:root{
  --primary:#6366F1;
  --secondary:#06B6D4;
  --accent:#8B5CF6;
  --bg:#F8FAFC;
  --dark:#0F172A;
  --light:#FFFFFF;
  --gray:#6B7280;
  --success:#10B981;
  --warning:#F59E0B;
  --danger:#EF4444;
  --radius:16px;
  --radius-sm:8px;
  --shadow:0 4px 20px rgba(99,102,241,0.12);
  --shadow-hover:0 12px 36px rgba(99,102,241,0.24);
  --font-heading:"Inter","PingFang SC",sans-serif;
  --font-body:"Inter","PingFang SC",sans-serif;
}

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

body{
  font-family:var(--font-body);
  color:var(--dark);
  background:var(--bg);
  line-height:1.8;
  font-size:16px;
}

/* 顶部栏 */
.top-bar{
  background:var(--dark);
  color:rgba(255,255,255,0.75);
  font-size:13px;
  padding:10px 0;
  border-bottom:1px solid rgba(99,102,241,0.2);
}
.top-bar .container{
  display:flex;
  justify-content:space-between;
  align-items:center;
  max-width:1280px;
  margin:0 auto;
  padding:0 24px;
}
.top-bar a{color:rgba(255,255,255,0.75);text-decoration:none;transition:color 0.3s;}
.top-bar a:hover{color:var(--primary);}

/* 导航栏 */
.header{
  background:white;
  color:var(--dark);
  padding:0;
  position:sticky;
  top:0;
  z-index:1000;
  box-shadow:0 2px 20px rgba(0,0,0,0.06);
  border-bottom:3px solid var(--primary);
}
.header .container{
  display:flex;
  justify-content:space-between;
  align-items:center;
  max-width:1280px;
  margin:0 auto;
  padding:0 24px;
  height:72px;
}
.logo{
  font-size:24px;
  font-weight:800;
  font-family:var(--font-heading);
  color:var(--primary);
  letter-spacing:-0.5px;
}
.nav{display:flex;gap:32px;align-items:center;}
.nav a{
  color:var(--dark);
  text-decoration:none;
  font-weight:500;
  font-size:15px;
  transition:all 0.3s;
  position:relative;
  padding:8px 0;
}
.nav a::after{
  content:'';
  position:absolute;
  bottom:0;
  left:0;
  width:0;
  height:2px;
  background:var(--primary);
  transition:width 0.3s;
}
.nav a:hover::after{width:100%;}
.nav a:hover{color:var(--primary);}

/* Hero */
.hero{
  background:linear-gradient(135deg,var(--dark) 0%,color-mix(in srgb,var(--primary) 30%,var(--dark)) 100%);
  color:white;
  padding:120px 0 100px;
  position:relative;
  overflow:hidden;
}
.hero .container{
  max-width:1280px;
  margin:0 auto;
  padding:0 24px;
  position:relative;
  z-index:1;
}
.hero h1{
  font-size:52px;
  font-weight:800;
  font-family:var(--font-heading);
  line-height:1.2;
  margin-bottom:24px;
}
.hero p{
  font-size:20px;
  color:rgba(255,255,255,0.8);
  max-width:640px;
  margin-bottom:40px;
  line-height:1.8;
}
.hero .btn-group{display:flex;gap:16px;flex-wrap:wrap;}

/* 按钮 */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:14px 32px;
  border-radius:var(--radius-sm);
  font-weight:600;
  font-size:15px;
  text-decoration:none;
  transition:all 0.4s;
  cursor:pointer;
  border:none;
}
.btn-primary{
  background:linear-gradient(135deg,var(--primary),var(--accent));
  color:white;
  box-shadow:0 4px 16px rgba(99,102,241,0.3);
}
.btn-primary:hover{
  transform:translateY(-2px);
  box-shadow:0 8px 28px rgba(99,102,241,0.5);
}
.btn-outline{
  background:transparent;
  color:white;
  border:2px solid rgba(255,255,255,0.4);
}
.btn-outline:hover{
  background:rgba(255,255,255,0.1);
  border-color:white;
  transform:translateY(-2px);
}

/* 卡片 */
.card{
  background:white;
  border-radius:var(--radius);
  padding:36px 28px;
  box-shadow:var(--shadow);
  transition:all 0.4s;
  position:relative;
  overflow:hidden;
  border:1px solid rgba(99,102,241,0.1);
}
.card::before{
  content:'';
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:3px;
  background:linear-gradient(90deg,var(--primary),var(--accent));
  transform:scaleX(0);
  transform-origin:left;
  transition:transform 0.4s;
}
.card:hover::before{transform:scaleX(1);}
.card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-hover);
}
.card .icon{
  width:56px;
  height:56px;
  background:linear-gradient(135deg,var(--primary),var(--accent));
  border-radius:12px;
  display:flex;
  align-items:center;
  justify-content:center;
  font-size:24px;
  margin-bottom:20px;
  color:white;
}
.card h3{
  font-size:20px;
  font-weight:700;
  font-family:var(--font-heading);
  margin-bottom:12px;
  color:var(--dark);
}
.card p{
  color:#6B7280;
  line-height:1.8;
  font-size:15px;
}

/* 卡片网格 */
.card-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(320px,1fr));
  gap:32px;
  padding:80px 24px;
  max-width:1280px;
  margin:0 auto;
}
.features-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:32px;
  padding:80px 24px;
  max-width:1280px;
  margin:0 auto;
}

/* 区块标题 */
.section-header{
  text-align:center;
  margin-bottom:64px;
  padding:0 24px;
}
.section-header h2{
  font-size:40px;
  font-weight:800;
  font-family:var(--font-heading);
  color:var(--dark);
  margin-bottom:16px;
}
.section-header p{
  font-size:18px;
  color:#6B7280;
  max-width:600px;
  margin:0 auto;
}

/* CTA区 */
.cta{
  background:linear-gradient(135deg,var(--dark),color-mix(in srgb,var(--primary) 20%,var(--dark)));
  color:white;
  padding:100px 24px;
  text-align:center;
}
.cta h2{
  font-size:40px;
  font-weight:800;
  font-family:var(--font-heading);
  margin-bottom:16px;
}
.cta p{
  font-size:18px;
  color:rgba(255,255,255,0.8);
  margin-bottom:40px;
}

/* 页脚 */
.footer{
  background:var(--dark);
  color:rgba(255,255,255,0.7);
  padding:80px 24px 40px;
}
.footer .container{max-width:1280px;margin:0 auto;}
.footer-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
  gap:48px;
  margin-bottom:48px;
}
.footer h4{color:white;font-weight:700;margin-bottom:20px;font-size:16px;}
.footer a{
  color:rgba(255,255,255,0.6);
  text-decoration:none;
  display:block;
  margin-bottom:12px;
  transition:all 0.3s;
  font-size:14px;
}
.footer a:hover{color:var(--primary);}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,0.1);
  padding-top:32px;
  text-align:center;
  font-size:13px;
  color:rgba(255,255,255,0.4);
}

/* 返回顶部 */
.back-to-top{
  position:fixed;
  bottom:32px;
  right:32px;
  width:48px;
  height:48px;
  background:var(--primary);
  color:white;
  border:none;
  border-radius:50%;
  cursor:pointer;
  font-size:20px;
  box-shadow:0 4px 16px rgba(99,102,241,0.4);
  transition:all 0.4s;
  opacity:0;
  visibility:hidden;
  z-index:999;
}
.back-to-top.visible{opacity:1;visibility:visible;}
.back-to-top:hover{transform:translateY(-4px);}

/* 表单 */
.form-input,
input[type="text"],
input[type="email"],
input[type="tel"],
textarea,
select{
  width:100%;
  padding:14px 18px;
  border:2px solid #E5E7EB;
  border-radius:var(--radius-sm);
  font-size:15px;
  transition:all 0.3s;
  background:white;
}
.form-input:focus,
input:focus,
textarea:focus,
select:focus{
  outline:none;
  border-color:var(--primary);
  box-shadow:0 0 0 4px rgba(99,102,241,0.1);
}
.form-group{margin-bottom:24px;}
.form-label{
  display:block;
  margin-bottom:8px;
  font-weight:600;
  color:var(--dark);
  font-size:14px;
}

/* 表格 */
table{
  width:100%;
  border-collapse:collapse;
  margin:24px 0;
  background:white;
  border-radius:var(--radius);
  overflow:hidden;
  box-shadow:var(--shadow);
}
th,td{
  padding:16px 20px;
  text-align:left;
  border-bottom:1px solid #F1F5F9;
}
th{
  background:var(--dark);
  color:white;
  font-weight:600;
  font-size:14px;
}
tr:hover{background:var(--bg);}

/* 面包屑 */
.breadcrumb{
  padding:20px 0;
  font-size:14px;
  color:#6B7280;
  max-width:1280px;
  margin:0 auto;
  padding-left:24px;
  padding-right:24px;
}
.breadcrumb a{color:var(--primary);text-decoration:none;}
.breadcrumb a:hover{text-decoration:underline;}

/* 分页 */
.pagination{
  display:flex;
  gap:8px;
  justify-content:center;
  margin:48px 0;
  flex-wrap:wrap;
}
.pagination a,
.pagination span{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-width:44px;
  height:44px;
  padding:0 16px;
  border-radius:var(--radius-sm);
  text-decoration:none;
  font-weight:500;
  transition:all 0.3s;
}
.pagination a{
  background:white;
  color:var(--dark);
  border:2px solid #E5E7EB;
}
.pagination a:hover{
  border-color:var(--primary);
  color:var(--primary);
}
.pagination .current{
  background:var(--primary);
  color:white;
  border:2px solid var(--primary);
}

/* 警告框 */
.alert{
  padding:18px 24px;
  border-radius:var(--radius-sm);
  margin:20px 0;
  font-size:15px;
  display:flex;
  align-items:center;
  gap:12px;
  border-left:4px solid;
}
.alert-success{background:#F0FDF4;color:#166534;border-left-color:var(--success);}
.alert-warning{background:#FFFBEB;color:#92400E;border-left-color:var(--warning);}
.alert-error{background:#FEF2F2;color:#991B1B;border-left-color:var(--danger);}
.alert-info{background:#EFF6FF;color:#1E40AF;border-left-color:var(--primary);}

/* 徽章 */
.badge{
  display:inline-flex;
  align-items:center;
  padding:4px 12px;
  border-radius:100px;
  font-size:12px;
  font-weight:600;
}
.badge-primary{background:rgba(99,102,241,0.1);color:var(--primary);}
.badge-success{background:rgba(16,185,129,0.1);color:var(--success);}

/* 动画 */
@keyframes fadeInUp{
  from{opacity:0;transform:translateY(30px);}
  to{opacity:1;transform:translateY(0);}
}
.fade-in-up{animation:fadeInUp 0.6s ease-out forwards;}

/* 响应式 */
@media(max-width:1024px){
  .hero h1{font-size:44px;}
  .section-header h2{font-size:32px;}
}
@media(max-width:768px){
  .nav{display:none;}
  .hero{padding:80px 0 60px;}
  .hero h1{font-size:32px;}
  .hero p{font-size:16px;}
  .card-grid{grid-template-columns:1fr;padding:40px 16px;}
  .card{padding:28px 24px;}
  .section-header h2{font-size:26px;}
  .cta h2{font-size:28px;}
  .footer-grid{grid-template-columns:1fr 1fr;}
}
@media(max-width:480px){
  .hero h1{font-size:26px;}
  .btn{padding:12px 24px;font-size:14px;}
  .footer-grid{grid-template-columns:1fr;}
}