/* ============================================================
   /assets/site.css — 宝马娱乐会馆 共享样式
   1 Reset  2 Tokens  3 Base  4 Layout  5 Typography
   6 Components  7 Header  8 Footer  9 Motion  10 Responsive
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h,76px) + 28px)}
body,h1,h2,h3,h4,h5,p,ul,ol,dl,dd,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,picture,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
input,select,textarea{font:inherit}
::selection{background:var(--cyan);color:var(--ink)}

/* ---------- 2. Tokens ---------- */
:root{
  --ink:#05070A;
  --ink-2:#0E1419;
  --line:#1B2830;
  --cyan:#00E8D1;
  --blue:#2F6BFF;
  --gold:#F2B45C;
  --magenta:#FF2E7E;
  --text:#F3F6F8;
  --muted:#A7B4C0;
  --paper:#E9EEF2;
  --paper-ink:#0B1116;
  --cyan-soft:rgba(0,232,209,.45);
  --gold-soft:rgba(242,180,92,.45);
  --magenta-soft:rgba(255,46,126,.45);
  --font-head:"HarmonyOS Sans SC","Noto Sans SC",system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Noto Sans SC",system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --header-h:76px;
  --pad:clamp(16px,4vw,40px);
  --maxw:1280px;
  --ease:cubic-bezier(.2,.7,.2,1);
  --cut:14px;
}

/* ---------- 3. Base ---------- */
html,body{min-height:100%}
body{
  background:
    radial-gradient(1100px 560px at 82% -8%, rgba(47,107,255,.16), transparent 62%),
    radial-gradient(900px 520px at 4% 2%, rgba(0,232,209,.10), transparent 58%),
    var(--ink);
  color:var(--text);
  font-family:var(--font-body);
  font-size:clamp(16px,.32vw + 15px,17px);
  line-height:1.85;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4{font-family:var(--font-head);font-weight:900;line-height:1.18;letter-spacing:-.02em;color:var(--text)}
h5,h6{font-family:var(--font-head);font-weight:700;line-height:1.3}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}
a:focus-visible,button:focus-visible{outline-color:var(--cyan)}

/* ---------- 4. Layout ---------- */
.wrap{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--pad)}
.main-offset{padding-top:calc(var(--header-h) + 8px)}
.section{padding-block:clamp(48px,7vw,92px)}
.section--tight{padding-block:clamp(32px,4vw,52px)}
.grid{display:grid;gap:clamp(16px,2.4vw,32px)}
.grid--split,.grid--2{grid-template-columns:minmax(0,1fr)}

/* ---------- 5. Typography / text utilities ---------- */
.kicker{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.3em;
  color:var(--cyan);text-transform:uppercase;
}
.kicker::before{content:"";width:22px;height:1px;background:var(--cyan);display:block}
.annotation{
  writing-mode:vertical-rl;text-orientation:mixed;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.26em;
  color:var(--muted);text-transform:uppercase;line-height:1;
}
.annotation--flip{transform:rotate(180deg)}
.data-num{
  font-family:var(--font-mono);font-variant-numeric:tabular-nums;
  letter-spacing:.04em;color:var(--gold);
}
.prose{max-width:66ch;color:#dbe3ea}
.prose>*+*{margin-top:1.2em}
.prose h2{
  font-family:var(--font-head);font-size:clamp(22px,1.6vw + 14px,30px);
  line-height:1.32;letter-spacing:-.02em;color:var(--text);margin-top:2.1em;
}
.prose h3{font-family:var(--font-head);font-size:clamp(18px,1vw + 14px,23px);line-height:1.4;color:var(--text);margin-top:1.8em}
.prose ul li,.prose ol li{position:relative;padding-left:1.15em;margin-top:.5em}
.prose ul li::before{content:"";position:absolute;left:0;top:.95em;width:7px;height:1px;background:var(--cyan)}
.prose ol{counter-reset:prose}
.prose ol li{counter-increment:prose}
.prose ol li::before{
  content:counter(prose,decimal-leading-zero);
  position:absolute;left:0;top:.1em;
  font-family:var(--font-mono);font-size:11px;color:var(--gold);
}
.prose a{color:var(--cyan);border-bottom:1px solid var(--cyan-soft)}
.prose strong{color:#fff;font-weight:700}
.tag{
  display:inline-flex;align-items:center;gap:.5em;
  padding:4px 10px;border:1px solid var(--line);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--muted);text-transform:uppercase;line-height:1.6;
}
.tag--cyan{color:var(--cyan);border-color:var(--cyan-soft);background:rgba(0,232,209,.06)}
.tag--gold{color:var(--gold);border-color:var(--gold-soft);background:rgba(242,180,92,.06)}
.tag--magenta{color:var(--magenta);border-color:var(--magenta-soft);background:rgba(255,46,126,.07)}

/* ---------- 6. Components ---------- */
.btn{
  --btn-line:var(--line);
  --btn-fg:var(--text);
  --btn-bg:transparent;
  position:relative;display:inline-flex;align-items:center;justify-content:center;gap:.55em;
  min-height:44px;padding:0 1.35em;
  font-family:var(--font-head);font-weight:700;font-size:14px;letter-spacing:.04em;line-height:1.2;
  color:var(--btn-fg);background:var(--btn-bg);
  border:1px solid var(--btn-line);
  clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)));
  transition:background .3s var(--ease),color .3s var(--ease),border-color .3s var(--ease),transform .3s var(--ease);
  text-align:center;
}
.btn::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:
    linear-gradient(to bottom right,transparent calc(50% - .6px),var(--btn-line) calc(50% - .6px),var(--btn-line) calc(50% + .6px),transparent calc(50% + .6px)) right top/var(--cut) var(--cut) no-repeat,
    linear-gradient(to bottom right,transparent calc(50% - .6px),var(--btn-line) calc(50% - .6px),var(--btn-line) calc(50% + .6px),transparent calc(50% + .6px)) left bottom/var(--cut) var(--cut) no-repeat;
}
.btn:hover{transform:translate(-2px,-2px)}
.btn:focus-visible{outline:none;box-shadow:inset 0 0 0 2px var(--cyan)}
.btn--cta{--btn-line:var(--cyan);--btn-fg:var(--cyan);--btn-bg:rgba(0,232,209,.07)}
.btn--cta:hover{--btn-bg:var(--cyan);--btn-fg:var(--ink)}
.btn--ghost{--btn-line:var(--line);--btn-fg:var(--text)}
.btn--ghost:hover{--btn-line:var(--cyan);--btn-fg:var(--cyan);--btn-bg:rgba(0,232,209,.06)}
.btn--solid{--btn-bg:var(--cyan);--btn-fg:var(--ink);--btn-line:var(--cyan)}
.btn--solid:hover{--btn-bg:#7CF6EB}
.btn--gold{--btn-line:var(--gold);--btn-fg:var(--gold);--btn-bg:rgba(242,180,92,.08)}
.btn--gold:hover{--btn-bg:var(--gold);--btn-fg:var(--ink)}

.panel{
  position:relative;
  background:var(--ink-2);
  border:1px solid var(--line);
  padding:clamp(18px,2.4vw,32px);
  clip-path:polygon(0 0,calc(100% - 18px) 0,100% 18px,100% 100%,18px 100%,0 calc(100% - 18px));
}
.panel::before{content:"";position:absolute;left:0;top:0;width:36px;height:2px;background:var(--cyan);z-index:2}
.panel::after{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:2;
  background:
    linear-gradient(to bottom right,transparent calc(50% - .6px),var(--line) calc(50% - .6px),var(--line) calc(50% + .6px),transparent calc(50% + .6px)) right top/18px 18px no-repeat,
    linear-gradient(to bottom right,transparent calc(50% - .6px),var(--line) calc(50% - .6px),var(--line) calc(50% + .6px),transparent calc(50% + .6px)) left bottom/18px 18px no-repeat;
}
.panel--paper{background:var(--paper);color:var(--paper-ink);border-color:#C9D4DC}
.panel--paper h2,.panel--paper h3{color:var(--paper-ink)}
.panel--paper .kicker{color:#0E7A73}

.media{
  position:relative;overflow:hidden;display:block;
  background:linear-gradient(150deg,#0E1419,#05070A);
  border:1px solid var(--line);
  aspect-ratio:16/9;
  clip-path:polygon(0 0,calc(100% - 16px) 0,100% 16px,100% 100%,16px 100%,0 calc(100% - 16px));
}
.media>img,.media>svg,.media>picture>img{width:100%;height:100%;object-fit:cover}
.media>picture{display:block;width:100%;height:100%}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:0;
  background:linear-gradient(180deg,rgba(5,7,10,0) 45%,rgba(5,7,10,.72));
}
.media figcaption{
  position:absolute;left:14px;bottom:12px;z-index:1;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--muted);
}
.media--wide{aspect-ratio:21/9}
.media--tall{aspect-ratio:3/4}
.media--square{aspect-ratio:1/1}
.media--framed{border-color:rgba(0,232,209,.28)}
.media--framed::before{
  content:"";position:absolute;inset:10px;z-index:1;pointer-events:none;
  border:1px solid rgba(243,246,248,.14);
}

.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;
  color:var(--muted);text-transform:uppercase;
}
.breadcrumb a{color:var(--muted);transition:color .25s var(--ease)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb .sep{color:var(--line)}
.breadcrumb [aria-current="page"]{color:var(--cyan)}

.toc{position:sticky;top:calc(var(--header-h) + 24px);align-self:start}
.toc-link{
  display:block;padding:8px 0 8px 14px;
  border-left:1px solid var(--line);
  font-size:14px;line-height:1.5;color:var(--muted);
  transition:color .25s var(--ease),border-color .25s var(--ease),padding .25s var(--ease);
}
.toc-link:hover{color:var(--text)}
.toc-link[aria-current="true"]{color:var(--cyan);border-left-color:var(--cyan);padding-left:20px}

/* ---------- 7. Header ---------- */
.skip-link{
  position:fixed;top:-120px;left:clamp(10px,3vw,24px);z-index:200;
  display:inline-flex;align-items:center;min-height:42px;padding:0 18px;
  background:var(--cyan);color:var(--ink);
  font-family:var(--font-head);font-weight:700;font-size:14px;
  clip-path:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,0 100%);
  transition:top .24s var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{top:12px;outline:none}

.site-header{
  position:fixed;inset:0 0 auto 0;z-index:90;
  background:transparent;border-bottom:1px solid transparent;
  transition:background .35s var(--ease),border-color .35s var(--ease),box-shadow .35s var(--ease);
}
.header-inner{
  display:flex;align-items:center;gap:clamp(8px,1.4vw,20px);
  width:100%;max-width:var(--maxw);margin-inline:auto;
  padding-inline:var(--pad);
  height:var(--header-h);
  transition:height .35s var(--ease);
}
.site-header[data-scrolled] .header-inner{height:62px}

.brand{display:inline-flex;align-items:center;gap:10px;flex:none;padding:6px 0}
.brand-mark{
  position:relative;width:26px;height:26px;flex:none;
  border:1px solid var(--cyan-soft);
  background:linear-gradient(140deg,rgba(0,232,209,.24),rgba(47,107,255,.14) 58%,transparent);
  clip-path:polygon(0 0,100% 0,100% 64%,64% 100%,0 100%);
}
.brand-mark::after{
  content:"";position:absolute;left:6px;right:6px;top:50%;height:1px;
  background:var(--cyan);opacity:.9;
}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-name{
  font-family:var(--font-head);font-weight:900;font-size:17px;
  letter-spacing:-.01em;color:var(--text);transition:color .25s var(--ease);
}
.brand-sub{
  margin-top:4px;font-family:var(--font-mono);font-size:10px;
  letter-spacing:.32em;color:var(--muted);
}
.brand-sub::before{
  content:"";display:inline-block;width:12px;height:1px;
  margin-right:6px;vertical-align:middle;background:var(--cyan);
}
.brand:hover .brand-name{color:var(--cyan)}

.brand-scale{
  display:none;width:12px;height:34px;flex:none;position:relative;
  background:repeating-linear-gradient(to bottom,var(--line) 0 1px,transparent 1px 6px);
}
.brand-scale::after{content:"";position:absolute;left:0;right:0;bottom:0;height:1px;background:var(--cyan)}
.brand-year{
  display:none;writing-mode:vertical-rl;text-orientation:mixed;
  font-family:var(--font-mono);font-size:10px;letter-spacing:.28em;
  color:var(--muted);line-height:1;
}

.site-nav{margin-left:auto}
.nav-list{display:flex;align-items:center;gap:clamp(4px,1.3vw,22px)}
.nav-link{
  position:relative;display:inline-block;padding:8px 2px;
  font-size:14.5px;letter-spacing:.02em;color:#CBD5DD;
  transition:color .25s var(--ease);
}
.nav-link::after{
  content:"";position:absolute;left:0;right:0;bottom:2px;height:1px;
  background:var(--cyan);transform:scaleX(0);transform-origin:left;
  transition:transform .3s var(--ease);
}
.nav-link:hover{color:var(--text)}
.nav-link:hover::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--cyan)}
.nav-link[aria-current="page"]::after{transform:scaleX(1)}

.header-cta{flex:none;margin-left:clamp(6px,1.2vw,18px)}
.header-progress{
  position:absolute;left:0;right:0;bottom:0;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--blue));
  transform:scaleX(0);transform-origin:0 50%;
  will-change:transform;
}

.nav-toggle{
  display:none;flex:none;width:44px;height:40px;
  align-items:center;justify-content:center;flex-direction:column;gap:5px;
  border:1px solid var(--line);color:var(--cyan);
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,0 100%);
  transition:border-color .25s var(--ease),color .25s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan-soft)}
.nav-toggle-bar{
  display:block;width:18px;height:1.5px;background:currentColor;
  transition:transform .3s var(--ease),opacity .2s var(--ease);
}
.site-header[data-open] .nav-toggle-bar:nth-child(1){transform:translateY(6.5px) rotate(45deg)}
.site-header[data-open] .nav-toggle-bar:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle-bar:nth-child(3){transform:translateY(-6.5px) rotate(-45deg)}

/* ---------- 8. Footer ---------- */
.site-footer{
  position:relative;margin-top:clamp(48px,8vw,96px);
  background:var(--ink-2);border-top:1px solid var(--line);
  padding-top:clamp(36px,5vw,64px);
}
.footer-rule{position:absolute;left:0;right:0;top:0;height:1px;background:var(--line)}
.footer-rule::before{
  content:"";position:absolute;left:0;top:0;height:1px;
  width:clamp(80px,18vw,220px);background:var(--cyan);
}
.footer-body{
  display:grid;gap:clamp(28px,4vw,56px);
  grid-template-columns:minmax(0,1fr);
}
.footer-brand-col{max-width:42ch}
.footer-brand-name{
  font-family:var(--font-head);font-weight:900;font-size:22px;
  letter-spacing:-.02em;color:var(--text);
}
.footer-brand-line{
  margin-top:8px;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.24em;color:var(--muted);text-transform:uppercase;
}
.footer-note{margin-top:16px;font-size:14.5px;line-height:1.85;color:#B9C5CF}
.footer-code{
  margin-top:18px;display:inline-block;padding:4px 10px;
  border:1px solid var(--line);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;color:var(--gold);
}
.footer-cols{
  display:grid;gap:clamp(20px,3vw,40px);
  grid-template-columns:minmax(0,1fr);
}
.footer-col-title{
  position:relative;margin-bottom:14px;padding-left:13px;
  font-family:var(--font-mono);font-size:11px;font-weight:400;
  letter-spacing:.26em;color:var(--muted);text-transform:uppercase;line-height:1.6;
}
.footer-col-title::before{
  content:"";position:absolute;left:0;top:.55em;width:6px;height:6px;
  background:var(--cyan);transform:rotate(45deg);
}
.footer-links{display:grid;gap:2px}
.footer-links--plain{display:grid;gap:10px}
.footer-link{
  display:inline-block;padding:5px 0;font-size:14.5px;color:#C6D1DA;
  transition:color .25s var(--ease),transform .25s var(--ease);
}
.footer-link:hover{color:var(--cyan);transform:translateX(4px)}
.footer-contact-item{display:flex;flex-direction:column;gap:2px;line-height:1.6}
.footer-contact-label{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.22em;
  color:var(--muted);text-transform:uppercase;
}
.footer-contact-value{font-size:14.5px;color:#DCE4EB;word-break:break-word}
.footer-contact-note{margin-top:12px;font-size:12.5px;line-height:1.7;color:var(--muted)}
.footer-bottom{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:10px 28px;
  margin-top:clamp(28px,4vw,48px);
  border-top:1px solid var(--line);
  padding-block:20px 28px;
}
.footer-service{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  line-height:1.8;color:var(--muted);
}
.footer-legal{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px 18px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--muted);
}
.footer-icp{color:#C6D1DA}
.footer-copy{color:var(--muted)}

.to-top{
  position:fixed;right:clamp(14px,3vw,32px);bottom:clamp(14px,3vw,32px);z-index:80;
  display:grid;place-items:center;width:46px;height:46px;
  background:rgba(14,20,25,.94);border:1px solid var(--cyan-soft);color:var(--cyan);
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,12px 100%,0 calc(100% - 12px));
  transition:background .25s var(--ease),color .25s var(--ease),transform .25s var(--ease);
  box-shadow:0 12px 30px rgba(0,0,0,.5);
}
.to-top:hover{background:var(--cyan);color:var(--ink);transform:translateY(-3px)}
.to-top[hidden]{display:none}
.to-top-arrow{
  display:block;width:10px;height:10px;margin-top:4px;
  border-left:1.5px solid currentColor;border-top:1.5px solid currentColor;
  transform:rotate(45deg);
}

/* ---------- 9. Motion ---------- */
[data-reveal]{
  opacity:0;transform:translate3d(-24px,24px,0);
  transition:opacity .48s var(--ease),transform .48s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}
@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;
  }
  [data-reveal]{opacity:1;transform:none}
}

/* ---------- 10. Responsive ---------- */
@media (min-width:560px){
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:720px){
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:900px){
  .brand-scale,.brand-year{display:block}
  .grid--split{grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);align-items:start}
  .grid--split.is-flipped{grid-template-columns:minmax(0,.85fr) minmax(0,1.15fr)}
  .grid--split.is-flipped>:first-child{order:2}
  .footer-body{grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr)}
  .footer-cols{grid-template-columns:repeat(3,minmax(0,1fr))}
  .site-header[data-scrolled]{
    background:rgba(14,20,25,.95);
    backdrop-filter:blur(12px);
    -webkit-backdrop-filter:blur(12px);
    border-bottom-color:var(--line);
    box-shadow:0 18px 40px rgba(0,0,0,.45);
  }
}
@media (max-width:899px){
  .site-header{
    background:rgba(5,7,10,.88);
    backdrop-filter:blur(8px);
    -webkit-backdrop-filter:blur(8px);
    border-bottom:1px solid var(--line);
  }
  .site-header[data-scrolled]{background:rgba(14,20,25,.97)}
  .nav-toggle{display:flex;margin-left:8px}
  .header-cta{margin-left:auto;min-height:38px;padding:0 12px;font-size:12.5px;--cut:10px}
  .brand-name{font-size:15px}
  .brand-sub{display:none}
  .site-nav{
    position:absolute;top:100%;left:0;right:0;
    background:rgba(10,15,19,.985);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    padding:6px var(--pad) 20px;
    max-height:calc(100vh - var(--header-h));
    overflow-y:auto;
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .3s var(--ease),transform .3s var(--ease),visibility .3s;
    box-shadow:0 24px 44px rgba(0,0,0,.55);
  }
  .site-header[data-open] .site-nav{opacity:1;visibility:visible;transform:none}
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .nav-item{border-bottom:1px solid var(--line)}
  .nav-item:last-child{border-bottom:0}
  .nav-link{display:block;padding:14px 0;font-size:17px}
  .nav-link::after{display:none}
  .nav-link[aria-current="page"]{padding-left:16px}
  .nav-link[aria-current="page"]::before{
    content:"";position:absolute;left:0;top:50%;width:6px;height:6px;
    background:var(--cyan);transform:translateY(-50%) rotate(45deg);
  }
  .footer-legal{width:100%}
}
@media (max-width:420px){
  .header-cta{font-size:11.5px;padding:0 10px}
  .brand-mark{width:22px;height:22px}
}