/* ==========================================================================
   万博体育官网 - style.css
   Urban Sports AI Lab + Dynamic Story Engine + Referee Review Console
   ========================================================================== */

:root{
  --navy-900:#0a0f1e;
  --navy-800:#0e152a;
  --navy-700:#141d38;
  --navy-600:#1c2848;
  --concrete-100:#f4f5f7;
  --concrete-200:#e7e9ec;
  --concrete-300:#d3d6dc;
  --concrete-500:#9096a3;
  --cyan-400:#3ce0e0;
  --cyan-500:#18c3c9;
  --cyan-600:#0f9aa0;
  --orange-500:#ff7a33;
  --orange-600:#e85f18;
  --purple-500:#8b5cf6;
  --white:#ffffff;
  --ink-900:#141824;
  --ink-700:#333a4d;
  --ink-500:#5c6478;
  --ink-300:#8890a0;
  --line:#dfe2e8;
  --line-dark:#26314f;
  --radius-sm:6px;
  --radius-md:12px;
  --radius-lg:20px;
  --shadow-1:0 8px 24px rgba(10,15,30,.08);
  --shadow-2:0 16px 40px rgba(10,15,30,.14);
  --maxw:1180px;
  --font-base: "PingFang SC","Microsoft YaHei","Hiragino Sans GB","Noto Sans SC",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--font-base);
  color:var(--ink-900);
  background:var(--concrete-100);
  line-height:1.75;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
ul,ol{margin:0;padding:0;}
li{list-style:none;}
button{font-family:inherit;cursor:pointer;}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px;}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;}

/* ---------- Typography ---------- */
h1,h2,h3,h4{margin:0 0 .6em;font-weight:700;color:var(--ink-900);letter-spacing:.01em;}
h1{font-size:clamp(28px,4.2vw,44px);line-height:1.3;}
h2{font-size:clamp(22px,3vw,32px);line-height:1.4;}
h3{font-size:clamp(18px,2.2vw,22px);line-height:1.5;}
p{margin:0 0 1.1em;color:var(--ink-700);}
.lead{font-size:18px;color:var(--ink-700);}

/* ---------- Header / Nav ---------- */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(10,15,30,.94);
  backdrop-filter:blur(6px);
  border-bottom:1px solid var(--line-dark);
}
.nav-wrap{
  display:flex;align-items:center;justify-content:space-between;
  height:68px;
}
.brand{display:flex;align-items:center;gap:10px;color:var(--white);font-weight:700;font-size:18px;}
.brand img{width:34px;height:34px;}
.brand small{display:block;font-weight:400;font-size:11px;color:var(--concrete-500);}
.main-nav{display:flex;gap:4px;}
.main-nav a{
  display:inline-block;padding:10px 14px;border-radius:var(--radius-sm);
  color:var(--concrete-300);font-size:14.5px;font-weight:500;
  transition:background .15s,color .15s;
  white-space:nowrap;
}
.main-nav a:hover,.main-nav a.is-active{background:var(--navy-600);color:var(--white);}
.nav-toggle{
  display:none;background:transparent;border:1px solid var(--line-dark);
  border-radius:var(--radius-sm);width:42px;height:36px;position:relative;
}
.nav-toggle span,.nav-toggle::before,.nav-toggle::after{
  content:"";position:absolute;left:9px;right:9px;height:2px;background:var(--white);
}
.nav-toggle span{top:17px;}
.nav-toggle::before{top:11px;}
.nav-toggle::after{top:23px;}

/* ---------- Hero ---------- */
.hero{
  background:radial-gradient(1200px 600px at 85% -10%, rgba(60,224,224,.18), transparent 60%),
             linear-gradient(160deg,var(--navy-900),var(--navy-700) 60%,var(--navy-600));
  color:var(--white);
  padding:64px 0 72px;
  border-bottom:4px solid var(--cyan-500);
}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center;}
.hero .kicker{
  display:inline-flex;align-items:center;gap:8px;
  color:var(--cyan-400);font-size:13px;font-weight:700;letter-spacing:.08em;
  text-transform:uppercase;margin-bottom:14px;
}
.hero h1{color:var(--white);}
.hero .lead{color:var(--concrete-300);font-size:17px;}
.hero .sub{color:var(--concrete-500);font-size:14.5px;}
.hero-figure{
  background:rgba(255,255,255,.03);
  border:1px solid rgba(255,255,255,.12);
  border-radius:var(--radius-lg);
  padding:18px;
}
.hero-figure figcaption{
  margin-top:10px;font-size:12.5px;color:var(--concrete-500);text-align:center;
}
.btn-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px;}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:12px 22px;border-radius:999px;font-weight:700;font-size:14.5px;
  border:1px solid transparent;transition:transform .15s,opacity .15s;
}
.btn:hover{transform:translateY(-1px);}
.btn-primary{background:var(--orange-500);color:var(--white);}
.btn-primary:hover{background:var(--orange-600);}
.btn-ghost{background:transparent;border-color:rgba(255,255,255,.35);color:var(--white);}
.btn-ghost:hover{background:rgba(255,255,255,.08);}
.btn-dark{background:var(--navy-800);color:var(--white);}

/* ---------- Section scaffolding ---------- */
section{padding:64px 0;}
.section-alt{background:var(--white);}
.section-head{max-width:760px;margin:0 auto 36px;text-align:center;}
.section-head.left{margin:0 0 32px;text-align:left;}
.section-head .kicker{
  display:inline-block;color:var(--cyan-600);font-weight:700;font-size:13px;
  letter-spacing:.08em;text-transform:uppercase;margin-bottom:10px;
}
.section-head p{color:var(--ink-500);}

/* ---------- Stat / interface chips (concept UI) ---------- */
.chip-row{display:flex;flex-wrap:wrap;gap:10px;margin:18px 0;}
.chip{
  background:var(--navy-800);border:1px solid var(--line-dark);
  color:var(--cyan-400);font-size:12.5px;font-weight:700;letter-spacing:.03em;
  padding:8px 14px;border-radius:999px;
}
.chip b{color:var(--white);margin-left:6px;}

/* ---------- Cards ---------- */
.grid{display:grid;gap:24px;}
.grid-2{grid-template-columns:repeat(2,1fr);}
.grid-3{grid-template-columns:repeat(3,1fr);}
.grid-4{grid-template-columns:repeat(4,1fr);}

.card{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-md);
  padding:26px;box-shadow:var(--shadow-1);height:100%;
}
.card h3{margin-bottom:10px;}
.card p{color:var(--ink-500);font-size:14.5px;margin-bottom:0;}
.card .tag{
  display:inline-block;font-size:12px;font-weight:700;color:var(--cyan-600);
  background:rgba(24,195,201,.1);padding:3px 10px;border-radius:999px;margin-bottom:12px;
}

.link-card{
  display:block;background:var(--white);border:1px solid var(--line);
  border-radius:var(--radius-md);padding:20px 22px;transition:border-color .15s,box-shadow .15s;
}
.link-card:hover{border-color:var(--cyan-500);box-shadow:var(--shadow-1);}
.link-card .arrow{color:var(--cyan-600);font-weight:700;}

/* ---------- Articles ---------- */
.article-block{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-lg);
  padding:36px 40px;margin-bottom:28px;box-shadow:var(--shadow-1);
}
.article-block .meta{
  display:flex;gap:10px;align-items:center;margin-bottom:14px;flex-wrap:wrap;
}
.article-block .meta .tag{margin-bottom:0;}
.article-block h2{margin-bottom:16px;}
.article-block h3{margin-top:26px;}
.article-block p{color:var(--ink-700);}
.example-box{
  background:var(--concrete-100);border-left:3px solid var(--orange-500);
  border-radius:var(--radius-sm);padding:16px 20px;margin:18px 0;font-size:14.5px;
}
.example-box .label{
  display:block;font-weight:700;color:var(--orange-600);font-size:12.5px;
  letter-spacing:.04em;margin-bottom:6px;text-transform:uppercase;
}
.example-box code{
  background:var(--navy-900);color:var(--cyan-400);padding:1px 7px;border-radius:4px;font-size:13px;
}
.inline-links{
  display:flex;gap:14px;flex-wrap:wrap;margin-top:18px;padding-top:18px;border-top:1px dashed var(--line);
}
.inline-links a{
  font-size:14px;font-weight:600;color:var(--cyan-600);
  border-bottom:1px solid transparent;
}
.inline-links a:hover{border-bottom-color:var(--cyan-600);}

/* ---------- Summary cards for homepage roll-up ---------- */
.summary-card{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-md);
  padding:22px 24px;box-shadow:var(--shadow-1);
}
.summary-card h4{margin-bottom:8px;font-size:16.5px;}
.summary-card p{font-size:14px;color:var(--ink-500);margin-bottom:12px;}
.summary-card a{font-size:13.5px;font-weight:700;color:var(--cyan-600);}

/* ---------- FAQ ---------- */
.faq-list{border-top:1px solid var(--line);}
.faq-item{border-bottom:1px solid var(--line);}
.faq-q{
  width:100%;display:flex;justify-content:space-between;align-items:center;gap:16px;
  background:transparent;border:none;text-align:left;padding:18px 4px;
  font-size:15.5px;font-weight:700;color:var(--ink-900);
}
.faq-q::after{
  content:"+";font-size:22px;font-weight:400;color:var(--cyan-600);flex-shrink:0;
  transition:transform .2s;
}
.faq-item.is-open .faq-q::after{transform:rotate(45deg);}
.faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.faq-a p{padding:0 4px 18px;color:var(--ink-500);font-size:14.5px;margin:0;}

/* ---------- Tabs (street map / referee vision / VAR / app) ---------- */
.tabs-nav{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px;}
.tab-btn{
  padding:9px 18px;border-radius:999px;border:1px solid var(--line);
  background:var(--white);font-size:14px;font-weight:700;color:var(--ink-500);
}
.tab-btn.is-active{background:var(--navy-800);border-color:var(--navy-800);color:var(--white);}
.tab-panel{display:none;}
.tab-panel.is-active{display:block;}

/* ---------- Timeline (story) ---------- */
.timeline{position:relative;padding-left:28px;}
.timeline::before{content:"";position:absolute;left:6px;top:6px;bottom:6px;width:2px;background:var(--line);}
.timeline-item{position:relative;padding-bottom:26px;}
.timeline-item::before{
  content:"";position:absolute;left:-28px;top:4px;width:12px;height:12px;border-radius:50%;
  background:var(--cyan-500);border:3px solid var(--white);box-shadow:0 0 0 1px var(--cyan-500);
}
.timeline-item h4{margin-bottom:4px;font-size:15.5px;}
.timeline-item p{font-size:14px;color:var(--ink-500);margin-bottom:0;}

/* ---------- Relationship / NPC network ---------- */
.rel-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;}
.rel-node{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-md);
  padding:18px;cursor:pointer;transition:border-color .15s,transform .15s;
}
.rel-node:hover{border-color:var(--cyan-500);transform:translateY(-2px);}
.rel-node.is-active{border-color:var(--orange-500);box-shadow:0 0 0 2px rgba(255,122,51,.18);}
.rel-node .role{font-size:12px;font-weight:700;color:var(--cyan-600);text-transform:uppercase;letter-spacing:.05em;}
.rel-node h4{margin:6px 0;font-size:16px;}
.rel-node .val{font-size:13px;color:var(--ink-500);}
.rel-detail{
  margin-top:18px;background:var(--navy-900);color:var(--concrete-300);
  border-radius:var(--radius-md);padding:22px 24px;font-size:14.5px;
}
.rel-detail b{color:var(--white);}

/* ---------- FAQ / info grid section backgrounds ---------- */
.section-dark{background:var(--navy-900);color:var(--concrete-300);}
.section-dark h2,.section-dark h3{color:var(--white);}
.section-dark p{color:var(--concrete-300);}
.section-dark .card{background:var(--navy-800);border-color:var(--line-dark);}
.section-dark .card p{color:var(--concrete-500);}

/* ---------- App interface mock ---------- */
.app-mock{
  background:var(--navy-900);border-radius:28px;padding:22px;border:1px solid var(--line-dark);
  max-width:320px;margin:0 auto;
}
.app-mock-screen{background:var(--navy-800);border-radius:18px;padding:18px;}
.app-mock-row{
  display:flex;justify-content:space-between;align-items:center;
  background:var(--navy-600);border-radius:10px;padding:12px 14px;margin-bottom:10px;font-size:13px;color:var(--white);
}
.app-mock-row small{display:block;color:var(--concrete-500);font-size:11px;margin-top:2px;}

/* ---------- Download page ---------- */
.platform-card{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-lg);
  padding:30px;text-align:center;box-shadow:var(--shadow-1);
}
.platform-card .icon{width:56px;height:56px;margin:0 auto 16px;}
.status-pill{
  display:inline-block;margin-top:14px;font-size:12.5px;font-weight:700;
  background:var(--concrete-200);color:var(--ink-500);padding:5px 12px;border-radius:999px;
}

/* ---------- About / company ---------- */
.about-box{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius-lg);
  padding:34px 38px;
}

/* ---------- Footer ---------- */
.site-footer{background:var(--navy-900);color:var(--concrete-500);padding:48px 0 26px;}
.footer-grid{display:grid;grid-template-columns:1.4fr repeat(2,1fr);gap:32px;margin-bottom:28px;}
.footer-brand{display:flex;align-items:center;gap:10px;color:var(--white);font-weight:700;font-size:17px;margin-bottom:10px;}
.footer-brand img{width:28px;height:28px;}
.site-footer h5{color:var(--white);font-size:14px;margin-bottom:14px;}
.site-footer a{display:block;color:var(--concrete-500);font-size:13.5px;padding:4px 0;}
.site-footer a:hover{color:var(--cyan-400);}
.footer-bottom{
  border-top:1px solid var(--line-dark);padding-top:20px;font-size:12.5px;color:var(--ink-300);
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;
}

/* ---------- Back to top ---------- */
.back-top{
  position:fixed;right:22px;bottom:22px;width:44px;height:44px;border-radius:50%;
  background:var(--navy-800);color:var(--white);border:1px solid var(--line-dark);
  display:flex;align-items:center;justify-content:center;font-size:18px;
  opacity:0;pointer-events:none;transition:opacity .2s,transform .2s;z-index:90;
}
.back-top.is-visible{opacity:1;pointer-events:auto;}
.back-top:hover{transform:translateY(-3px);}

/* ---------- Breadcrumb ---------- */
.breadcrumb{font-size:13px;color:var(--concrete-500);margin-bottom:8px;}
.breadcrumb a{color:var(--concrete-300);}
.breadcrumb a:hover{color:var(--cyan-400);}

/* ---------- Page accent variants ---------- */
.page-street .hero{background:radial-gradient(1200px 600px at 85% -10%, rgba(255,122,51,.18), transparent 60%), linear-gradient(160deg,var(--navy-900),#1a2338 60%,var(--navy-600));}
.page-story .hero{background:radial-gradient(1200px 600px at 85% -10%, rgba(139,92,246,.18), transparent 60%), linear-gradient(160deg,var(--navy-900),var(--navy-700) 60%,#241b3d);}
.page-referee .hero{border-bottom-color:var(--orange-500);}
.page-npc .hero{background:radial-gradient(1200px 600px at 85% -10%, rgba(60,224,224,.22), transparent 60%), linear-gradient(160deg,var(--navy-900),var(--navy-700) 60%,var(--navy-600));}

/* ---------- Utility ---------- */
.mt-0{margin-top:0;}
.text-center{text-align:center;}
.small-note{font-size:12.5px;color:var(--ink-300);}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr);}
  .grid-3{grid-template-columns:repeat(2,1fr);}
  .footer-grid{grid-template-columns:1fr 1fr;}
}

@media (max-width:900px){
  .hero-grid{grid-template-columns:1fr;}
  .hero-figure{order:-1;}
}

@media (max-width:768px){
  .main-nav{
    position:fixed;top:68px;left:0;right:0;bottom:0;
    background:var(--navy-900);flex-direction:column;padding:16px;
    transform:translateX(100%);transition:transform .2s;overflow-y:auto;
  }
  .main-nav.is-open{transform:translateX(0);}
  .main-nav a{padding:14px 12px;font-size:16px;border-bottom:1px solid var(--line-dark);}
  .nav-toggle{display:block;}
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}
  .article-block{padding:26px 22px;}
  .footer-grid{grid-template-columns:1fr;gap:24px;}
  section{padding:44px 0;}
}

@media (max-width:430px){
  .container{padding:0 16px;}
  h1{font-size:26px;}
  .article-block{padding:20px 16px;}
  .btn{padding:11px 18px;font-size:14px;}
}