/* ===========================================================
   yf-theme.css —— 江门市微快信科技官网主题（仿 yifeilun 现代 SaaS 风格）
   配色：深蓝科技渐变 + 青色点缀；卡片化、数据高亮、留白充足
   =========================================================== */
:root{
  --nav-h:64px;
  --primary:#0f2027;
  --primary2:#203a43;
  --primary3:#2c5364;
  --accent:#13c2c2;
  --accent-d:#08979c;
  --blue:#1890ff;
  --blue-d:#0c6cd4;
  --bg:#ffffff;
  --bg-soft:#f4f8fc;
  --text:#28384a;
  --muted:#6b7c93;
  --line:#e6edf5;
  --shadow:0 10px 30px rgba(20,50,80,.10);
  --shadow-lg:0 18px 50px rgba(20,50,80,.16);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",Arial,sans-serif;
  color:var(--text);background:var(--bg);line-height:1.7;-webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
.container{max-width:1200px;margin:0 auto;padding:0 20px}
section{position:relative}

/* ---------- 顶部导航 ---------- */
.yf-nav{
  position:sticky;top:0;z-index:100;height:var(--nav-h);
  background:rgba(15,32,39,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.yf-nav .container{height:100%;display:flex;align-items:center;justify-content:space-between}
.yf-logo{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:18px}
.yf-logo .mark{
  width:34px;height:34px;border-radius:9px;
  background:linear-gradient(135deg,var(--accent),var(--accent-d));
  display:flex;align-items:center;justify-content:center;font-size:18px;
  box-shadow:0 6px 16px rgba(19,194,194,.45);
}
.yf-menu{display:flex;align-items:center;gap:28px}
.yf-menu a{color:rgba(255,255,255,.82);font-size:15px;font-weight:500;transition:color .2s}
.yf-menu a:hover,.yf-menu a.active{color:#fff}
.yf-menu a.active::after{
  content:"";display:block;height:2px;background:var(--accent);border-radius:2px;margin-top:4px;
}
.yf-nav-cta{
  background:linear-gradient(135deg,var(--accent),var(--accent-d));
  color:#fff;padding:9px 18px;border-radius:8px;font-size:14px;font-weight:600;
  box-shadow:0 8px 20px rgba(19,194,194,.35);transition:transform .1s,opacity .2s;
}
.yf-nav-cta:hover{opacity:.92;transform:translateY(-1px)}
.yf-burger{display:none;color:#fff;font-size:24px;cursor:pointer;background:none;border:0}

/* ---------- Hero ---------- */
.yf-hero{
  background:radial-gradient(1200px 600px at 70% -10%,rgba(19,194,194,.25),transparent),
             linear-gradient(135deg,var(--primary) 0%,var(--primary2) 50%,var(--primary3) 100%);
  color:#fff;padding:96px 0 84px;overflow:hidden;
}
.yf-hero .container{display:flex;flex-direction:column;align-items:center;text-align:center}
.yf-hero h1{font-size:46px;line-height:1.25;font-weight:800;letter-spacing:.5px;margin-bottom:18px}
.yf-hero h1 .hl{color:var(--accent)}
.yf-hero p.lead{font-size:18px;color:rgba(255,255,255,.82);max-width:760px;margin-bottom:30px}
.yf-hero .btn-row{display:flex;gap:16px;flex-wrap:wrap;justify-content:center;margin-bottom:46px}
.yf-btn{
  display:inline-block;padding:13px 30px;border-radius:10px;font-size:16px;font-weight:600;transition:transform .1s,opacity .2s,box-shadow .2s;
}
.yf-btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent-d));color:#fff;box-shadow:0 12px 30px rgba(19,194,194,.4)}
.yf-btn-ghost{background:rgba(255,255,255,.1);color:#fff;border:1px solid rgba(255,255,255,.3)}
.yf-btn:hover{opacity:.92;transform:translateY(-2px)}
.yf-platforms{display:flex;gap:26px;align-items:center;flex-wrap:wrap;justify-content:center;opacity:.92}
.yf-platforms .pf{display:flex;flex-direction:column;align-items:center;gap:8px;font-size:12px;color:rgba(255,255,255,.78)}
.yf-platforms .pf .ic{
  width:46px;height:46px;border-radius:50%;background:rgba(255,255,255,.12);
  display:flex;align-items:center;justify-content:center;font-size:22px;
}

/* ---------- 数据统计条 ---------- */
.yf-stats{background:var(--bg-soft);padding:54px 0;border-bottom:1px solid var(--line)}
.yf-stats .grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center}
.yf-stats .num{font-size:40px;font-weight:800;color:var(--accent-d);line-height:1.1}
.yf-stats .num span{font-size:22px}
.yf-stats .lbl{color:var(--muted);font-size:15px;margin-top:6px}

/* ---------- 通用 section ---------- */
.yf-section{padding:80px 0}
.yf-section.soft{background:var(--bg-soft)}
.yf-st{text-align:center;max-width:720px;margin:0 auto 50px}
.yf-st .eyebrow{color:var(--accent-d);font-weight:700;letter-spacing:2px;font-size:13px;text-transform:uppercase}
.yf-st h2{font-size:32px;font-weight:800;margin:12px 0 12px;color:var(--primary)}
.yf-st p{color:var(--muted);font-size:16px}

/* ---------- 卡片网格 ---------- */
.yf-grid{display:grid;gap:24px}
.yf-grid.c3{grid-template-columns:repeat(3,1fr)}
.yf-grid.c2{grid-template-columns:repeat(2,1fr)}
.yf-grid.c4{grid-template-columns:repeat(4,1fr)}
.yf-card{
  background:#fff;border:1px solid var(--line);border-radius:16px;padding:30px 26px;
  box-shadow:var(--shadow);transition:transform .15s,box-shadow .2s,border-color .2s;
}
.yf-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:rgba(19,194,194,.4)}
.yf-card .ic{
  width:56px;height:56px;border-radius:14px;margin-bottom:18px;
  background:linear-gradient(135deg,rgba(19,194,194,.15),rgba(24,144,255,.12));
  display:flex;align-items:center;justify-content:center;font-size:28px;
}
.yf-card h3{font-size:19px;margin-bottom:10px;color:var(--primary)}
.yf-card p{color:var(--muted);font-size:14.5px}

/* ---------- 阶段 / 步骤 ---------- */
.yf-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;counter-reset:s}
.yf-step{position:relative;background:#fff;border:1px solid var(--line);border-radius:16px;padding:30px 24px;box-shadow:var(--shadow)}
.yf-step .idx{
  width:40px;height:40px;border-radius:50%;background:linear-gradient(135deg,var(--accent),var(--accent-d));
  color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;margin-bottom:16px;font-size:18px;
}
.yf-step h3{font-size:18px;margin-bottom:8px;color:var(--primary)}
.yf-step p{color:var(--muted);font-size:14px}

/* ---------- 案例 ---------- */
.yf-case{background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--shadow);transition:transform .15s,box-shadow .2s}
.yf-case:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg)}
.yf-case .top{height:120px;background:linear-gradient(135deg,var(--primary2),var(--primary3));display:flex;align-items:center;justify-content:center;color:#fff;font-size:30px}
.yf-case .body{padding:22px}
.yf-case .body .tag{display:inline-block;font-size:12px;color:var(--accent-d);background:rgba(19,194,194,.12);padding:3px 10px;border-radius:20px;margin-bottom:10px}
.yf-case .body h3{font-size:17px;color:var(--primary);margin-bottom:8px}
.yf-case .body p{color:var(--muted);font-size:14px}
.yf-case .body .metrics{display:flex;gap:18px;margin-top:14px;color:var(--primary);font-weight:700;font-size:14px}
.yf-case .body .metrics span small{display:block;color:var(--muted);font-weight:400;font-size:12px}

/* ---------- 为什么选择（优势） ---------- */
.yf-why{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.yf-why .item{display:flex;gap:14px;align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:14px;padding:22px;box-shadow:var(--shadow)}
.yf-why .item .ic{font-size:26px}
.yf-why .item h4{font-size:16px;color:var(--primary);margin-bottom:6px}
.yf-why .item p{color:var(--muted);font-size:13.5px}

/* ---------- 底部 CTA ---------- */
.yf-cta{
  background:radial-gradient(900px 400px at 50% -20%,rgba(19,194,194,.3),transparent),
             linear-gradient(135deg,var(--primary),var(--primary3));
  color:#fff;text-align:center;padding:84px 0;
}
.yf-cta h2{font-size:34px;font-weight:800;margin-bottom:14px}
.yf-cta p{color:rgba(255,255,255,.82);font-size:17px;margin-bottom:28px}
.yf-cta .btn-row{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.yf-cta .tel{margin-top:22px;font-size:15px;color:rgba(255,255,255,.85)}
.yf-cta .tel b{color:#fff;font-size:18px}

/* ---------- 页脚 ---------- */
.yf-footer{background:#0b171c;color:rgba(255,255,255,.7);padding:56px 0 26px}
.yf-footer .grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:34px}
.yf-footer h4{color:#fff;font-size:16px;margin-bottom:16px}
.yf-footer p,.yf-footer li{font-size:14px;line-height:1.9;color:rgba(255,255,255,.66)}
.yf-footer ul{list-style:none}
.yf-footer a{color:rgba(255,255,255,.7);transition:color .2s}
.yf-footer a:hover{color:var(--accent)}
.yf-footer .contact-line{display:flex;gap:8px;align-items:center;margin-bottom:8px}
.yf-footer .contact-line .ic{width:22px;text-align:center}
.yf-footer .bottom{border-top:1px solid rgba(255,255,255,.1);margin-top:34px;padding-top:20px;font-size:13px;color:rgba(255,255,255,.5);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* ---------- 响应式 ---------- */
@media(max-width:980px){
  .yf-grid.c3,.yf-grid.c4,.yf-why{grid-template-columns:repeat(2,1fr)}
  .yf-steps{grid-template-columns:repeat(2,1fr)}
  .yf-stats .grid{grid-template-columns:repeat(2,1fr);gap:30px 16px}
  .yf-footer .grid{grid-template-columns:1fr 1fr}
}
@media(max-width:640px){
  .yf-menu{display:none;position:absolute;top:var(--nav-h);left:0;right:0;background:var(--primary);flex-direction:column;padding:14px 20px;gap:14px}
  .yf-menu.open{display:flex}
  .yf-burger{display:block}
  .yf-hero h1{font-size:30px}
  .yf-hero p.lead{font-size:15px}
  .yf-grid.c3,.yf-grid.c4,.yf-grid.c2,.yf-why,.yf-steps{grid-template-columns:1fr}
  .yf-stats .grid{grid-template-columns:1fr 1fr}
  .yf-footer .grid{grid-template-columns:1fr}
  .yf-st h2{font-size:26px}
}