*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--ink:#1c1917;--muted:#57534e;--line:#e7e5e4;--accent:#ea580c;--accent2:#0f766e;--bg:#fff;--max:1140px}
html{scroll-behavior:smooth}
body{font-family:"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--ink);line-height:1.78;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--accent2);text-decoration:none}
a:hover{text-decoration:underline}
.shell{max-width:var(--max);margin:0 auto;padding:0 20px}

.site-header{border-bottom:1px solid var(--line);background:#fff;position:sticky;top:0;z-index:100}
.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:64px}
.brand{display:flex;align-items:center;gap:12px;color:var(--ink);text-decoration:none}
.brand img{width:42px;height:42px;border-radius:12px}
.brand strong{display:block;font-size:17px}
.brand small{font-size:11px;color:var(--muted);letter-spacing:.05em}
.primary-nav{display:flex;gap:18px;font-size:14px}
.primary-nav a{color:var(--ink);text-decoration:none}
.menu-toggle{display:none;border:1px solid var(--line);background:#fff;padding:8px 14px;border-radius:8px;cursor:pointer}
.mobile-nav{display:none;flex-direction:column;padding:12px 20px;border-top:1px solid var(--line);background:#fff}
.mobile-nav.open{display:flex}
.mobile-nav a{padding:10px 0;border-bottom:1px solid var(--line);color:var(--ink);text-decoration:none}
.ads-wrap{border-bottom:1px solid var(--line);padding:8px 0;background:#fafaf9}

.hero{padding:52px 0 36px;text-align:center;border-bottom:1px solid var(--line)}
.hero-kicker{font-size:12px;letter-spacing:.18em;color:var(--accent);margin-bottom:14px}
.hero h1{font-family:Georgia,serif;font-size:clamp(28px,4vw,40px);line-height:1.28;margin-bottom:18px;max-width:820px;margin-left:auto;margin-right:auto}
.hero-lead{font-size:18px;color:#444;max-width:680px;margin:0 auto 20px}
.hero-note{font-size:14px;color:var(--muted)}

.tri-features{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;padding:48px 0;border-bottom:1px solid var(--line)}
.feat-card{border:1px solid var(--line);border-radius:14px;padding:28px 24px;background:#fff}
.feat-card .num{font-size:32px;font-weight:700;color:var(--accent);opacity:.35;line-height:1;margin-bottom:12px}
.feat-card h3{font-size:18px;margin-bottom:10px}
.feat-card p{font-size:14px;color:var(--muted);line-height:1.7}

.content{padding:48px 0;border-bottom:1px solid var(--line)}
.content h2{font-family:Georgia,serif;font-size:26px;margin-bottom:16px}
.content h3{font-size:17px;margin:28px 0 10px;color:var(--accent2)}
.content p{margin-bottom:16px;color:#333;text-align:justify}
.content ul,.content ol{margin:0 0 16px 22px;color:#333}
.content li{margin-bottom:8px}

.preview-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:28px 0}
.preview-grid figure{border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#fff}
.preview-grid figcaption{padding:10px 12px;font-size:13px;color:var(--muted)}

.faq{padding:48px 0}
.faq-item{padding:18px 0;border-bottom:1px solid var(--line)}
.faq-item h4{font-size:16px;margin-bottom:8px}
.faq-item p{font-size:15px;color:var(--muted)}

.read-row{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:28px}
.read-row a{display:block;border:1px solid var(--line);border-radius:10px;padding:18px;color:var(--ink);text-decoration:none}
.read-row a:hover{border-color:var(--accent);box-shadow:0 4px 16px rgba(0,0,0,.04)}
.read-row span{font-size:13px;color:var(--muted);display:block;margin-top:6px}

.page-hero{padding:40px 0 20px;border-bottom:1px solid var(--line)}
.page-hero h1{font-family:Georgia,serif;font-size:30px;margin-bottom:10px}
.article{max-width:740px;padding:32px 0 48px}
.article p{margin-bottom:16px;text-align:justify;color:#333}
.article h2{font-size:21px;margin:28px 0 12px}
.related{margin-top:36px;padding:20px;background:#fafaf9;border-radius:10px;border:1px solid var(--line)}
.related h3{font-size:15px;margin-bottom:10px}

.site-footer{background:#fafaf9;border-top:1px solid var(--line);padding:32px 0;margin-top:40px;font-size:14px;color:var(--muted)}
.footer-links{display:flex;flex-wrap:wrap;gap:16px;margin-bottom:10px}
.footer-links a{color:var(--muted)}
.error-page{min-height:55vh;display:flex;align-items:center;justify-content:center;text-align:center;padding:40px}
.error-page h1{font-size:64px;color:var(--line)}

@media(max-width:860px){
  .tri-features,.preview-grid,.read-row{grid-template-columns:1fr}
  .primary-nav{display:none}
  .menu-toggle{display:block}
}