/* ============================================================
   演示总站 · 深色深空科技风样式
   底色 #070a14 / 主色 #38f0ff / 渐变辅色 #9b6bff
   ============================================================ */

:root{
  --bg:#070a14;
  --bg-soft:#0c1120;
  --bg-card:#0e1526;
  --line:rgba(56,240,255,.16);
  --line-soft:rgba(255,255,255,.06);
  --primary:#38f0ff;
  --accent:#9b6bff;
  --text:#e8f0ff;
  --text-dim:#8ea0c0;
  --text-mute:#5d6b88;
  --radius:16px;
  --shadow:0 10px 40px rgba(0,0,0,.45);
}

*{box-sizing:border-box;margin:0;padding:0}

html{scroll-behavior:smooth}

body{
  font-family:"Segoe UI",-apple-system,"Microsoft YaHei","PingFang SC",system-ui,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}

/* 背景层：粒子 canvas + 渐变光晕 */
#bg-canvas{
  position:fixed;inset:0;z-index:0;
  width:100%;height:100%;pointer-events:none;
}
.bg-glow{
  position:fixed;z-index:0;pointer-events:none;filter:blur(90px);opacity:.5;
}
.bg-glow.a{top:-180px;left:-120px;width:480px;height:480px;background:radial-gradient(circle,#38f0ff,transparent 70%);}
.bg-glow.b{bottom:-200px;right:-140px;width:520px;height:520px;background:radial-gradient(circle,#9b6bff,transparent 70%);}

.wrap{position:relative;z-index:2;max-width:1200px;margin:0 auto;padding:0 22px;}

/* ---------- 顶部导航 ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(14px);
  background:rgba(7,10,20,.72);
  border-bottom:1px solid var(--line-soft);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:64px;}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:.5px;}
.brand .dot{width:12px;height:12px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--accent));box-shadow:0 0 14px var(--primary);}
.brand a{color:var(--text);text-decoration:none;font-size:18px;}
.nav-links{display:flex;gap:26px;}
.nav-links a{color:var(--text-dim);text-decoration:none;font-size:14px;transition:color .2s;}
.nav-links a:hover{color:var(--primary);}

/* ---------- Hero 简介 ---------- */
.hero{padding:64px 0 30px;text-align:center;}
.hero h1{
  font-size:40px;line-height:1.25;font-weight:800;letter-spacing:.5px;
  background:linear-gradient(120deg,#fff 10%,var(--primary) 55%,var(--accent) 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero p{margin:18px auto 0;max-width:680px;color:var(--text-dim);font-size:15.5px;}
.hero .stat{display:flex;justify-content:center;gap:34px;margin-top:28px;flex-wrap:wrap;}
.hero .stat div{text-align:center;}
.hero .stat b{display:block;font-size:24px;color:var(--primary);}
.hero .stat span{font-size:12.5px;color:var(--text-mute);}

/* ---------- 工具栏：搜索 + 筛选 ---------- */
.toolbar{padding:22px 0 4px;}
.search{max-width:520px;margin:0 auto 16px;}
.search input{
  width:100%;padding:12px 18px;border-radius:999px;
  background:var(--bg-card);border:1px solid var(--line);
  color:var(--text);font-size:14px;outline:none;transition:.2s;
}
.search input::placeholder{color:var(--text-mute);}
.search input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(56,240,255,.12);}

/* ---------- 分类筛选 ---------- */
.filters{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;padding:8px 0;}
.filter-btn{
  border:1px solid var(--line);background:var(--bg-card);color:var(--text-dim);
  padding:7px 16px;border-radius:999px;font-size:13.5px;cursor:pointer;transition:.2s;
}
.filter-btn:hover{color:var(--text);border-color:var(--primary);}
.filter-btn.active{
  color:#04111a;background:linear-gradient(135deg,var(--primary),var(--accent));
  border-color:transparent;font-weight:600;
}
/* 技术栈二级筛选：用辅色区分 */
.stacks .filter-btn.active{
  color:#fff;background:linear-gradient(135deg,var(--accent),#6b8bff);
}
.stacks .filter-label{
  width:100%;text-align:center;font-size:12px;color:var(--text-mute);
  letter-spacing:1px;margin-top:6px;
}

/* ---------- 卡片列表 ---------- */
.grid{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:22px;padding:26px 0 60px;
}
.card{
  background:var(--bg-card);border:1px solid var(--line-soft);border-radius:var(--radius);
  overflow:hidden;transition:.28s;position:relative;
}
.card::before{
  content:"";position:absolute;inset:0;border-radius:var(--radius);padding:1px;
  background:linear-gradient(135deg,rgba(56,240,255,.0),rgba(155,107,255,.0));
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);
  -webkit-mask-composite:xor;mask-composite:exclude;opacity:0;transition:.28s;pointer-events:none;
}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow);border-color:transparent;}
.card:hover::before{opacity:1;background:linear-gradient(135deg,var(--primary),var(--accent));}
.thumb{position:relative;aspect-ratio:16/10;background:#0a0f1e;overflow:hidden;}
.thumb img{width:100%;height:100%;object-fit:cover;display:block;transition:.4s;}
.card:hover .thumb img{transform:scale(1.05);}
.thumb .ph{
  position:absolute;inset:0;display:flex;align-items:center;justify-content:center;
  text-align:center;padding:16px;font-weight:700;color:#cdd9f5;
  background:linear-gradient(135deg,#101a35,#1a1140);
}
.thumb .cat-tag{
  position:absolute;top:10px;left:10px;font-size:12px;padding:3px 10px;border-radius:999px;
  background:rgba(7,10,20,.7);color:var(--primary);border:1px solid var(--line);backdrop-filter:blur(4px);
}
.thumb .stack-tag{
  position:absolute;top:10px;right:10px;font-size:12px;padding:3px 10px;border-radius:999px;
  background:rgba(155,107,255,.18);color:#cbb6ff;border:1px solid rgba(155,107,255,.5);backdrop-filter:blur(4px);
}
.card-body{padding:16px 18px 18px;}
.card-body h3{font-size:16.5px;margin-bottom:6px;}
.card-body .intro{font-size:13.5px;color:var(--text-dim);min-height:42px;}
.card-actions{display:flex;gap:10px;margin-top:14px;}
.btn{
  flex:1;text-align:center;text-decoration:none;font-size:13.5px;padding:9px 0;border-radius:10px;
  border:1px solid var(--line);transition:.2s;cursor:pointer;
}
.btn.primary{color:#04111a;background:linear-gradient(135deg,var(--primary),var(--accent));border-color:transparent;font-weight:600;}
.btn.primary:hover{filter:brightness(1.08);}
.btn.ghost{color:var(--text);}
.btn.ghost:hover{border-color:var(--primary);color:var(--primary);}
.empty{padding:50px 0;text-align:center;color:var(--text-mute);grid-column:1/-1;}

/* ---------- 面包屑 ---------- */
.crumb{padding:26px 0 0;font-size:13px;color:var(--text-mute);}
.crumb a{color:var(--text-dim);text-decoration:none;}
.crumb a:hover{color:var(--primary);}
.crumb span{margin:0 8px;color:var(--text-mute);}

/* ---------- 详情页 ---------- */
.detail{padding:10px 0 60px;}
.detail-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:18px;}
.detail-head h1{font-size:28px;}
.detail-head .cat{font-size:13px;color:var(--primary);border:1px solid var(--line);padding:4px 12px;border-radius:999px;}
.detail-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:24px;}
.preview-box{
  background:var(--bg-card);border:1px solid var(--line-soft);border-radius:var(--radius);
  overflow:hidden;min-height:420px;position:relative;
}
.preview-box iframe{width:100%;height:560px;border:0;background:#fff;}
.preview-fallback{
  position:absolute;inset:0;display:none;flex-direction:column;align-items:center;justify-content:center;gap:14px;
  background:linear-gradient(135deg,#0c1426,#161033);color:var(--text-dim);text-align:center;padding:20px;
}
.info-box{background:var(--bg-card);border:1px solid var(--line-soft);border-radius:var(--radius);padding:22px;}
.info-box h2{font-size:16px;margin-bottom:10px;color:var(--primary);}
.info-box p{font-size:14px;color:var(--text-dim);margin-bottom:16px;}
.info-box .meta{font-size:13px;color:var(--text-mute);margin-bottom:18px;}
.info-box .meta b{color:var(--text);font-weight:600;}
.tags{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:20px;}
.tags span{font-size:12px;color:var(--text-dim);background:rgba(56,240,255,.08);border:1px solid var(--line);padding:3px 10px;border-radius:999px;}
.info-actions{display:flex;flex-direction:column;gap:10px;}

/* ---------- 页脚 ---------- */
.footer{border-top:1px solid var(--line-soft);padding:30px 0;margin-top:20px;position:relative;z-index:2;}
.footer-inner{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;}
.footer .copy{font-size:13px;color:var(--text-mute);}
.footer .copy a{color:var(--text-dim);text-decoration:none;}
.footer .copy a:hover{color:var(--primary);}
.footer .links{display:flex;gap:18px;}
.footer .links a{font-size:13px;color:var(--text-dim);text-decoration:none;}
.footer .links a:hover{color:var(--primary);}

/* ---------- SEO 隐形文本层（绝对定位移出可视区，禁止 display:none） ---------- */
.seo-hidden{
  position:absolute;left:-99999px;top:auto;width:1px;height:1px;overflow:hidden;
  font-size:1px;line-height:1px;color:transparent;background:transparent;border:0;opacity:0;
}

/* ---------- 响应式 ---------- */
@media(max-width:860px){
  .detail-grid{grid-template-columns:1fr;}
  .preview-box iframe{height:420px;}
  .hero h1{font-size:30px;}
  .nav-links{display:none;}
}