/* ============================================================
   VOLTMAX TOOLS — B2B 外贸独立站样式
   说明：占位品牌，正式品牌名确定后全局替换即可
   配色：深蓝 #0f2b46 主色 / 橙 #e8762d 强调色（CTA/WhatsApp）
   ============================================================ */
:root{
  --navy:#0f2b46; --navy-2:#16395c; --ink:#1c2530; --muted:#5b6b7c;
  --line:#e3e8ee; --bg:#ffffff; --bg-soft:#f5f7fa; --accent:#e8762d;
  --accent-dark:#c95f1d; --wa:#25d366; --radius:10px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:"Segoe UI",Arial,"Helvetica Neue",sans-serif;color:var(--ink);
  background:var(--bg);line-height:1.65;font-size:16px}
img{max-width:100%;display:block}
a{color:var(--navy);text-decoration:none}
.container{max-width:1120px;margin:0 auto;padding:0 20px}

/* ---------- 顶部导航 ---------- */
.topbar{background:var(--navy);color:#cfe0f0;font-size:13px}
.topbar .container{display:flex;justify-content:space-between;align-items:center;
  min-height:38px;gap:12px;flex-wrap:wrap}
.topbar a{color:#fff}
header.site{position:sticky;top:0;z-index:50;background:#fff;
  border-bottom:1px solid var(--line);box-shadow:0 1px 4px rgba(15,43,70,.06)}
.nav{display:flex;align-items:center;justify-content:space-between;
  min-height:66px;gap:16px;flex-wrap:wrap}
.logo{font-size:22px;font-weight:700;color:var(--navy);letter-spacing:.5px}
.logo span{color:var(--accent)}
nav.menu{display:flex;gap:26px;flex-wrap:wrap}
nav.menu a{font-weight:600;font-size:15px;color:var(--ink);padding:6px 0;
  border-bottom:2px solid transparent}
nav.menu a:hover,nav.menu a.active{color:var(--navy);border-color:var(--accent)}

/* ---------- 按钮 ---------- */
.btn{display:inline-block;padding:12px 26px;border-radius:8px;font-weight:700;
  font-size:15px;transition:.15s;border:2px solid transparent}
.btn-accent{background:var(--accent);color:#fff}
.btn-accent:hover{background:var(--accent-dark)}
.btn-ghost{border-color:#fff;color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.12)}
.btn-navy{background:var(--navy);color:#fff}
.btn-navy:hover{background:var(--navy-2)}

/* ---------- Hero ---------- */
.hero{background:linear-gradient(rgba(15,43,70,.82),rgba(15,43,70,.82)),
  url("../img/hero.jpg") center/cover no-repeat;color:#fff;
  padding:96px 0;text-align:center}
.hero h1{font-size:40px;line-height:1.25;max-width:820px;margin:0 auto 18px}
.hero p{font-size:18px;max-width:720px;margin:0 auto 30px;color:#d9e4ef}
.hero .btn{margin:0 8px 10px}

/* ---------- 信任条 ---------- */
.trust{background:var(--navy-2);color:#e8f0f8;padding:14px 0}
.trust .container{display:flex;justify-content:center;gap:34px;flex-wrap:wrap;
  font-size:14px;font-weight:600;letter-spacing:.3px}

/* ---------- 区块通用 ---------- */
section{padding:72px 0}
section.alt{background:var(--bg-soft)}
.kicker{color:var(--accent);font-weight:700;font-size:13px;letter-spacing:2px;
  text-transform:uppercase;margin-bottom:10px}
h2.sec{font-size:30px;color:var(--navy);margin-bottom:14px;line-height:1.3}
p.sec-lead{color:var(--muted);max-width:760px;margin-bottom:38px}

/* ---------- 产品卡片 ---------- */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;transition:.15s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-3px);box-shadow:0 8px 22px rgba(15,43,70,.10)}
.card .ph{background:#e9edf2;aspect-ratio:4/3;display:flex;align-items:center;
  justify-content:center;color:#9aa7b5;font-size:13px}
.card .body{padding:18px 18px 20px;display:flex;flex-direction:column;gap:8px;flex:1}
.card h3{font-size:17px;color:var(--navy)}
.card .spec{font-size:13.5px;color:var(--muted)}
.card .more{margin-top:auto;padding-top:10px;font-weight:700;color:var(--accent);font-size:14px}

/* ---------- 卖点 / 平台区 ---------- */
.feature{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 22px}
.feature .ic{width:46px;height:46px;border-radius:10px;background:var(--bg-soft);
  display:flex;align-items:center;justify-content:center;margin-bottom:14px;
  color:var(--navy);font-size:22px;font-weight:700}
.feature h3{font-size:17px;color:var(--navy);margin-bottom:8px}
.feature p{font-size:14.5px;color:var(--muted)}
.split{display:grid;grid-template-columns:1.05fr .95fr;gap:46px;align-items:center}
.compare{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  font-size:14.5px}
.compare div{display:grid;grid-template-columns:1fr 1fr}
.compare .head{background:var(--navy);color:#fff;font-weight:700}
.compare .head span{padding:12px 16px}
.compare .row span{padding:11px 16px;border-top:1px solid var(--line)}
.compare .row span:first-child{color:var(--muted)}
.compare .row span:last-child{font-weight:600;color:var(--navy)}

/* ---------- 参数表 / 单品页 ---------- */
.p-layout{display:grid;grid-template-columns:1.05fr .95fr;gap:44px;align-items:start}
.p-layout .ph{background:#e9edf2;border-radius:var(--radius);aspect-ratio:4/3;
  display:flex;align-items:center;justify-content:center;color:#9aa7b5}
.p-layout h1{font-size:30px;color:var(--navy);line-height:1.3;margin-bottom:10px}
.p-sub{color:var(--muted);margin-bottom:22px}
.spec-table{width:100%;border-collapse:collapse;font-size:14.5px;margin:18px 0 24px}
.spec-table th,.spec-table td{border:1px solid var(--line);padding:10px 14px;text-align:left}
.spec-table th{background:var(--bg-soft);width:42%;color:var(--navy)}
.badges{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:22px}
.badge{background:var(--bg-soft);border:1px solid var(--line);color:var(--navy);
  padding:6px 14px;border-radius:999px;font-size:13px;font-weight:700}

/* ---------- FAQ ---------- */
.faq details{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:18px 22px;margin-bottom:12px}
.faq summary{font-weight:700;color:var(--navy);cursor:pointer;font-size:15.5px}
.faq details p{margin-top:10px;color:var(--muted);font-size:14.5px}

/* ---------- CTA 条 ---------- */
.cta-band{background:var(--navy);color:#fff;text-align:center;padding:64px 0}
.cta-band h2{font-size:28px;margin-bottom:12px}
.cta-band p{color:#c8d6e4;margin-bottom:26px}

/* ---------- 页脚 ---------- */
footer.site{background:#0b2036;color:#9fb2c5;padding:52px 0 26px;font-size:14px}
footer.site h4{color:#fff;font-size:15px;margin-bottom:14px}
.f-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1.1fr;gap:36px;margin-bottom:34px}
.f-grid a{display:block;margin-bottom:8px;color:#9fb2c5}
.f-grid a:hover{color:#fff}
.copyright{border-top:1px solid rgba(255,255,255,.12);padding-top:20px;
  display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;font-size:13px}

/* ---------- WhatsApp 悬浮按钮 ---------- */
.wa-float{position:fixed;right:22px;bottom:22px;z-index:99;width:60px;height:60px;
  border-radius:50%;background:var(--wa);display:flex;align-items:center;
  justify-content:center;box-shadow:0 6px 18px rgba(0,0,0,.25)}
.wa-float svg{width:32px;height:32px;fill:#fff}

/* ---------- 表单 ---------- */
.form{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:28px}
.form label{display:block;font-weight:700;font-size:14px;margin:14px 0 6px;color:var(--navy)}
.form input,.form select,.form textarea{width:100%;padding:11px 13px;
  border:1px solid var(--line);border-radius:8px;font-size:15px;font-family:inherit}
.form input:focus,.form select:focus,.form textarea:focus{outline:2px solid var(--accent);border-color:transparent}
.form .btn{margin-top:20px;width:100%}
.contact-grid{display:grid;grid-template-columns:1fr 1.2fr;gap:44px;align-items:start}
.contact-item{display:flex;gap:14px;margin-bottom:20px}
.contact-item .ic{width:42px;height:42px;border-radius:10px;background:var(--bg-soft);
  display:flex;align-items:center;justify-content:center;color:var(--navy);font-weight:700}
.contact-item h4{font-size:15px;color:var(--navy)}
.contact-item p{font-size:14px;color:var(--muted)}

/* ---------- 响应式 ---------- */
@media(max-width:900px){
  .grid-3{grid-template-columns:1fr 1fr}
  .grid-4{grid-template-columns:1fr 1fr}
  .split,.p-layout,.contact-grid{grid-template-columns:1fr}
  .f-grid{grid-template-columns:1fr 1fr}
  .hero h1{font-size:30px}
  h2.sec{font-size:25px}
  section{padding:52px 0}
}
@media(max-width:600px){
  .grid-3,.grid-4{grid-template-columns:1fr}
  .f-grid{grid-template-columns:1fr}
  nav.menu{gap:16px}
  .hero{padding:64px 0}
}