/* ===== 基础变量与重置 ===== */
:root{
  --primary:#1f5cff;
  --primary-dark:#1748d6;
  --primary-light:#eaf2ff;
  --text:#1f2733;
  --text-soft:#5b6675;
  --bg:#ffffff;
  --bg-alt:#f5f8ff;
  --line:#e3e9f3;
  --radius:14px;
  --maxw:1140px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",Segoe UI,Roboto,Helvetica,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:var(--maxw);margin:0 auto;padding:0 20px}

/* ===== 按钮 ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:11px 22px;border-radius:999px;font-size:15px;font-weight:600;
  transition:transform .15s ease,box-shadow .2s ease,background .2s ease;cursor:pointer;border:1px solid transparent;
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:var(--primary);color:#fff;box-shadow:0 8px 20px rgba(31,92,255,.28)}
.btn-primary:hover{background:var(--primary-dark)}
.btn-line{background:#fff;color:var(--primary);border-color:var(--primary)}
.btn-line:hover{background:var(--primary-light)}
.btn-ghost{background:transparent;color:var(--primary);border-color:var(--line);padding:8px 18px}
.btn-ghost:hover{background:var(--primary-light)}
.btn-lg{padding:14px 30px;font-size:16px}

/* ===== 顶部导航 ===== */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand-logo{display:flex;align-items:center}
.brand-logo img{height:36px;width:auto}
.top-nav{display:flex;align-items:center;gap:26px}
.top-nav a{color:var(--text-soft);font-size:15px;font-weight:500}
.top-nav a:hover{color:var(--primary)}
.nav-toggle{display:none;background:none;border:none;font-size:24px;color:var(--text);cursor:pointer}

/* ===== Hero ===== */
.hero{background:linear-gradient(180deg,#f5f8ff 0%,#ffffff 100%);padding:64px 0 56px}
.hero-inner{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center}
.product-title{display:flex;align-items:center;gap:14px;margin-bottom:14px}
.product-icon{display:flex}
.product-title h1{font-size:44px;font-weight:800;letter-spacing:1px;color:var(--text)}
.hero-sub{font-size:19px;color:var(--primary);font-weight:600;margin-bottom:14px}
.hero-desc{font-size:16px;color:var(--text-soft);max-width:520px;margin-bottom:26px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:24px}
.hero-tags{display:flex;flex-wrap:wrap;gap:10px;list-style:none}
.hero-tags li{font-size:13px;color:var(--text-soft);background:var(--primary-light);padding:6px 14px;border-radius:999px}
.hero-art{display:flex;justify-content:center}

/* ===== 通用区块 ===== */
.section{padding:64px 0}
.section-alt{background:var(--bg-alt)}
.sec-title{font-size:30px;font-weight:800;text-align:center;margin-bottom:12px}
.sec-lead{text-align:center;color:var(--text-soft);max-width:680px;margin:0 auto 40px;font-size:16px}

/* ===== 简介 ===== */
.intro-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.intro-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.intro-card h3{font-size:19px;margin-bottom:10px;color:var(--primary)}
.intro-card p{color:var(--text-soft);font-size:15px}

/* ===== 功能 ===== */
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.feature-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;transition:box-shadow .2s ease,transform .2s ease}
.feature-card:hover{box-shadow:0 12px 30px rgba(31,92,255,.12);transform:translateY(-3px)}
.feature-img{background:var(--primary-light);border-radius:12px;padding:18px;margin-bottom:16px;display:flex;justify-content:center}
.feature-card h3{font-size:18px;margin-bottom:8px}
.feature-card p{color:var(--text-soft);font-size:14.5px}

/* ===== 下载 ===== */
.download{background:linear-gradient(180deg,#ffffff,#f5f8ff)}
.download-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;max-width:760px;margin:0 auto}
.dl-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px;text-align:center;box-shadow:0 6px 18px rgba(31,92,255,.08)}
.dl-icon{display:flex;justify-content:center;margin-bottom:14px}
.dl-card h3{font-size:21px;margin-bottom:6px}
.dl-meta{color:var(--text-soft);font-size:14px;margin-bottom:18px}
.dl-tip{text-align:center;color:var(--text-soft);font-size:14px;margin-top:28px}
.dl-tip a{color:var(--primary);font-weight:600}

/* ===== 页脚 ===== */
.site-footer{background:#11203f;color:#c7d2e6;padding:26px 0;text-align:center;font-size:14px;line-height:2}
.site-footer p{margin:0}

/* ===== 响应式 ===== */
@media (max-width:880px){
  .hero-inner{grid-template-columns:1fr}
  .hero-art{order:-1}
  .intro-grid,.feature-grid{grid-template-columns:1fr 1fr}
  .download-grid{grid-template-columns:1fr}
  .product-title h1{font-size:36px}
}
@media (max-width:560px){
  .top-nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;flex-direction:column;gap:0;padding:10px 20px;border-bottom:1px solid var(--line)}
  .top-nav.open{display:flex}
  .top-nav a{padding:12px 0;border-bottom:1px solid var(--line);width:100%}
  .nav-toggle{display:block}
  .intro-grid,.feature-grid{grid-template-columns:1fr}
  .product-title h1{font-size:32px}
  .sec-title{font-size:25px}
}