/* === xc-bf.com — Core Stylesheet === */
/* Design: dark-tech + amber accent, VARIANCE 9 / MOTION 6 / DENSITY 3 */

/* === 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:#d4d4dc;
  background:#0a0a0f;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}

/* === CSS VARIABLES === */
:root{
  --bg:#0a0a0f;
  --bg2:#0f0f17;
  --bg3:#14141f;
  --bg-card:rgba(255,255,255,0.025);
  --border:rgba(255,255,255,0.06);
  --border-strong:rgba(255,255,255,0.1);
  --accent:#f0b90b;
  --accent-glow:rgba(240,185,11,0.15);
  --accent-dim:rgba(240,185,11,0.08);
  --text:#e0e0e0;
  --text-dim:#888899;
  --text-muted:#5a5a6e;
  --radius:12px;
  --radius-sm:8px;
  --max-w:1100px;
  --header-h:64px;
}

/* === TYPOGRAPHY === */
h1,h2,h3,h4{color:#f0f0f0;line-height:1.2;font-weight:700}
h1{font-size:clamp(2rem,4.5vw,3.25rem);letter-spacing:-0.03em}
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(--accent);text-decoration:none;transition:color .2s}
a:hover{color:#f7d44a}

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

/* === NAVIGATION === */
.site-nav{
  position:sticky;top:0;z-index:100;
  background:rgba(10,10,15,0.92);backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);height:var(--header-h);
}
.site-nav .container{
  display:flex;align-items:center;justify-content:space-between;
  height:100%;
}
.nav-logo{
  font-size:1.25rem;font-weight:800;letter-spacing:-0.02em;
  color:#f0f0f0;white-space:nowrap;
}
.nav-logo span{color:var(--accent)}
.nav-links{display:flex;align-items:center;gap:32px;list-style:none}
.nav-links a{
  color:var(--text-dim);font-size:0.9rem;font-weight:500;
  transition:color .2s;white-space:nowrap;
}
.nav-links a:hover,.nav-links a.active{color:#f0f0f0}
.nav-cta{
  display:inline-flex;align-items:center;gap:6px;
  background:var(--accent);color:#0a0a0f!important;
  padding:8px 18px;border-radius:999px;
  font-weight:700;font-size:0.85rem;
  transition:transform .15s,box-shadow .15s;
}
.nav-cta:hover{transform:translateY(-1px);box-shadow:0 4px 20px var(--accent-glow)}

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

/* === HERO === */
.hero{
  padding:80px 0 80px;
  background:radial-gradient(ellipse 70% 60% at 50% 0%,rgba(240,185,11,0.06),transparent 60%);
}
.hero .container{
  display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;
}
.hero-eyebrow{
  font-size:0.75rem;text-transform:uppercase;letter-spacing:0.2em;
  color:var(--accent);margin-bottom:16px;font-weight:600;
}
.hero-title{font-size:clamp(2.25rem,5.5vw,3.75rem);margin-bottom:20px}
.hero-title span{color:var(--accent)}
.hero-sub{
  font-size:1.05rem;color:var(--text-dim);max-width:48ch;
  line-height:1.6;margin-bottom:32px;
}
.hero-ctas{display:flex;gap:14px;flex-wrap:wrap}
.btn-primary{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--accent);color:#0a0a0f;
  padding:13px 28px;border-radius:999px;
  font-weight:700;font-size:0.95rem;
  transition:transform .15s,box-shadow .15s;
  white-space:nowrap;
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 30px var(--accent-glow);color:#0a0a0f}
.btn-outline{
  display:inline-flex;align-items:center;gap:8px;
  background:transparent;color:#f0f0f0;
  padding:13px 28px;border-radius:999px;
  font-weight:600;font-size:0.95rem;
  border:1px solid var(--border-strong);
  transition:border-color .2s,background .2s;
  white-space:nowrap;
}
.btn-outline:hover{border-color:var(--accent);background:var(--accent-dim);color:#f0f0f0}
.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)}
.hero-visual-placeholder{
  width:100%;height:100%;display:flex;align-items:center;justify-content:center;
  color:var(--text-muted);font-size:0.85rem;
}
.hero-visual img{width:100%;height:100%;object-fit:cover}

/* === SECTIONS === */
.section{padding:80px 0}
.section-alt{background:var(--bg2)}
.section-header{margin-bottom:48px}
.section-header.centered{text-align:center}
.section-eyebrow{
  font-size:0.7rem;text-transform:uppercase;letter-spacing:0.22em;
  color:var(--accent);margin-bottom:12px;font-weight:600;
}
.section-title{font-size:clamp(1.5rem,3vw,2.25rem);margin-bottom:12px}
.section-desc{color:var(--text-dim);max-width:60ch;font-size:0.95rem;line-height:1.6}

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

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

/* === NEWS (2-col large cards) === */
.news-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(320px,1fr));
  gap:24px;
}
.news-card{
  background:var(--bg-card);border:1px solid var(--border);
  border-radius:var(--radius);overflow:hidden;
  transition:border-color .25s,transform .25s;
  display:flex;flex-direction:column;
}
.news-card:hover{border-color:var(--border-strong);transform:translateY(-2px)}
.news-card-img{
  width:100%;height:200px;
  background:linear-gradient(135deg,var(--bg3),var(--bg2));
  display:flex;align-items:center;justify-content:center;
  color:var(--text-muted);font-size:0.8rem;
;overflow:hidden}
.news-card-img img{width:100%;height:100%;object-fit:cover}
.news-card-body{padding:20px 24px 24px;flex:1;display:flex;flex-direction:column}
.news-card-body h3{font-size:1.05rem;margin-bottom:8px}
.news-card-body h3 a{color:#f0f0f0}
.news-card-body h3 a:hover{color:var(--accent)}
.news-card-desc{font-size:0.9rem;color:var(--text-dim);line-height:1.6;margin-bottom:12px;flex:1}
.news-card-date{font-size:0.78rem;color:var(--text-muted)}

/* === GUIDE (3-col cards) === */
.guide-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
  gap:24px;
}
.guide-card{
  background:var(--bg-card);border:1px solid var(--border);
  border-radius:var(--radius);overflow:hidden;
  transition:border-color .25s,transform .25s;
}
.guide-card:hover{border-color:var(--border-strong);transform:translateY(-2px)}
.guide-card-img{
  width:100%;height:180px;
  background:linear-gradient(135deg,var(--bg3),var(--bg2));
  display:flex;align-items:center;justify-content:center;
  color:var(--text-muted);font-size:0.8rem;
;overflow:hidden}
.guide-card-img img{width:100%;height:100%;object-fit:cover}
.guide-card-body{padding:18px 20px 20px}
.guide-card-body h3{font-size:1rem;margin-bottom:6px}
.guide-card-body h3 a{color:#f0f0f0}
.guide-card-body h3 a:hover{color:var(--accent)}
.guide-card-body p{font-size:0.85rem;color:var(--text-dim);line-height:1.5;margin:0}

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

/* === FOOTER === */
.site-footer{
  background:var(--bg2);border-top:1px solid var(--border);
  padding:56px 0 32px;
}
.footer-grid{
  display:grid;
  grid-template-columns:2fr 1fr 1fr 1fr;
  gap:40px;margin-bottom:40px;
}
.footer-brand p{color:var(--text-dim);font-size:0.9rem;line-height:1.7;margin-top:12px;max-width:36ch}
.footer-col h4{font-size:0.85rem;text-transform:uppercase;letter-spacing:0.08em;margin-bottom:16px;color:var(--text)}
.footer-col ul{list-style:none}
.footer-col ul li{margin-bottom:10px}
.footer-col ul li a{color:var(--text-dim);font-size:0.9rem;transition:color .2s}
.footer-col ul li a:hover{color:#f0f0f0}
.footer-bottom{
  border-top:1px solid var(--border);padding-top:24px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;
  font-size:0.8rem;color:var(--text-muted);
}
.footer-bottom a{color:var(--text-dim)}

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

/* === ARTICLE LIST (栏目页) === */
.article-list{display:flex;flex-direction:column;gap:0}
.article-list-item{
  display:grid;grid-template-columns:1fr auto;
  gap:20px;padding:22px 0;border-bottom:1px solid var(--border);
  align-items:start;
}
.article-list-item:last-child{border-bottom:none}
.article-list-item h3{font-size:1.1rem;margin-bottom:6px}
.article-list-item h3 a{color:#f0f0f0}
.article-list-item h3 a:hover{color:var(--accent)}
.article-list-desc{font-size:0.9rem;color:var(--text-dim);line-height:1.6;margin-bottom:8px;max-width:80ch}
.article-list-date{font-size:0.78rem;color:var(--text-muted);white-space:nowrap}

/* === ARTICLE DETAIL === */
.article-detail{max-width:780px;margin:0 auto}
.article-header{margin-bottom:40px;padding-bottom:32px;border-bottom:1px solid var(--border)}
.article-header h1{font-size:clamp(1.75rem,4vw,2.5rem);margin-bottom:16px}
.article-meta{
  display:flex;gap:20px;flex-wrap:wrap;font-size:0.85rem;color:var(--text-muted)
}
.article-body{line-height:1.9}
.article-body h2{
  font-size:1.35rem;margin:40px 0 16px;padding-bottom:8px;
  border-bottom:1px solid var(--border)
}
.article-body h3{font-size:1.1rem;margin:28px 0 12px}
.article-body p{margin-bottom:20px;color:#c8c8d4}
.article-body ul,.article-body ol{margin-bottom:20px;padding-left:24px}
.article-body li{margin-bottom:8px;color:#c8c8d4}
.article-body img{max-width:100%;height:auto;border-radius:var(--radius-sm);margin:24px 0}
.article-body blockquote{
  border-left:3px solid var(--accent);padding:12px 20px;
  margin:24px 0;background:var(--accent-dim);border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  font-style:italic;color:var(--text-dim);
}
.article-footer{
  margin-top:48px;padding-top:24px;border-top:1px solid var(--border);
}
.article-tags{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px}
.article-tag{
  display:inline-block;padding:4px 12px;
  background:var(--bg-card);border:1px solid var(--border);
  border-radius:999px;font-size:0.78rem;color:var(--text-dim);
}
.related-articles{margin-top:32px}
.related-articles h3{font-size:1.1rem;margin-bottom:16px}
.related-articles ul{list-style:none}
.related-articles ul li{margin-bottom:10px}
.related-articles ul li a{font-size:0.95rem}

/* === PAGINATION === */
.pagination{
  display:flex;justify-content:center;gap:8px;margin-top:32px
}
.pagination a,.pagination span{
  display:inline-flex;align-items:center;justify-content:center;
  min-width:40px;height:40px;padding:0 12px;
  border:1px solid var(--border);border-radius:var(--radius-sm);
  font-size:0.9rem;color:var(--text-dim);transition:all .2s;
}
.pagination a:hover{border-color:var(--accent);color:var(--accent)}
.pagination .current{background:var(--accent);color:#0a0a0f;border-color:var(--accent);font-weight:700}
.pagination .disabled{opacity:0.3;pointer-events:none}

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

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

/* === RISK WARNING === */
.risk-warning{
  background:rgba(240,185,11,0.04);border:1px solid rgba(240,185,11,0.12);
  border-radius:var(--radius-sm);padding:16px 20px;
  font-size:0.85rem;color:var(--text-dim);line-height:1.6;margin-top:32px;
}
.risk-warning strong{color:var(--accent)}

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

/* === RESPONSIVE === */
@media (max-width:768px){
  .nav-links{display:none}
  .nav-links.open{
    display:flex;flex-direction:column;
    position:absolute;top:var(--header-h);left:0;right:0;
    background:rgba(10,10,15,0.98);backdrop-filter:blur(16px);
    padding:24px;gap:20px;border-bottom:1px solid var(--border);
  }
  .nav-toggle{display:block}
  .hero .container{grid-template-columns:1fr;gap:40px}
  .hero-visual{}
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .article-list-item{grid-template-columns:1fr}
}
@media (max-width:480px){
  .hero{padding:48px 0 56px}
  .hero-ctas{flex-direction:column}
  .section{padding:56px 0}
  .stats-grid{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr}
  .pagination a,.pagination span{min-width:36px;height:36px;font-size:0.8rem}
  .news-grid{grid-template-columns:1fr}
  .guide-grid{grid-template-columns:1fr}
}

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