/* === TaiXu AI v6 — 终极科技风 === */
:root{
  --bg:#03050b; --bg2:#080c1a; --bg3:#0c1228;
  --card:rgba(14,22,48,.7); --card-hover:rgba(22,34,68,.85);
  --card-border:rgba(100,80,255,.18); --card-border-hover:rgba(100,80,255,.5);
  --line:rgba(100,80,255,.12); --line-bright:rgba(100,80,255,.35);
  --text:#dce2ff; --text2:#7882b8; --text3:#4a5278;
  --brand:#7c5cff; --brand2:#22d3ee; --brand3:#10b981; --brand4:#ec4899;
  --grad:linear-gradient(135deg,#7c5cff,#22d3ee,#10b981);
  --grad2:linear-gradient(135deg,#7c5cff,#ec4899);
  --grad3:linear-gradient(135deg,#22d3ee,#7c5cff);
  --glow:0 0 60px rgba(124,92,255,.25);
  --glow2:0 0 40px rgba(34,211,238,.2);
  --max-w:1200px; --radius:12px; --radius-sm:8px;
}
*{margin:0;padding:0;box-sizing:border-box}
body{
  background:var(--bg); color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  line-height:1.6; min-height:100vh; display:flex; flex-direction:column; overflow-x:hidden;
}
a{color:var(--brand2);text-decoration:none;transition:color .2s}
a:hover{color:var(--brand)}
img{max-width:100%}

/* ===== 粒子背景 ===== */
#particles-canvas{position:fixed;top:0;left:0;width:100%;height:100%;z-index:0;pointer-events:none}

/* ===== 导航 ===== */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  background:rgba(3,5,11,.85); backdrop-filter:blur(24px);
  border-bottom:1px solid var(--line);
}
.nav-inner{
  max-width:var(--max-w);margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
  padding:0 24px;height:64px;
}
.nav-brand{
  display:flex;align-items:center;gap:10px;
  font-size:18px;font-weight:700;color:var(--text);
}
.nav-brand img{width:32px;height:32px;object-fit:contain;border-radius:6px}
.nav-links{display:flex;gap:24px;align-items:center}
.nav-links a{
  color:var(--text2);font-size:14px;padding:6px 0;
  position:relative;transition:color .2s;
}
.nav-links a::after{
  content:"";position:absolute;bottom:0;left:0;right:0;
  height:2px;background:var(--grad);border-radius:2px;
  transform:scaleX(0);transition:transform .2s;
}
.nav-links a:hover{color:var(--text)}
.nav-links a:hover::after{transform:scaleX(1)}
.nav-toggle{display:none;background:none;border:none;color:var(--text);font-size:24px;cursor:pointer}

/* ===== HERO ===== */
.hero{
  padding:120px 24px 80px; position:relative; z-index:1;
  text-align:center;
}
.hero::before{
  content:"";position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,var(--line-bright),transparent);
}
.hero-inner{max-width:800px;margin:0 auto;position:relative;z-index:2}
.hero .badge{
  display:inline-block;padding:6px 18px;border-radius:20px;
  background:rgba(124,92,255,.12); border:1px solid rgba(124,92,255,.25);
  color:var(--brand2); font-size:13px; margin-bottom:24px; backdrop-filter:blur(4px);
}
.hero h1{font-size:52px;font-weight:800;line-height:1.12;margin-bottom:20px;letter-spacing:-1px}
@media(max-width:640px){.hero h1{font-size:32px}}
.hero-sub{font-size:16px;color:var(--text2);max-width:640px;margin:0 auto 32px;line-height:1.7}
.grad{background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.grad2{background:var(--grad2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

/* ===== 按钮 ===== */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:12px 28px;border-radius:var(--radius-sm);
  font-size:14px;font-weight:600;cursor:pointer;
  transition:all .25s; border:none; position:relative; overflow:hidden;
}
.btn-primary{
  background:var(--grad); color:#fff;
  box-shadow:0 0 30px rgba(124,92,255,.3);
}
.btn-primary:hover{
  transform:translateY(-2px); box-shadow:0 0 50px rgba(124,92,255,.5);
}
.btn-outline{
  background:transparent; border:1px solid var(--line-bright);
  color:var(--text);
}
.btn-outline:hover{
  background:rgba(124,92,255,.1); border-color:var(--brand); transform:translateY(-2px);
}
.btn-group{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

/* ===== 通用区块 ===== */
.section{padding:80px 24px;position:relative;z-index:1}
.section-alt{background:var(--bg2)}
.section-inner{max-width:var(--max-w);margin:0 auto}
.section-head{text-align:center;margin-bottom:48px}
.section-head h2{font-size:32px;font-weight:700;margin-bottom:12px}
.section-sub{color:var(--text2);font-size:15px;max-width:600px;margin:0 auto}

/* ===== 网格 ===== */
.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}

/* ===== 卡片 ===== */
.card{
  background:var(--card); border:1px solid var(--card-border);
  border-radius:var(--radius); padding:32px 24px;
  transition:all .3s; backdrop-filter:blur(8px);
}
.card:hover{
  background:var(--card-hover); border-color:var(--card-border-hover);
  transform:translateY(-4px); box-shadow:var(--glow);
}
.card-icon{font-size:36px;margin-bottom:16px}
.card h3{font-size:17px;font-weight:700;margin-bottom:10px}
.card p{font-size:14px;color:var(--text2);line-height:1.7}

/* ===== 数据统计 ===== */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;max-width:900px;margin:0 auto}
.stat{text-align:center;padding:24px}
.stat-num{font-size:36px;font-weight:800;background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.stat-label{font-size:13px;color:var(--text2);margin-top:4px}

/* ===== 步骤 ===== */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:32px;max-width:900px;margin:0 auto}
.step{text-align:center;padding:32px 20px}
.step-icon{width:64px;height:64px;border-radius:50%;background:rgba(124,92,255,.12);border:1px solid rgba(124,92,255,.2);display:flex;align-items:center;justify-content:center;font-size:28px;margin:0 auto 16px}
.step h4{font-size:16px;font-weight:700;margin-bottom:8px}
.step p{font-size:13px;color:var(--text2)}

/* ===== 特性列表 ===== */
.feature-list{list-style:none;margin-top:12px}
.feature-list li{font-size:13px;color:var(--text2);padding:4px 0}

/* ===== 对比表格 ===== */
.table-wrap{overflow-x:auto}
.compare-table{width:100%;border-collapse:collapse;font-size:13px;min-width:600px}
.compare-table th,.compare-table td{padding:12px 16px;text-align:center;border-bottom:1px solid var(--line)}
.compare-table th{font-weight:600;color:var(--text2)}
.compare-table .hl{color:var(--brand2);font-weight:600}
.compare-table tbody tr:hover{background:rgba(124,92,255,.05)}

/* ===== 品牌墙 ===== */
.brand-wall{display:flex;flex-wrap:wrap;gap:32px;justify-content:center;align-items:center;padding:40px 0}
.brand-item{font-size:14px;color:var(--text3);padding:12px 24px;border:1px solid var(--line);border-radius:8px;transition:all .3s}
.brand-item:hover{color:var(--text2);border-color:var(--card-border-hover);background:var(--card)}
.brand-item strong{color:var(--text2)}

/* ===== 产品展示 ===== */
.product-showcase{position:relative;text-align:center;padding:60px 0}
.product-showcase img{max-width:100%;border-radius:16px;border:1px solid var(--card-border)}
.product-showcase .glow-ring{position:absolute;width:120%;height:120%;top:-10%;left:-10%;background:radial-gradient(ellipse,var(--glow),transparent 70%);pointer-events:none;z-index:-1}

/* ===== FAQ ===== */
.faq-item{border-bottom:1px solid var(--line);padding:20px 0;cursor:pointer}
.faq-q{display:flex;justify-content:space-between;align-items:center;font-weight:600;font-size:15px}
.faq-q span{color:var(--brand2);transition:transform .3s}
.faq-a{max-height:0;overflow:hidden;transition:max-height .3s,opacity .3s;opacity:0;color:var(--text2);font-size:14px;padding-top:0}
.faq-item.open .faq-a{max-height:300px;opacity:1;padding-top:12px}
.faq-item.open .faq-q span{transform:rotate(45deg)}

/* ===== 页脚 ===== */
footer{margin-top:auto;border-top:1px solid var(--line);padding:60px 24px 20px;position:relative;z-index:1}
.footer-inner{max-width:var(--max-w);margin:0 auto;display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px}
.footer-brand{display:flex;align-items:center;gap:10px;font-size:16px;font-weight:700;margin-bottom:12px}
.footer-brand img{width:28px;height:28px;border-radius:4px}
.footer-desc{font-size:13px;color:var(--text3);line-height:1.6}
.footer-col h4{font-size:14px;font-weight:700;margin-bottom:16px;color:var(--text)}
.footer-col a{display:block;font-size:13px;color:var(--text2);padding:4px 0}
.footer-col a:hover{color:var(--brand2)}
.footer-bottom{max-width:var(--max-w);margin:40px auto 0;padding-top:20px;border-top:1px solid var(--line);display:flex;justify-content:space-between;font-size:12px;color:var(--text3)}

/* ===== 动画 ===== */
.fade-up{opacity:0;transform:translateY(30px);animation:fadeUp .6s ease forwards}
.fade-in{opacity:0;animation:fadeIn .5s ease forwards}
.delay-1{animation-delay:.1s}.delay-2{animation-delay:.2s}
.delay-3{animation-delay:.3s}.delay-4{animation-delay:.4s}
.delay-5{animation-delay:.5s}.delay-6{animation-delay:.6s}

@keyframes fadeUp{to{opacity:1;transform:translateY(0)}}
@keyframes fadeIn{to{opacity:1}}

.pulse{animation:pulse 2s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.5}}

.float{animation:float 3s ease-in-out infinite}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-8px)}}

/* ===== CTA横幅 ===== */
.cta-banner{
  background:linear-gradient(135deg,rgba(124,92,255,.12),rgba(34,211,238,.08));
  border:1px solid var(--card-border); border-radius:var(--radius);
  padding:48px 32px; text-align:center;
}
.cta-banner h2{font-size:28px;margin-bottom:12px}
.cta-banner p{color:var(--text2);margin-bottom:24px}

/* ===== 技术栈标签 ===== */
.tech-tags{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}
.tech-tag{font-size:11px;padding:3px 10px;border-radius:4px;background:rgba(124,92,255,.1);border:1px solid rgba(124,92,255,.15);color:var(--brand2)}

/* ===== 响应式 ===== */
@media(max-width:900px){
  .grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}
  .footer-inner{grid-template-columns:1fr 1fr}
  .hero h1{font-size:36px}
  .stats{grid-template-columns:repeat(2,1fr)}
  .steps{grid-template-columns:1fr}
}
@media(max-width:640px){
  .nav-links{display:none}
  .nav-links.show{display:flex;flex-direction:column;position:absolute;top:64px;left:0;right:0;background:rgba(3,5,11,.95);padding:16px;gap:12px;border-bottom:1px solid var(--line)}
  .nav-toggle{display:block}
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  .footer-inner{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;gap:8px;text-align:center}
  .hero h1{font-size:28px}
  .btn-group{flex-direction:column;align-items:center}
  .stats{grid-template-columns:repeat(2,1fr)}
}