*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --primary:#e74c3c;
  --primary-dark:#c0392b;
  --secondary:#2c3e50;
  --accent:#3498db;
  --bg:#f8f9fa;
  --text:#333;
  --text-light:#666;
  --white:#fff;
  --shadow:0 4px 20px rgba(0,0,0,.08);
  --radius:8px;
}
html{scroll-behavior:smooth}
body{font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",Arial,sans-serif;color:var(--text);line-height:1.7;background:var(--bg)}
a{color:var(--accent);text-decoration:none;transition:color .2s}
a:hover{color:var(--primary)}
img{max-width:100%;height:auto}
.container{max-width:1200px;margin:0 auto;padding:0 20px}

/* Header */
.site-header{background:var(--white);box-shadow:var(--shadow);position:sticky;top:0;z-index:1000}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:14px 0}
.logo{display:flex;align-items:center;gap:10px;font-size:1.4rem;font-weight:700;color:var(--primary)}
.logo-icon{width:36px;height:36px;background:var(--primary);border-radius:6px;display:flex;align-items:center;justify-content:center;color:var(--white);font-weight:800;font-size:1.1rem}
.nav-menu{display:flex;gap:28px;list-style:none}
.nav-menu a{color:var(--secondary);font-weight:500;font-size:.95rem}
.nav-menu a:hover,.nav-menu a.active{color:var(--primary)}
.btn-download-header{background:var(--primary);color:var(--white)!important;padding:8px 22px;border-radius:var(--radius);font-weight:600}
.btn-download-header:hover{background:var(--primary-dark);color:var(--white)!important}
.menu-toggle{display:none;background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--secondary)}

/* Hero */
.hero{background:linear-gradient(135deg,#e74c3c 0%,#c0392b 50%,#2c3e50 100%);color:var(--white);padding:80px 0 90px;text-align:center}
.hero h1{font-size:2.6rem;margin-bottom:18px;font-weight:700;line-height:1.3}
.hero p{font-size:1.15rem;opacity:.92;max-width:680px;margin:0 auto 32px}
.btn-primary{display:inline-block;background:var(--white);color:var(--primary);padding:14px 40px;border-radius:var(--radius);font-size:1.05rem;font-weight:700;transition:transform .2s,box-shadow .2s}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 24px rgba(0,0,0,.2);color:var(--primary)}
.btn-outline{display:inline-block;border:2px solid var(--white);color:var(--white);padding:12px 32px;border-radius:var(--radius);font-weight:600;margin-left:12px}
.btn-outline:hover{background:rgba(255,255,255,.15);color:var(--white)}

/* Sections */
.section{padding:70px 0}
.section-title{text-align:center;margin-bottom:50px}
.section-title h2{font-size:2rem;color:var(--secondary);margin-bottom:10px}
.section-title p{color:var(--text-light);font-size:1.05rem}
.section-alt{background:var(--white)}

/* Features Grid */
.features-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:30px}
.feature-card{background:var(--white);padding:36px 28px;border-radius:var(--radius);box-shadow:var(--shadow);text-align:center;transition:transform .3s}
.feature-card:hover{transform:translateY(-6px)}
.feature-icon{width:64px;height:64px;background:linear-gradient(135deg,var(--primary),var(--primary-dark));border-radius:50%;display:flex;align-items:center;justify-content:center;margin:0 auto 20px;font-size:1.6rem;color:var(--white)}
.feature-card h3{font-size:1.2rem;margin-bottom:12px;color:var(--secondary)}
.feature-card p{color:var(--text-light);font-size:.95rem}

/* Stats */
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center}
.stat-item{padding:30px 16px}
.stat-number{font-size:2.4rem;font-weight:800;color:var(--primary);margin-bottom:6px}
.stat-label{color:var(--text-light);font-size:.95rem}

/* Reviews */
.reviews-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.review-card{background:var(--bg);padding:30px;border-radius:var(--radius);border-left:4px solid var(--primary)}
.review-card p{font-style:italic;color:var(--text-light);margin-bottom:16px;line-height:1.8}
.review-author{font-weight:600;color:var(--secondary)}

/* Security */
.security-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.security-card{padding:28px;background:var(--bg);border-radius:var(--radius)}
.security-card h3{font-size:1.1rem;margin-bottom:10px;color:var(--secondary)}
.security-card p{color:var(--text-light);font-size:.93rem}

/* FAQ */
.faq-list{max-width:860px;margin:0 auto}
.faq-item{background:var(--white);margin-bottom:12px;border-radius:var(--radius);box-shadow:0 2px 8px rgba(0,0,0,.04);overflow:hidden}
.faq-question{padding:18px 24px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:600;color:var(--secondary);user-select:none}
.faq-question::after{content:"+";font-size:1.4rem;color:var(--primary);transition:transform .3s}
.faq-item.active .faq-question::after{transform:rotate(45deg)}
.faq-answer{max-height:0;overflow:hidden;transition:max-height .4s ease;padding:0 24px}
.faq-item.active .faq-answer{max-height:600px;padding:0 24px 18px}
.faq-answer p{color:var(--text-light);font-size:.93rem;line-height:1.8}

/* Daily Update */
.daily-update{background:linear-gradient(135deg,#fff5f5,#fff);border:1px solid #fde8e8;border-radius:var(--radius);padding:28px 32px;margin-bottom:40px}
.daily-update .tag{display:inline-block;background:var(--primary);color:var(--white);font-size:.8rem;padding:3px 12px;border-radius:20px;margin-bottom:12px}
.daily-update h3{font-size:1.25rem;color:var(--secondary);margin-bottom:10px}
.daily-update p{color:var(--text-light);margin-bottom:8px}
.daily-update .date{color:var(--primary);font-size:.85rem;font-weight:600}

/* Download Page */
.download-hero{padding:60px 0;text-align:center;background:var(--white)}
.download-hero h1{font-size:2.2rem;color:var(--secondary);margin-bottom:12px}
.download-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;margin-top:40px}
.download-card{background:var(--bg);padding:40px 28px;border-radius:var(--radius);text-align:center;transition:box-shadow .3s}
.download-card:hover{box-shadow:var(--shadow)}
.download-card .os-icon{font-size:3rem;margin-bottom:16px}
.download-card h3{margin-bottom:8px;color:var(--secondary)}
.download-card p{color:var(--text-light);font-size:.9rem;margin-bottom:20px}
.btn-download{display:inline-block;background:var(--primary);color:var(--white);padding:12px 36px;border-radius:var(--radius);font-weight:600;transition:background .2s}
.btn-download:hover{background:var(--primary-dark);color:var(--white)}
.download-steps{max-width:700px;margin:50px auto 0}
.download-steps h2{text-align:center;margin-bottom:30px;color:var(--secondary)}
.step-item{display:flex;gap:16px;margin-bottom:20px;align-items:flex-start}
.step-num{width:36px;height:36px;background:var(--primary);color:var(--white);border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;flex-shrink:0}
.step-text h4{margin-bottom:4px;color:var(--secondary)}
.step-text p{color:var(--text-light);font-size:.93rem}

/* Article */
.article-header{background:var(--white);padding:50px 0 30px}
.article-header h1{font-size:2rem;color:var(--secondary);margin-bottom:12px;line-height:1.4}
.article-meta{color:var(--text-light);font-size:.9rem;margin-bottom:8px}
.article-body{max-width:800px;margin:0 auto;padding:30px 20px 60px}
.article-body h2{font-size:1.4rem;color:var(--secondary);margin:30px 0 14px;padding-left:12px;border-left:4px solid var(--primary)}
.article-body h3{font-size:1.15rem;color:var(--secondary);margin:24px 0 10px}
.article-body p{margin-bottom:16px;color:var(--text-light);line-height:1.9}
.article-body ul,.article-body ol{margin:12px 0 16px 24px;color:var(--text-light)}
.article-body li{margin-bottom:8px;line-height:1.8}
.article-nav{display:flex;justify-content:space-between;margin-top:40px;padding-top:24px;border-top:1px solid #eee}
.articles-list{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.article-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:transform .3s}
.article-card:hover{transform:translateY(-4px)}
.article-card-body{padding:24px}
.article-card h3{font-size:1.1rem;margin-bottom:10px;color:var(--secondary)}
.article-card p{color:var(--text-light);font-size:.9rem;margin-bottom:14px}
.read-more{color:var(--primary);font-weight:600;font-size:.9rem}

/* Footer */
.site-footer{background:var(--secondary);color:rgba(255,255,255,.8);padding:50px 0 24px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px;margin-bottom:36px}
.footer-grid h4{color:var(--white);margin-bottom:16px;font-size:1rem}
.footer-grid p,.footer-grid li{font-size:.9rem;line-height:2}
.footer-grid ul{list-style:none}
.footer-grid a{color:rgba(255,255,255,.7)}
.footer-grid a:hover{color:var(--white)}
.footer-bottom{text-align:center;padding-top:24px;border-top:1px solid rgba(255,255,255,.1);font-size:.85rem}

/* Responsive */
@media(max-width:992px){
  .features-grid,.reviews-grid,.security-grid,.download-cards,.articles-list{grid-template-columns:repeat(2,1fr)}
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:768px){
  .nav-menu{display:none;position:absolute;top:100%;left:0;right:0;background:var(--white);flex-direction:column;padding:16px 20px;gap:12px;box-shadow:var(--shadow)}
  .nav-menu.open{display:flex}
  .menu-toggle{display:block}
  .hero h1{font-size:1.8rem}
  .hero{padding:50px 0 60px}
  .btn-outline{display:block;margin:16px auto 0;width:fit-content}
  .features-grid,.reviews-grid,.security-grid,.download-cards,.articles-list,.stats-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
}