/* =========================================================
   BEAT 品牌站 · 共享样式表 /assets/site.css
   墨夜黑 × 暖白 × 品牌金 × 电光蓝
   ========================================================= */

/* ---------- 01 · 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,h6,p,ul,ol,dl,dd,figure,blockquote,pre{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
img,svg,video{display:block;max-width:100%}
table{width:100%;border-collapse:collapse}

/* ---------- 02 · Tokens ---------- */
:root{
  --ink:#0A0C10;
  --ink-2:#161A21;
  --paper:#F6F3EC;
  --rule:#E2DCCE;
  --gold:#E9B23C;
  --gold-hi:#F5C65B;
  --gold-deep:#A87C1E;
  --volt:#2D63F5;
  --volt-soft:#9DBAFF;
  --volt-deep:#1E4ACB;
  --mute:#6E7480;

  --on-dark:#F6F3EC;
  --on-dark-soft:rgba(246,243,236,.74);
  --on-dark-faint:rgba(246,243,236,.46);
  --line-dark:rgba(226,220,206,.15);
  --line-dark-2:rgba(226,220,206,.32);

  --font-sans:"HarmonyOS Sans SC","PingFang SC","Source Han Sans SC","Noto Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular","Roboto Mono",ui-monospace,Menlo,Consolas,monospace;

  --shell-wide:1440px;
  --shell:1240px;
  --shell-narrow:860px;
  --gut:clamp(18px,4vw,64px);
  --beat:clamp(56px,8vw,120px);

  --ease:cubic-bezier(.2,.7,.2,1);
  --t-fast:160ms;
  --t:200ms;
  --t-slow:240ms;

  --sh-1:0 1px 0 rgba(10,12,16,.05),0 14px 30px -24px rgba(10,12,16,.55);
  --sh-2:0 26px 48px -32px rgba(10,12,16,.72);
}

/* ---------- 03 · Base ---------- */
body{
  font-family:var(--font-sans);
  font-size:17px;
  font-weight:400;
  line-height:1.8;
  color:var(--ink);
  background:var(--paper);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
h1,h2,h3,h4,h5,h6{font-weight:800;line-height:1.14;letter-spacing:-.02em}
strong,b{font-weight:700}
:focus-visible{outline:2px solid var(--gold);outline-offset:2px;border-radius:2px}
::selection{background:var(--gold);color:var(--ink)}

/* ---------- 04 · Utilities ---------- */
.mono{font-family:var(--font-mono);font-weight:500;letter-spacing:.06em;font-variant-numeric:tabular-nums}
.visually-hidden{position:absolute!important;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.stack-sm>*+*{margin-top:12px}
.stack>*+*{margin-top:20px}
.stack-lg>*+*{margin-top:32px}
.measure{max-width:62ch}

/* ---------- 05 · Layout ---------- */
.container{width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:var(--gut)}
.container--wide{max-width:var(--shell-wide)}
.container--narrow{max-width:var(--shell-narrow)}

.section{position:relative;padding-block:var(--beat)}
.section--tight{padding-block:clamp(36px,5vw,64px)}
.section--paper{background:var(--paper);color:var(--ink)}
.section--dark{background:var(--ink);color:var(--on-dark)}
.section--slate{background:var(--ink-2);color:var(--on-dark)}

.coord-band{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:6px 20px;
  padding:10px 0;
  border-top:1px solid var(--rule);
  border-bottom:1px solid var(--rule);
  font-family:var(--font-mono);
  font-size:11px;font-weight:500;
  letter-spacing:.18em;text-transform:uppercase;
  color:var(--mute);
}
.coord-band span{white-space:nowrap}
.section--dark .coord-band,.section--slate .coord-band{border-color:var(--line-dark);color:var(--on-dark-faint)}

.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.2em;text-transform:uppercase;
  color:var(--volt-deep);
}
.eyebrow::before{content:"";flex:0 0 auto;width:24px;height:1px;background:var(--gold)}
.section--dark .eyebrow,.section--slate .eyebrow{color:var(--volt-soft)}

.h-display{font-size:clamp(34px,5.6vw,62px);font-weight:900;line-height:1.05;letter-spacing:-.02em}
.h-section{font-size:clamp(26px,3.4vw,42px);font-weight:800;line-height:1.14;letter-spacing:-.02em}
.h-sub{font-size:clamp(19px,2vw,24px);font-weight:700;line-height:1.34;letter-spacing:-.01em}
.h-card{font-size:17px;font-weight:700;line-height:1.4;letter-spacing:-.01em}

.lede{font-size:clamp(18px,2vw,22px);line-height:1.72;color:rgba(10,12,16,.84)}
.section--dark .lede,.section--slate .lede{color:var(--on-dark-soft)}
.prose{max-width:68ch}
.prose p+p{margin-top:1.2em}
.text-soft{color:var(--mute)}
.section--dark .text-soft,.section--slate .text-soft{color:var(--on-dark-faint)}

/* ---------- 06 · Grid ---------- */
.grid-2{display:grid;gap:clamp(16px,2.2vw,26px);grid-template-columns:1fr}
.grid-3{display:grid;gap:clamp(16px,2.2vw,26px);grid-template-columns:1fr}
.grid-layered{display:grid;gap:clamp(16px,2.2vw,26px);grid-template-columns:1fr}
@media (min-width:720px){
  .grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:900px){
  .grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media (min-width:960px){
  .grid-layered{grid-template-columns:repeat(3,minmax(0,1fr));align-items:start}
  .grid-layered>*:nth-child(2){margin-top:26px}
  .grid-layered>*:nth-child(3){margin-top:52px}
}
.split{display:grid;gap:clamp(28px,5vw,64px);grid-template-columns:1fr}
@media (min-width:960px){
  .split{grid-template-columns:minmax(0,7fr) minmax(0,5fr);align-items:center}
  .split--reverse{grid-template-columns:minmax(0,5fr) minmax(0,7fr)}
}
.with-rail{display:block}
@media (min-width:1080px){
  .with-rail{display:grid;grid-template-columns:minmax(0,1fr) minmax(200px,300px);gap:clamp(28px,4vw,64px);align-items:start}
}

/* ---------- 07 · Card ---------- */
.card{
  position:relative;
  display:flex;flex-direction:column;gap:12px;
  padding:clamp(20px,2.6vw,30px);
  background:#FFFFFF;
  border:1px solid var(--rule);
  border-radius:3px;
  box-shadow:var(--sh-1);
  transition:transform var(--t) var(--ease),border-color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.card:hover{transform:translateY(-2px);border-color:var(--gold);box-shadow:var(--sh-2)}
.card:active{transform:translateY(0)}
.card p{font-size:15px;line-height:1.72;color:rgba(10,12,16,.76)}
.card--dark{background:var(--ink-2);border-color:var(--line-dark);color:var(--on-dark);box-shadow:none}
.card--dark:hover{border-color:var(--gold);box-shadow:var(--sh-2)}
.card--dark p{color:var(--on-dark-soft)}
.card__meta{
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.16em;text-transform:uppercase;color:var(--mute);
}
.card--dark .card__meta{color:var(--on-dark-faint)}

/* ---------- 08 · Index strip ---------- */
.index-strip{display:grid;grid-template-columns:1fr;border-bottom:1px solid var(--rule)}
.index-strip a{
  display:flex;flex-direction:column;gap:6px;
  padding:20px 22px;
  border-top:1px solid var(--rule);
  font-size:14px;font-weight:600;color:var(--ink);
  transition:background-color var(--t) var(--ease),color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.index-strip a:hover{background:rgba(233,178,60,.1);box-shadow:inset 0 -2px 0 0 var(--gold)}
.index-strip__num{
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.16em;color:var(--volt-deep);
}
@media (min-width:720px){.index-strip{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (min-width:1024px){.index-strip{grid-template-columns:repeat(4,minmax(0,1fr))}}

/* ---------- 09 · Rail note ---------- */
.rail-note{
  border-left:2px solid var(--gold);
  padding:2px 0 2px 16px;
  max-width:34ch;
  font-size:14px;line-height:1.72;color:var(--mute);
}
.section--dark .rail-note,.section--slate .rail-note{color:var(--on-dark-faint)}

/* ---------- 10 · Figure ---------- */
.figure{
  position:relative;display:block;
  overflow:hidden;
  border:1px solid var(--rule);
  border-radius:3px;
  background:linear-gradient(150deg,#161A21 0%,#0A0C10 100%);
}
.figure__img{width:100%;height:100%;object-fit:cover}
.figure__cap{
  margin-top:10px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.12em;text-transform:uppercase;color:var(--mute);
}
.figure--wide{aspect-ratio:21/9}
.figure--split{aspect-ratio:16/10}
.figure--square{aspect-ratio:1/1}
.figure--tall{aspect-ratio:3/4}
@media (max-width:640px){
  .figure--wide{aspect-ratio:16/10}
  .figure--tall{aspect-ratio:4/5}
}

/* ---------- 11 · Breadcrumbs ---------- */
.crumbs ol{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.06em;color:var(--mute);
}
.crumbs li{display:flex;align-items:center}
.crumbs li+li::before{content:"/";margin-right:10px;color:var(--rule)}
.crumbs a{
  color:var(--volt-deep);
  transition:color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.crumbs a:hover{color:var(--gold-deep);box-shadow:inset 0 -1px 0 0 var(--gold-deep)}
.crumbs [aria-current="page"]{color:var(--mute)}

/* ---------- 12 · Buttons & tags ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 22px;
  border:1px solid transparent;border-radius:2px;
  font-size:15px;font-weight:600;line-height:1.2;letter-spacing:.01em;
  transition:background-color var(--t) var(--ease),color var(--t) var(--ease),border-color var(--t) var(--ease),transform var(--t-fast) var(--ease);
}
.btn--gold{background:var(--gold);color:var(--ink)}
.btn--gold:hover{background:var(--gold-hi)}
.btn--gold:active{transform:translateY(1px)}
.btn--volt{background:var(--volt);color:#FFFFFF}
.btn--volt:hover{background:var(--volt-deep)}
.btn--ghost{border-color:var(--rule);color:var(--ink)}
.btn--ghost:hover{border-color:var(--gold);color:var(--gold-deep)}
.btn--ghost-dark{border-color:var(--line-dark-2);color:var(--on-dark)}
.btn--ghost-dark:hover{border-color:var(--gold);color:var(--gold)}
.btn--pulse{animation:beat-pulse 2.4s var(--ease) infinite}
@keyframes beat-pulse{
  0%,64%,100%{box-shadow:0 0 0 0 rgba(233,178,60,0)}
  10%{box-shadow:0 0 0 3px rgba(233,178,60,.34)}
  34%{box-shadow:0 0 0 9px rgba(233,178,60,0)}
}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;
  border:1px solid var(--rule);border-radius:2px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.12em;text-transform:uppercase;color:var(--mute);
}
.tag--gold{border-color:rgba(233,178,60,.55);color:var(--gold-deep)}
.section--dark .tag,.section--slate .tag{border-color:var(--line-dark-2);color:var(--on-dark-faint)}
.section--dark .tag--gold,.section--slate .tag--gold{border-color:rgba(233,178,60,.55);color:var(--gold)}

/* ---------- 13 · Skip link ---------- */
.skip-link{
  position:absolute;left:var(--gut);top:6px;z-index:120;
  padding:10px 16px;
  background:var(--gold);color:var(--ink);
  font-size:14px;font-weight:700;border-radius:2px;
  transform:translateY(-240%);
  transition:transform var(--t) var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ---------- 14 · Header ---------- */
.beat-header{
  position:sticky;top:0;z-index:90;
  background:var(--ink);
  color:var(--on-dark);
  border-bottom:1px solid var(--line-dark);
}
.header-frame{
  position:relative;
  display:flex;align-items:center;
  gap:clamp(12px,2vw,32px);
  width:100%;max-width:var(--shell-wide);
  margin-inline:auto;
  padding-inline:var(--gut);
  min-height:70px;
}

.brand-set{display:flex;align-items:baseline;gap:12px;flex:0 0 auto;min-width:0}
.brand-mark{
  display:inline-flex;align-items:baseline;gap:8px;
  font-weight:900;letter-spacing:-.02em;
  transition:opacity var(--t) var(--ease);
}
.brand-mark:hover{opacity:.82}
.brand-glyph{color:var(--gold);font-size:13px;line-height:1;transform:translateY(-1px)}
.brand-word{font-size:20px;line-height:1;letter-spacing:.02em}
.brand-sub{
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.16em;color:var(--on-dark-faint);white-space:nowrap;
}
@media (max-width:640px){.brand-sub{display:none}}

.nav-cmd{display:flex;flex:1 1 auto;align-items:center;justify-content:center;gap:16px}
.nav-list{display:flex;align-items:center;gap:clamp(2px,1vw,14px)}
.nav-list li{flex:0 0 auto}
.nav-list a{
  position:relative;display:block;
  padding:9px 10px;
  font-size:14px;font-weight:500;
  color:var(--on-dark-soft);white-space:nowrap;
  transition:color var(--t) var(--ease);
}
.nav-list a::after{
  content:"";position:absolute;left:10px;right:10px;bottom:0;height:1px;
  background:var(--gold);
  transform:scaleX(0);transform-origin:left center;
  transition:transform var(--t) var(--ease),background-color var(--t) var(--ease);
}
.nav-list a:hover{color:var(--on-dark)}
.nav-list a:hover::after{transform:scaleX(1);background:var(--gold)}
.nav-list a[aria-current="page"]{color:var(--on-dark)}
.nav-list a[aria-current="page"]::after{transform:scaleX(1);background:var(--gold)}
.nav-foot{display:none;font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--on-dark-faint)}

.header-actions{display:flex;align-items:center;gap:14px;flex:0 0 auto}
.status-strip{
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.08em;color:var(--on-dark-faint);white-space:nowrap;
}
@media (max-width:1279px){.status-strip{display:none}}

.nav-toggle{
  display:inline-flex;align-items:center;justify-content:center;
  width:42px;height:42px;flex:0 0 auto;
  border:1px solid var(--line-dark-2);border-radius:2px;
  color:var(--on-dark);
  transition:border-color var(--t) var(--ease),background-color var(--t) var(--ease);
}
.nav-toggle:hover{border-color:var(--gold);background:rgba(233,178,60,.08)}
.nav-toggle-bars{position:relative;display:block;width:16px;height:11px}
.nav-toggle-bars::before,
.nav-toggle-bars::after{
  content:"";position:absolute;left:0;right:0;height:1px;
  background:currentColor;
  transition:transform var(--t) var(--ease),opacity var(--t) var(--ease);
}
.nav-toggle-bars::before{top:0}
.nav-toggle-bars::after{bottom:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{transform:translateY(-5px) rotate(-45deg)}

@media (max-width:1023px){
  .nav-cmd{
    position:absolute;left:0;right:0;top:100%;
    flex-direction:column;align-items:stretch;justify-content:flex-start;gap:0;
    padding:8px var(--gut) 20px;
    background:var(--ink);
    border-bottom:1px solid var(--line-dark-2);
    box-shadow:0 26px 40px -30px rgba(0,0,0,.9);
    max-height:0;
    opacity:0;
    visibility:hidden;
    overflow:hidden;
    transition:max-height var(--t-slow) var(--ease),opacity var(--t) var(--ease),visibility 0s linear var(--t-slow);
  }
  .nav-cmd[data-open]{
    max-height:560px;
    opacity:1;
    visibility:visible;
    transition:max-height var(--t-slow) var(--ease),opacity var(--t) var(--ease),visibility 0s;
  }
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .nav-list a{
    padding:14px 2px;
    font-size:16px;
    border-bottom:1px solid rgba(226,220,206,.1);
  }
  .nav-list a::after{display:none}
  .nav-list a[aria-current="page"]{
    color:var(--gold);
    box-shadow:inset 2px 0 0 0 var(--gold);
    padding-left:12px;
  }
  .nav-foot{display:block;padding-top:16px}
}
@media (min-width:1024px){
  .nav-toggle{display:none}
}

.read-meter{
  position:absolute;left:0;right:0;bottom:-1px;height:1px;
  overflow:hidden;pointer-events:none;
}
.read-meter-fill{
  display:block;width:100%;height:100%;
  background:linear-gradient(90deg,var(--gold-deep),var(--gold));
  transform:scaleX(0);transform-origin:left center;
}

/* ---------- 15 · Footer ---------- */
.beat-footer{
  background:var(--ink);
  color:var(--on-dark-soft);
  border-top:1px solid var(--line-dark);
  padding-top:clamp(48px,7vw,84px);
  font-size:14px;
}
.footer-frame{
  display:grid;grid-template-columns:1fr;gap:clamp(30px,5vw,72px);
  width:100%;max-width:var(--shell);margin-inline:auto;
  padding-inline:var(--gut);
}
@media (min-width:880px){
  .footer-frame{grid-template-columns:minmax(230px,1fr) minmax(0,2.2fr)}
}
.footer-wordmark{
  display:inline-block;
  font-size:26px;font-weight:900;letter-spacing:.02em;color:var(--paper);
  transition:color var(--t) var(--ease);
}
.footer-wordmark:hover{color:var(--gold)}
.footer-tagline{margin-top:10px;max-width:28ch;font-size:13px;line-height:1.7;color:var(--on-dark-faint)}
.region-chip{
  display:inline-flex;align-items:center;gap:8px;
  margin-top:18px;padding:5px 12px;
  border:1px solid rgba(233,178,60,.42);border-radius:2px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.16em;text-transform:uppercase;color:var(--gold);
}
.region-chip::before{content:"";flex:0 0 auto;width:5px;height:5px;border-radius:50%;background:var(--gold)}

.footer-cols{display:grid;grid-template-columns:1fr;gap:clamp(22px,4vw,44px)}
@media (min-width:560px){.footer-cols{grid-template-columns:repeat(3,minmax(0,1fr))}}
.footer-col-title{
  margin-bottom:14px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.2em;text-transform:uppercase;color:var(--volt-soft);
}
.footer-col li+li{margin-top:2px}
.footer-col a{
  display:inline-block;padding:5px 0;
  font-size:14px;color:var(--on-dark-soft);
  transition:color var(--t) var(--ease),box-shadow var(--t) var(--ease);
}
.footer-col a:hover{color:var(--gold);box-shadow:inset 0 -1px 0 0 var(--gold)}

.footer-contact{
  display:flex;flex-wrap:wrap;gap:8px 28px;
  width:100%;max-width:var(--shell);
  margin:clamp(40px,6vw,72px) auto 0;
  padding:22px var(--gut);
  border-top:1px solid var(--line-dark);
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.05em;color:var(--on-dark-faint);
}
.footer-contact span{overflow-wrap:anywhere}

.footer-legal{
  margin-top:6px;
  border-top:1px solid rgba(226,220,206,.1);
  background:rgba(0,0,0,.34);
}
.footer-legal-inner{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:10px 20px;
  width:100%;max-width:var(--shell);margin-inline:auto;
  padding:16px var(--gut);
  font-size:12px;color:var(--on-dark-faint);
}
.icp{
  padding:4px 10px;
  border:1px dashed var(--line-dark-2);border-radius:2px;
  font-family:var(--font-mono);font-weight:500;letter-spacing:.06em;
  user-select:text;-webkit-user-select:text;
  transition:color var(--t) var(--ease),border-color var(--t) var(--ease);
}
.icp::selection{background:var(--gold);color:var(--ink)}
.icp:hover{color:var(--gold);border-color:rgba(233,178,60,.6)}
.footer-domain{color:var(--on-dark-faint)}
.footer-copy{color:var(--on-dark-faint)}

/* ---------- 16 · Reveal ---------- */
[data-reveal]{
  opacity:1;transform:none;
  transition:opacity var(--t-slow) var(--ease),transform var(--t-slow) var(--ease);
}
.js-on [data-reveal]{opacity:0;transform:translateY(16px)}
.js-on [data-reveal].is-in{opacity:1;transform:none}

/* ---------- 17 · Reduced motion ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
    transition-duration:.001ms!important;
  }
  .btn--pulse{animation:none;box-shadow:0 0 0 1px rgba(233,178,60,.5)}
  .js-on [data-reveal],
  .js-on [data-reveal].is-in{opacity:1;transform:none}
}