/* WPK 苹果下载 - 主题样式 */
:root {
  --c1: #2563eb;
  --c2: #4f46e5;
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: #ffffff;
  -webkit-font-smoothing: antialiased;
  margin: 0;
}

/* 渐变文字 */
.gradient-text {
  background: linear-gradient(120deg, #2563eb 0%, #4f46e5 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 网格背景 */
.bg-grid {
  background-image:
    linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 44px 44px;
}

/* 导航毛玻璃 */
.nav-blur {
  background: rgba(255,255,255,0.82);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  box-shadow: 0 6px 28px rgba(15,23,42,0.08);
}

/* 卡片 hover */
.card-hover {
  transition: transform .35s cubic-bezier(.22,.61,.36,1), box-shadow .35s ease, border-color .35s ease;
}
.card-hover:hover {
  transform: translateY(-9px);
  box-shadow: 0 26px 50px rgba(37,99,235,0.14);
  border-color: #c7d2fe;
}

/* 按钮发光 */
.btn-glow {
  transition: all .3s ease;
  box-shadow: 0 10px 30px rgba(37,99,235,0.4);
}
.btn-glow:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 42px rgba(79,70,229,0.55);
}

/* 入场动画 */
.fade-in {
  animation: fadeUp .8s ease both;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(28px); }
  to { opacity: 1; transform: translateY(0); }
}

/* FAQ 手风琴 */
.faq-item {
  border-bottom: 1px solid var(--line);
}
.faq-question {
  cursor: pointer;
  background: transparent;
  border: none;
  width: 100%;
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s ease;
}
.faq-item.open .faq-answer {
  max-height: 420px;
}
.faq-icon {
  transition: transform .3s ease;
}
.faq-item.open .faq-icon {
  transform: rotate(180deg);
}

/* iOS 徽章 */
.ios-badge {
  background: linear-gradient(135deg, #2563eb, #4f46e5);
  color: #fff;
}