*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--tg-blue:#0088cc;--tg-dark:#005f8c;--tg-light:#e8f4fd;--tg-accent:#00aaff;--tg-gradient:linear-gradient(135deg,#0088cc 0%,#005f8c 100%);--text-primary:#1a1a2e;--text-secondary:#4a4a6a;--bg-white:#ffffff;--bg-light:#f5f9fc;--border-color:#e0e8f0;--shadow:0 2px 12px rgba(0,136,204,0.1);--shadow-lg:0 8px 30px rgba(0,136,204,0.15);--radius:12px;--max-width:1200px;--transition:all 0.3s ease}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei','Helvetica Neue',Helvetica,Arial,sans-serif;color:var(--text-primary);line-height:1.8;background:var(--bg-white)}
a{text-decoration:none;color:var(--tg-blue);transition:var(--transition)}
a:hover{color:var(--tg-dark)}
img{max-width:100%;height:auto;display:block}
.container{max-width:var(--max-width);margin:0 auto;padding:0 20px}

/* Header */
.site-header{background:var(--tg-white,#fff);border-bottom:1px solid var(--border-color);position:sticky;top:0;z-index:1000;backdrop-filter:blur(10px);background:rgba(255,255,255,0.95)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 0}
.logo{display:flex;align-items:center;gap:10px;font-size:1.4rem;font-weight:700;color:var(--tg-blue)}
.logo img{width:36px;height:36px}
.logo:hover{color:var(--tg-dark)}
nav ul{display:flex;list-style:none;gap:24px}
nav a{color:var(--text-secondary);font-weight:500;font-size:0.95rem;padding:6px 0;border-bottom:2px solid transparent;transition:var(--transition)}
nav a:hover,nav a.active{color:var(--tg-blue);border-bottom-color:var(--tg-blue)}
.mobile-menu{display:none;background:none;border:none;cursor:pointer;padding:8px}
.mobile-menu span{display:block;width:24px;height:2px;background:var(--text-primary);margin:5px 0;transition:var(--transition)}

/* Hero */
.hero{background:var(--tg-gradient);color:#fff;padding:80px 0;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,rgba(255,255,255,0.05) 0%,transparent 70%);animation:rotate 20s linear infinite}
@keyframes rotate{from{transform:rotate(0deg)}to{transform:rotate(360deg)}}
.hero h1{font-size:2.8rem;margin-bottom:20px;position:relative;text-shadow:0 2px 4px rgba(0,0,0,0.1)}
.hero p{font-size:1.2rem;opacity:0.95;max-width:700px;margin:0 auto 30px;position:relative;line-height:1.8}
.hero-buttons{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;position:relative}
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:50px;font-weight:600;font-size:1rem;transition:var(--transition);cursor:pointer;border:none}
.btn-primary{background:#fff;color:var(--tg-blue);box-shadow:0 4px 15px rgba(0,0,0,0.15)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(0,0,0,0.2);color:var(--tg-dark)}
.btn-outline{background:transparent;color:#fff;border:2px solid rgba(255,255,255,0.5)}
.btn-outline:hover{background:rgba(255,255,255,0.1);border-color:#fff;color:#fff}

/* Sections */
.section{padding:80px 0}
.section-light{background:var(--bg-light)}
.section-title{text-align:center;margin-bottom:50px}
.section-title h2{font-size:2rem;color:var(--text-primary);margin-bottom:12px}
.section-title p{color:var(--text-secondary);font-size:1.1rem;max-width:600px;margin:0 auto}

/* Cards */
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px}
.card{background:#fff;border-radius:var(--radius);padding:30px;box-shadow:var(--shadow);transition:var(--transition);border:1px solid var(--border-color)}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.card-icon{width:56px;height:56px;border-radius:12px;display:flex;align-items:center;justify-content:center;margin-bottom:16px;font-size:1.5rem}
.card-icon.blue{background:var(--tg-light);color:var(--tg-blue)}
.card h3{font-size:1.2rem;margin-bottom:10px;color:var(--text-primary)}
.card p{color:var(--text-secondary);font-size:0.95rem;line-height:1.7}

/* Feature rows */
.feature-row{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;margin-bottom:60px}
.feature-row.reverse{direction:rtl}
.feature-row.reverse > *{direction:ltr}
.feature-img{border-radius:var(--radius);box-shadow:var(--shadow-lg);overflow:hidden}
.feature-img img{width:100%;height:auto}
.feature-content h2{font-size:1.8rem;margin-bottom:16px;color:var(--text-primary)}
.feature-content h3{font-size:1.3rem;margin:20px 0 10px;color:var(--text-primary)}
.feature-content p{color:var(--text-secondary);line-height:1.8;margin-bottom:12px}
.feature-content ul{list-style:none;margin:16px 0}
.feature-content li{padding:8px 0;padding-left:24px;position:relative;color:var(--text-secondary)}
.feature-content li::before{content:'✓';position:absolute;left:0;color:var(--tg-blue);font-weight:700}

/* Download section */
.download-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px}
.download-card{text-align:center;padding:30px 20px;border-radius:var(--radius);background:#fff;box-shadow:var(--shadow);border:1px solid var(--border-color);transition:var(--transition)}
.download-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.download-card .icon{font-size:2.5rem;margin-bottom:12px}
.download-card h4{margin-bottom:8px;font-size:1.1rem}
.download-card p{color:var(--text-secondary);font-size:0.85rem;margin-bottom:16px}
.download-card .btn{padding:10px 24px;font-size:0.9rem}

/* FAQ */
.faq-item{background:#fff;border-radius:var(--radius);margin-bottom:12px;box-shadow:var(--shadow);border:1px solid var(--border-color);overflow:hidden}
.faq-item summary{padding:18px 24px;cursor:pointer;font-weight:600;font-size:1.05rem;color:var(--text-primary);list-style:none;display:flex;justify-content:space-between;align-items:center;transition:var(--transition);-webkit-appearance:none;-moz-appearance:none;appearance:none}
.faq-item summary::after{content:'+';font-size:1.4rem;color:var(--tg-blue);transition:var(--transition)}
.faq-item[open] summary::after{content:'−'}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::-moz-list-bullet{list-style:none}
.faq-item summary::marker{display:none}
.faq-item .faq-content{padding:0 24px 20px;color:var(--text-secondary);line-height:1.8}

/* Table */
.compare-table{width:100%;border-collapse:collapse;background:#fff;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.compare-table th,.compare-table td{padding:14px 20px;text-align:left;border-bottom:1px solid var(--border-color)}
.compare-table th{background:var(--tg-blue);color:#fff;font-weight:600}
.compare-table tr:hover{background:var(--tg-light)}

/* Breadcrumb */
.breadcrumb{padding:16px 0;font-size:0.9rem;color:var(--text-secondary)}
.breadcrumb a{color:var(--tg-blue)}
.breadcrumb span{margin:0 8px}

/* Article */
.article-content{max-width:800px;margin:0 auto}
.article-content h2{font-size:1.6rem;margin:40px 0 16px;color:var(--text-primary);padding-left:16px;border-left:4px solid var(--tg-blue)}
.article-content h3{font-size:1.25rem;margin:28px 0 12px;color:var(--text-primary)}
.article-content h4{font-size:1.1rem;margin:20px 0 10px;color:var(--text-primary)}
.article-content p{color:var(--text-secondary);margin-bottom:14px;line-height:1.9}
.article-content ul,.article-content ol{margin:14px 0 14px 24px;color:var(--text-secondary)}
.article-content li{margin-bottom:8px;line-height:1.7}
.article-content blockquote{background:var(--tg-light);border-left:4px solid var(--tg-blue);padding:16px 20px;border-radius:0 8px 8px 0;margin:20px 0;color:var(--text-secondary)}
.article-content code{background:var(--bg-light);padding:2px 8px;border-radius:4px;font-size:0.9em;color:var(--tg-blue)}

/* Footer */
.site-footer{background:#1a1a2e;color:rgba(255,255,255,0.7);padding:60px 0 30px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
.footer-brand p{margin-top:12px;line-height:1.7;font-size:0.9rem}
.footer-col h4{color:#fff;margin-bottom:16px;font-size:1rem}
.footer-col ul{list-style:none}
.footer-col li{margin-bottom:8px}
.footer-col a{color:rgba(255,255,255,0.6);font-size:0.9rem}
.footer-col a:hover{color:var(--tg-accent)}
.footer-bottom{text-align:center;padding-top:24px;border-top:1px solid rgba(255,255,255,0.1);font-size:0.85rem}

/* Page header */
.page-header{background:var(--tg-gradient);color:#fff;padding:60px 0 40px;text-align:center}
.page-header h1{font-size:2.2rem;margin-bottom:12px}
.page-header p{opacity:0.9;font-size:1.1rem}

/* Tags */
.tag{display:inline-block;padding:4px 12px;border-radius:20px;font-size:0.8rem;background:var(--tg-light);color:var(--tg-blue);margin:4px}

/* Steps */
.steps{counter-reset:step}
.step-item{display:flex;gap:20px;margin-bottom:30px;position:relative}
.step-num{width:48px;height:48px;border-radius:50%;background:var(--tg-blue);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:1.2rem;flex-shrink:0}
.step-content h4{font-size:1.1rem;margin-bottom:6px}
.step-content p{color:var(--text-secondary);line-height:1.7}

/* Responsive */
@media(max-width:768px){
  .hero h1{font-size:1.8rem}
  .hero p{font-size:1rem}
  .feature-row{grid-template-columns:1fr;gap:30px}
  .feature-row.reverse{direction:ltr}
  .footer-grid{grid-template-columns:1fr 1fr}
  nav ul{display:none;position:absolute;top:100%;left:0;right:0;background:#fff;flex-direction:column;padding:20px;box-shadow:var(--shadow-lg);gap:12px}
  nav ul.open{display:flex}
  .mobile-menu{display:block}
  .card-grid{grid-template-columns:1fr}
  .section{padding:50px 0}
  .hero{padding:50px 0}
}

/* Structured data hidden */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}

/* Skip to content for accessibility */
.skip-link{position:absolute;top:-40px;left:0;background:var(--tg-blue);color:#fff;padding:8px 16px;z-index:10000;transition:top 0.3s}
.skip-link:focus{top:0}

/* Print */
@media print{.site-header,.site-footer,.hero-buttons{display:none}.hero{padding:20px 0}.section{padding:20px 0}}