/* ==========================================================================
   博奥赛场 · 共享样式 /assets/site.css
   01 令牌  02 重置  03 排版  04 基础组件  05 头部  06 页脚  07 响应式  08 降级
   ========================================================================== */

/* 01 设计令牌 ------------------------------------------------------------- */
:root{
  --night:#061310;
  --stand:#0C2A21;
  --turf:#174536;
  --orange:#F26522;
  --whistle:#FFC531;
  --cyan:#3DD6C4;
  --brick:#C2452F;
  --paper:#F4EEE2;
  --paper-white:#FCFAF4;
  --ink:#14201B;
  --muted:#6E8078;
  --line:#D9D2C3;

  --ink-2:#3A4842;
  --on-dark-dim:rgba(244,238,226,.72);
  --on-dark-faint:rgba(244,238,226,.46);
  --line-dark:rgba(244,238,226,.18);
  --rule:rgba(20,32,27,.16);

  --f-display:'Barlow Condensed','Oswald','Noto Sans SC','Source Han Sans SC',sans-serif;
  --f-body:'Inter','Noto Sans SC','PingFang SC','Microsoft YaHei',sans-serif;
  --f-data:'IBM Plex Mono','JetBrains Mono','Roboto Mono',monospace;

  --w-max:1240px;
  --gut:clamp(16px,4vw,40px);
  --rail:288px;
  --rail-gap:40px;
  --header-h:78px;
  --header-h-compact:60px;
  --measure:36em;

  --t:200ms ease-out;
}

/* 02 重置 ----------------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--night);
  color:var(--paper-white);
  font-family:var(--f-body);
  font-size:16px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4,h5,h6{
  margin:0;
  font-family:var(--f-display);
  font-weight:900;
  line-height:1.12;
  letter-spacing:-.01em;
}
p{margin:0 0 1em;}
p:last-child{margin-bottom:0;}
ul,ol{margin:0 0 1em;padding-left:1.2em;}
a{color:var(--orange);text-decoration:underline;text-underline-offset:3px;}
a:hover{text-decoration-thickness:2px;}
strong,b{font-weight:700;}
small{font-size:13px;}
hr{border:0;border-top:1px solid var(--rule);margin:32px 0;}
::selection{background:var(--whistle);color:var(--ink);}

:focus-visible{
  outline:3px solid var(--whistle);
  outline-offset:2px;
  box-shadow:0 0 0 2px var(--ink);
}

/* 03 排版 ----------------------------------------------------------------- */
.display{font-family:var(--f-display);font-weight:900;letter-spacing:-.01em;line-height:1.02;}
.prose p{max-width:var(--measure);}
.prose h2{font-size:clamp(26px,3.2vw,40px);margin-top:1.6em;}
.prose h3{font-size:20px;font-weight:700;margin-top:1.4em;}
.on-dark{color:var(--paper-white);--rule:var(--line-dark);}
.on-dark .prose p,.on-dark p{color:var(--on-dark-dim);}
.on-dark .fig>figcaption{color:var(--on-dark-faint);}

/* 04 基础组件 ------------------------------------------------------------- */
.wrap{
  width:100%;
  max-width:var(--w-max);
  margin-inline:auto;
  padding-inline:var(--gut);
}
.u-under-header{padding-top:calc(var(--header-h) + 1px);}
.grid-rail{display:grid;grid-template-columns:minmax(0,1fr);gap:32px;}
@media (min-width:1120px){
  .grid-rail{grid-template-columns:minmax(0,1fr) var(--rail);gap:var(--rail-gap);align-items:start;}
}

.skip-link{
  position:fixed;
  left:var(--gut);
  top:10px;
  z-index:200;
  padding:10px 18px;
  background:var(--whistle);
  color:var(--ink);
  font-weight:700;
  font-size:14px;
  text-decoration:none;
  border:2px solid var(--ink);
  transform:translateY(-220%);
  transition:transform var(--t);
}
.skip-link:focus,.skip-link:focus-visible{transform:translateY(0);}

.btn{
  --btn-bg:var(--orange);
  --btn-fg:var(--ink);
  --btn-bd:var(--orange);
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 22px;
  font:inherit;
  font-size:15px;
  font-weight:700;
  line-height:1.2;
  letter-spacing:.02em;
  color:var(--btn-fg);
  background:var(--btn-bg);
  border:2px solid var(--btn-bd);
  border-radius:0;
  text-decoration:none;
  cursor:pointer;
  box-shadow:3px 3px 0 0 rgba(6,19,16,.55);
  transition:transform var(--t),box-shadow var(--t),background-color var(--t),color var(--t),border-color var(--t);
}
.btn:hover{transform:translate(-1px,-1px);box-shadow:5px 5px 0 0 rgba(6,19,16,.55);}
.btn:active{transform:translate(1px,1px);box-shadow:1px 1px 0 0 rgba(6,19,16,.55);}
.btn--sm{padding:8px 15px;font-size:13px;letter-spacing:.04em;box-shadow:2px 2px 0 0 rgba(6,19,16,.5);}
.btn--sm:hover{box-shadow:4px 4px 0 0 rgba(6,19,16,.5);}
.btn--cta{white-space:nowrap;}
.btn--ghost{
  --btn-bg:transparent;
  --btn-fg:currentColor;
  --btn-bd:currentColor;
  box-shadow:none;
}
.btn--ghost:hover{background:rgba(242,101,34,.14);box-shadow:none;transform:none;}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:2px 8px;
  font-family:var(--f-data);
  font-size:11px;
  font-weight:600;
  line-height:1.8;
  letter-spacing:.1em;
  border:1px solid currentColor;
  color:var(--cyan);
  background:transparent;
}
.tag--orange{color:var(--orange);}
.tag--yellow{color:var(--whistle);}
.tag--muted{color:var(--muted);}
.tag--brick{color:var(--brick);}

.dot{
  display:inline-block;
  width:6px;
  height:6px;
  border-radius:50%;
  background:currentColor;
  flex:0 0 auto;
}

.panel{
  position:relative;
  background:var(--stand);
  border:1px solid var(--turf);
  padding:clamp(18px,2.4vw,28px);
  transition:transform var(--t),border-color var(--t),box-shadow var(--t);
}
.panel--paper{
  background:var(--paper-white);
  color:var(--ink);
  border-color:var(--line);
  --rule:rgba(20,32,27,.16);
}
.panel--hover:hover{
  transform:translateY(-2px);
  border-color:var(--orange);
  box-shadow:0 8px 0 -4px rgba(242,101,34,.35);
}

.section-head{display:grid;gap:10px;margin-bottom:clamp(20px,3vw,36px);}
.section-head__num{
  margin:0;
  font-family:var(--f-data);
  font-size:12px;
  font-weight:600;
  letter-spacing:.2em;
  color:var(--orange);
}
.section-head__title{margin:0;font-size:clamp(26px,3.2vw,40px);}
.section-head__lede{margin:0;max-width:var(--measure);color:var(--muted);}
.section-head__stat{
  margin:0;
  font-family:var(--f-data);
  font-size:13px;
  font-variant-numeric:tabular-nums;
  letter-spacing:.04em;
  color:var(--cyan);
}
.on-dark .section-head__lede{color:var(--on-dark-dim);}

.stat{display:grid;gap:2px;}
.stat__value{
  font-family:var(--f-data);
  font-weight:600;
  font-size:28px;
  line-height:1.1;
  font-variant-numeric:tabular-nums;
  letter-spacing:-.01em;
}
.stat__value--lg{font-size:44px;}
.stat__value--sm{font-size:16px;}
.stat__label{
  font-size:12px;
  letter-spacing:.14em;
  color:var(--muted);
}
.on-dark .stat__label{color:var(--on-dark-faint);}

.media-frame{
  position:relative;
  display:block;
  width:100%;
  aspect-ratio:16 / 10;
  overflow:hidden;
  border:1px solid var(--turf);
  background:
    repeating-linear-gradient(135deg,rgba(23,69,54,.65) 0 2px,transparent 2px 12px),
    var(--stand);
}
.media-frame>img,
.media-frame>picture>img{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:3px;
  background:linear-gradient(90deg,var(--orange) 0 26%,var(--whistle) 26% 52%,var(--cyan) 52% 74%,transparent 74%);
  opacity:.9;
}
.media-frame--wide{aspect-ratio:21 / 9;}
.media-frame--tall{aspect-ratio:4 / 5;}
.media-frame--square{aspect-ratio:1 / 1;}

.fig{margin:0;display:grid;gap:8px;}
.fig>figcaption{
  font-family:var(--f-data);
  font-size:13px;
  letter-spacing:.02em;
  color:var(--muted);
}

details{border-top:1px solid var(--rule);}
details:last-of-type{border-bottom:1px solid var(--rule);}
summary{
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:16px;
  padding:14px 0;
  font-weight:700;
  cursor:pointer;
  list-style:none;
}
summary::-webkit-details-marker{display:none;}
summary::after{
  content:"+";
  font-family:var(--f-data);
  font-weight:600;
  color:var(--orange);
  line-height:1.4;
}
details[open] summary::after{content:"–";}

/* 05 头部 ----------------------------------------------------------------- */
.site-header{
  position:fixed;
  inset:0 0 auto 0;
  z-index:90;
  --hdr-fg:var(--paper-white);
  --hdr-dim:rgba(252,250,244,.66);
  --hdr-num:var(--whistle);
  --hdr-hair:rgba(252,250,244,.22);
  --hdr-bg:transparent;
  background:var(--hdr-bg);
  color:var(--hdr-fg);
  border-bottom:1px solid var(--hdr-hair);
  padding-top:3px;
  transition:background-color var(--t),color var(--t),border-color var(--t),box-shadow var(--t);
}
.site-header[data-solid]{
  --hdr-fg:var(--ink);
  --hdr-dim:#4C5A54;
  --hdr-num:var(--orange);
  --hdr-hair:var(--line);
  --hdr-bg:var(--paper);
  box-shadow:0 1px 0 rgba(6,19,16,.06),0 12px 30px rgba(6,19,16,.12);
}
.site-header[data-open]{
  --hdr-fg:var(--ink);
  --hdr-dim:#4C5A54;
  --hdr-num:var(--orange);
  --hdr-hair:var(--line);
  --hdr-bg:var(--paper);
}
.site-header__inner{
  width:100%;
  max-width:var(--w-max);
  margin-inline:auto;
  padding-inline:var(--gut);
  min-height:var(--header-h);
  display:flex;
  align-items:center;
  gap:clamp(10px,2vw,28px);
  transition:min-height var(--t);
}
.site-header[data-solid] .site-header__inner{min-height:var(--header-h-compact);}

.scroll-progress{
  position:fixed;
  top:0;
  left:0;
  right:0;
  height:3px;
  z-index:120;
  pointer-events:none;
  background:rgba(6,19,16,.26);
}
.scroll-progress>span{
  display:block;
  width:100%;
  height:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--orange),var(--whistle));
  will-change:transform;
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
  color:inherit;
  text-decoration:none;
}
.brand:hover{text-decoration:none;}
.brand__mark{
  position:relative;
  display:block;
  width:22px;
  height:30px;
  flex:0 0 auto;
}
.brand__mark::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:20px;
  background:var(--orange);
  clip-path:polygon(0 0,100% 0,100% 70%,0 100%);
}
.brand__mark::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:6px;
  background:var(--whistle);
}
.brand__text{display:flex;flex-direction:column;gap:3px;}
.brand__name{
  font-family:var(--f-display);
  font-weight:900;
  font-size:20px;
  line-height:1;
  letter-spacing:.02em;
  color:inherit;
}
.brand__tag{
  font-size:11px;
  line-height:1;
  letter-spacing:.16em;
  color:inherit;
  opacity:.66;
}

.site-nav{margin-left:auto;}
.nav-index{
  display:flex;
  align-items:stretch;
  gap:0;
  margin:0;
  padding:0;
  list-style:none;
}
.nav-index__item{display:flex;}
.nav-item{
  display:flex;
  flex-direction:column;
  gap:1px;
  padding:10px 12px;
  color:var(--hdr-fg);
  text-decoration:none;
  border-bottom:2px solid transparent;
  transition:color var(--t),border-color var(--t),background-color var(--t);
}
.nav-item:hover{text-decoration:none;border-bottom-color:var(--orange);}
.nav-item__num{
  font-family:var(--f-data);
  font-size:10px;
  font-weight:600;
  line-height:1;
  letter-spacing:.16em;
  color:var(--hdr-num);
}
.nav-item__label{
  font-size:14px;
  font-weight:600;
  line-height:1.3;
  letter-spacing:.02em;
  white-space:nowrap;
}
.nav-item:hover .nav-item__label{color:var(--orange);}
.nav-item[aria-current="page"]{border-bottom-color:var(--orange);}
.nav-item[aria-current="page"] .nav-item__label{color:var(--orange);}

.header-actions{
  display:flex;
  align-items:center;
  gap:12px;
  margin-left:8px;
}
.header-link{
  color:var(--hdr-dim);
  font-size:13px;
  font-weight:600;
  text-decoration:none;
  padding:6px 2px;
  border-bottom:1px solid transparent;
  white-space:nowrap;
  transition:color var(--t),border-color var(--t);
}
.header-link:hover{color:var(--hdr-fg);border-bottom-color:var(--orange);text-decoration:none;}

.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:9px 12px;
  font:inherit;
  font-size:12px;
  font-weight:700;
  letter-spacing:.12em;
  color:inherit;
  background:transparent;
  border:1px solid var(--hdr-hair);
  border-radius:0;
  cursor:pointer;
  transition:border-color var(--t),background-color var(--t);
}
.nav-toggle:hover{border-color:var(--orange);}
.nav-toggle__bars{display:grid;gap:4px;width:16px;}
.nav-toggle__bars span{
  display:block;
  height:2px;
  background:currentColor;
  transition:transform var(--t),opacity var(--t);
}
.site-header[data-open] .nav-toggle__bars span:nth-child(1){transform:translateY(6px) rotate(45deg);}
.site-header[data-open] .nav-toggle__bars span:nth-child(2){opacity:0;}
.site-header[data-open] .nav-toggle__bars span:nth-child(3){transform:translateY(-6px) rotate(-45deg);}

/* 06 页脚 ----------------------------------------------------------------- */
.site-footer{
  position:relative;
  margin-top:clamp(56px,8vw,110px);
  background:var(--night);
  color:var(--paper);
  border-top:1px solid var(--line-dark);
  padding-top:clamp(40px,6vw,72px);
}
.footer-plate{
  position:relative;
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1.4fr);
  gap:clamp(24px,4vw,48px);
  padding:clamp(24px,4vw,44px);
  margin-bottom:60px;
  background:var(--paper);
  color:var(--ink);
  border:1px solid var(--line);
  box-shadow:6px 6px 0 0 var(--turf),12px 12px 0 0 rgba(242,101,34,.30);
  --rule:rgba(20,32,27,.16);
}
.footer-plate::before{
  content:"看台索引 / INDEX";
  position:absolute;
  top:-12px;
  left:clamp(16px,4vw,32px);
  padding:3px 10px;
  background:var(--orange);
  color:var(--ink);
  font-family:var(--f-data);
  font-size:10px;
  font-weight:600;
  letter-spacing:.18em;
  line-height:1.6;
}
.footer-brand{display:grid;gap:16px;align-content:start;}
.footer-brand__note{
  margin:0;
  font-size:14px;
  line-height:1.7;
  color:var(--ink-2);
  max-width:30em;
}
.footer-brand__meta{
  display:flex;
  align-items:center;
  gap:8px;
  margin:0;
  font-family:var(--f-data);
  font-size:12px;
  letter-spacing:.02em;
  color:#4C5A54;
}
.footer-brand__meta .dot{background:var(--orange);}

.footer-cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(16px,2.4vw,28px);
}
.footer-col__title{
  display:flex;
  align-items:center;
  gap:8px;
  margin:0 0 14px;
  font-family:var(--f-display);
  font-size:15px;
  font-weight:800;
  letter-spacing:.06em;
  color:var(--ink);
}
.footer-col__title::before{
  content:"";
  width:10px;
  height:3px;
  background:var(--orange);
  flex:0 0 auto;
}
.footer-col__list{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:8px;
}
.footer-col__list a{
  display:inline-block;
  font-size:14px;
  color:#3A4842;
  text-decoration:none;
  padding-bottom:1px;
  border-bottom:1px solid transparent;
  transition:color var(--t),border-color var(--t);
}
.footer-col__list a:hover{color:var(--orange);border-bottom-color:var(--orange);}

.footer-fix{
  grid-column:1 / -1;
  margin:0;
  padding-top:16px;
  border-top:1px solid var(--line);
  font-size:13px;
  line-height:1.7;
  color:#4C5A54;
}
.footer-fix a{
  color:var(--brick);
  font-weight:600;
  text-decoration:none;
  border-bottom:1px solid currentColor;
}

.footer-meta{
  border-top:1px solid var(--line-dark);
  padding-block:24px 34px;
}
.footer-meta__inner{display:grid;gap:10px;}
.footer-meta__line{
  margin:0;
  font-size:13px;
  line-height:1.7;
  color:var(--on-dark-dim);
}
.footer-meta__line a{color:var(--whistle);text-decoration:none;border-bottom:1px solid rgba(255,197,49,.4);}
.footer-meta__line a:hover{border-bottom-color:var(--whistle);}
.footer-meta__line--dim{
  font-family:var(--f-data);
  font-size:12px;
  letter-spacing:.02em;
  color:var(--on-dark-faint);
}
.footer-meta__copy{
  margin:0;
  font-family:var(--f-data);
  font-size:12px;
  letter-spacing:.08em;
  color:rgba(244,238,226,.38);
}

/* 07 响应式 --------------------------------------------------------------- */
@media (max-width:1120px){
  .header-link{display:none;}
}
@media (max-width:1023px){
  :root{--header-h:68px;--header-h-compact:56px;}

  .nav-toggle{display:inline-flex;}

  .site-nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    margin-left:0;
    background:var(--stand);
    color:var(--paper-white);
    border-top:1px solid var(--line-dark);
    padding:8px var(--gut) 26px;
    max-height:calc(100vh - var(--header-h));
    max-height:calc(100dvh - var(--header-h));
    overflow-y:auto;
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    transition:opacity var(--t),transform var(--t),visibility 0s linear 200ms;
    box-shadow:0 28px 48px rgba(0,0,0,.5);
  }
  .site-header[data-open] .site-nav{
    opacity:1;
    visibility:visible;
    transform:translateY(0);
    transition:opacity var(--t),transform var(--t),visibility 0s linear 0s;
  }
  .nav-index{display:block;}
  .nav-item{
    flex-direction:row;
    align-items:baseline;
    gap:14px;
    padding:14px 4px;
    border-bottom:1px solid var(--line-dark);
    border-left:0;
    color:var(--paper-white);
  }
  .nav-item__num{font-size:11px;color:var(--whistle);}
  .nav-item__label{font-size:16px;white-space:normal;}
  .nav-item:hover .nav-item__label,
  .nav-item[aria-current="page"] .nav-item__label{color:var(--whistle);}
  .nav-item[aria-current="page"]{border-bottom-color:var(--orange);}

  .header-actions{margin-left:auto;gap:10px;}

  .footer-plate{grid-template-columns:minmax(0,1fr);box-shadow:5px 5px 0 0 var(--turf),10px 10px 0 0 rgba(242,101,34,.28);}
}
@media (max-width:640px){
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px 16px;}
  .footer-plate{margin-bottom:44px;}
}
@media (max-width:480px){
  .brand__tag{display:none;}
  .site-header__inner{gap:10px;}
  .nav-toggle__text{display:none;}
  .nav-toggle{padding:9px 10px;}
  .btn--cta{padding:8px 12px;font-size:12px;letter-spacing:0;}
  .footer-plate{box-shadow:4px 4px 0 0 var(--turf),8px 8px 0 0 rgba(242,101,34,.28);}
}

/* 08 降级 ----------------------------------------------------------------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation:none !important;
    transition:none !important;
  }
  .btn:hover,.btn:active,.panel--hover:hover{transform:none;}
}