/* =========================================================
   SMSZone 静态站样式  |  纯 CSS，无框架依赖
   设计原则：轻量、响应式、语义清晰、首屏不依赖 JS
   ========================================================= */
:root{
  --bg:#ffffff;
  --bg-soft:#f5f8ff;
  --bg-deep:#0b1f3a;
  --ink:#0f1b2d;
  --ink-soft:#4a5a72;
  --line:#e3e9f4;
  --brand:#1f7aec;
  --brand-2:#16c6c0;
  --brand-deep:#0b56c4;
  --warn:#c2410c;
  --radius:16px;
  --radius-sm:10px;
  --shadow:0 10px 30px rgba(15,40,90,.08);
  --shadow-lg:0 20px 50px rgba(15,40,90,.14);
  --maxw:1140px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.7;
  font-size:16px;
}
img{max-width:100%;display:block}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}
.skip-link{position:absolute;left:-999px;top:0;background:var(--brand);color:#fff;padding:8px 14px;z-index:99}
.skip-link:focus{left:8px;top:8px}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.9);
  backdrop-filter:saturate(180%) blur(10px);
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;color:var(--ink)}
.brand img{width:32px;height:32px}
.nav-links{display:flex;gap:6px;align-items:center;list-style:none}
.nav-links a{
  color:var(--ink-soft);padding:8px 12px;border-radius:8px;font-size:15px;font-weight:600;
}
.nav-links a:hover{background:var(--bg-soft);color:var(--ink);text-decoration:none}
.nav-links a.active{color:var(--brand)}
.nav-cta{background:var(--brand);color:#fff!important;padding:8px 16px!important;transition:.18s}
.nav-cta:hover{background:var(--brand-deep)!important;color:#fff!important;text-decoration:none}
.nav-toggle{display:none;background:none;border:1px solid var(--line);border-radius:8px;padding:8px 10px;cursor:pointer}
.nav-toggle span{display:block;width:20px;height:2px;background:var(--ink);margin:4px 0}

/* ---------- 按钮 ---------- */
.btn{display:inline-block;padding:13px 24px;border-radius:12px;font-weight:700;font-size:15px;cursor:pointer;border:0;transition:.18s}
.btn-primary{background:linear-gradient(120deg,var(--brand),var(--brand-2));color:#fff}
.btn-primary:hover{box-shadow:var(--shadow-lg);transform:translateY(-1px);text-decoration:none}
.btn-ghost{background:#fff;color:var(--brand);border:1px solid var(--line)}
.btn-ghost:hover{border-color:var(--brand);text-decoration:none}

/* ---------- Hero ---------- */
.hero{
  background:
    radial-gradient(900px 400px at 80% -10%,rgba(22,198,192,.18),transparent),
    radial-gradient(700px 380px at 0% 10%,rgba(31,122,236,.16),transparent),
    var(--bg-soft);
  padding:72px 0 64px;overflow:hidden;
}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center}
.hero h1{font-size:clamp(30px,4.4vw,46px);line-height:1.2;letter-spacing:-.5px;margin-bottom:18px}
.hero .accent{background:linear-gradient(120deg,var(--brand),var(--brand-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{font-size:18px;color:var(--ink-soft);margin-bottom:26px;max-width:520px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.hero-stats{display:flex;gap:30px;margin-top:34px;flex-wrap:wrap}
.hero-stats .num{font-size:26px;font-weight:800;color:var(--brand-deep)}
.hero-stats .lbl{font-size:13px;color:var(--ink-soft)}
.hero-art{background:#fff;border-radius:20px;box-shadow:var(--shadow-lg);padding:18px}

/* ---------- 通用区块 ---------- */
section{padding:60px 0}
.section-head{text-align:center;max-width:680px;margin:0 auto 40px}
.section-head .eyebrow{color:var(--brand);font-weight:700;letter-spacing:1px;font-size:13px;text-transform:uppercase}
.section-head h1,.section-head h2{font-size:clamp(24px,3vw,34px);margin:10px 0 12px}
.section-head p{color:var(--ink-soft)}
.bg-soft{background:var(--bg-soft)}

/* ---------- 卡片网格 ---------- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;box-shadow:var(--shadow);transition:.18s;
}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.card .ico{width:46px;height:46px;margin-bottom:14px}
.card h3{font-size:19px;margin-bottom:8px}
.card p{color:var(--ink-soft);font-size:15px}

/* ---------- 步骤 ---------- */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;counter-reset:step}
.step{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 24px}
.step::before{counter-increment:step;content:"0" counter(step);position:absolute;top:-16px;left:24px;background:linear-gradient(120deg,var(--brand),var(--brand-2));color:#fff;font-weight:800;width:36px;height:36px;display:grid;place-items:center;border-radius:10px}
.step h3{margin:14px 0 8px;font-size:18px}
.step p{color:var(--ink-soft);font-size:15px}

/* ---------- 表格 ---------- */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
table{width:100%;border-collapse:collapse;min-width:560px}
th,td{padding:14px 16px;text-align:left;border-bottom:1px solid var(--line);font-size:15px}
thead th{background:var(--bg-soft);font-weight:700;color:var(--ink)}
tbody tr:hover{background:#fafcff}
.tag{display:inline-block;background:var(--bg-soft);border:1px solid var(--line);border-radius:999px;padding:3px 10px;font-size:13px;color:var(--ink-soft)}

/* ---------- 面包屑 ---------- */
.breadcrumb{padding:18px 0 0;font-size:14px;color:var(--ink-soft)}
.breadcrumb ol{list-style:none;display:flex;gap:8px;flex-wrap:wrap}
.breadcrumb li+li::before{content:"›";margin-right:8px;color:var(--line)}
.breadcrumb a{color:var(--ink-soft)}

/* ---------- FAQ ---------- */
.faq details{border:1px solid var(--line);border-radius:var(--radius-sm);padding:0 18px;margin-bottom:12px;background:#fff}
.faq summary{cursor:pointer;font-weight:700;padding:16px 0;list-style:none;display:flex;justify-content:space-between;align-items:center}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:22px;color:var(--brand);font-weight:700}
.faq details[open] summary::after{content:"−"}
.faq details p{padding:0 0 16px;color:var(--ink-soft)}

/* ---------- CTA ---------- */
.cta{background:linear-gradient(120deg,var(--brand-deep),var(--brand));color:#fff;border-radius:24px;padding:48px;text-align:center}
.cta h2{color:#fff;font-size:28px;margin-bottom:10px}
.cta p{color:rgba(255,255,255,.85);margin-bottom:22px}

/* ---------- 页脚 ---------- */
.site-footer{background:var(--bg-deep);color:#cdd8ec;font-size:14px;padding:48px 0 28px;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:28px}
.site-footer h4{color:#fff;font-size:15px;margin-bottom:14px}
.site-footer ul{list-style:none}
.site-footer li{margin-bottom:8px}
.site-footer a{color:#9fb2d4}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);margin-top:30px;padding-top:18px;color:#8295b8;font-size:13px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* ---------- 响应式 ---------- */
@media (max-width:880px){
  .hero-grid{grid-template-columns:1fr;gap:30px}
  .cards,.steps{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .nav-links{
    position:absolute;top:64px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;gap:0;padding:8px 20px 16px;display:none;
  }
  .nav-links.open{display:flex}
  .nav-links a{padding:12px 4px;border-radius:0}
  .nav-toggle{display:block}
}
@media (max-width:560px){
  .footer-grid{grid-template-columns:1fr}
  .hero-stats{gap:20px}
  section{padding:44px 0}
}