/* ===== 基础 ===== */
:root {
  --purple-900: #1a0b2e;
  --purple-800: #2a1454;
  --purple-700: #4a1d96;
  --purple-600: #6d28d9;
  --purple-500: #8b5cf6;
  --purple-400: #a78bfa;
  --purple-100: #ede9fe;
  --accent: #c084fc;
  --text-dark: #1e1b2e;
  --text-gray: #6b6580;
  --bg-white: #ffffff;
  --bg-light: #f7f5ff;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text-dark);
  background: var(--bg-white);
  line-height: 1.6;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

.gradient-text {
  background: linear-gradient(135deg, var(--purple-500), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.icon { width: 20px; height: 20px; fill: currentColor; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border-radius: 10px; font-weight: 600; text-decoration: none;
  cursor: pointer; border: none; transition: all .25s ease;
}
.btn-primary {
  background: linear-gradient(135deg, var(--purple-600), var(--purple-500));
  color: #fff; padding: 14px 32px; font-size: 17px;
  box-shadow: 0 8px 24px rgba(109, 40, 217, .35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(109, 40, 217, .45); }
.btn-primary.disabled, .btn-primary.disabled:hover {
  background: #c9c2d8; box-shadow: none; cursor: not-allowed; transform: none; color: #fff;
}
.btn-ghost { color: #fff; padding: 14px 28px; font-size: 17px; border: 1px solid rgba(255,255,255,.5); }
.btn-ghost:hover { background: rgba(255,255,255,.12); }
.btn-outline { color: var(--purple-600); border: 1.5px solid var(--purple-500); }
.btn-outline:hover { background: var(--purple-100); }
.btn-sm { padding: 8px 20px; font-size: 14px; }
.btn-lg { padding: 16px 40px; font-size: 18px; }

/* ===== 导航 ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(26, 11, 46, .85); backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.nav-container {
  max-width: 1100px; margin: 0 auto; padding: 0 24px;
  height: 64px; display: flex; align-items: center; gap: 32px;
}
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 10px; font-weight: 800; font-size: 15px;
  background: linear-gradient(135deg, var(--purple-500), var(--accent)); color: #fff;
}
.logo-text { color: #fff; font-size: 20px; font-weight: 700; letter-spacing: 1px; }
.nav-links { display: flex; gap: 28px; margin-left: auto; }
.nav-links a { color: rgba(255,255,255,.8); text-decoration: none; font-size: 15px; transition: color .2s; }
.nav-links a:hover { color: #fff; }

/* ===== Hero ===== */
.hero {
  position: relative; min-height: 88vh;
  display: flex; align-items: center; justify-content: center;
  text-align: center; overflow: hidden; padding: 120px 24px 80px;
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(139, 92, 246, .45), transparent),
    linear-gradient(160deg, var(--purple-900) 0%, var(--purple-800) 45%, #3b1a78 100%);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(circle 300px at 15% 30%, rgba(192, 132, 252, .18), transparent),
    radial-gradient(circle 400px at 85% 70%, rgba(139, 92, 246, .22), transparent);
}
.hero-content { position: relative; z-index: 1; max-width: 820px; }
.hero h1 { color: #fff; font-size: clamp(34px, 5.5vw, 56px); line-height: 1.25; font-weight: 800; margin-bottom: 20px; }
.hero-sub { color: rgba(255,255,255,.75); font-size: clamp(15px, 2vw, 18px); margin-bottom: 36px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 56px; }
.hero-stats {
  display: flex; justify-content: center; gap: clamp(24px, 6vw, 72px); flex-wrap: wrap;
}
.stat strong {
  display: block; font-size: clamp(30px, 4vw, 42px); font-weight: 800; color: #fff;
}
.stat strong small { font-size: .5em; font-weight: 600; color: var(--accent); margin-left: 2px; }
.stat span { color: rgba(255,255,255,.6); font-size: 14px; }

/* ===== 通用 Section ===== */
.section { padding: 90px 0; }
.section-alt { background: var(--bg-light); }
.section-title { text-align: center; font-size: clamp(28px, 4vw, 38px); font-weight: 800; margin-bottom: 12px; }
.section-sub { text-align: center; color: var(--text-gray); font-size: 16px; margin-bottom: 56px; }

/* ===== 功能卡片 ===== */
.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px;
}
.feature-card {
  background: #fff; border-radius: 18px; padding: 36px 28px; text-align: center;
  border: 1px solid #efe9fd; transition: all .3s ease;
}
.feature-card:hover {
  transform: translateY(-6px); border-color: var(--purple-400);
  box-shadow: 0 16px 40px rgba(109, 40, 217, .12);
}
.feature-icon {
  width: 64px; height: 64px; margin: 0 auto 20px; border-radius: 18px;
  display: flex; align-items: center; justify-content: center; font-size: 30px;
  background: linear-gradient(135deg, var(--purple-100), #f3e8ff);
}
.feature-card h3 { font-size: 19px; margin-bottom: 10px; }
.feature-card p { color: var(--text-gray); font-size: 14.5px; }

/* ===== 应用标签 ===== */
.app-tags { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.app-tags span {
  padding: 12px 26px; border-radius: 999px; background: #fff; font-size: 15px;
  border: 1px solid #e7defc; color: var(--text-dark); transition: all .25s;
}
.app-tags span:hover { background: var(--purple-600); color: #fff; border-color: var(--purple-600); transform: translateY(-2px); }

/* ===== 下载区 ===== */
.download-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 22px;
}
.download-card {
  background: #fff; border-radius: 18px; padding: 34px 24px; text-align: center;
  border: 1px solid #efe9fd; transition: all .3s ease;
}
.download-card:hover {
  transform: translateY(-5px); box-shadow: 0 14px 36px rgba(109, 40, 217, .13);
  border-color: var(--purple-400);
}
.download-card .platform-icon {
  width: 68px; height: 68px; margin: 0 auto 16px; border-radius: 18px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--purple-600), var(--purple-500));
}
.download-card .platform-icon svg { width: 34px; height: 34px; fill: #fff; }
.download-card h3 { font-size: 18px; margin-bottom: 4px; }
.download-card .platform-sub { color: var(--text-gray); font-size: 13px; margin-bottom: 18px; }
.download-card .file-info { color: var(--text-gray); font-size: 12px; margin-top: 10px; }
.download-tip { text-align: center; color: var(--text-gray); font-size: 13px; margin-top: 28px; }

/* ===== FAQ ===== */
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
.faq-item {
  background: #fff; border-radius: 14px; padding: 20px 26px;
  border: 1px solid #efe9fd;
}
.faq-item summary {
  cursor: pointer; font-weight: 600; font-size: 16px; list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
.faq-item summary::after { content: "+"; font-size: 22px; color: var(--purple-500); transition: transform .25s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { color: var(--text-gray); font-size: 14.5px; margin-top: 12px; }

/* ===== 法律条款页 ===== */
.legal-page { padding: 110px 0 60px; min-height: 70vh; }
.legal-container { max-width: 860px; margin: 0 auto; padding: 0 24px; }
.legal-page h1 { font-size: 32px; font-weight: 800; margin-bottom: 8px; }
.legal-updated { color: var(--text-gray); font-size: 14px; margin-bottom: 40px; }
.legal-section { margin-bottom: 38px; }
.legal-section h2 {
  font-size: 20px; color: var(--purple-700); margin-bottom: 14px;
  padding-left: 12px; border-left: 4px solid var(--purple-500);
}
.legal-section p { color: #4a4460; font-size: 15px; line-height: 1.9; margin-bottom: 10px; }
.legal-section ul { padding-left: 24px; margin-bottom: 10px; }
.legal-section li { color: #4a4460; font-size: 15px; line-height: 1.9; margin-bottom: 6px; }
.legal-link { color: var(--purple-600); text-decoration: none; border-bottom: 1px dashed var(--purple-400); }
.legal-link:hover { color: var(--purple-500); }

/* ===== 页脚 ===== */
.footer {
  background: var(--purple-900); color: rgba(255,255,255,.65);
  padding: 48px 0 32px; text-align: center;
}
.footer-brand { font-size: 20px; font-weight: 700; color: #fff; margin-bottom: 10px; }
.footer-brand .logo-icon { margin-right: 8px; }
.footer-brand p { font-size: 13px; font-weight: 400; color: rgba(255,255,255,.5); margin-top: 6px; }
.footer-links { display: flex; gap: 24px; justify-content: center; margin-top: 20px; }
.footer-links a { color: rgba(255,255,255,.7); font-size: 14px; text-decoration: none; }
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: 13px; margin-top: 24px; color: rgba(255,255,255,.35); }

/* ===== 响应式 ===== */
@media (max-width: 720px) {
  .nav-links { display: none; }
  .hero { min-height: 78vh; }
  .section { padding: 64px 0; }
}