/* ===== Clash 落地页 C 版 · 暗色琥珀能量风 + 侧边栏布局 ===== */
:root{
  --bg:#0e0b08;
  --bg-2:#16110b;
  --surface:rgba(255,255,255,.04);
  --surface-2:rgba(255,255,255,.07);
  --line:rgba(255,255,255,.10);
  --text:#f6efe7;
  --muted:#b9a892;
  --amber:#fbbf24;
  --coral:#fb7185;
  --grad:linear-gradient(120deg,#fbbf24,#fb7185);
  --radius:20px;
  --side:268px;
  --shadow:0 20px 50px rgba(0,0,0,.5);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--text);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
.grad-text{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.section-pad{padding:90px 56px}
.eyebrow{display:inline-block;font-size:12px;letter-spacing:3px;font-weight:800;
  color:var(--amber);text-transform:uppercase;margin-bottom:14px}

/* 侧边栏 */
.side{position:fixed;top:0;left:0;bottom:0;width:var(--side);background:var(--bg-2);
  border-right:1px solid var(--line);padding:34px 26px;display:flex;flex-direction:column;z-index:60}
.brand{display:flex;align-items:center;gap:11px;font-weight:900;font-size:21px;margin-bottom:36px}
.brand .bm{width:38px;height:38px;border-radius:11px;background:var(--grad);display:grid;place-items:center;
  color:#1a1206;font-weight:900;font-size:19px}
.brand small{display:block;font-size:11px;color:var(--muted);font-weight:600;letter-spacing:1px}
.side nav{display:flex;flex-direction:column;gap:4px;flex:1}
.side nav a{padding:11px 14px;border-radius:12px;color:var(--muted);font-weight:600;font-size:15px;transition:.2s}
.side nav a:hover{background:var(--surface-2);color:#fff}
.side .cta{margin-top:20px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 24px;
  border-radius:999px;font-weight:700;font-size:15px;cursor:pointer;border:1px solid transparent;transition:.25s;white-space:nowrap}
.btn-primary{background:var(--grad);color:#1a1206;box-shadow:0 12px 30px rgba(251,113,133,.3)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 38px rgba(251,113,133,.45)}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--text)}
.btn-ghost:hover{border-color:var(--amber);color:#fff}
.btn-lg{padding:15px 32px;font-size:16px}
.side .social{margin-top:22px;font-size:13px;color:var(--muted)}

/* 主内容 */
.main{margin-left:var(--side)}
.topbar{display:none}
.hamburger{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer}
.hamburger span{width:24px;height:2px;background:var(--text);border-radius:2px}

/* HERO */
.hero{position:relative;padding:110px 56px 80px;overflow:hidden}
.hero::before{content:"";position:absolute;inset:0;
  background:radial-gradient(50% 60% at 85% 10%,rgba(251,113,133,.20),transparent 60%),
             radial-gradient(40% 50% at 10% 90%,rgba(251,191,36,.16),transparent 60%);pointer-events:none}
.hero-grid{position:relative;display:grid;grid-template-columns:1.15fr .85fr;gap:50px;align-items:center}
.hero h1{font-size:54px;line-height:1.08;font-weight:900;letter-spacing:-1px}
.hero .sub{color:var(--muted);font-size:18px;margin:24px 0 30px;max-width:520px}
.hero .acts{display:flex;gap:14px;flex-wrap:wrap}
.hero .tags{display:flex;gap:10px;flex-wrap:wrap;margin-top:26px}
.hero .tags span{font-size:13px;color:var(--amber);border:1px solid var(--line);
  background:var(--surface);padding:6px 12px;border-radius:999px}

/* 速度仪表视觉 */
.gauge{background:var(--surface);border:1px solid var(--line);border-radius:28px;padding:34px;
  box-shadow:var(--shadow);position:relative;overflow:hidden}
.gauge .ring{width:170px;height:170px;border-radius:50%;margin:0 auto 18px;
  background:conic-gradient(var(--amber) 0 82%,rgba(255,255,255,.08) 82% 100%);
  display:grid;place-items:center;position:relative}
.gauge .ring::after{content:"";position:absolute;width:128px;height:128px;border-radius:50%;background:var(--bg-2)}
.gauge .ring b{position:relative;font-size:38px;font-weight:900}
.gauge .ring b small{font-size:15px;color:var(--muted)}
.gauge .row{display:flex;justify-content:space-between;padding:11px 0;border-bottom:1px solid var(--line);font-size:14px}
.gauge .row:last-child{border:0}
.gauge .row em{color:var(--amber);font-style:normal;font-weight:700}

/* 统计条 */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.stats .s{padding:34px 24px;text-align:center;border-right:1px solid var(--line)}
.stats .s:last-child{border:0}
.stats .s b{display:block;font-size:36px;font-weight:900;background:var(--grad);
  -webkit-background-clip:text;background-clip:text;color:transparent}
.stats .s span{color:var(--muted);font-size:14px}

/* 区块标题 */
.head{max-width:680px;margin:0 auto 50px;text-align:center}
.head h2{font-size:36px;font-weight:900;letter-spacing:-.5px;margin:10px 0 14px}
.head p{color:var(--muted);font-size:16px}

/* 特性：编号列表 */
.feats{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.feat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:28px;transition:.25s}
.feat:hover{border-color:var(--amber);transform:translateY(-3px)}
.feat .n{font-size:13px;font-weight:800;color:var(--coral);letter-spacing:1px}
.feat h3{font-size:20px;margin:8px 0 10px}
.feat p{color:var(--muted);font-size:15px}

/* 全幅强调块 */
.band{background:linear-gradient(120deg,rgba(251,191,36,.12),rgba(251,113,133,.12));
  border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.band-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.band .b{text-align:center}
.band .b .ic{font-size:30px;margin-bottom:10px}
.band .b h3{font-size:18px;margin-bottom:6px}
.band .b p{color:var(--muted);font-size:14px}

/* 步骤：横向 */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.step{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:30px;position:relative}
.step .no{position:absolute;top:-16px;left:24px;width:38px;height:38px;border-radius:12px;
  background:var(--grad);color:#1a1206;display:grid;place-items:center;font-weight:900}
.step h3{font-size:18px;margin:6px 0 8px}
.step p{color:var(--muted);font-size:15px}

/* 协议胶囊 */
.protos{display:flex;flex-wrap:wrap;gap:12px;justify-content:center}
.protos span{background:var(--surface);border:1px solid var(--line);border-radius:999px;
  padding:11px 20px;font-weight:700;font-size:15px;transition:.2s}
.protos span:hover{border-color:var(--amber);color:var(--amber)}

/* FAQ */
.faqs{max-width:820px;margin:0 auto;display:grid;gap:14px}
.faq{background:var(--surface);border:1px solid var(--line);border-radius:14px;overflow:hidden}
.faq summary{padding:18px 22px;cursor:pointer;font-weight:700;font-size:16px;list-style:none;
  display:flex;justify-content:space-between;align-items:center;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:22px;color:var(--amber);font-weight:800}
.faq[open] summary::after{content:"−"}
.faq-body{padding:0 22px 20px;color:var(--muted);font-size:15px}

/* CTA */
.cta-band{text-align:center;padding:84px 56px}
.cta-band h2{font-size:34px;font-weight:900;margin-bottom:12px}
.cta-band p{color:var(--muted);font-size:17px;margin-bottom:26px}

/* 页脚 */
.foot{border-top:1px solid var(--line);padding:50px 56px 30px;background:var(--bg-2)}
.foot-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:30px}
.foot p.d{color:var(--muted);font-size:14px;margin-top:14px;max-width:320px}
.foot h4{font-size:15px;margin-bottom:16px;color:#fff}
.foot a{display:block;color:var(--muted);font-size:14px;margin-bottom:10px}
.foot a:hover{color:#fff}
.foot .kw{display:inline-block;background:var(--surface);border:1px solid var(--line);border-radius:8px;
  padding:5px 10px;font-size:13px;color:var(--muted);margin:0 6px 6px 0}
.foot-bottom{margin-top:34px;padding-top:22px;border-top:1px solid var(--line);
  display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;color:var(--muted);font-size:13px}

/* 返回顶部 */
.to-top{position:fixed;right:24px;bottom:24px;width:46px;height:46px;border-radius:50%;
  background:var(--grad);color:#1a1206;display:grid;place-items:center;font-size:20px;font-weight:900;
  opacity:0;pointer-events:none;transition:.3s;z-index:40}
.to-top.show{opacity:1;pointer-events:auto}

/* 响应式 */
@media(max-width:1100px){
  .hero-grid{grid-template-columns:1fr;gap:34px}
  .stats{grid-template-columns:repeat(2,1fr)}
  .stats .s:nth-child(2){border-right:0}
  .feats,.band-grid,.steps{grid-template-columns:1fr}
}
@media(max-width:860px){
  :root{--side:0px}
  .side{transform:translateX(-100%);transition:.3s;width:280px}
  .side.open{transform:translateX(0)}
  .main{margin-left:0}
  .topbar{display:flex;position:sticky;top:0;z-index:55;align-items:center;justify-content:space-between;
    padding:14px 18px;background:rgba(14,11,8,.9);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
  .hamburger{display:flex}
  .section-pad,.hero,.cta-band,.foot{padding-left:20px;padding-right:20px}
  .hero{padding-top:60px}
  .hero h1{font-size:36px}
  .head h2{font-size:26px}
  .foot-grid{grid-template-columns:1fr}
  .foot-bottom{flex-direction:column}
  .stats{grid-template-columns:repeat(2,1fr)}
}