/* === bian-coin.com — Core Stylesheet === */
/* Design: ink paper ranking + ink black, VARIANCE 5 / MOTION 4 / DENSITY 4 */

/* === RESET & BASE === */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
  font-size:16px;line-height:1.7;color:#1a1d23;
  background:#ffffff;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}

/* === CSS VARIABLES === */
:root{
  --c1:#ffffff;
  --c12:#f6f6f4;
  --c13:#ededeb;
  --c1-card:#fafaf9;
  --c5:#e2e2df;
  --c5-strong:#c9c9c5;
  --c7:#16181d;
  --c7-glow:rgba(22,24,29,0.12);
  --c7-dim:rgba(22,24,29,0.05);
  --c10:#1a1d23;
  --c10-dim:#555b64;
  --c10-muted:#8a9099;
  --c13:2px;
  --c13-lg:2px;
  --c13-sm:8px;
  --c16:1100px;
  --c17:64px;
}

/* === TYPOGRAPHY === */
h1,h2,h3,h4{color:#111318;font-family:'Helvetica Neue','PingFang SC','Microsoft YaHei',sans-serif;line-height:1.22;font-weight:800}
h1{font-size:clamp(2rem,4.2vw,3rem);letter-spacing:-0.025em}
h2{font-size:clamp(1.5rem,3vw,2.25rem);letter-spacing:-0.02em}
h3{font-size:1.125rem;letter-spacing:-0.01em}
p{margin-bottom:1rem}
a{color:var(--c7);text-decoration:none;transition:color .2s}
a:hover{color:#3c4048}

/* === CONTAINER === */
.bian-container{max-width:var(--c16);margin:0 auto;padding:0 24px}

/* === NAVIGATION === */
.bian-site-nav{
  position:sticky;top:0;z-index:100;
  background:rgba(255,255,255,0.96);backdrop-filter:blur(16px);
  border-bottom:1px solid var(--c5);height:var(--c17);
}
.bian-site-nav .bian-container{
  display:flex;align-items:center;justify-content:space-between;
  height:100%;
}
.bian-nav-logo{
  font-size:1.25rem;font-weight:800;letter-spacing:-0.02em;
  color:#111318;white-space:nowrap;
}
.bian-nav-logo span{color:var(--c7)}
.bian-nav-links{display:flex;align-items:center;gap:32px;list-style:none}
.bian-nav-links a{
  color:var(--c10-dim);font-size:0.9rem;font-weight:500;
  transition:color .2s;white-space:nowrap;
}
.bian-nav-links a:hover,.bian-nav-links a.bian-active{color:#111318}
.bian-nav-cta{
  display:inline-flex;align-items:center;gap:6px;
  background:var(--c7);color:#ffffff!important;
  padding:8px 18px;border-radius:999px;
  font-weight:700;font-size:0.85rem;
  transition:transform .15s,box-shadow .15s;
}
.bian-nav-cta:hover{transform:translateY(-1px);box-shadow:0 4px 20px var(--c7-glow)}

/* Mobile nav toggle */
.bian-nav-toggle{display:none;background:none;border:none;color:#f0f0f0;font-size:1.5rem;cursor:pointer;padding:8px}

/* === HERO === */
.bian-hero{
  padding:80px 0 80px;
  background:radial-gradient(ellipse 70% 60% at 50% 0%,rgba(22,24,29,0.04),transparent 60%);
}
.bian-hero .bian-container{
  display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;
}
.bian-hero-eyebrow{
  font-size:0.75rem;text-transform:uppercase;letter-spacing:0.2em;
  color:var(--c7);margin-bottom:16px;font-weight:600;
}
.bian-hero-title{font-size:clamp(2rem,4.2vw,3rem);margin-bottom:20px}
.bian-hero-title span{color:var(--c7)}
.bian-hero-sub{
  font-size:1.05rem;color:var(--c10-dim);max-width:48ch;
  line-height:1.6;margin-bottom:32px;
}
.bian-hero-ctas{display:flex;gap:14px;flex-wrap:wrap}
.bian-btn-primary{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--c7);color:#ffffff;
  padding:13px 28px;border-radius:999px;
  font-weight:700;font-size:0.95rem;
  transition:transform .15s,box-shadow .15s;
  white-space:nowrap;
}
.bian-btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 30px var(--c7-glow);color:#ffffff}
.bian-btn-outline{
  display:inline-flex;align-items:center;gap:8px;
  background:transparent;color:#1a1d23;
  padding:13px 28px;border-radius:999px;
  font-weight:600;font-size:0.95rem;
  border:1px solid var(--c5-strong);
  transition:border-color .2s,background .2s;
  white-space:nowrap;
}
.bian-btn-outline:hover{border-color:var(--c7);background:var(--c7-dim);color:#1a1d23}
.bian-hero-visual{position:relative;aspect-ratio:4/3;border-radius:16px;overflow:hidden;box-shadow:0 20px 60px rgba(0,0,0,0.4),0 0 0 1px rgba(255,255,255,0.06)}
.bian-hero-visual-placeholder{
  width:100%;height:100%;display:flex;align-items:center;justify-content:center;
  color:var(--c10-muted);font-size:0.85rem;
}
.bian-hero-visual img{width:100%;height:100%;object-fit:cover}

/* === SECTIONS === */
.bian-section{padding:80px 0}
.bian-section-alt{background:var(--c12)}
.bian-section-header{margin-bottom:48px}
.bian-section-header.bian-centered{text-align:center}
.bian-section-eyebrow{
  font-size:0.7rem;text-transform:uppercase;letter-spacing:0.22em;
  color:var(--c7);margin-bottom:12px;font-weight:600;
}
.bian-section-title{font-size:clamp(1.5rem,3vw,2.25rem);margin-bottom:12px}
.bian-section-desc{color:var(--c10-dim);max-width:60ch;font-size:0.95rem;line-height:1.6}

/* === FEATURES GRID === */
.bian-features-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
  gap:28px;
}
.bian-feature-card{
  background:var(--c1-card);border:1px solid var(--c5);
  border-radius:var(--c13);padding:32px 28px;
  transition:border-color .25s,transform .25s;
}
.bian-feature-card:hover{border-color:var(--c5-strong);transform:translateY(-2px)}
.bian-feature-icon{
  width:64px;height:64px;border-radius:var(--c13-sm);
  background:var(--c7-dim);display:flex;align-items:center;
  justify-content:center;margin-bottom:20px;font-size:1.3rem;
}
.bian-feature-card h3{font-size:1.05rem;margin-bottom:10px}
.bian-feature-card p{font-size:0.9rem;color:var(--c10-dim);line-height:1.6;margin:0}

/* === STATS === */
.bian-stats-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
  gap:20px;
}
.bian-stat-card{
  text-align:center;padding:32px 20px;
  background:var(--c1-card);border:1px solid var(--c5);
  border-radius:var(--c13);
}
.bian-stat-value{
  font-size:2.5rem;font-weight:800;color:var(--c7);
  letter-spacing:-0.02em;line-height:1;
}
.bian-stat-label{font-size:0.85rem;color:var(--c10-dim);margin-top:8px}

/* === NEWS (2-col large cards) === */
.bian-news-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(320px,1fr));
  gap:24px;
}
.bian-news-card{
  background:var(--c1-card);border:1px solid var(--c5);
  border-radius:var(--c13);overflow:hidden;
  transition:border-color .25s,transform .25s;
  display:flex;flex-direction:column;
}
.bian-news-card:hover{border-color:var(--c5-strong);transform:translateY(-2px)}
.bian-news-card-img{
  width:100%;height:200px;
  background:linear-gradient(135deg,var(--c13),var(--c12));
  display:flex;align-items:center;justify-content:center;
  color:var(--c10-muted);font-size:0.8rem;
;overflow:hidden}
.bian-news-card-img img{width:100%;height:100%;object-fit:cover}
.bian-news-card-body{padding:20px 24px 24px;flex:1;display:flex;flex-direction:column}
.bian-news-card-body h3{font-size:1.05rem;margin-bottom:8px}
.bian-news-card-body h3 a{color:#111318}
.bian-news-card-body h3 a:hover{color:var(--c7)}
.bian-news-card-desc{font-size:0.9rem;color:var(--c10-dim);line-height:1.6;margin-bottom:12px;flex:1}
.bian-news-card-date{font-size:0.78rem;color:var(--c10-muted)}

/* === GUIDE (3-col cards) === */
.bian-guide-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
  gap:24px;
}
.bian-guide-card{
  background:var(--c1-card);border:1px solid var(--c5);
  border-radius:var(--c13);overflow:hidden;
  transition:border-color .25s,transform .25s;
}
.bian-guide-card:hover{border-color:var(--c5-strong);transform:translateY(-2px)}
.bian-guide-card-img{
  width:100%;height:180px;
  background:linear-gradient(135deg,var(--c13),var(--c12));
  display:flex;align-items:center;justify-content:center;
  color:var(--c10-muted);font-size:0.8rem;
;overflow:hidden}
.bian-guide-card-img img{width:100%;height:100%;object-fit:cover}
.bian-guide-card-body{padding:18px 20px 20px}
.bian-guide-card-body h3{font-size:1rem;margin-bottom:6px}
.bian-guide-card-body h3 a{color:#111318}
.bian-guide-card-body h3 a:hover{color:var(--c7)}
.bian-guide-card-body p{font-size:0.85rem;color:var(--c10-dim);line-height:1.5;margin:0}

/* === TRUST / PARTNER LOGO WALL === */
.bian-trust-grid{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:center;
  gap:40px 48px;padding:20px 0;
}
.bian-trust-item{
  height:56px;display:flex;align-items:center;
  opacity:0.85;transition:opacity .3s;
}
.bian-trust-item svg,.bian-trust-item img{height:100%;width:auto}
.bian-trust-item:hover{opacity:0.8}

/* === FOOTER === */
.bian-site-footer{
  background:var(--c12);border-top:1px solid var(--c5);
  padding:56px 0 32px;
}
.bian-footer-grid{
  display:grid;
  grid-template-columns:2fr 1fr 1fr 1fr;
  gap:40px;margin-bottom:40px;
}
.bian-footer-brand p{color:var(--c10-dim);font-size:0.9rem;line-height:1.7;margin-top:12px;max-width:36ch}
.bian-footer-col h4{font-size:0.85rem;text-transform:uppercase;letter-spacing:0.08em;margin-bottom:16px;color:var(--c10)}
.bian-footer-col ul{list-style:none}
.bian-footer-col ul li{margin-bottom:10px}
.bian-footer-col ul li a{color:var(--c10-dim);font-size:0.9rem;transition:color .2s}
.bian-footer-col ul li a:hover{color:#111318}
.bian-footer-bottom{
  border-top:1px solid var(--c5);padding-top:24px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;
  font-size:0.8rem;color:var(--c10-muted);
}
.bian-footer-bottom a{color:var(--c10-dim)}

/* === BREADCRUMB === */
.bian-breadcrumb{padding:16px 0;font-size:0.85rem}
.bian-breadcrumb ol{list-style:none;display:flex;flex-wrap:wrap;gap:4px;align-items:center}
.bian-breadcrumb li{color:var(--c10-dim);display:flex;align-items:center;gap:4px}
.bian-breadcrumb a{color:var(--c10-dim)}
.bian-breadcrumb a:hover{color:var(--c7)}
.bian-breadcrumb .bian-sep{color:var(--c10-muted);margin:0 4px}

/* === ARTICLE LIST (栏目页) === */
.bian-article-list{display:flex;flex-direction:column;gap:0}
.bian-article-list-item{
  display:grid;grid-template-columns:1fr auto;
  gap:20px;padding:22px 0;border-bottom:1px solid var(--c5);
  align-items:start;
}
.bian-article-list-item:last-child{border-bottom:none}
.bian-article-list-item h3{font-size:1.1rem;margin-bottom:6px}
.bian-article-list-item h3 a{color:#111318}
.bian-article-list-item h3 a:hover{color:var(--c7)}
.bian-article-list-desc{font-size:0.9rem;color:var(--c10-dim);line-height:1.6;margin-bottom:8px;max-width:80ch}
.bian-article-list-date{font-size:0.78rem;color:var(--c10-muted);white-space:nowrap}

/* === ARTICLE DETAIL === */
.bian-article-detail{max-width:780px;margin:0 auto}
.bian-article-header{margin-bottom:40px;padding-bottom:32px;border-bottom:1px solid var(--c5)}
.bian-article-header h1{font-size:clamp(1.75rem,4vw,2.5rem);margin-bottom:16px}
.bian-article-meta{
  display:flex;gap:20px;flex-wrap:wrap;font-size:0.85rem;color:var(--c10-muted)
}
.bian-article-body{line-height:1.9}
.bian-article-body h2{
  font-size:1.35rem;margin:40px 0 16px;padding-bottom:8px;
  border-bottom:1px solid var(--c5)
}
.bian-article-body h3{font-size:1.1rem;margin:28px 0 12px}
.bian-article-body p{margin-bottom:20px;color:#3c4048}
.bian-article-body ul,.bian-article-body ol{margin-bottom:20px;padding-left:24px}
.bian-article-body li{margin-bottom:8px;color:#3c4048}
.bian-article-body img{max-width:100%;height:auto;border-radius:var(--c13-sm);margin:24px 0}
.bian-article-body blockquote{
  border-left:3px solid var(--c7);padding:12px 20px;
  margin:24px 0;background:var(--c7-dim);border-radius:0 var(--c13-sm) var(--c13-sm) 0;
  font-style:italic;color:var(--c10-dim);
}
.bian-article-footer{
  margin-top:48px;padding-top:24px;border-top:1px solid var(--c5);
}
.bian-article-tags{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px}
.bian-article-tag{
  display:inline-block;padding:4px 12px;
  background:var(--c1-card);border:1px solid var(--c5);
  border-radius:999px;font-size:0.78rem;color:var(--c10-dim);
}
.bian-related-articles{margin-top:32px}
.bian-related-articles h3{font-size:1.1rem;margin-bottom:16px}
.bian-related-articles ul{list-style:none}
.bian-related-articles ul li{margin-bottom:10px}
.bian-related-articles ul li a{font-size:0.95rem}

/* === PAGINATION === */
.bian-pagination{
  display:flex;justify-content:center;gap:8px;margin-top:32px
}
.bian-pagination a,.bian-pagination span{
  display:inline-flex;align-items:center;justify-content:center;
  min-width:40px;height:40px;padding:0 12px;
  border:1px solid var(--c5);border-radius:var(--c13-sm);
  font-size:0.9rem;color:var(--c10-dim);transition:all .2s;
}
.bian-pagination a:hover{border-color:var(--c7);color:var(--c7)}
.bian-pagination .bian-current{background:var(--c7);color:#ffffff;border-color:var(--c7);font-weight:700}
.bian-pagination .bian-disabled{opacity:0.3;pointer-events:none}

/* === 404 === */
.bian-error-page{text-align:center;padding:100px 0}
.bian-error-page h1{font-size:6rem;color:var(--c7);line-height:1}
.bian-error-page p{color:var(--c10-dim);font-size:1.1rem;margin:16px 0 32px}
.bian-error-links{display:flex;justify-content:center;gap:16px;flex-wrap:wrap}

/* === SCROLL REVEAL === */
.bian-reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.bian-reveal.bian-visible{opacity:1;transform:translateY(0)}

/* === RISK WARNING === */
.bian-risk-warning{
  background:rgba(22,24,29,0.03);border:1px solid rgba(22,24,29,0.12);
  border-radius:var(--c13-sm);padding:16px 20px;
  font-size:0.85rem;color:var(--c10-dim);line-height:1.6;margin-top:32px;
}
.bian-risk-warning strong{color:var(--c7)}

/* === SECTION DIVIDER (subtle) === */
.bian-section-divider{height:1px;background:var(--c5);max-width:var(--c16);margin:0 auto}

/* === RESPONSIVE === */
@media (max-width:768px){
  .bian-nav-links{display:none}
  .bian-nav-links.bian-open{
    display:flex;flex-direction:column;
    position:absolute;top:var(--c17);left:0;right:0;
    background:rgba(255,255,255,0.98);backdrop-filter:blur(16px);
    padding:24px;gap:20px;border-bottom:1px solid var(--c5);
  }
  .bian-nav-toggle{display:block}
  .bian-hero .bian-container{grid-template-columns:1fr;gap:40px}
  .bian-hero-visual{}
  .bian-footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .bian-article-list-item{grid-template-columns:1fr}
}
@media (max-width:480px){
  .bian-hero{padding:48px 0 56px}
  .bian-hero-ctas{flex-direction:column}
  .bian-section{padding:56px 0}
  .bian-stats-grid{grid-template-columns:1fr 1fr}
  .bian-footer-grid{grid-template-columns:1fr}
  .bian-pagination a,.bian-pagination span{min-width:36px;height:36px;font-size:0.8rem}
  .bian-news-grid{grid-template-columns:1fr}
  .bian-guide-grid{grid-template-columns:1fr}
}

/* === NAV LOGO IMG === */
.bian-nav-logo img{display:block;height:36px;width:auto}
.bian-footer-brand .bian-nav-logo img{height:32px}

/* === REDUCED MOTION === */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  .bian-reveal{opacity:1;transform:none;transition:none}
  .bian-btn-primary,.bian-btn-outline,.bian-nav-cta,.bian-news-card,.bian-guide-card,.bian-bento-card,.bian-feature-card{transition:none}
  .bian-btn-primary:hover,.bian-btn-outline:hover,.bian-nav-cta:hover,.bian-news-card:hover,.bian-guide-card:hover,.bian-bento-card:hover,.bian-feature-card:hover{transform:none;box-shadow:none}
}

/* === RANKING HERO (bian-coin variant) === */
.rank-hero{padding:56px 0 0}
.rank-hero .bian-container{display:grid;grid-template-columns:0.9fr 1.1fr;gap:56px;align-items:center}
.rank-hero .bian-hero-content{text-align:left}
.rank-hero .bian-hero-sub{margin:0 0 32px}
.rank-hero .bian-hero-ctas{justify-content:flex-start}
.rank-board{border:1px solid #e2e2df;background:#ffffff}
.rank-card{
  display:flex;align-items:center;gap:18px;padding:18px 22px;
  border-bottom:1px solid #e2e2df;transition:background .15s;
}
.rank-card:last-child{border-bottom:none}
.rank-card:hover{background:#f6f6f4}
.rank-num{
  font-size:2.6rem;font-weight:800;color:#16181d;min-width:64px;line-height:1;
  font-family:'Helvetica Neue',Arial,sans-serif;
}
.rank-num.first{color:#111318}
.rank-info{flex:1;min-width:0}
.rank-name{font-weight:800;font-size:0.98rem;color:#111318;margin-bottom:6px}
.rank-meta{display:flex;gap:14px;flex-wrap:wrap}
.rank-meta span{font-size:0.72rem;color:#8a9099}
.rank-meta b{color:#1a1d23;font-weight:700}
.rank-badge{
  flex-shrink:0;padding:4px 12px;border:1px solid #16181d;border-radius:2px;
  font-size:0.72rem;font-weight:800;color:#16181d;letter-spacing:0.05em;
}
/* === EXCHANGE TABLE === */
.ex-table{width:100%;border-collapse:collapse;background:#ffffff;border:1px solid #e2e2df}
.ex-table th{text-align:left;padding:13px 16px;background:#f6f6f4;border-bottom:1px solid #e2e2df;font-size:0.76rem;font-weight:800;color:#555b64;letter-spacing:0.06em;text-transform:uppercase}
.ex-table td{padding:14px 16px;border-bottom:1px solid #ececea;font-size:0.88rem;color:#1a1d23}
.ex-table tr:last-child td{border-bottom:none}
.ex-table .hl{font-weight:800;color:#111318}
/* === RESPONSIVE === */
@media (max-width:768px){
  .rank-hero .bian-container{grid-template-columns:1fr;gap:32px}
  .ex-table th:nth-child(4),.ex-table td:nth-child(4){display:none}
  .rank-card{flex-wrap:wrap;gap:8px 14px}
}