/* 基础主题 */
:root{
  --bg:#0e1a22;
  --card:#112430;
  --ink:#e9f3f7;
  --muted:#a9c1cc;
  --brand:#27d2cc;
  --btn:#2b8cff;
  --btn-ghost:rgba(255,255,255,.08);
  --ring:rgba(39,210,204,.25);
  --radius:18px;
  --container: 1080px;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font:16px/1.6 -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,"Noto Sans SC","PingFang SC","Hiragino Sans GB",sans-serif;
  color:var(--ink);
  background: radial-gradient(1000px 500px at 50% -20%, #132936 0%, transparent 60%) , var(--bg);
}
.container{
  width: min(100% - 32px, var(--container));
  margin: 0 auto;
}

/* 顶部导航：与主容器严格对齐 */
.site-header{
  position:sticky; top:0; z-index:10;
  background: linear-gradient(180deg, rgba(6,14,20,.85), rgba(6,14,20,.65));
  backdrop-filter: blur(8px);
  border-bottom:1px solid rgba(255,255,255,.06);
}
.header-inner{
  display:flex; align-items:center; justify-content:space-between;
  min-height:76px;
}
.brand{display:flex; align-items:center; gap:12px; text-decoration:none}
.brand-logo{width:42px; height:42px; object-fit:cover; border-radius:50%; box-shadow:0 0 0 2px rgba(255,255,255,.06)}
.brand-tagline{color:var(--brand); font-weight:700; letter-spacing:.5px}

.top-actions{display:flex; align-items:center; gap:12px}
.btn-outline{
  display:inline-block; padding:10px 18px; border-radius:14px;
  border:1px solid rgba(255,255,255,.14); color:var(--ink); text-decoration:none;
  background:rgba(255,255,255,.06);
}
.btn-outline:hover{border-color:var(--brand); box-shadow:0 0 0 3px var(--ring) inset}

/* 卡片/文案区域 */
.hero-card{
  margin:28px auto;
  background: linear-gradient(180deg, rgba(17,36,48,.9), rgba(17,36,48,.75));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius);
  padding:28px;
  box-shadow: 0 8px 30px rgba(0,0,0,.25);
}
h1{font-size:clamp(28px, 4vw, 44px); line-height:1.25; margin:0 0 10px}
h2{font-size:clamp(22px, 3vw, 34px); margin:14px 0}
h3{margin:0 0 10px; font-size:22px}
p{color:var(--muted); margin:.4rem 0}

/* 三列内容卡 */
.blocks .cards{
  display:grid; gap:18px;
  grid-template-columns: repeat(3, 1fr);
}
.card{
  background:var(--card); border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius); padding:20px;
}
.card-actions{display:flex; gap:12px; margin-top:12px; flex-wrap:wrap}
.btn{
  display:inline-block; padding:10px 16px; border-radius:12px;
  background:var(--btn); color:#fff; text-decoration:none; border:none;
}
.btn.ghost{background:var(--btn-ghost); color:var(--ink)}

/* 商务合作表单 */
.contact-form{display:grid; gap:14px}
.contact-form .grid{
  display:grid; gap:12px; grid-template-columns: repeat(3,1fr);
}
label{display:grid; gap:6px; color:var(--ink)}
input,textarea{
  width:100%; padding:10px 12px; border-radius:12px; border:1px solid rgba(255,255,255,.12);
  background:#0d1a23; color:var(--ink);
}
input:focus,textarea:focus{outline:none; border-color:var(--brand); box-shadow:0 0 0 3px var(--ring)}
.site-footer{margin:40px 0 24px; color:var(--muted)}

/* 响应式：手机端卡片竖排，保持顶栏对齐 */
@media (max-width: 980px){
  .blocks .cards{grid-template-columns:1fr}
  .contact-form .grid{grid-template-columns:1fr}
  .brand-logo{width:36px;height:36px}
}