/* ============================================================
   /assets/site.css — 千亿球友会 共享外壳
   ============================================================ */

:root{
  --ink-900:#060D1E;
  --ink-800:#0D1830;
  --ink-700:#17274A;
  --cyan:#3EF2D6;
  --amber:#FFB43A;
  --violet:#A47CFF;
  --rock:#C3CAD6;
  --cream:#F4EFE4;
  --moss:#7FA88B;
  --terracotta:#C97B5A;

  --cyan-08:rgba(62,242,214,.08);
  --cyan-12:rgba(62,242,214,.12);
  --cyan-28:rgba(62,242,214,.28);
  --cyan-45:rgba(62,242,214,.45);
  --violet-12:rgba(164,124,255,.12);
  --violet-45:rgba(164,124,255,.45);

  --font-display:"Inter","HarmonyOS Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Source Han Sans SC","Noto Sans SC","PingFang SC","HarmonyOS Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-serif:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",Georgia,serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;

  --ease:cubic-bezier(.2,.7,.3,1);
  --dur:.2s;

  --shell:min(calc(100% - clamp(32px,6vw,48px)),1320px);
  --shell-narrow:min(calc(100% - clamp(32px,6vw,48px)),1120px);
}

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;
  background-color:var(--ink-900);
  background-image:
    radial-gradient(900px 520px at 10% -10%,rgba(62,242,214,.10),transparent 62%),
    radial-gradient(760px 460px at 94% 2%,rgba(164,124,255,.09),transparent 60%),
    radial-gradient(1000px 620px at 50% 112%,rgba(255,180,58,.05),transparent 66%);
  color:var(--rock);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.85;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd{margin:0;}
ul,ol{margin:0;padding:0;list-style:none;}
img,svg,video,picture{max-width:100%;display:block;}
a{color:inherit;}
button{font:inherit;color:inherit;}
address{font-style:normal;}
table{border-collapse:collapse;}

:where(h1,h2,h3,h4){font-family:var(--font-display);color:var(--cream);font-weight:800;line-height:1.16;letter-spacing:-.01em;}

::selection{background:var(--cyan);color:#04121A;}

:focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:2px;
  box-shadow:0 0 0 4px rgba(6,13,30,.9);
}

/* ---------- 工具类 ---------- */
.container{width:var(--shell);margin-inline:auto;}
.container-wide{width:min(calc(100% - clamp(24px,4vw,40px)),1400px);margin-inline:auto;}
.mono{font-family:var(--font-mono);font-size:.8125rem;letter-spacing:.04em;}
.muted{color:rgba(195,202,214,.7);}
.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}
.divider{height:1px;background:var(--ink-700);border:0;margin-block:clamp(28px,4vw,48px);}

/* ---------- 跳至主要内容 ---------- */
.skip-link{
  position:fixed;
  top:-64px;left:16px;
  z-index:200;
  padding:10px 18px;
  background:var(--cyan);
  color:#04121A;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.06em;
  text-decoration:none;
  border-radius:2px;
  transition:top var(--dur) var(--ease);
}
.skip-link:focus{top:12px;}

/* ============================================================
   头部
   ============================================================ */
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:linear-gradient(180deg,rgba(6,13,30,.97),rgba(6,13,30,.88));
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
  border-bottom:1px solid rgba(62,242,214,.16);
  color:var(--rock);
}
.header-inner{
  width:var(--shell);
  margin-inline:auto;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:clamp(16px,2vw,32px);
  min-height:84px;
  transition:min-height var(--dur) var(--ease);
}
.site-header[data-scrolled="true"] .header-inner{min-height:56px;}

/* 品牌 */
.brand{
  display:flex;
  flex-direction:column;
  gap:2px;
  text-decoration:none;
  color:var(--cream);
  flex:0 0 auto;
}
.brand-name{
  display:inline-flex;
  align-items:baseline;
  gap:8px;
  font-family:var(--font-display);
  font-size:19px;
  font-weight:800;
  letter-spacing:.01em;
  line-height:1.2;
}
.brand-qy{
  font-size:11px;
  color:var(--cyan);
  border:1px solid var(--cyan-45);
  border-radius:2px;
  padding:1px 5px;
  letter-spacing:.1em;
}
.brand-meta{
  display:flex;
  align-items:center;
  gap:10px;
  font-size:12px;
  line-height:1.4;
  color:rgba(195,202,214,.72);
}
.brand-sub{letter-spacing:.02em;}
.brand-version{
  color:var(--amber);
  padding-left:10px;
  border-left:1px solid var(--ink-700);
}

/* 导航 */
.site-nav{
  display:flex;
  align-items:center;
  gap:clamp(14px,1.8vw,30px);
}
.nav-list{
  display:flex;
  align-items:center;
  gap:clamp(8px,1.3vw,22px);
}
.nav-item{display:block;}
.nav-link{
  display:inline-flex;
  align-items:baseline;
  gap:5px;
  padding:6px 2px 7px;
  font-size:14px;
  line-height:1.4;
  color:var(--rock);
  text-decoration:none;
  border-bottom:2px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease),background-color var(--dur) var(--ease);
}
.nav-num{
  font-size:10.5px;
  letter-spacing:.08em;
  color:rgba(62,242,214,.55);
  transition:color var(--dur) var(--ease);
}
.nav-link:hover{color:var(--cream);border-bottom-color:var(--cyan-45);}
.nav-link:hover .nav-num{color:var(--cyan);}
.nav-link[aria-current="page"]{
  color:var(--cyan);
  border-bottom-color:var(--cyan);
}
.nav-link[aria-current="page"] .nav-num{color:var(--amber);}

/* 按钮 */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 20px;
  font-family:var(--font-body);
  font-size:14px;
  font-weight:600;
  line-height:1;
  letter-spacing:.03em;
  text-decoration:none;
  border:1px solid transparent;
  border-radius:2px;
  cursor:pointer;
  transition:background-color var(--dur) var(--ease),border-color var(--dur) var(--ease),color var(--dur) var(--ease),transform var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.btn-cta{
  background:var(--amber);
  border-color:var(--amber);
  color:#1A1004;
}
.btn-cta:hover{
  background:#FFC868;
  border-color:#FFC868;
  box-shadow:0 0 0 3px rgba(255,180,58,.18);
}
.btn-cta:active{transform:translateY(1px);}
.btn-ghost{
  background:transparent;
  border-color:var(--cyan-45);
  color:var(--cyan);
}
.btn-ghost:hover{background:var(--cyan-12);border-color:var(--cyan);}
.btn-quiet{
  background:transparent;
  border-color:var(--ink-700);
  color:var(--rock);
}
.btn-quiet:hover{border-color:var(--violet-45);color:var(--cream);}
.nav-cta{flex:0 0 auto;white-space:nowrap;}

/* 移动索引按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:8px 11px;
  background:transparent;
  border:1px solid var(--ink-700);
  border-radius:2px;
  color:var(--cyan);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  cursor:pointer;
  transition:border-color var(--dur) var(--ease),background-color var(--dur) var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan-45);background:var(--cyan-08);}
.nav-toggle-box{
  display:inline-flex;
  flex-direction:column;
  justify-content:center;
  gap:4px;
  width:16px;
  height:14px;
}
.nav-toggle-bar{
  display:block;
  height:1.5px;
  background:currentColor;
  border-radius:1px;
  transition:transform var(--dur) var(--ease),opacity var(--dur) var(--ease);
}
.site-header[data-open="true"] .nav-toggle-bar:nth-child(1){transform:translateY(2.75px) rotate(45deg);}
.site-header[data-open="true"] .nav-toggle-bar:nth-child(2){transform:translateY(-2.75px) rotate(-45deg);}
.nav-toggle-text{line-height:1;}

/* 滚动进度 */
.header-progress{
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:2px;
  background:transparent;
  pointer-events:none;
  overflow:hidden;
}
.header-progress-bar{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--cyan),var(--violet),var(--amber));
  transition:width .1s linear;
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer{
  margin-top:clamp(48px,8vw,96px);
  padding-top:clamp(48px,7vw,80px);
  background:linear-gradient(180deg,rgba(13,24,48,.55),#03080F 78%);
  border-top:1px solid var(--ink-700);
  color:var(--rock);
}
.footer-inner{width:var(--shell);margin-inline:auto;}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1.3fr;
  gap:clamp(28px,4vw,56px);
  align-items:start;
}
.footer-col{min-width:0;}

.footer-brand{
  display:flex;
  align-items:baseline;
  gap:8px;
  font-family:var(--font-display);
  font-size:18px;
  font-weight:800;
  color:var(--cream);
  letter-spacing:.01em;
}
.footer-brand-qy{
  font-size:10.5px;
  color:var(--terracotta);
  border:1px solid rgba(201,123,90,.6);
  border-radius:2px;
  padding:1px 5px;
  letter-spacing:.1em;
}
.footer-brand-line{
  margin-top:10px;
  font-size:14px;
  line-height:1.7;
  color:rgba(195,202,214,.78);
  max-width:30ch;
}
.footer-meta{
  margin-top:14px;
  font-size:12px;
  color:rgba(195,202,214,.6);
}
.footer-address{
  margin-top:6px;
  font-size:13px;
  line-height:1.7;
  color:rgba(195,202,214,.6);
  max-width:32ch;
}

.footer-title{
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:500;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--cyan);
  padding-bottom:10px;
  border-bottom:1px solid var(--ink-700);
  margin-bottom:14px;
}
.footer-list{display:flex;flex-direction:column;gap:2px;}
.footer-list a{
  display:inline-block;
  padding:5px 0 5px 0;
  font-size:14.5px;
  color:var(--rock);
  text-decoration:none;
  border-left:2px solid transparent;
  padding-left:0;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease),padding-left var(--dur) var(--ease);
}
.footer-list a:hover{
  color:var(--cream);
  border-left-color:var(--cyan);
  padding-left:10px;
}

.ticket{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:7px 12px;
  background:var(--cream);
  color:#3A2A18;
  border:1px solid var(--terracotta);
  box-shadow:3px 3px 0 rgba(201,123,90,.32);
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.04em;
  line-height:1.3;
}
.footer-channel-line{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:8px;
  margin-top:16px;
  font-size:13.5px;
  line-height:1.6;
}
.footer-channel-key{
  font-size:10.5px;
  letter-spacing:.14em;
  color:var(--violet);
  border:1px solid var(--violet-45);
  border-radius:2px;
  padding:1px 6px;
}
.footer-channel-val{
  color:var(--cream);
  word-break:break-all;
}
.footer-status{
  display:flex;
  align-items:center;
  gap:8px;
  margin-top:16px;
  font-size:12.5px;
  color:rgba(195,202,214,.72);
}
.status-dot{
  width:7px;height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--moss);
  box-shadow:0 0 0 3px rgba(127,168,139,.18);
}

.footer-legal{
  margin-top:clamp(32px,5vw,56px);
  padding:20px 0 30px;
  border-top:1px solid rgba(23,39,74,.95);
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  font-size:13px;
  color:rgba(195,202,214,.62);
}
.footer-copy{letter-spacing:.02em;}
.legal-list{display:flex;flex-wrap:wrap;gap:6px 20px;}
.legal-list a{
  color:var(--rock);
  text-decoration:none;
  transition:color var(--dur) var(--ease);
}
.legal-list a:hover{color:var(--cyan);}

/* ============================================================
   页面骨架与通用组件
   ============================================================ */
.section{padding-block:clamp(56px,9vw,128px);}
.section-tight{padding-block:clamp(36px,5vw,64px);}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--cyan);
  margin-bottom:18px;
}
.eyebrow::before{content:"";width:28px;height:1px;background:currentColor;}
.section-title{
  font-size:clamp(28px,3.6vw,44px);
  max-width:22ch;
}
.lede{
  font-family:var(--font-serif);
  font-size:clamp(17px,1.4vw,20px);
  line-height:1.75;
  color:rgba(195,202,214,.92);
  max-width:38ch;
}
.prose{max-width:72ch;font-size:16.5px;line-height:1.85;}
.prose p{margin-bottom:1.2em;}
.prose p:last-child{margin-bottom:0;}
.prose h3{margin:1.8em 0 .6em;font-size:22px;}
.prose ul{margin:0 0 1.2em;padding-left:0;}
.prose li{
  position:relative;
  padding-left:22px;
  margin-bottom:.5em;
}
.prose li::before{
  content:"";
  position:absolute;
  left:0;top:.85em;
  width:8px;height:1px;
  background:var(--cyan);
}

/* 栅格 */
.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:clamp(16px,2.2vw,28px);
}
.span-3{grid-column:span 3;}
.span-4{grid-column:span 4;}
.span-5{grid-column:span 5;}
.span-6{grid-column:span 6;}
.span-7{grid-column:span 7;}
.span-8{grid-column:span 8;}
.span-9{grid-column:span 9;}
.span-10{grid-column:span 10;}
.span-12{grid-column:span 12;}

/* 框景 */
.frame{
  position:relative;
  border:1px solid var(--cyan-28);
  padding:clamp(18px,2.6vw,34px);
  background:
    linear-gradient(180deg,rgba(13,24,48,.55),rgba(6,13,30,.2));
  overflow:hidden;
}
.frame-inner{
  position:relative;
  border:1px solid rgba(23,39,74,.95);
  padding:clamp(16px,2.4vw,30px);
  z-index:1;
}
.frame::after{
  content:"";
  position:absolute;
  top:0;left:0;
  width:76px;height:2px;
  background:linear-gradient(90deg,var(--cyan),transparent);
}
.frame-sweep{
  position:absolute;
  top:0;bottom:0;
  width:38%;
  left:-45%;
  background:linear-gradient(90deg,transparent,rgba(62,242,214,.10),transparent);
  animation:frame-sweep 8s linear infinite;
  pointer-events:none;
  z-index:0;
}
@keyframes frame-sweep{
  0%{left:-45%;}
  60%,100%{left:115%;}
}

/* 研究板卡片 */
.card{
  position:relative;
  display:flex;
  flex-direction:column;
  background:linear-gradient(180deg,rgba(23,39,74,.55),rgba(13,24,48,.8));
  border:1px solid var(--ink-700);
  padding:clamp(18px,2vw,26px);
  transition:transform var(--dur) var(--ease),border-color var(--dur) var(--ease),background-color var(--dur) var(--ease);
}
.card:hover{
  transform:translateY(-4px);
  border-color:var(--cyan-45);
}
.card-index{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  color:rgba(62,242,214,.5);
  transition:color var(--dur) var(--ease);
}
.card:hover .card-index{color:var(--amber);}
.card-head{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:12px;
  padding-bottom:12px;
  margin-bottom:14px;
  border-bottom:1px solid var(--ink-700);
}
.card-body{font-size:15px;line-height:1.8;color:rgba(195,202,214,.85);}

/* 标签 */
.tag{
  display:inline-block;
  padding:2px 8px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  line-height:1.6;
  border:1px solid transparent;
  border-radius:2px;
}
.tag-cyan{color:var(--cyan);border-color:var(--cyan-45);background:var(--cyan-08);}
.tag-violet{color:var(--violet);border-color:var(--violet-45);background:var(--violet-12);}
.tag-amber{color:var(--amber);border-color:rgba(255,180,58,.45);background:rgba(255,180,58,.10);}
.tag-moss{color:var(--moss);border-color:rgba(127,168,139,.5);background:rgba(127,168,139,.10);}
.tag-terracotta{color:var(--terracotta);border-color:rgba(201,123,90,.5);background:rgba(201,123,90,.10);}

/* 面包屑 */
.crumbs{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:6px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:rgba(195,202,214,.6);
}
.crumbs li{display:inline-flex;align-items:center;gap:6px;}
.crumbs li:not(:last-child)::after{content:"/";color:rgba(23,39,74,1);color:rgba(195,202,214,.35);}
.crumbs a{
  color:var(--cyan);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.crumbs a:hover{border-bottom-color:var(--cyan);}
.crumbs [aria-current="page"]{color:var(--cream);}

/* 图片容器基础规则 */
.media{
  position:relative;
  overflow:hidden;
  width:100%;
  background:
    repeating-linear-gradient(0deg,rgba(23,39,74,.55) 0 1px,transparent 1px 32px),
    repeating-linear-gradient(90deg,rgba(23,39,74,.55) 0 1px,transparent 1px 32px),
    linear-gradient(140deg,var(--ink-700),var(--ink-800) 55%,var(--ink-900));
  border:1px solid var(--ink-700);
  border-radius:2px;
}
.media img,
.media video,
.media picture{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
}
.media-21x9{aspect-ratio:21 / 9;}
.media-16x9{aspect-ratio:16 / 9;}
.media-4x3{aspect-ratio:4 / 3;}
.media-1x1{aspect-ratio:1 / 1;}
.media-caption{
  margin-top:10px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.04em;
  color:rgba(195,202,214,.6);
}

/* 渐显协议 */
.js-reveal [data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .24s var(--ease),transform .24s var(--ease);
}
.js-reveal [data-reveal].is-visible{
  opacity:1;
  transform:none;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:1100px){
  .brand-sub{display:none;}
  .brand-meta{gap:0;}
}

@media (max-width:960px){
  .header-inner{min-height:66px;}
  .site-header[data-scrolled="true"] .header-inner{min-height:56px;}

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

  .site-nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    display:none;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    padding:6px clamp(16px,5vw,24px) 24px;
    background:rgba(13,24,48,.99);
    border-bottom:1px solid var(--ink-700);
    box-shadow:0 28px 48px rgba(0,0,0,.5);
    max-height:calc(100vh - 66px);
    overflow-y:auto;
  }
  .site-header[data-open="true"] .site-nav{display:flex;}

  .nav-list{flex-direction:column;align-items:stretch;gap:0;}
  .nav-item{border-bottom:1px solid rgba(23,39,74,.9);}
  .nav-link{
    display:flex;
    width:100%;
    padding:14px 0 14px 12px;
    font-size:15px;
    border-bottom:none;
    border-left:2px solid transparent;
  }
  .nav-link:hover{border-left-color:var(--cyan-45);border-bottom-color:transparent;}
  .nav-link[aria-current="page"]{
    border-bottom-color:transparent;
    border-left-color:var(--cyan);
    background:var(--cyan-08);
  }
  .nav-cta{
    width:100%;
    margin-top:18px;
    padding:14px 20px;
  }

  .footer-grid{grid-template-columns:1fr 1fr;}
  .footer-identity{grid-column:1 / -1;}
}

@media (max-width:980px){
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr));}
  .span-7,.span-8,.span-9,.span-10,.span-12{grid-column:span 6;}
  .span-4,.span-5,.span-6{grid-column:span 3;}
  .span-3{grid-column:span 3;}
}

@media (max-width:620px){
  .grid-12{grid-template-columns:minmax(0,1fr);}
  .grid-12 > *{grid-column:span 1 !important;}
  .brand-name{font-size:16px;}
  .footer-grid{grid-template-columns:1fr;}
  .footer-legal{flex-direction:column;align-items:flex-start;}
  .section-title{max-width: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;
  }
  .js-reveal [data-reveal]{opacity:1;transform:none;}
  .card:hover{transform:none;}
  .frame-sweep{display:none;}
}