*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--primary:#1a8cff;--primary-dark:#0d6fd4;--accent:#00c2ff;--bg:#f5f8fc;--card:#fff;--text:#1a1a2e;--text-light:#5a6270;--border:#e2e8f0;--shadow:0 2px 16px rgba(26,140,255,.08);--radius:12px;--max:1200px}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:var(--text);background:var(--bg);line-height:1.75}
a{color:var(--primary);text-decoration:none;transition:color .2s}
a:hover{color:var(--primary-dark)}
img{max-width:100%;height:auto;display:block}
.container{max-width:var(--max);margin:0 auto;padding:0 20px}

/* Header */
.site-header{background:var(--card);box-shadow:0 1px 8px rgba(0,0,0,.06);position:sticky;top:0;z-index:100}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;max-width:var(--max);margin:0 auto}
.logo-link{display:flex;align-items:center;gap:10px;font-weight:700;font-size:1.15rem;color:var(--text)}
.logo-link img{width:40px;height:40px;border-radius:10px}
.logo-link:hover{color:var(--primary)}
.nav-main{display:flex;gap:6px}
.nav-main a{padding:8px 14px;border-radius:8px;color:var(--text-light);font-size:.95rem}
.nav-main a:hover,.nav-main a.active{background:rgba(26,140,255,.1);color:var(--primary)}
.menu-toggle{display:none;background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--text)}

/* Hero */
.hero{background:linear-gradient(135deg,#1a8cff 0%,#00c2ff 100%);color:#fff;padding:60px 20px 70px;text-align:center}
.hero h1{font-size:2rem;margin-bottom:12px;line-height:1.3}
.hero .subtitle{font-size:1.05rem;opacity:.92;max-width:680px;margin:0 auto 28px}
.hero-actions{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:50px;font-weight:600;font-size:1rem;border:none;cursor:pointer;transition:transform .2s,box-shadow .2s}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:#fff;color:var(--primary);box-shadow:0 4px 20px rgba(0,0,0,.15)}
.btn-outline{background:transparent;color:#fff;border:2px solid rgba(255,255,255,.7)}
.btn-outline:hover{background:rgba(255,255,255,.15)}
.hero-meta{margin-top:24px;font-size:.88rem;opacity:.8}

/* Sections */
.section{padding:56px 0}
.section-title{text-align:center;margin-bottom:40px}
.section-title h2{font-size:1.65rem;margin-bottom:8px;color:var(--text)}
.section-title p{color:var(--text-light);max-width:600px;margin:0 auto}
.section-alt{background:var(--card)}

/* Feature grid */
.feature-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px}
.feature-card{background:var(--card);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:transform .2s}
.feature-card:hover{transform:translateY(-4px)}
.feature-card img{width:100%;aspect-ratio:9/16;object-fit:cover;object-position:top}
.feature-card .card-body{padding:20px}
.feature-card h3{font-size:1.1rem;margin-bottom:8px}
.feature-card p{color:var(--text-light);font-size:.92rem}

/* Content blocks */
.content-block{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;margin-bottom:48px}
.content-block.reverse{direction:rtl}
.content-block.reverse>*{direction:ltr}
.content-block img{border-radius:var(--radius);box-shadow:var(--shadow);max-width:320px;margin:0 auto}
.content-block h3{font-size:1.3rem;margin-bottom:12px;color:var(--primary)}
.content-block p{color:var(--text-light);margin-bottom:12px}

/* Steps */
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px;counter-reset:step}
.step-card{background:var(--card);border-radius:var(--radius);padding:28px 24px;box-shadow:var(--shadow);position:relative}
.step-card::before{counter-increment:step;content:counter(step);position:absolute;top:-14px;left:20px;width:32px;height:32px;background:var(--primary);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.9rem}
.step-card h4{margin-bottom:8px;margin-top:8px}
.step-card p{color:var(--text-light);font-size:.9rem}

/* FAQ */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:var(--card);border-radius:var(--radius);margin-bottom:12px;box-shadow:var(--shadow);overflow:hidden}
.faq-item summary{padding:18px 24px;font-weight:600;cursor:pointer;list-style:none;display:flex;justify-content:space-between;align-items:center}
.faq-item summary::after{content:"+";font-size:1.3rem;color:var(--primary)}
.faq-item[open] summary::after{content:"−"}
.faq-item .faq-answer{padding:0 24px 18px;color:var(--text-light);font-size:.93rem}

/* Article / legal pages */
.page-hero{background:linear-gradient(135deg,#1a8cff,#00c2ff);color:#fff;padding:48px 20px;text-align:center}
.page-hero h1{font-size:1.8rem;margin-bottom:8px}
.page-hero p{opacity:.88}
.article-content{max-width:860px;margin:0 auto;padding:40px 20px}
.article-content h2{font-size:1.3rem;margin:32px 0 12px;color:var(--primary)}
.article-content h3{font-size:1.1rem;margin:24px 0 8px}
.article-content p,.article-content li{color:var(--text-light);margin-bottom:12px}
.article-content ul,.article-content ol{padding-left:24px;margin-bottom:16px}
.article-content ul li{list-style:disc}
.article-content ol li{list-style:decimal}

/* Error pages */
.error-page{min-height:70vh;display:flex;align-items:center;justify-content:center;text-align:center;padding:40px 20px}
.error-page h1{font-size:5rem;color:var(--primary);line-height:1}
.error-page h2{margin:12px 0;font-size:1.5rem}
.error-page p{color:var(--text-light);margin-bottom:24px}

/* Breadcrumb */
.breadcrumb{padding:12px 0;font-size:.88rem;color:var(--text-light)}
.breadcrumb a{color:var(--text-light)}
.breadcrumb a:hover{color:var(--primary)}

/* Internal links */
.link-box{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:32px}
.link-box a{padding:10px 20px;background:var(--card);border-radius:8px;box-shadow:var(--shadow);font-size:.9rem;color:var(--primary)}

/* Footer */
.site-footer{background:#0f1a2e;color:rgba(255,255,255,.75);padding:48px 20px 24px}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:32px;max-width:var(--max);margin:0 auto 32px}
.footer-grid h4{color:#fff;margin-bottom:14px;font-size:1rem}
.footer-grid a,.footer-grid p{display:block;color:rgba(255,255,255,.65);font-size:.9rem;margin-bottom:8px}
.footer-grid a:hover{color:#fff}
.footer-bottom{text-align:center;padding-top:24px;border-top:1px solid rgba(255,255,255,.1);font-size:.85rem;color:rgba(255,255,255,.5);max-width:var(--max);margin:0 auto}

/* Download banner */
.download-banner{background:linear-gradient(135deg,#1a8cff,#0066cc);color:#fff;border-radius:var(--radius);padding:40px;text-align:center;margin:40px 0}
.download-banner h3{font-size:1.4rem;margin-bottom:12px}
.download-banner p{opacity:.9;margin-bottom:20px}

/* TOC */
.toc{background:var(--card);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);margin-bottom:32px}
.toc h3{font-size:1rem;margin-bottom:12px}
.toc ol{padding-left:20px}
.toc li{margin-bottom:6px;font-size:.92rem}

/* Mobile */
@media(max-width:768px){
  .nav-main{display:none;position:absolute;top:100%;left:0;right:0;background:var(--card);flex-direction:column;padding:12px;box-shadow:0 4px 12px rgba(0,0,0,.1)}
  .nav-main.open{display:flex}
  .menu-toggle{display:block}
  .header-inner{position:relative}
  .hero h1{font-size:1.5rem}
  .hero{padding:40px 16px 50px}
  .content-block{grid-template-columns:1fr;gap:24px}
  .content-block.reverse{direction:ltr}
  .section{padding:40px 0}
  .feature-card img{max-height:400px}
}