/* meifanr.com - 比特币安全 - 美繁 */
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Source Han Sans SC','Noto Sans SC',sans-serif;background:#F0F9FA;color:#263238;line-height:1.8;font-size:16px}
a{color:#0097A7;text-decoration:none;transition:color .2s}
a:hover{color:#00695C}
img{max-width:100%;height:auto}

.s7f2a-wrap{max-width:1200px;margin:0 auto;padding:0 20px}
.s7f2a-hdr{background:#004D40;color:#fff;padding:16px 0;position:sticky;top:0;z-index:100;box-shadow:0 2px 8px rgba(0,0,0,.15)}
.s7f2a-hdr-inner{display:flex;align-items:center;justify-content:space-between;max-width:1200px;margin:0 auto;padding:0 20px}
.s7f2a-logo{font-size:22px;font-weight:700;color:#fff}
.s7f2a-logo span{color:#26C6DA}
.s7f2a-nav{display:flex;gap:24px;list-style:none}
.s7f2a-nav a{color:rgba(255,255,255,.85);font-size:14px}
.s7f2a-nav a:hover,.s7f2a-nav a.active{color:#fff}
.s7f2a-mob-toggle{display:none;background:none;border:none;color:#fff;font-size:24px;cursor:pointer}

.s7f2a-hero{background:linear-gradient(135deg,#0097A7,#26C6DA);color:#fff;padding:60px 0;text-align:center}
.s7f2a-hero h1{font-size:clamp(24px,4vw,42px);margin-bottom:16px;font-weight:700}
.s7f2a-hero p{font-size:18px;opacity:.9;max-width:600px;margin:0 auto}

.s7f2a-bread{padding:12px 0;font-size:13px;color:#888}
.s7f2a-bread a{color:#888}
.s7f2a-bread a:hover{color:#0097A7}

.s7f2a-main{padding:40px 0}

.s7f2a-content{display:grid;grid-template-columns:240px 1fr;gap:32px}
.s7f2a-sidenav{background:#FFF;border-radius:12px;padding:20px;box-shadow:0 2px 12px rgba(0,0,0,0.08);position:sticky;top:80px;height:fit-content}
.s7f2a-sidenav ul{list-style:none}
.s7f2a-sidenav li{margin-bottom:8px}
.s7f2a-sidenav a{display:block;padding:8px 12px;border-radius:6px;font-size:14px;color:#263238}
.s7f2a-sidenav a:hover,.s7f2a-sidenav a.active{background:#E0F7FA;color:#0097A7}
.s7f2a-article{background:#FFF;border-radius:12px;padding:32px;box-shadow:0 2px 12px rgba(0,0,0,0.08)}
@media(max-width:768px){.s7f2a-content{grid-template-columns:1fr}.s7f2a-sidenav{display:none}}

.s7f2a-article h1{font-size:28px;margin-bottom:16px;border-left:none;padding-left:0;color:#004D40}
.s7f2a-article h2{font-size:22px;margin:28px 0 14px;color:#0097A7;padding-left:12px;border-left:4px solid #0097A7}
.s7f2a-article h3{font-size:18px;margin:20px 0 10px;color:#263238}
.s7f2a-article p{margin-bottom:16px}
.s7f2a-article ul,.s7f2a-article ol{margin:0 0 16px 20px}
.s7f2a-article li{margin-bottom:6px}
.s7f2a-article blockquote{border-left:4px solid #0097A7;padding:12px 20px;margin:16px 0;background:#E0F7FA;border-radius:0 8px 8px 0}
.s7f2a-article strong{color:#00695C}

.s7f2a-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin:32px 0}
.s7f2a-card{background:#FFF;border:1px solid #E0E0E0;border-radius:12px;padding:24px;transition:transform .2s,box-shadow .2s}
.s7f2a-card:hover{transform:translateY(-4px);box-shadow:0 2px 12px rgba(0,0,0,0.08)}
.s7f2a-card h3{font-size:18px;margin-bottom:8px;color:#0097A7}
.s7f2a-card p{font-size:14px;color:#666;margin-bottom:12px}
.s7f2a-card .s7f2a-btn{display:inline-block;padding:8px 20px;background:linear-gradient(135deg,#0097A7,#26C6DA);color:#fff;border-radius:6px;font-size:14px;font-weight:500}
.s7f2a-card .s7f2a-btn:hover{opacity:.9;color:#fff}

.s7f2a-articles-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:24px;margin:32px 0}
.s7f2a-acard{background:#FFF;border-radius:12px;padding:24px;box-shadow:0 2px 12px rgba(0,0,0,0.08);transition:transform .2s}
.s7f2a-acard:hover{transform:translateY(-3px)}
.s7f2a-acard h3{font-size:17px;margin-bottom:8px}
.s7f2a-acard h3 a{color:#263238}
.s7f2a-acard h3 a:hover{color:#0097A7}
.s7f2a-acard p{font-size:14px;color:#777}
.s7f2a-acard .s7f2a-meta{font-size:12px;color:#999;margin-top:8px}

.s7f2a-ftr{background:#004D40;color:rgba(255,255,255,.7);padding:32px 0;margin-top:60px;text-align:center;font-size:13px}
.s7f2a-ftr a{color:rgba(255,255,255,.8)}
.s7f2a-ftr-links{display:flex;justify-content:center;gap:20px;margin-bottom:12px;flex-wrap:wrap}

.s7f2a-warning{background:#FFF3E0;border:1px solid #FFB74D;border-radius:8px;padding:16px;margin:16px 0}
.s7f2a-warning strong{color:#E65100}
.s7f2a-tip{background:#E0F7FA;border:1px solid #80DEEA;border-radius:8px;padding:16px;margin:16px 0}
.s7f2a-tip strong{color:#006064}

@media(max-width:768px){
  .s7f2a-hero{padding:40px 0}
  .s7f2a-hero h1{font-size:24px}
  .s7f2a-article{padding:20px}
  .s7f2a-nav{display:none;position:absolute;top:100%;left:0;right:0;background:#004D40;flex-direction:column;padding:16px}
  .s7f2a-nav.open{display:flex}
  .s7f2a-mob-toggle{display:block}
  .s7f2a-cards{grid-template-columns:1fr}
  .s7f2a-articles-grid{grid-template-columns:1fr}
}