:root{--dark:#0b0e14;--card:#131722;--card2:#1a2030;--accent:#38bdf8;--accent-dark:#0ea5e9;--text:#e5e7eb;--text-body:#d1d5db;--muted:#9ca3af;--border:#1f2937;--radius:14px}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:"PingFang SC","Microsoft YaHei",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:var(--dark);color:var(--text);line-height:1.7;font-size:16px;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none;transition:color .2s}
a:hover{color:var(--accent-dark)}
img{display:block;max-width:100%}
.container{max-width:1200px;margin:0 auto;padding:0 24px}
/* 顶栏 */
.nav-tech{display:flex;justify-content:space-between;align-items:center;padding:14px 5%;background:rgba(11,14,20,.92);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}
.nav-tech .logo{font-size:18px;font-weight:800;color:var(--accent);display:flex;align-items:center;gap:10px}
.nav-tech .logo img{border-radius:6px}
.nav-tech nav{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.nav-tech nav a{color:var(--muted);font-size:14px;font-weight:500;padding:8px 16px;border-radius:8px}
.nav-tech nav a:hover{color:var(--accent)}
.nav-tech nav a.active{background:var(--accent);color:#0b0e14;font-weight:700}
.sub-btn{background:var(--accent);color:#0b0e14!important;padding:9px 20px;border-radius:8px;font-weight:700!important;font-size:14px}
.sub-btn:hover{background:var(--accent-dark)!important}
/* Hero 虚化背景 + 居中文字 */
.hero{position:relative;text-align:center;padding:110px 0;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;background:url("../images/hero-sky.jpg") center/cover no-repeat;filter:blur(18px);transform:scale(1.15);z-index:0}
.hero::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(11,14,20,.55) 0%,rgba(11,14,20,.82) 60%,var(--dark) 100%);z-index:1}
.hero .container{position:relative;z-index:2}
.hero .hero-text{max-width:780px;margin:0 auto}
.hero .hero-text h1{font-size:46px;font-weight:900;margin-bottom:18px;letter-spacing:-1px;line-height:1.2;color:#fff}
.hero .hero-text h1 .accent{color:var(--accent)}
.hero .hero-text .sub{color:#cbd5e1;font-size:17px;margin-bottom:32px;line-height:1.8}
.hero-btns{display:flex;gap:14px;flex-wrap:wrap;justify-content:center}
.btn-accent{background:var(--accent);color:#0b0e14;padding:14px 34px;border-radius:8px;font-weight:700;font-size:16px;display:inline-block;box-shadow:0 8px 24px rgba(56,189,248,.35)}
.btn-accent:hover{background:var(--accent-dark);color:#0b0e14}
.btn-ghost{border:1px solid rgba(255,255,255,.35);color:#fff;padding:14px 34px;border-radius:8px;font-weight:600;font-size:16px;display:inline-block;background:rgba(255,255,255,.06)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
/* 区块 */
.section{padding:60px 0}
.section-title{font-size:30px;font-weight:800;color:#fff;text-align:center;margin-bottom:12px;letter-spacing:-.5px}
.section-sub{color:var(--muted);font-size:16px;text-align:center;margin-bottom:44px;max-width:640px;margin-left:auto;margin-right:auto}
/* 图片卡片网格 */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}
.img-card{background:var(--card);border-radius:var(--radius);overflow:hidden;border:1px solid var(--border);transition:transform .25s,border-color .25s}
.img-card:hover{transform:translateY(-6px);border-color:var(--accent)}
.img-card .card-img{height:190px;overflow:hidden;position:relative}
.img-card .card-img img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.img-card:hover .card-img img{transform:scale(1.06)}
.img-card .card-body{padding:22px}
.img-card .card-tag{display:inline-block;background:rgba(56,189,248,.14);color:var(--accent);padding:4px 12px;border-radius:6px;font-size:12px;font-weight:600;margin-bottom:10px}
.img-card .card-body h3{font-size:18px;color:#fff;margin-bottom:8px}
.img-card .card-body p{color:var(--muted);font-size:14px;line-height:1.7}
/* 正文区 */
.content-section{background:var(--card);border-radius:var(--radius);padding:44px;border:1px solid var(--border)}
.content-section h2{font-size:23px;color:#fff;margin:28px 0 12px}
.content-section h2:first-child{margin-top:0}
.content-section p{margin-bottom:14px;color:var(--text-body);line-height:1.9}
.content-section ul,.content-section ol{margin:14px 0;padding-left:24px;color:var(--text-body)}
.content-section li{margin-bottom:8px}
.content-section strong{color:var(--accent)}
/* FAQ */
.faq-item{border-bottom:1px solid var(--border);padding:20px 0}
.faq-item:last-child{border-bottom:none}
.faq-item h2{font-size:18px;color:#fff;margin-bottom:8px;margin-top:0}
.faq-item p{color:var(--muted);line-height:1.8}
/* 页面头 */
.page-head{padding:56px 0 0;text-align:center}
.page-head h1{font-size:36px;font-weight:900;color:#fff;margin-bottom:12px;letter-spacing:-.5px}
.page-head p{color:var(--muted);font-size:16px;max-width:640px;margin:0 auto}
/* 文章 */
article{background:var(--card);border-radius:var(--radius);padding:0 0 36px;border:1px solid var(--border);max-width:860px;margin:40px auto;overflow:hidden}
article .art-hero{height:280px;overflow:hidden}
article .art-hero img{width:100%;height:100%;object-fit:cover}
article .art-body{padding:32px 40px 0}
article h1{font-size:30px;font-weight:800;color:#fff;margin-bottom:10px;letter-spacing:-.5px}
.meta{font-size:13px;color:var(--muted);margin-bottom:26px;padding-bottom:18px;border-bottom:1px solid var(--border)}
article h2{font-size:22px;color:#fff;margin:30px 0 12px}
article p{margin-bottom:14px;color:var(--text-body);line-height:1.9}
article ul,article ol{margin:0 0 18px 24px;color:var(--text-body)}
article li{margin-bottom:8px}
article strong{color:var(--accent)}
/* CTA */
.cta-strip{background:linear-gradient(135deg,#0e3a47,#0b2b38);text-align:center;padding:64px 24px;border-radius:var(--radius);margin:40px auto}
.cta-strip h2{font-size:28px;margin-bottom:12px;color:#fff}
.cta-strip p{opacity:.85;margin-bottom:28px;color:var(--text-body)}
/* footer */
footer{background:var(--card);padding:48px 5% 30px;border-top:1px solid var(--border)}
footer .f-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:20px}
footer h4{color:#fff;font-size:15px;margin-bottom:12px}
footer a{color:var(--muted);display:block;margin-bottom:8px;font-size:13px}
footer a:hover{color:var(--accent)}
footer .f-bot{border-top:1px solid var(--border);padding-top:20px;text-align:center;font-size:13px;color:var(--muted)}
@media(max-width:768px){
  .nav-tech{flex-direction:column;gap:10px;padding:12px 5%}
  .nav-tech nav{justify-content:center}
  .nav-tech nav a{padding:6px 12px;font-size:13px}
  .hero{padding:70px 0}
  .hero .hero-text h1{font-size:28px}
  .card-grid{grid-template-columns:1fr 1fr}
  .content-section{padding:24px}
  article .art-body{padding:24px 24px 0}
  footer .f-grid{grid-template-columns:1fr 1fr}
  body{font-size:16px}
}
@media(max-width:480px){
  .hero-btns{flex-direction:column}
  .card-grid{grid-template-columns:1fr}
  .nav-tech nav a{padding:5px 8px;font-size:12px}
}