/* 阳麦科技YanMi 频道宣传站 —— 黑白科技风 */
:root{
  --black:#0a0a0a;
  --ink:#161616;
  --card:#ffffff;
  --line:#e8e8e8;
  --muted:#6b6b6b;
  --red:#ff0033;
  --radius:14px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif;
  background:#fafafa;color:var(--ink);line-height:1.7;
}
img{display:block;max-width:100%}
a{text-decoration:none;color:inherit}
.container{max-width:1080px;margin:0 auto;padding:0 24px}
.section{padding:88px 0}
.section-alt{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section-title{font-size:30px;letter-spacing:2px;text-align:center;margin-bottom:12px;position:relative}
.section-title::after{content:"";display:block;width:56px;height:3px;background:var(--black);margin:16px auto 0}
.section-sub{text-align:center;color:var(--muted);margin-bottom:48px}

/* 导航 */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;background:rgba(255,255,255,.88);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav-inner{max-width:1080px;margin:0 auto;padding:12px 24px;display:flex;align-items:center;gap:28px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:17px}
.brand img{width:34px;height:34px;border-radius:50%;border:1px solid var(--line)}
.nav-links{display:flex;gap:24px;margin-left:auto;font-size:15px;color:#333}
.nav-links a{position:relative;padding:4px 0}
.nav-links a:hover{color:var(--black)}
.nav-links a::after{content:"";position:absolute;left:0;bottom:0;width:0;height:2px;background:var(--black);transition:width .25s}
.nav-links a:hover::after{width:100%}
.btn{display:inline-block;padding:10px 26px;border-radius:999px;font-size:15px;font-weight:600;transition:transform .15s,box-shadow .15s;white-space:nowrap}
.btn:hover{transform:translateY(-2px)}
.btn-sub{background:var(--red);color:#fff;box-shadow:0 6px 18px rgba(255,0,51,.28)}
.btn-ghost{background:rgba(255,255,255,.12);color:#fff;border:1px solid rgba(255,255,255,.55)}
.btn-outline{border:2px solid var(--black);color:var(--black);background:#fff}

/* Hero */
.hero{position:relative;min-height:96vh;display:flex;align-items:center;justify-content:center;text-align:center;color:#fff;overflow:hidden;padding:120px 24px 80px}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:center}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(5,5,5,.72) 0%,rgba(5,5,5,.55) 45%,rgba(5,5,5,.85) 100%)}
.hero-content{position:relative;z-index:2;max-width:720px}
.hero-avatar{width:150px;height:150px;border-radius:50%;margin:0 auto 22px;border:5px solid #fff;box-shadow:0 12px 40px rgba(0,0,0,.5);background:#fff}
.hero h1{font-size:44px;letter-spacing:4px;margin-bottom:6px}
.handle{color:#d7d7d7;font-size:17px;margin-bottom:26px}
.tagline{font-size:18px;color:#eee;margin-bottom:34px}
.hero-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

/* 频道简介 */
.about-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:48px;display:grid;grid-template-columns:1.6fr 1fr;gap:48px;box-shadow:0 10px 34px rgba(0,0,0,.05)}
.greeting{font-size:20px;font-weight:700;margin-bottom:14px}
.about-text p{margin-bottom:14px;color:#333}
.about-facts{display:flex;flex-direction:column;gap:18px;justify-content:center;border-left:1px solid var(--line);padding-left:36px}
.fact span{display:block;font-size:13px;color:var(--muted);letter-spacing:1px}
.fact strong{font-size:19px}

/* 频道方向 */
.topics-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.topic-card{background:#fafafa;border:1px solid var(--line);border-radius:var(--radius);padding:34px 26px;transition:transform .2s,box-shadow .2s,background .2s}
.topic-card:hover{transform:translateY(-6px);box-shadow:0 16px 34px rgba(0,0,0,.09);background:#fff}
.topic-icon{font-size:38px;margin-bottom:16px}
.topic-card h3{font-size:17px;margin-bottom:10px}
.topic-card p{font-size:14px;color:var(--muted)}

/* 精选视频 */
.videos-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.video-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:transform .2s,box-shadow .2s;display:block}
.video-card:hover{transform:translateY(-6px);box-shadow:0 18px 40px rgba(0,0,0,.12)}
.thumb{position:relative;aspect-ratio:16/9;overflow:hidden;background:#000}
.thumb img{width:100%;height:100%;object-fit:cover;transition:transform .35s}
.video-card:hover .thumb img{transform:scale(1.05)}
.play{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:58px;height:58px;border-radius:50%;background:rgba(0,0,0,.62);color:#fff;display:flex;align-items:center;justify-content:center;font-size:20px;transition:background .2s}
.video-card:hover .play{background:var(--red)}
.video-info{padding:18px 20px 22px}
.video-info h3{font-size:15px;line-height:1.55;margin-bottom:10px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;min-height:47px}
.video-info p{font-size:13px;color:var(--muted)}
.more-videos{text-align:center;margin-top:44px}

/* 关注我 */
.social-row{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.social-btn{display:flex;align-items:center;gap:14px;background:#fafafa;border:1px solid var(--line);border-radius:var(--radius);padding:20px;transition:transform .2s,box-shadow .2s,background .2s}
.social-btn:hover{transform:translateY(-4px);box-shadow:0 12px 28px rgba(0,0,0,.08);background:#fff}
.social-btn strong{display:block;font-size:15px}
.social-btn span{font-size:13px;color:var(--muted)}
.social-icon{width:46px;height:46px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:20px;color:#fff;flex-shrink:0}
.social-icon.yt{background:var(--red)}
.social-icon.x{background:#000}
.social-icon.tg{background:#229ED9}
.social-icon.web{background:#333}

/* 页脚 */
.footer{background:var(--black);color:#bbb;text-align:center;padding:52px 24px;font-size:14px}
.footer-avatar{width:64px;height:64px;border-radius:50%;margin:0 auto 16px;border:2px solid #444;background:#fff}
.footer-note{font-size:12px;color:#777;margin-top:8px}

/* 滚动显现 */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s ease,transform .7s ease}
.reveal.visible{opacity:1;transform:none}

/* 响应式 */
@media(max-width:900px){
  .topics-grid{grid-template-columns:repeat(2,1fr)}
  .videos-grid{grid-template-columns:repeat(2,1fr)}
  .social-row{grid-template-columns:repeat(2,1fr)}
  .about-card{grid-template-columns:1fr;padding:32px}
  .about-facts{border-left:none;border-top:1px solid var(--line);padding-left:0;padding-top:24px}
  .nav-links{display:none}
}
@media(max-width:560px){
  .hero h1{font-size:32px;letter-spacing:2px}
  .videos-grid{grid-template-columns:1fr}
  .topics-grid{grid-template-columns:1fr}
  .section{padding:64px 0}
  .nav-inner{gap:14px}
  .nav .btn-sub{padding:8px 18px;font-size:14px}
}