-brand__tip{
  margin-top:.75rem;padding-left:.65rem;
  border-left:2px solid var(--amber);
  font-size:.78rem;line-height:1.7;color:var(--steel);
}

.footer-col__title{
  font-family:var(--font-mono);font-size:.7rem;font-weight:500;
  letter-spacing:.22em;line-height:1.4;color:var(--cyan);
}
.footer-col__list{margin-top:.85rem;display:grid;gap:.5rem}
.footer-col__link{
  display:inline-block;font-size:.9rem;line-height:1.6;color:var(--steel-2);
  border-bottom:1px solid transparent;
  transition:color .16s var(--ease),border-color .16s var(--ease);
}
.footer-col__link:hover{color:var(--mist);border-bottom-color:var(--cyan)}

.footer-contact__title{
  font-family:var(--font-mono);font-size:.7rem;font-weight:500;
  letter-spacing:.22em;line-height:1.4;color:var(--cyan);
}
.footer-contact__list{margin-top:.85rem;display:grid;gap:.6rem}
.footer-contact__item{display:grid;gap:.1rem}
.footer-contact__key{font-family:var(--font-mono);font-size:.66rem;letter-spacing:.18em;line-height:1.4;color:var(--steel)}
.footer-contact__value{font-size:.88rem;line-height:1.6;color:var(--mist);word-break:break-word}
.footer-contact__note{
  margin-top:.85rem;padding-left:.65rem;
  border-left:2px solid var(--coral);
  font-size:.78rem;line-height:1.7;color:var(--steel);
}

.footer-legal{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:.5rem 1.5rem;
  padding-block:.95rem;
  border-top:1px solid var(--line-soft);
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.06em;line-height:1.6;
  color:var(--steel);
}
.footer-legal__copy,.footer-legal__icp{margin:0}
.footer-legal__links{display:flex;flex-wrap:wrap;gap:.5rem 1.1rem}
.footer-legal__link{color:var(--steel-2);transition:color .16s var(--ease)}
.footer-legal__link:hover{color:var(--cyan)}

/* ---------- 8 响应式 ---------- */
@media (max-width:1240px){
  .brand__claim{display:none}
  .primary-nav__label{font-size:.84rem}
  .primary-nav__link{padding:.4rem .55rem}
}
@media (max-width:1120px){
  .header-divider{display:none}
  .nav-toggle{display:inline-flex}
  .brand-slab{flex:1 1 auto}
  .header-cta{font-size:.8rem;padding:.55rem .85rem}
  .primary-nav{
    display:none;flex-basis:100%;order:6;
    margin-top:.35rem;padding:.6rem 0 1rem;
    border-top:1px solid var(--line-soft);
  }
  .site-header[data-open] .primary-nav{display:block;animation:drawer-in .24s var(--ease)}
  .primary-nav__list{flex-direction:column;align-items:stretch;gap:.3rem}
  .primary-nav__link{
    grid-template-columns:auto 1fr;align-items:center;gap:.8rem;
    padding:.75rem .85rem;
    background:rgba(14,42,71,.55);
    border:1px solid var(--line-soft);
  }
  .primary-nav__num{font-size:.72rem;letter-spacing:.2em}
  .primary-nav__label{font-size:.95rem}
  .primary-nav__foot{display:block}
  .site-header.is-scrolled .header-main__inner{min-height:0}
}
@media (max-width:900px){
  .rail__status{display:none}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .split{grid-template-columns:minmax(0,1fr)}
  .footer-shell{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:640px){
  body{font-size:15.5px}
  .brand__name{font-size:1.2rem}
  .brand__mark{font-size:1rem}
  .header-cta{padding:.5rem .7rem;font-size:.75rem}
  .nav-toggle{width:40px;height:40px}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .footer-shell{grid-template-columns:minmax(0,1fr)}
  .footer-legal{justify-content:flex-start}
  .rail__list{gap:.75rem}
  .rail__tag{font-size:.6rem}
}
@media (max-width:420px){
  .header-cta{display:none}
}

/* ---------- 9 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;
  }
}