/* 51Facebook 首页专属样式（mobile-first） */
:root{
  --fb:#1877F2; --fb-dark:#0f63d6; --ink:#1c2b33; --muted:#5f6b76;
  --bg-soft:#f0f2f5; --card:#ffffff; --line:#e3e7ec; --radius:12px;
}
.fb51{font-size:16px;line-height:1.75;color:var(--ink);overflow-wrap:anywhere}
.fb51 h1,.fb51 h2,.fb51 h3{line-height:1.35;color:var(--ink);margin:0 0 .6em}
.fb51 p{margin:0 0 1em}
.fb51 a{color:var(--fb)}
.fb51 img{max-width:100%;height:auto}

/* ===== Hero ===== */
.fb51-hero{background:#e9f1fd;border:1px solid #d7e6fb;border-radius:16px;padding:28px 22px;margin:0 0 26px}
.fb51-kicker{display:inline-block;font-size:13px;font-weight:600;color:var(--fb);background:#fff;border:1px solid #cfe0f8;border-radius:999px;padding:6px 14px;margin-bottom:14px}
.fb51-hero h1{font-size:clamp(1.55rem,6vw,2.4rem);font-weight:700;margin-bottom:12px}
.fb51-sub{font-size:1.02rem;color:#33424d;max-width:34em;margin-bottom:20px}
.fb51-btns{display:flex;flex-direction:column;gap:12px;margin-bottom:18px}
.fb51-btn{display:flex;align-items:center;justify-content:center;min-height:52px;padding:0 24px;border-radius:10px;font-size:1.02rem;font-weight:700;text-decoration:none!important}
.fb51-btn.primary{background:var(--fb);color:#fff!important}
.fb51-btn.primary:hover{background:var(--fb-dark)}
.fb51-btn.ghost{background:#fff;color:var(--fb)!important;border:1.5px solid var(--fb)}
.fb51-btn.ghost:hover{background:#e9f1fd}
.fb51-trust{display:flex;flex-wrap:wrap;gap:8px 18px;font-size:.88rem;color:var(--muted)}
.fb51-trust span{display:inline-flex;align-items:center;gap:6px}
.fb51-trust svg{flex:0 0 auto;color:var(--fb)}

/* ===== 快捷标签条（仅手机） ===== */
.fb51-strip{display:flex;gap:10px;overflow-x:auto;padding:4px 2px 14px;margin:0 0 8px;-webkit-overflow-scrolling:touch;scrollbar-width:none}
.fb51-strip::-webkit-scrollbar{display:none}
.fb51-strip a{flex:0 0 auto;display:inline-flex;align-items:center;min-height:44px;padding:0 16px;background:#fff;border:1px solid var(--line);border-radius:999px;font-size:.92rem;font-weight:600;color:var(--ink);text-decoration:none!important;white-space:nowrap}
.fb51-strip a:active{background:#e9f1fd}

/* ===== 通用区块 ===== */
.fb51-sec{margin:34px 0}
.fb51-h2{font-size:clamp(1.25rem,4.6vw,1.6rem);font-weight:700;padding-bottom:10px;border-bottom:2px solid var(--fb);margin-bottom:18px}
.fb51-lead{color:var(--muted);margin:-6px 0 18px}

/* ===== 五大入口卡片 ===== */
.fb51-cards{display:grid;grid-template-columns:1fr;gap:14px}
.fb51-card{display:flex;flex-direction:column;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:0 1px 3px rgba(16,42,67,.06);transition:transform .18s ease,box-shadow .18s ease}
.fb51-card:hover{transform:translateY(-3px);box-shadow:0 8px 22px rgba(16,42,67,.10)}
.fb51-ico{width:48px;height:48px;border-radius:14px;background:#e9f1fd;display:flex;align-items:center;justify-content:center;margin-bottom:12px;color:var(--fb)}
.fb51-card h3{font-size:1.12rem;font-weight:700;margin-bottom:6px}
.fb51-card p{font-size:.94rem;color:var(--muted);margin-bottom:12px;flex:1}
.fb51-card .go{display:inline-flex;align-items:center;min-height:44px;font-weight:700;font-size:.96rem}

/* ===== 热门问题 ===== */
.fb51-qlist{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:1fr;gap:10px}
.fb51-qlist li{background:#fff;border:1px solid var(--line);border-radius:10px}
.fb51-qlist a{display:flex;align-items:center;justify-content:space-between;gap:10px;min-height:52px;padding:10px 16px;font-size:.97rem;color:var(--ink);text-decoration:none!important}
.fb51-qlist a:hover{color:var(--fb)}
.fb51-qlist .arr{color:var(--fb);flex:0 0 auto}

/* ===== 最新教程 ===== */
.fb51-latest{display:grid;grid-template-columns:1fr;gap:14px}
.fb51-post{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column}
.fb51-post .thumb{display:block;aspect-ratio:16/10;overflow:hidden;background:var(--bg-soft)}
.fb51-post .thumb img{width:100%;height:100%;object-fit:cover;display:block}
.fb51-post .bd{padding:16px 18px 18px;display:flex;flex-direction:column;flex:1}
.fb51-post h3{font-size:1.05rem;font-weight:700;margin-bottom:8px}
.fb51-post h3 a{color:var(--ink);text-decoration:none!important}
.fb51-post h3 a:hover{color:var(--fb)}
.fb51-post p{font-size:.92rem;color:var(--muted);margin-bottom:0;flex:1}
.fb51-more{display:block;text-align:center;margin-top:18px}
.fb51-more a{display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:0 28px;border:1.5px solid var(--fb);border-radius:10px;font-weight:700;text-decoration:none!important}

/* ===== 为什么可信 ===== */
.fb51-why{display:grid;grid-template-columns:1fr;gap:14px}
.fb51-why .item{background:var(--bg-soft);border-radius:var(--radius);padding:18px}
.fb51-why .item h3{font-size:1.02rem;display:flex;align-items:center;gap:8px;margin-bottom:6px;color:var(--fb)}
.fb51-why .item p{font-size:.93rem;color:#33424d;margin:0}

/* ===== FAQ ===== */
.fb51-faq details{background:#fff;border:1px solid var(--line);border-radius:10px;margin-bottom:10px}
.fb51-faq summary{list-style:none;display:flex;align-items:center;justify-content:space-between;gap:10px;min-height:56px;padding:12px 16px;font-weight:700;font-size:.98rem;cursor:pointer}
.fb51-faq summary::-webkit-details-marker{display:none}
.fb51-faq summary .pm{flex:0 0 auto;color:var(--fb);font-size:1.2rem;font-weight:400}
.fb51-faq .ans{padding:0 16px 16px;font-size:.95rem;color:#33424d}

/* ===== CTA + 声明 ===== */
.fb51-cta{background:#e9f1fd;border:1px solid #d7e6fb;border-radius:16px;padding:28px 22px;text-align:center;margin:36px 0 18px}
.fb51-cta h2{font-size:clamp(1.25rem,4.6vw,1.6rem);margin-bottom:8px}
.fb51-cta p{color:#33424d;margin-bottom:18px}
.fb51-cta .fb51-btn{max-width:340px;margin:0 auto}
.fb51-note{font-size:.82rem;color:#8a94a0;text-align:center;line-height:1.7}

/* ===== 底部快捷栏（仅手机） ===== */
.fb51-bar{display:none}
@media (max-width:767px){
  body.fb51-hasbar{padding-bottom:78px}
  .fb51-bar{display:flex;position:fixed;left:0;right:0;bottom:0;z-index:999;background:#fff;border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom)}
  .fb51-bar a{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;min-height:64px;font-size:.72rem;color:var(--muted);text-decoration:none!important}
  .fb51-bar a.on{color:var(--fb);font-weight:700}
  .fb51-bar svg{width:22px;height:22px}
  .fb51-bar a{display:flex}
}

/* ===== 桌面增强 ===== */
@media (min-width:768px){
  .fb51-strip{display:none}
  .fb51-hero{padding:44px 48px}
  .fb51-btns{flex-direction:row}
  .fb51-btn{width:auto}
  .fb51-cards{grid-template-columns:repeat(3,1fr)}
  .fb51-qlist{grid-template-columns:1fr 1fr}
  .fb51-latest{grid-template-columns:repeat(3,1fr)}
  .fb51-why{grid-template-columns:repeat(3,1fr)}
}

/* ===== Logo / 导航手机端触控 ===== */
.site-logo img,.custom-logo-link img{max-height:44px;width:auto}
@media (max-width:767px){
  .site-logo img,.custom-logo-link img{max-height:36px}
  .main-navigation .main-nav ul li a,.menu-toggle{min-height:44px}
  .menu-toggle{font-size:1rem}
}