/* ===== 必嬴 / BIYING ARCHIVE — shared site kit ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:16px;line-height:1.75;letter-spacing:.01em;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:700;line-height:1.12;letter-spacing:-.01em;color:var(--ink-950);margin:0}
p{margin:0}
a{color:inherit;text-decoration:none}
ul,ol{margin:0;padding:0;list-style:none}
img,svg{display:block;max-width:100%;height:auto}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--amber-bright);outline-offset:3px}

:root{
  --ink-950:#0E1A2B;
  --ink-900:#16283F;
  --paper:#F6F1E7;
  --sheet:#FFFDF8;
  --steel:#6B7C8C;
  --steel-200:#AEB9C2;
  --amber:#C8902F;
  --amber-bright:#D9A441;
  --cinnabar:#B6402E;
  --ink:#1E1E1E;
  --rule:#D8D2C6;
  --font-display:"Songti SC","Noto Serif SC","Source Han Serif SC","SimSun",serif;
  --font-body:"PingFang SC","Noto Sans SC","Helvetica Neue",Arial,sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono","SFMono-Regular",Menlo,monospace;
  --gutter:clamp(20px,5vw,56px);
  --maxw:1280px;
  --shadow-sheet:0 1px 0 rgba(14,26,43,.05),0 22px 42px -32px rgba(14,26,43,.55);
}

/* ---------- skip link ---------- */
.skip-link{position:fixed;left:14px;top:14px;z-index:200;transform:translateY(-180%);
  background:var(--amber-bright);color:var(--ink-950);padding:11px 18px;font-size:14px;
  letter-spacing:.06em;box-shadow:0 12px 24px -12px rgba(14,26,43,.7);transition:transform .2s ease}
.skip-link:focus-visible{transform:none}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:80;background:var(--ink-950);color:var(--paper);
  border-bottom:1px solid rgba(174,185,194,.22)}
.header-inner{width:min(1400px,100% - var(--gutter)*2);margin-inline:auto;display:flex;
  align-items:center;justify-content:space-between;gap:clamp(16px,3vw,40px);
  min-height:78px;padding-block:12px}
.brand-cluster{display:flex;align-items:center;gap:clamp(12px,2vw,22px);min-width:0}
.brand{display:flex;flex-direction:column;gap:5px;line-height:1;padding:3px 0}
.brand-cn{font-family:var(--font-display);font-size:clamp(21px,2.1vw,26px);letter-spacing:.14em;color:var(--paper)}
.brand-en{font-family:var(--font-mono);font-size:10px;letter-spacing:.28em;text-transform:uppercase;color:var(--steel-200)}
.version-tag{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);
  font-size:11px;letter-spacing:.1em;color:var(--amber-bright);
  border:1px solid rgba(200,144,47,.45);padding:5px 10px;white-space:nowrap}
.tag-dot{display:block;width:5px;height:5px;background:var(--cinnabar)}
.nav-cluster{display:flex;align-items:center;gap:clamp(10px,1.6vw,22px);min-width:0}
.site-nav{display:flex;align-items:center}
.nav-list{display:flex;align-items:center;gap:2px}
.site-nav a{position:relative;display:block;padding:10px 12px;font-size:14px;letter-spacing:.05em;
  color:var(--steel-200);transition:color .18s ease}
.site-nav a::after{content:"";position:absolute;left:12px;right:12px;bottom:5px;height:1px;
  background:var(--amber-bright);transform:scaleX(0);transform-origin:left center;transition:transform .24s ease}
.site-nav a:hover,.site-nav a:focus-visible{color:var(--paper)}
.site-nav a:hover::after,.site-nav a:focus-visible::after{transform:scaleX(1)}
.site-nav a[aria-current="page"]{color:var(--amber-bright)}
.site-nav a[aria-current="page"]::after{transform:scaleX(1);background:var(--amber)}
.nav-toggle{display:none;align-items:center;gap:10px;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.18em;color:var(--paper);border:1px solid rgba(174,185,194,.42);padding:10px 14px;
  transition:border-color .2s ease,color .2s ease}
.nav-toggle .bar{display:block;width:16px;height:1px;background:currentColor;
  transition:transform .2s ease,opacity .2s ease}
.nav-toggle[aria-expanded="true"]{border-color:var(--amber-bright);color:var(--amber-bright)}
.nav-toggle[aria-expanded="true"] .bar:nth-child(1){transform:translateY(4px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .bar:nth-child(3){transform:translateY(-4px) rotate(-45deg)}
.nav-toggle-text{white-space:nowrap}

/* 档案检索入口 */
.search-dock{position:relative;display:flex}
.search-entry{display:inline-flex;align-items:center;gap:10px;padding:9px 14px;font-size:13px;
  letter-spacing:.08em;color:var(--paper);border:1px solid rgba(174,185,194,.42);
  background:rgba(255,253,248,.04);transition:border-color .2s ease,background-color .2s ease}
.search-entry:hover,.search-entry:focus-visible{border-color:var(--amber-bright);background:rgba(200,144,47,.14)}
.search-entry-label{white-space:nowrap}
.search-entry-hint{position:absolute;top:calc(100% + 10px);right:0;width:min(286px,72vw);
  padding:12px 14px;background:var(--ink-900);border:1px solid rgba(174,185,194,.3);
  color:var(--steel-200);font-family:var(--font-mono);font-size:11px;line-height:1.9;
  letter-spacing:.06em;box-shadow:0 24px 44px -20px rgba(6,12,22,.85);opacity:0;visibility:hidden;
  transform:translateY(-6px);pointer-events:none;z-index:10;
  transition:opacity .2s ease,transform .2s ease,visibility .2s ease}
.search-dock:hover .search-entry-hint,
.search-dock:focus-within .search-entry-hint{opacity:1;visibility:visible;transform:none}

/* 滚动进度 */
.progress-rail{position:absolute;left:0;right:0;bottom:-1px;height:2px;
  background:rgba(174,185,194,.18);pointer-events:none}
.progress-fill{display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--amber),var(--cinnabar));transition:width .12s linear}

/* ---------- footer ---------- */
.site-footer{margin-top:clamp(48px,8vw,96px);background:var(--ink-950);color:var(--steel-200);
  border-top:1px solid rgba(200,144,47,.4)}
.footer-inner{width:min(var(--maxw),100% - var(--gutter)*2);margin-inline:auto;display:grid;
  grid-template-columns:1.6fr 1fr 1.2fr 1fr 1fr;gap:clamp(24px,3vw,48px);
  padding-block:clamp(40px,6vw,72px)}
.footer-brand{min-width:0}
.footer-brand-link{display:inline-flex;flex-direction:column;gap:7px;font-family:var(--font-display);
  font-size:clamp(22px,2.2vw,27px);letter-spacing:.12em;color:var(--paper);line-height:1}
.footer-brand-link:hover{color:var(--amber-bright)}
.footer-brand-en{font-family:var(--font-mono);font-size:10px;letter-spacing:.3em;
  text-transform:uppercase;color:var(--steel-200)}
.footer-brand-note{margin-top:16px;max-width:30ch;font-size:14px;line-height:1.8;color:var(--steel)}
.footer-batch{display:inline-block;margin-top:16px;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.14em;color:var(--amber-bright);border:1px solid rgba(200,144,47,.45);padding:5px 10px}
.footer-col{min-width:0}
.footer-title{font-family:var(--font-mono);font-size:11px;font-weight:500;letter-spacing:.24em;
  text-transform:uppercase;color:var(--steel);margin-bottom:16px}
.footer-list{display:grid;gap:9px}
.footer-link{font-size:14px;color:var(--steel-200);transition:color .18s ease}
.footer-link:hover,.footer-link:focus-visible{color:var(--amber-bright)}
.footer-text{display:inline-block;font-family:var(--font-mono);font-size:13px;letter-spacing:.02em;
  line-height:1.7;color:var(--paper);word-break:break-word}
.footer-meta{margin-top:14px;font-size:12px;line-height:1.7;color:var(--steel)}
.footer-base{width:min(var(--maxw),100% - var(--gutter)*2);margin-inline:auto;display:flex;
  flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 28px;
  padding-block:20px;border-top:1px solid rgba(174,185,194,.18);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--steel)}
.footer-copy,.footer-icp,.footer-status{margin:0}
.footer-status{color:var(--steel-200)}

/* ---------- layout helpers ---------- */
#main-content{display:block}
.container{width:min(var(--maxw),100% - var(--gutter)*2);margin-inline:auto}
.section{padding-block:clamp(56px,8vw,108px)}
.section--tight{padding-block:clamp(32px,4vw,56px)}
.band{background:var(--ink-900);color:var(--paper);padding-block:clamp(28px,4vw,52px);
  border-block:1px solid rgba(174,185,194,.18)}
.band h2,.band h3,.band h1{color:var(--paper)}

/* ---------- typography ---------- */
.display{font-size:clamp(2.5rem,6.4vw,5.5rem);line-height:.98;letter-spacing:-.02em}
.eyebrow{display:inline-block;font-family:var(--font-mono);font-size:12px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--steel)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.note-vertical{writing-mode:vertical-rl;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.3em;text-transform:uppercase;color:var(--steel)}
.text-steel{color:var(--steel)}
.rule{height:1px;background:var(--rule);border:0;margin:0}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:10px;padding:14px 24px;font-size:14px;
  line-height:1.2;letter-spacing:.08em;border:1px solid transparent;border-radius:0;
  transition:background-color .2s ease,color .2s ease,border-color .2s ease,transform .2s ease}
.btn:hover{transform:translateY(-2px)}
.btn--solid{background:var(--amber);border-color:var(--amber);color:var(--ink-950);font-weight:600}
.btn--solid:hover{background:var(--amber-bright);border-color:var(--amber-bright)}
.btn--ghost{background:transparent;border-color:rgba(107,124,140,.55);color:var(--ink-950)}
.btn--ghost:hover{border-color:var(--amber);background:rgba(200,144,47,.1)}
.btn--stamp{background:var(--cinnabar);border-color:var(--cinnabar);color:var(--paper);font-weight:600}
.btn--stamp:hover{background:#9E3525;border-color:#9E3525}
.btn--ghost-dark{background:transparent;border-color:rgba(174,185,194,.5);color:var(--paper)}
.btn--ghost-dark:hover{border-color:var(--amber-bright);color:var(--amber-bright)}

/* ---------- breadcrumbs ---------- */
.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:10px;font-family:var(--font-mono);
  font-size:12px;letter-spacing:.08em;color:var(--steel)}
.crumbs li{display:inline-flex;align-items:center;gap:10px}
.crumbs li + li::before{content:"/";color:var(--steel-200)}
.crumbs a{transition:color .18s ease}
.crumbs a:hover,.crumbs a:focus-visible{color:var(--amber)}

/* ---------- panels ---------- */
.sheet{background:var(--sheet);border:1px solid var(--rule);box-shadow:var(--shadow-sheet);
  padding:clamp(20px,3vw,36px)}
.sheet--dark{background:var(--ink-900);border-color:rgba(174,185,194,.22);color:var(--paper)}
.sheet--dark h2,.sheet--dark h3,.sheet--dark h4{color:var(--paper)}

/* ---------- grids ---------- */
.grid{display:grid;gap:clamp(16px,2.4vw,32px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.split{display:grid;gap:clamp(24px,4vw,56px);
  grid-template-columns:minmax(0,1fr) minmax(0,1.6fr)}

/* ---------- image frames ---------- */
.frame{position:relative;display:block;overflow:hidden;background:var(--ink-900);
  border:1px solid var(--rule);aspect-ratio:16/10;margin:0}
.frame__img,.frame img{width:100%;height:100%;object-fit:cover;display:block;
  transition:transform .6s ease}
.frame:hover .frame__img,.frame:hover img{transform:scale(1.02)}
.frame__label{position:absolute;left:0;bottom:0;padding:6px 12px;background:var(--ink-950);
  color:var(--paper);font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  text-transform:uppercase}
.frame__stamp{position:absolute;top:12px;right:12px;padding:4px 8px;background:var(--cinnabar);
  color:var(--paper);font-family:var(--font-mono);font-size:11px;letter-spacing:.14em}
.frame--wide{aspect-ratio:21/9}
.frame--tall{aspect-ratio:4/5}
.frame--square{aspect-ratio:1/1}
.frame--paper{background:var(--paper)}

/* ---------- reveal ---------- */
[data-reveal]{transition:opacity .55s ease,transform .55s ease}
[data-reveal-state="pending"]{opacity:0;transform:translateY(14px)}
[data-reveal-state="shown"]{opacity:1;transform:none}

/* ---------- responsive ---------- */
@media (max-width:1080px){
  .footer-inner{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:1000px){
  .header-inner{flex-wrap:wrap;gap:0;padding-block:0;min-height:0}
  .brand-cluster{flex:1 1 100%;justify-content:space-between;padding-block:14px}
  .nav-cluster{flex:1 1 100%;justify-content:space-between;gap:12px;padding-block:10px;
    border-top:1px solid rgba(174,185,194,.18)}
  .nav-toggle{display:inline-flex}
  .site-nav{position:absolute;left:0;right:0;top:100%;display:none;background:var(--ink-950);
    border-bottom:1px solid rgba(200,144,47,.35);padding:8px var(--gutter) 20px;
    box-shadow:0 30px 48px -22px rgba(6,12,22,.8)}
  .site-nav[data-open]{display:block}
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .site-nav a{padding:15px 0 15px 18px;font-size:16px;color:var(--paper);
    border-bottom:1px solid rgba(174,185,194,.14)}
  .site-nav a::after{display:none}
  .site-nav a[aria-current="page"]{color:var(--amber-bright)}
  .site-nav a[aria-current="page"]::before{content:"";position:absolute;left:0;top:50%;
    width:6px;height:6px;background:var(--amber-bright);transform:translateY(-50%)}
  .grid--2,.grid--3,.split{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:640px){
  .brand-en{letter-spacing:.2em}
  .version-tag{font-size:10px;padding:4px 8px}
  .search-entry{padding:8px 11px;font-size:12px}
  .footer-inner{grid-template-columns:minmax(0,1fr)}
  .footer-brand{grid-column:auto}
  .footer-base{font-size:10px;letter-spacing:.04em}
}
@media (max-width:420px){
  .brand-cluster{gap:10px}
  .nav-toggle-text{display: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}
  .frame:hover .frame__img,.frame:hover img{transform:none}
  .btn:hover{transform:none}
  [data-reveal-state="pending"]{opacity:1;transform:none}
}