/* roulang page: index */
:root{
  --ink:#241C33;
  --ink-deep:#1B1426;
  --ink-soft:#6E5A8C;
  --accent:#E0563B;
  --accent-hover:#C2452C;
  --amber:#C9922E;
  --moss:#4E7A5E;
  --paper:#F8F5F0;
  --paper-alt:#EFEAE2;
  --line:#DCD4C8;
  --text:#1C1A22;
  --muted:#6B6472;
  --radius:6px;
  --shadow:0 2px 8px rgba(36,28,51,.08);
  --shadow-lg:0 10px 26px rgba(36,28,51,.14);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:112px}
body{
  font-family:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  background:var(--paper);color:var(--text);font-size:16px;line-height:1.85;
  -webkit-font-smoothing:antialiased;
}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
button,input{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

.wrap{width:100%;max-width:1200px;margin:0 auto;padding:0 24px}
.wrap-narrow{max-width:760px}
.sec{padding:80px 0}
.sec-alt{background:var(--paper-alt)}
.sec-head{max-width:760px;margin-bottom:32px}
.sec-head h2{font-size:32px;line-height:1.3;font-weight:700;color:var(--ink);letter-spacing:-.01em}
.sec-head p{font-size:15px;color:var(--muted);margin-top:10px;line-height:1.8}
.hl{color:var(--accent)}

/* header */
.site-header{
  position:sticky;top:0;z-index:60;background:rgba(248,245,240,.96);
  backdrop-filter:saturate(140%) blur(8px);
  border-bottom:1px solid var(--line);transition:box-shadow .18s ease;
}
.site-header.is-stuck{box-shadow:0 4px 18px rgba(36,28,51,.12)}
.header-inner{
  display:flex;align-items:center;justify-content:space-between;
  height:64px;max-width:1200px;margin:0 auto;padding:0 24px;
}
.brand{display:flex;align-items:center;gap:10px}
.brand-mark{
  width:34px;height:34px;border-radius:6px;background:var(--ink);color:#F3EEE6;
  display:grid;place-items:center;font-weight:700;font-size:17px;line-height:1;
}
.brand-name{font-weight:700;font-size:17px;color:var(--ink);letter-spacing:.02em}

/* buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:44px;padding:12px 22px;border-radius:4px;border:1.5px solid transparent;
  font-size:15px;font-weight:500;cursor:pointer;
  transition:background .18s ease,color .18s ease,transform .18s ease,border-color .18s ease;
}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-hover);transform:translateY(-1px)}
.btn-ghost{background:transparent;border-color:var(--ink);color:var(--ink)}
.btn-ghost:hover{background:var(--ink);color:#F3EEE6}
.btn-block{width:100%}

/* hero */
.hero{padding:56px 0 64px;background:var(--paper);border-bottom:1px solid var(--line)}
.hero-grid{display:grid;grid-template-columns:55fr 45fr;gap:48px;align-items:center}
.eyebrow{
  display:inline-block;font-size:13px;letter-spacing:.08em;color:var(--ink-soft);
  border-left:3px solid var(--accent);padding-left:9px;margin-bottom:16px;
}
.hero h1{font-size:44px;line-height:1.25;font-weight:700;color:var(--ink);letter-spacing:-.01em}
.hero-sub{font-size:17px;color:var(--ink);margin-top:16px;font-weight:500}
.hero-desc{font-size:16px;color:var(--muted);margin-top:12px;max-width:520px;line-height:1.85}
.hero-actions{display:flex;gap:14px;margin-top:26px;flex-wrap:wrap}
.hero-metrics{display:flex;gap:36px;margin-top:32px;padding-top:24px;border-top:1px solid var(--line);flex-wrap:wrap}
.hero-metrics li{display:flex;flex-direction:column}
.hero-metrics strong{
  font-size:22px;font-weight:700;color:var(--ink);
  font-variant-numeric:tabular-nums;letter-spacing:-.02em;line-height:1.3;
}
.hero-metrics span{font-size:13px;color:var(--muted);margin-top:2px}
.hero-figure{position:relative;border-radius:8px;overflow:hidden;box-shadow:var(--shadow-lg)}
.hero-figure img{width:100%;aspect-ratio:16/11;object-fit:cover}
.hero-figure figcaption{
  position:absolute;top:14px;left:14px;background:rgba(36,28,51,.84);color:#F3EEE6;
  font-size:13px;letter-spacing:.04em;padding:5px 11px;border-radius:4px;
}

/* anchor bar */
.anchor-bar{
  position:sticky;top:64px;z-index:55;background:var(--paper-alt);
  border-bottom:1px solid var(--line);
}
.anchor-inner{
  display:flex;gap:4px;justify-content:center;max-width:1200px;margin:0 auto;padding:0 24px;
  overflow-x:auto;scrollbar-width:none;
}
.anchor-inner::-webkit-scrollbar{display:none}
.anchor-inner a{
  flex:none;white-space:nowrap;padding:12px 14px;font-size:14px;color:var(--muted);
  border-bottom:2px solid transparent;transition:color .18s ease,border-color .18s ease;
}
.anchor-inner a:hover{color:var(--ink)}
.anchor-inner a.active{color:var(--ink);border-bottom-color:var(--accent)}

/* stats */
.stats{background:var(--ink);color:#F3EEE6;padding:44px 0}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr)}
.stat{padding:0 28px;border-left:1px solid rgba(243,238,230,.18)}
.stat:first-child{border-left:0;padding-left:0}
.stat-num{
  font-size:34px;font-weight:700;line-height:1.2;letter-spacing:-.02em;
  font-variant-numeric:tabular-nums;
}
.stat-num small{font-size:15px;font-weight:400;margin-left:4px;color:rgba(243,238,230,.7)}
.stat-label{font-size:13px;color:rgba(243,238,230,.68);margin-top:6px}

/* cards */
.card-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.card{
  display:block;background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow);
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.card:hover{transform:translateY(-2px);border-color:var(--accent);box-shadow:var(--shadow-lg)}
.card:hover .card-title{text-decoration:underline}
.card-thumb{position:relative;aspect-ratio:3/4;overflow:hidden;background:var(--paper-alt)}
.card-thumb img{width:100%;height:100%;object-fit:cover}
.badge{
  position:absolute;top:8px;left:8px;font-size:12px;line-height:1.6;
  padding:2px 8px;border-radius:3px;background:rgba(36,28,51,.84);color:#F3EEE6;font-weight:500;
}
.score{
  position:absolute;right:8px;bottom:8px;font-size:13px;font-weight:700;color:var(--amber);
  background:rgba(248,245,240,.95);padding:1px 7px;border-radius:3px;font-variant-numeric:tabular-nums;
}
.card-body{padding:12px 13px 14px}
.card-title{font-size:15px;font-weight:500;color:var(--ink);line-height:1.45}
.card-meta{font-size:13px;color:var(--muted);margin-top:4px}

/* update list */
.update-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.update-item{
  display:grid;grid-template-columns:160px 1fr;gap:16px;align-items:center;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:12px;
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.update-item:hover{transform:translateY(-2px);border-color:var(--ink-soft);box-shadow:var(--shadow-lg)}
.update-thumb{aspect-ratio:16/9;border-radius:4px;overflow:hidden;background:var(--paper-alt)}
.update-thumb img{width:100%;height:100%;object-fit:cover}
.update-title{font-size:16px;font-weight:500;color:var(--ink)}
.update-line{display:flex;align-items:center;gap:10px;margin-top:6px;flex-wrap:wrap}
.state{font-size:12px;padding:2px 9px;border-radius:999px;font-weight:500;line-height:1.7}
.state-on{background:rgba(78,122,94,.14);color:var(--moss)}
.state-done{background:rgba(110,90,140,.16);color:var(--ink-soft)}
.update-date{font-size:13px;color:var(--muted)}

/* channels */
.channel-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 56px}
.channel-row{
  display:flex;gap:16px;align-items:baseline;padding:22px 0;border-bottom:1px solid var(--line);
}
.channel-no{
  flex:none;width:26px;font-size:13px;font-weight:700;color:var(--accent);
  letter-spacing:.06em;font-variant-numeric:tabular-nums;
}
.channel-name{flex:none;width:92px;font-size:17px;font-weight:700;color:var(--ink)}
.channel-name a{border-bottom:1px solid transparent;transition:border-color .18s ease}
.channel-name a:hover{border-bottom-color:var(--accent)}
.channel-desc{font-size:14px;color:var(--muted);line-height:1.7}

/* compare table */
.cmp-table{
  width:100%;border-collapse:collapse;background:#fff;font-size:15px;
  border:1px solid var(--line);
}
.cmp-table th,.cmp-table td{padding:16px 20px;text-align:left;border-bottom:1px solid var(--line)}
.cmp-table thead th{background:var(--paper-alt);font-size:14px;font-weight:700;color:var(--ink)}
.cmp-table tbody th{font-weight:500;color:var(--text)}
.cmp-table tbody tr:last-child th,
.cmp-table tbody tr:last-child td{border-bottom:0}
.cmp-yes{color:var(--moss);font-weight:700}
.cmp-mid{color:var(--amber);font-weight:700}

/* milestones */
.ms-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.ms{position:relative;padding-top:30px}
.ms::before{
  content:"";position:absolute;top:0;left:0;width:11px;height:11px;border-radius:50%;
  background:var(--accent);
}
.ms::after{
  content:"";position:absolute;top:5px;left:20px;right:-24px;height:1px;background:var(--line);
}
.ms:last-child::after{display:none}
.ms-date{font-size:13px;color:var(--accent);font-weight:700;letter-spacing:.04em}
.ms-title{font-size:16px;font-weight:700;color:var(--ink);margin:6px 0 4px}
.ms-desc{font-size:14px;color:var(--muted);line-height:1.7}

/* rank */
.rank-list{border-top:1px solid var(--line)}
.rank-item{
  display:grid;grid-template-columns:58px 1fr 130px 74px 84px;gap:16px;align-items:center;
  padding:14px 18px;border-bottom:1px solid var(--line);transition:background .18s ease;
}
.rank-item:nth-child(even){background:#fff}
.rank-item:hover{background:#fff}
.rank-no{
  font-size:20px;font-weight:700;color:var(--ink-soft);
  font-variant-numeric:tabular-nums;letter-spacing:-.02em;
}
.rank-item:nth-child(-n+3) .rank-no{color:var(--accent)}
.rank-name{font-size:16px;font-weight:500;color:var(--ink)}
.rank-heat{font-size:14px;color:var(--muted);text-align:right;font-variant-numeric:tabular-nums}
.rank-score{font-size:15px;font-weight:700;color:var(--amber);text-align:right;font-variant-numeric:tabular-nums}
.tag{
  display:inline-block;font-size:12px;padding:2px 10px;border-radius:999px;
  background:rgba(110,90,140,.13);color:var(--ink-soft);font-weight:500;line-height:1.7;
  text-align:center;
}

/* topics */
.topic-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.topic-hero{
  grid-column:1 / -1;display:grid;grid-template-columns:1.1fr 1fr;
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
}
.topic-hero .topic-media{aspect-ratio:16/9;overflow:hidden;background:var(--paper-alt)}
.topic-hero .topic-media img{width:100%;height:100%;object-fit:cover}
.topic-body{padding:28px 30px;display:flex;flex-direction:column;justify-content:center}
.topic-body h3{font-size:22px;font-weight:700;color:var(--ink);line-height:1.4}
.topic-body p{font-size:14px;color:var(--muted);margin-top:10px;line-height:1.75}
.topic-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.topic-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  transition:transform .18s ease,box-shadow .18s ease;
}
.topic-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.topic-card .topic-media{aspect-ratio:16/9;overflow:hidden;background:var(--paper-alt)}
.topic-card .topic-media img{width:100%;height:100%;object-fit:cover}
.topic-card .topic-body{padding:20px 22px 24px}

/* news */
.news-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 40px}
.news-item{
  display:grid;grid-template-columns:120px 1fr;gap:16px;align-items:center;
  padding:16px 0;border-bottom:1px solid var(--line);
}
.news-thumb{aspect-ratio:16/9;border-radius:4px;overflow:hidden;background:var(--paper-alt)}
.news-thumb img{width:100%;height:100%;object-fit:cover}
.news-title{font-size:15px;font-weight:500;color:var(--ink);line-height:1.55;transition:color .18s ease}
.news-item:hover .news-title{color:var(--accent)}
.news-date{font-size:13px;color:var(--muted);margin-top:4px}

/* assure */
.assure-grid{display:grid;grid-template-columns:repeat(4,1fr)}
.assure-item{padding:0 28px;border-left:1px solid var(--line)}
.assure-item:first-child{border-left:0;padding-left:0}
.assure-no{
  font-size:13px;font-weight:700;color:var(--accent);letter-spacing:.08em;
  font-variant-numeric:tabular-nums;
}
.assure-title{font-size:17px;font-weight:700;color:var(--ink);margin:8px 0 6px}
.assure-desc{font-size:14px;color:var(--muted);line-height:1.7}

/* quick qa */
.qa-list{display:grid;gap:0}
.qa{
  display:grid;grid-template-columns:260px 1fr;gap:24px;
  padding:20px 0;border-bottom:1px solid var(--line);
}
.qa:first-child{border-top:1px solid var(--line)}
.qa-q{font-size:15px;font-weight:700;color:var(--ink)}
.qa-a{font-size:15px;color:var(--muted)}

/* faq */
.faq details{border-bottom:1px solid var(--line)}
.faq details:first-of-type{border-top:1px solid var(--line)}
.faq summary{
  list-style:none;cursor:pointer;display:flex;align-items:flex-start;
  justify-content:space-between;gap:20px;padding:20px 0;
  font-size:16px;font-weight:700;color:var(--ink);line-height:1.6;min-height:44px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";flex:none;color:var(--accent);font-weight:400;font-size:22px;line-height:1.1;
}
.faq details[open] summary::after{content:"−"}
.faq-a{font-size:15px;line-height:1.85;color:var(--muted);padding-bottom:22px;max-width:760px}

/* form band */
.form-band{background:var(--ink);color:#F3EEE6;padding:72px 0}
.form-inner{max-width:640px;margin:0 auto;padding:0 24px}
.form-inner h2{font-size:28px;line-height:1.35;font-weight:700;text-align:center}
.form-inner .form-sub{
  font-size:14px;color:rgba(243,238,230,.72);text-align:center;margin:12px 0 28px;line-height:1.75;
}
.field{margin-bottom:18px}
.field label{display:block;font-size:14px;color:rgba(243,238,230,.85);margin-bottom:6px}
.field input{
  width:100%;min-height:44px;padding:12px 14px;border-radius:4px;
  background:rgba(243,238,230,.07);border:1px solid rgba(243,238,230,.28);
  color:#F3EEE6;font-size:15px;transition:border-color .18s ease,box-shadow .18s ease;
}
.field input::placeholder{color:rgba(243,238,230,.4)}
.field input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 1px var(--accent)}
.form-note{font-size:13px;color:rgba(243,238,230,.58);margin-top:14px;text-align:center;line-height:1.7}

/* footer */
.site-footer{background:var(--ink-deep);color:#F3EEE6;padding:56px 0 0;border-top:1px solid rgba(243,238,230,.1)}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:40px;padding-bottom:44px}
.footer-brand{display:flex;align-items:center;gap:10px;margin-bottom:14px}
.footer-brand .brand-mark{background:var(--accent);color:#fff}
.footer-brand span{font-size:17px;font-weight:700}
.footer-desc{font-size:14px;color:rgba(243,238,230,.66);line-height:1.8;max-width:280px}
.footer-col h3{font-size:14px;font-weight:500;color:#F3EEE6;margin-bottom:14px;letter-spacing:.04em}
.footer-col li{margin-bottom:9px}
.footer-col a{font-size:14px;color:rgba(243,238,230,.72);transition:color .18s ease}
.footer-col a:hover{color:var(--accent);text-decoration:underline}
.footer-bottom{
  border-top:1px solid rgba(243,238,230,.12);padding:20px 0;
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  font-size:13px;color:rgba(243,238,230,.55);
}

@media (max-width:1024px){
  .sec{padding:60px 0}
  .hero{padding:44px 0 52px}
  .hero-grid{grid-template-columns:1fr;gap:36px}
  .hero h1{font-size:38px}
  .hero-desc{max-width:none}
  .card-grid{grid-template-columns:repeat(3,1fr);gap:20px}
  .ms-grid{grid-template-columns:repeat(2,1fr);gap:32px 24px}
  .ms:nth-child(2)::after{display:none}
  .assure-grid{grid-template-columns:repeat(2,1fr);gap:28px 0}
  .assure-item:nth-child(3){border-left:0;padding-left:0}
  .channel-grid{gap:0 40px}
  .sec-head h2{font-size:28px}
  .footer-grid{grid-template-columns:1.4fr 1fr 1fr;gap:32px}
}
@media (max-width:768px){
  .sec{padding:60px 0}
  .hero h1{font-size:32px}
  .hero-metrics{gap:28px}
  .anchor-inner{justify-content:flex-start}
  .stats{padding:36px 0}
  .stats-grid{grid-template-columns:1fr 1fr;gap:26px 0}
  .stat{padding:0 20px}
  .stat:nth-child(odd){border-left:0;padding-left:0}
  .stat-num{font-size:28px}
  .card-grid{grid-template-columns:repeat(2,1fr);gap:16px}
  .update-grid{grid-template-columns:1fr}
  .update-item{grid-template-columns:130px 1fr}
  .channel-grid{grid-template-columns:1fr;gap:0}
  .channel-row{padding:18px 0;gap:12px;flex-wrap:wrap}
  .channel-name{width:auto}
  .channel-desc{flex:1 1 100%;padding-left:38px}
  .cmp-table thead{display:none}
  .cmp-table,.cmp-table tbody,.cmp-table tr,.cmp-table th,.cmp-table td{display:block;width:100%}
  .cmp-table{border:0;background:transparent}
  .cmp-table tbody th{
    background:var(--paper-alt);border:1px solid var(--line);border-bottom:0;
    font-weight:700;padding:12px 16px;
  }
  .cmp-table tbody td{
    border:1px solid var(--line);border-top:0;padding:10px 16px;background:#fff;font-size:14px;
  }
  .cmp-table tbody td::before{
    content:attr(data-label);display:block;font-size:12px;color:var(--muted);margin-bottom:2px;
  }
  .cmp-table tbody tr{margin-bottom:16px}
  .rank-item{grid-template-columns:44px 1fr 78px;gap:12px;padding:14px 12px}
  .rank-heat,.rank-tag{display:none}
  .rank-score{text-align:right}
  .topic-grid{grid-template-columns:1fr}
  .topic-hero{grid-template-columns:1fr}
  .topic-body{padding:22px 20px}
  .news-grid{grid-template-columns:1fr}
  .qa{grid-template-columns:1fr;gap:6px;padding:16px 0}
  .ms-grid{grid-template-columns:1fr;gap:0}
  .ms{padding:0 0 26px 26px}
  .ms::before{top:6px}
  .ms::after{top:16px;left:5px;right:auto;bottom:0;width:1px;height:auto;transform:none}
  .ms:last-child::after{display:none}
  .form-inner h2{font-size:24px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:28px}
  .footer-desc{max-width:none}
}
@media (max-width:520px){
  .wrap{padding:0 16px}
  .header-inner{padding:0 16px}
  .header-inner .btn{padding:10px 16px;font-size:14px}
  .brand-name{font-size:16px}
  .hero h1{font-size:27px}
  .sec-head h2{font-size:24px}
  .hero-metrics{gap:22px}
  .hero-actions .btn{width:100%}
  .stat-num{font-size:24px}
  .card-grid{grid-template-columns:repeat(2,1fr);gap:14px}
  .card-body{padding:10px 11px 12px}
  .card-title{font-size:14px}
  .update-item{grid-template-columns:1fr}
  .update-thumb{aspect-ratio:16/9}
  .assure-grid{grid-template-columns:1fr;gap:0}
  .assure-item{padding:18px 0;border-left:0;border-top:1px solid var(--line)}
  .assure-item:first-child{border-top:0;padding-top:0}
  .news-item{grid-template-columns:100px 1fr;gap:12px}
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;gap:6px}
  .form-band{padding:52px 0}
  .form-inner{padding:0 16px}
}