*{margin:0;padding:0;box-sizing:border-box;}
body{font-family:-apple-system,"PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;background:#f8fafc;color:#1f2937;font-size:14px;line-height:1.6;}
a{text-decoration:none;color:#1f2937;}
a:hover{color:#0d9488;}
img{max-width:100%;vertical-align:top;}

.bb-head{background:#fff;border-bottom:1px solid #e5e7eb;position:sticky;top:0;z-index:50;}
.bb-head-inner{max-width:1200px;margin:0 auto;padding:14px 24px;display:flex;justify-content:space-between;align-items:center;gap:24px;}
.bb-logo{display:flex;align-items:center;gap:12px;}
.bb-logo-mark{width:44px;height:44px;background:linear-gradient(135deg,#0d9488,#14b8a6);border-radius:12px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:18px;letter-spacing:-1px;box-shadow:0 4px 12px rgba(13,148,136,.3);}
.bb-logo-name strong{display:block;font-size:20px;font-weight:700;color:#0f172a;letter-spacing:.5px;}
.bb-logo-name em{display:block;font-size:12px;color:#64748b;font-style:normal;margin-top:2px;}
.bb-search{display:flex;flex:1;max-width:480px;height:42px;background:#f1f5f9;border-radius:10px;overflow:hidden;border:1.5px solid transparent;transition:all .2s;}
.bb-search:focus-within{background:#fff;border-color:#0d9488;box-shadow:0 0 0 3px rgba(13,148,136,.15);}
.bb-search input{flex:1;border:none;background:transparent;padding:0 16px;font-size:14px;outline:none;color:#1f2937;}
.bb-search input::placeholder{color:#94a3b8;}
.bb-search button{padding:0 24px;background:#0d9488;color:#fff;font-size:14px;font-weight:600;border:none;cursor:pointer;display:flex;align-items:center;gap:6px;transition:background .2s;}
.bb-search button:hover{background:#0f766e;}
.bb-date{display:flex;align-items:center;gap:6px;font-size:13px;color:#475569;font-variant-numeric:tabular-nums;}
.bb-date-mono{background:#f1f5f9;padding:6px 12px;border-radius:8px;font-feature-settings:"tnum";font-weight:500;}

.bb-nav{background:#fff;border-bottom:1px solid #e5e7eb;}
.bb-nav-inner{max-width:1200px;margin:0 auto;padding:0 24px;display:flex;align-items:center;gap:4px;height:48px;overflow-x:auto;}
.bb-nav-inner::-webkit-scrollbar{height:0;}
.bb-nav-inner a{font-size:14px;color:#475569;padding:8px 16px;border-radius:8px;white-space:nowrap;transition:all .2s;}
.bb-nav-inner a:hover{color:#0d9488;background:#f0fdfa;}
.bb-nav-inner a.active{color:#fff;background:#0d9488;font-weight:600;}

.bb-main{max-width:1200px;margin:0 auto;padding:24px;}

.bb-dl{background:linear-gradient(135deg,#fff7ed 0%,#ffedd5 100%);border:1px solid #fed7aa;border-radius:14px;padding:18px 22px;margin-bottom:20px;display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap;}
.bb-dl-tag{display:inline-flex;align-items:center;gap:6px;background:#f97316;color:#fff;padding:4px 10px;border-radius:6px;font-size:12px;font-weight:700;}
.bb-dl-tag::before{content:"HOT";animation:bb-blink 1.6s infinite;}
@keyframes bb-blink{50%{opacity:.5;}}
.bb-dl-title{font-size:16px;font-weight:700;color:#1f2937;}
.bb-dl-desc{font-size:13px;color:#78716c;margin-top:2px;}
.bb-dl-btn{display:inline-flex;align-items:center;gap:6px;background:linear-gradient(135deg,#f97316,#ea580c);color:#fff;padding:10px 22px;border-radius:10px;font-size:14px;font-weight:700;white-space:nowrap;box-shadow:0 4px 14px rgba(249,115,22,.4);transition:transform .2s;}
.bb-dl-btn:hover{transform:translateY(-2px);color:#fff;}

.bb-search-tip{background:#f0fdfa;border:1px solid #99f6e4;color:#0f766e;padding:12px 20px;border-radius:10px;margin-bottom:20px;font-size:14px;}
.bb-search-tip strong{color:#0d9488;}

.bb-section{background:#fff;border-radius:16px;margin-bottom:20px;padding:24px;box-shadow:0 1px 3px rgba(15,23,42,.06);}
.bb-section-head{display:flex;align-items:baseline;gap:10px;margin-bottom:18px;padding-bottom:14px;border-bottom:2px solid #f1f5f9;position:relative;}
.bb-section-head::before{content:"";position:absolute;left:-24px;top:0;bottom:14px;width:4px;background:linear-gradient(180deg,#0d9488,#14b8a6);border-radius:2px;}
.bb-section-title{font-size:20px;font-weight:700;color:#0f172a;letter-spacing:.5px;}
.bb-section-count{font-size:13px;color:#94a3b8;font-weight:400;}

.bb-tool-list{display:grid;grid-template-columns:repeat(5,1fr);gap:12px;}
.bb-tool-item{display:block;}
.bb-tool-a{display:flex;align-items:center;gap:12px;padding:12px;border-radius:12px;background:#f8fafc;border:1px solid transparent;transition:all .25s;height:100%;}
.bb-tool-a:hover{background:#fff;border-color:#99f6e4;box-shadow:0 8px 20px rgba(13,148,136,.12);transform:translateY(-2px);}
.bb-tool-icon{width:44px;height:44px;border-radius:11px;display:flex;align-items:center;justify-content:center;flex-shrink:0;}
.bb-tool-icon svg{width:24px;height:24px;}
.bb-tool-text{display:flex;flex-direction:column;min-width:0;flex:1;}
.bb-tool-text strong{font-size:14px;font-weight:600;color:#1f2937;height:22px;line-height:22px;overflow:hidden;transition:color .2s;}
.bb-tool-text em{font-size:12px;color:#94a3b8;height:16px;line-height:16px;margin-top:3px;font-style:normal;overflow:hidden;}
.bb-tool-a:hover .bb-tool-text strong{color:#0d9488;}

.ic-teal{background:linear-gradient(135deg,#0d9488,#14b8a6);}
.ic-amber{background:linear-gradient(135deg,#f59e0b,#f97316);}
.ic-violet{background:linear-gradient(135deg,#8b5cf6,#a78bfa);}
.ic-rose{background:linear-gradient(135deg,#f43f5e,#fb7185);}
.ic-sky{background:linear-gradient(135deg,#0284c7,#38bdf8);}
.ic-emerald{background:linear-gradient(135deg,#059669,#34d399);}
.ic-indigo{background:linear-gradient(135deg,#4f46e5,#818cf8);}
.ic-fuchsia{background:linear-gradient(135deg,#c026d3,#e879f9);}
.ic-cyan{background:linear-gradient(135deg,#0891b2,#22d3ee);}
.ic-lime{background:linear-gradient(135deg,#65a30d,#a3e635);}
.ic-orange{background:linear-gradient(135deg,#ea580c,#fb923c);}
.ic-slate{background:linear-gradient(135deg,#475569,#94a3b8);}

.bb-about{background:#fff;border-radius:16px;padding:24px;margin-bottom:20px;box-shadow:0 1px 3px rgba(15,23,42,.06);}
.bb-about-head{font-size:18px;font-weight:700;color:#0f172a;margin-bottom:14px;padding-bottom:12px;border-bottom:2px solid #f1f5f9;}
.bb-about-body p{font-size:14px;color:#475569;line-height:2;margin-bottom:10px;}
.bb-about-body p:last-child{margin-bottom:0;}

.bb-flink{background:#fff;border-radius:16px;padding:18px 24px;margin-bottom:24px;display:flex;align-items:center;flex-wrap:wrap;gap:8px;box-shadow:0 1px 3px rgba(15,23,42,.06);}
.bb-flink-title{font-size:14px;color:#0f172a;font-weight:700;margin-right:8px;}
.bb-flink a{font-size:13px;color:#64748b;padding:4px 12px;background:#f1f5f9;border-radius:6px;transition:all .2s;}
.bb-flink a:hover{background:#0d9488;color:#fff;}

.bb-foot{background:#0f172a;color:#94a3b8;margin-top:24px;}
.bb-foot-inner{max-width:1200px;margin:0 auto;padding:32px 24px;text-align:center;}
.bb-foot-inner p{font-size:13px;margin:6px 0;}
.bb-foot-inner a{color:#cbd5e1;}

.bb-top{position:fixed;bottom:32px;right:32px;width:46px;height:46px;background:#0d9488;color:#fff;border-radius:50%;display:none;align-items:center;justify-content:center;font-size:20px;cursor:pointer;z-index:100;box-shadow:0 6px 20px rgba(13,148,136,.4);transition:all .25s;}
.bb-top:hover{background:#0f766e;transform:translateY(-3px);}
.bb-top.show{display:flex;}

@media (max-width:1100px){
.bb-tool-list{grid-template-columns:repeat(4,1fr);}
}
@media (max-width:900px){
.bb-tool-list{grid-template-columns:repeat(3,1fr);}
.bb-logo-name strong{font-size:18px;}
}
@media (max-width:768px){
.bb-head-inner{flex-direction:column;gap:12px;padding:12px 16px;}
.bb-logo{width:100%;justify-content:flex-start;}
.bb-search{width:100%;max-width:none;}
.bb-date{width:100%;justify-content:flex-end;}
.bb-date-mono{font-size:12px;padding:5px 10px;}
.bb-nav-inner{padding:0 16px;height:auto;flex-wrap:wrap;}
.bb-nav-inner a{font-size:13px;padding:6px 12px;}
.bb-main{padding:16px;}
.bb-section{padding:18px;border-radius:12px;}
.bb-section-head{margin-bottom:14px;padding-bottom:10px;}
.bb-section-title{font-size:17px;}
.bb-section-head::before{left:-18px;}
.bb-tool-list{grid-template-columns:repeat(2,1fr);gap:10px;}
.bb-tool-a{padding:10px;gap:10px;}
.bb-tool-icon{width:38px;height:38px;border-radius:9px;}
.bb-tool-icon svg{width:20px;height:20px;}
.bb-tool-text strong{font-size:13px;}
.bb-tool-text em{font-size:11px;}
.bb-dl{padding:14px 16px;flex-direction:column;align-items:stretch;}
.bb-dl-btn{text-align:center;justify-content:center;}
.bb-about{padding:18px;border-radius:12px;}
.bb-about-body p{font-size:13px;line-height:1.9;}
.bb-flink{padding:14px 16px;border-radius:12px;}
.bb-flink a{font-size:12px;padding:3px 10px;}
.bb-foot-inner{padding:24px 16px;}
.bb-top{bottom:20px;right:20px;width:40px;height:40px;font-size:18px;}
}
@media (max-width:480px){
.bb-tool-list{grid-template-columns:1fr;}
.bb-logo-name strong{font-size:16px;}
.bb-logo-name em{font-size:11px;}
.bb-nav-inner a{font-size:12px;padding:5px 10px;}
.bb-section-title{font-size:15px;}
.bb-tool-text strong{font-size:13px;}
}