/* ===== 基础重置 ===== */
:root{
  --blue:#4F8CFF; --purple:#7C5CFF; --ink:#1A2138; --grey:#6B7488;
  --line:#E7EBF3; --bg:#ffffff; --bg-soft:#F6F8FD;
  --grad:linear-gradient(120deg,#4F8CFF 0%,#7C5CFF 100%);
  --radius:18px; --shadow:0 18px 48px rgba(26,33,56,.10);
  --shadow-sm:0 6px 20px rgba(26,33,56,.07);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC","Microsoft YaHei","Segoe UI",system-ui,-apple-system,sans-serif;
  color:var(--ink); background:var(--bg); line-height:1.75; -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
.wrap{max-width:1160px;margin:0 auto;padding:0 24px}

/* ===== 按钮 ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:13px 26px;border-radius:999px;font-weight:600;font-size:15px;
  transition:transform .2s ease,box-shadow .2s ease,background .2s ease;cursor:pointer;
}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 10px 26px rgba(79,140,255,.38)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 34px rgba(124,92,255,.42)}
.btn-ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn-ghost:hover{border-color:var(--blue);color:var(--blue)}
.btn-light{background:#fff;color:var(--blue);box-shadow:0 14px 34px rgba(0,0,0,.18)}
.btn-light:hover{transform:translateY(-2px)}

/* ===== 导航 ===== */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);
  backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;gap:28px;height:70px}
.brand img{height:34px;width:auto}
.nav-links{display:flex;gap:26px;margin-left:auto;font-size:15px;color:var(--grey)}
.nav-links a{position:relative;transition:color .2s}
.nav-links a:hover{color:var(--blue)}
.nav-links a::after{content:"";position:absolute;left:0;bottom:-6px;width:0;height:2px;
  background:var(--grad);transition:width .25s}
.nav-links a:hover::after{width:100%}
.nav-cta{padding:9px 20px;font-size:14px}

/* ===== 首屏 ===== */
.hero{position:relative;overflow:hidden;
  background:radial-gradient(1200px 600px at 80% -10%,#EAF1FF 0%,transparent 60%),
             radial-gradient(900px 500px at 0% 10%,#F3EEFF 0%,transparent 55%),#fff}
.hero-inner{display:grid;grid-template-columns:1.05fr 1fr;gap:56px;align-items:center;
  padding:84px 0 96px}
.pill{display:inline-block;padding:7px 16px;border-radius:999px;font-size:13px;font-weight:600;
  color:var(--purple);background:#fff;border:1px solid var(--line);box-shadow:var(--shadow-sm);margin-bottom:22px}
.hero h1{font-size:44px;line-height:1.25;font-weight:800;letter-spacing:-.5px}
.hero h1{background:linear-gradient(120deg,#1A2138 40%,#4F8CFF 100%);-webkit-background-clip:text;
  background-clip:text;color:transparent}
.lead{margin:22px 0 30px;font-size:17px;color:var(--grey);max-width:560px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap}
.hero-stats{list-style:none;display:flex;gap:38px;margin-top:40px}
.hero-stats strong{display:block;font-size:26px;background:var(--grad);-webkit-background-clip:text;
  background-clip:text;color:transparent;font-weight:800}
.hero-stats span{font-size:13px;color:var(--grey)}
.hero-art img{border-radius:16px;animation:float 6s ease-in-out infinite}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-12px)}}

/* ===== 通用区块 ===== */
.section{padding:88px 0}
.section-alt{background:var(--bg-soft)}
.section-head{text-align:center;max-width:680px;margin:0 auto 52px}
.tag{display:inline-block;font-size:13px;font-weight:700;letter-spacing:1px;text-transform:uppercase;
  color:var(--blue);margin-bottom:14px}
h2{font-size:33px;font-weight:800;letter-spacing:-.4px;line-height:1.3}
.section-sub{margin-top:16px;color:var(--grey);font-size:16px}

/* ===== 功能卡片 ===== */
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px;
  box-shadow:var(--shadow-sm);transition:transform .25s,box-shadow .25s}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow)}
.ico{width:54px;height:54px;border-radius:15px;display:flex;align-items:center;justify-content:center;
  font-size:26px;margin-bottom:18px}
.ico-blue{background:#EAF1FF}.ico-orange{background:#FFF0E7}.ico-green{background:#E6F8F0}.ico-purple{background:#F1ECFF}
.card h3{font-size:18px;font-weight:700;margin-bottom:10px}
.card p{font-size:14.5px;color:var(--grey)}

/* ===== 为何选择 ===== */
.why-inner{display:grid;grid-template-columns:1fr 1.05fr;gap:60px;align-items:center}
.why-text h2{margin-bottom:16px}
.why-text>p{color:var(--grey);font-size:16px;margin-bottom:26px}
.check-list{list-style:none;display:grid;gap:18px}
.check-list li{position:relative;padding-left:34px;color:var(--grey);font-size:14.5px}
.check-list li::before{content:"✓";position:absolute;left:0;top:2px;width:22px;height:22px;
  border-radius:50%;background:var(--grad);color:#fff;font-size:13px;font-weight:700;
  display:flex;align-items:center;justify-content:center}
.check-list h4{font-size:16px;color:var(--ink);margin-bottom:2px}
.why-art img{border-radius:var(--radius);box-shadow:var(--shadow)}

/* ===== 使用教程 ===== */
.guide-wrap{display:grid;grid-template-columns:1.1fr .9fr;gap:56px;align-items:center}
.steps{list-style:none;display:grid;gap:26px}
.steps li{display:flex;gap:20px;align-items:flex-start}
.step-no{flex:none;width:46px;height:46px;border-radius:14px;background:var(--grad);color:#fff;
  font-size:20px;font-weight:800;display:flex;align-items:center;justify-content:center;
  box-shadow:0 8px 20px rgba(79,140,255,.35)}
.steps h3{font-size:19px;font-weight:700}
.steps h4{font-size:13px;font-weight:700;color:var(--blue);margin:2px 0 6px}
.steps p{font-size:14.5px;color:var(--grey)}
.guide-art img{border-radius:var(--radius);box-shadow:var(--shadow)}

/* ===== 下载 CTA ===== */
.download{background:var(--grad);color:#fff;text-align:center;padding:78px 0;position:relative;overflow:hidden}
.download::before{content:"";position:absolute;inset:0;
  background:radial-gradient(600px 300px at 50% -30%,rgba(255,255,255,.25),transparent 70%)}
.download-inner{position:relative}
.download h2{color:#fff;margin-bottom:14px}
.download p{color:rgba(255,255,255,.9);font-size:16px;margin-bottom:28px}
.download .btn-light{font-size:16px;padding:15px 34px}
.download-note{font-size:13px;color:rgba(255,255,255,.85);margin-top:18px}

/* ===== FAQ ===== */
.faq-wrap{max-width:820px}
.faq-list{display:grid;gap:14px}
details{background:#fff;border:1px solid var(--line);border-radius:14px;padding:4px 22px;
  box-shadow:var(--shadow-sm);transition:box-shadow .2s}
details[open]{box-shadow:var(--shadow)}
summary{list-style:none;cursor:pointer;padding:16px 0;display:flex;align-items:center;justify-content:space-between}
summary::-webkit-details-marker{display:none}
summary h3{font-size:16.5px;font-weight:700}
summary::after{content:"+";font-size:22px;color:var(--blue);font-weight:400;transition:transform .2s}
details[open] summary::after{transform:rotate(45deg)}
details p{padding:0 0 18px;color:var(--grey);font-size:14.5px}

/* ===== 页脚 ===== */
.footer{background:#141A2C;color:#C4CBDA}
.footer-inner{display:flex;justify-content:space-between;gap:40px;padding:52px 0;flex-wrap:wrap}
.footer-brand img{height:32px;width:auto;margin-bottom:14px;background:#fff;padding:6px 12px;border-radius:10px}
.footer-brand p{font-size:14px;color:#8A93A8;max-width:280px}
.footer-links{display:flex;gap:26px;flex-wrap:wrap;font-size:14px}
.footer-links a{color:#C4CBDA;transition:color .2s}
.footer-links a:hover{color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);padding:20px 0;font-size:13px;color:#6B7488}

/* ===== 响应式 ===== */
@media (max-width:900px){
  .hero-inner,.why-inner,.guide-wrap{grid-template-columns:1fr;gap:40px}
  .hero h1{font-size:34px}
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .nav-links{display:none}
  .why-art{order:-1}
}
@media (max-width:560px){
  .feature-grid{grid-template-columns:1fr}
  .hero-stats{gap:24px}
  .hero h1{font-size:28px}
  h2{font-size:26px}
  .nav-cta{display:none}
}