/* 🛡️ 基础重置 & 变量 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 100%; }
body {
  font-family: system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.5; color: #111827; background: #f9fafb;
  -webkit-font-smoothing: antialiased; overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }

/* 📐 容器 & 弹性网格（核心自适应逻辑） */
.container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.section { padding: 48px 0; }
.section-title {
  text-align: center; font-size: clamp(1.5rem, 4vw, 2rem); font-weight: 800;
  margin-bottom: 28px; color: #111827; letter-spacing: -0.01em;
}
.section-title::after {
  content: ''; display: block; width: 36px; height: 3px; background: #ef4444;
  margin: 6px auto 0; border-radius: 2px;
}
.grid { display: grid; gap: 16px; }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

/* 🔘 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 0.75rem 1.5rem; border-radius: 9999px; font-weight: 600;
  font-size: 0.95rem; transition: 0.2s ease; border: 2px solid transparent;
  cursor: pointer; min-height: 44px; white-space: nowrap;
}
.btn-primary { background: #ef4444; color: #fff; box-shadow: 0 4px 12px rgba(239,68,68,0.25); }
.btn-primary:hover { background: #dc2626; transform: translateY(-2px); }
.btn-outline { background: transparent; border-color: #ef4444; color: #ef4444; }
.btn-outline:hover { background: #ef4444; color: #fff; transform: translateY(-2px); }
.btn-lg { padding: 0.9rem 2rem; font-size: 1rem; }
.btn-block { display: flex; width: 100%; }

/* 📌 Header */
.header {
  background: rgba(255,255,255,0.92); backdrop-filter: blur(8px);
  border-bottom: 1px solid #e5e7eb; position: sticky; top: 0; z-index: 100;
}
.header-inner { display: flex; justify-content: space-between; align-items: center; height: 60px; }
.logo { font-size: 1.2rem; font-weight: 800; color: #ef4444; }

/* 🌄 Hero */
.hero {
  background: linear-gradient(160deg, #111827 0%, #ef4444 100%);
  color: #fff; padding: 48px 0 40px; position: relative; overflow: hidden;
}
.hero-inner { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 28px; }
.hero-title { font-size: clamp(1.8rem, 5vw, 2.6rem); font-weight: 800; line-height: 1.15; margin-bottom: 12px; }
.hero-title .highlight { color: #fca5a5; }
.hero-desc { font-size: clamp(1rem, 2vw, 1.1rem); opacity: 0.9; margin-bottom: 20px; max-width: 560px; line-height: 1.6; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-bottom: 20px; }
.hero-stats { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px 20px; font-size: 0.85rem; opacity: 0.85; font-weight: 500; }
.hero-visual { width: 100%; max-width: 320px; }
.hero-visual img { border-radius: 16px; box-shadow: 0 16px 32px rgba(0,0,0,0.3); }

/* 🃏 卡片 */
.card {
  background: #fff; padding: 20px; border-radius: 14px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04); border: 1px solid #e5e7eb; transition: 0.2s ease;
}
.card:hover { box-shadow: 0 6px 16px rgba(0,0,0,0.08); transform: translateY(-3px); }
.icon-box { font-size: 1.8rem; margin-bottom: 10px; background: #fef2f2; width: 48px; height: 48px; border-radius: 10px; display: flex; align-items: center; justify-content: center; }
.card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
.card p { color: #6b7280; font-size: 0.9rem; line-height: 1.6; }

/* 💬 评价 */
.quote-header { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.avatar { width: 38px; height: 38px; border-radius: 50%; background: linear-gradient(135deg, #ef4444, #f97316); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.95rem; }
.user-meta strong { display: block; font-size: 0.9rem; }
.user-meta span { font-size: 0.75rem; color: #6b7280; }
.rating { margin-left: auto; color: #f59e0b; font-size: 0.85rem; }
.quote-text { color: #374151; font-size: 0.92rem; line-height: 1.65; padding-left: 10px; border-left: 3px solid #fecaca; }
.quote-card.featured { background: linear-gradient(135deg, #fff5f5, #fff); border-color: #fecaca; position: relative; }
.badge { position: absolute; top: 12px; right: 12px; background: #ef4444; color: #fff; font-size: 0.65rem; font-weight: 700; padding: 3px 8px; border-radius: 99px; }

/* 🚀 步骤 */
.steps { background: #f8fafc; }
.steps-track { display: flex; flex-wrap: wrap; justify-content: center; gap: 20px; position: relative; }
.step { flex: 1 1 90px; text-align: center; }
.step-num { width: 36px; height: 36px; background: #ef4444; color: #fff; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center; font-weight: 800; font-size: 0.95rem; margin-bottom: 6px; }
.step p { font-weight: 600; font-size: 0.88rem; color: #4b5563; }

/* 📲 下载 */
.os-badge { display: inline-block; padding: 4px 10px; border-radius: 99px; font-size: 0.75rem; font-weight: 700; margin-bottom: 8px; }
.os-badge.android { background: #dcfce7; color: #166534; }
.os-badge.ios { background: #e0f2fe; color: #0369a1; }
.download-card { text-align: center; }
.download-card p { margin-bottom: 16px; }

/* 💬 客服（✅ 已严格压制尺寸 + 自适应） */
.contact { background: #fff; }
.contact-box {
  background: #f9fafb; border-radius: 16px; padding: 20px; border: 1px solid #e5e7eb;
  display: flex; flex-direction: column; align-items: center; gap: 20px;
  max-width: 600px; margin: 0 auto;
}
.contact-info { text-align: center; width: 100%; }
.contact-label { font-size: 1.05rem; font-weight: 700; margin-bottom: 10px; }
.wechat-row { display: flex; align-items: center; justify-content: center; gap: 10px; background: #fff; padding: 8px 14px; border-radius: 99px; box-shadow: 0 2px 6px rgba(0,0,0,0.04); margin-bottom: 10px; }
#wechat-id { font-family: monospace; font-weight: 700; color: #ef4444; font-size: 1rem; }
.btn-copy { background: #ef4444; color: #fff; border: none; padding: 5px 12px; border-radius: 99px; font-weight: 600; cursor: pointer; transition: 0.2s; }
.btn-copy:hover { background: #dc2626; }
.contact-hint { color: #6b7280; font-size: 0.85rem; line-height: 1.5; }
.contact-qr { text-align: center; }
.contact-qr img {
  width: 90px; height: 90px; border-radius: 10px; object-fit: cover;
  box-shadow: 0 2px 6px rgba(0,0,0,0.06); border: 1px solid #e5e7eb; background: #fff;
}
.qr-tip { margin-top: 6px; font-size: 0.75rem; color: #6b7280; }

/* 📄 Footer */
.footer { background: #111827; color: #9ca3af; text-align: center; padding: 28px 0 20px; font-size: 0.85rem; }
.disclaimer { margin: 6px 0; opacity: 0.8; line-height: 1.4; font-size: 0.8rem; }
.footer-nav { display: flex; justify-content: center; gap: 16px; margin-top: 10px; flex-wrap: wrap; }
.footer-nav a { color: #d1d5db; transition: 0.2s; }
.footer-nav a:hover { color: #fff; text-decoration: underline; }

/* 💡 Toast & 悬浮按钮 */
.toast {
  position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%) translateY(100px);
  background: #1f2937; color: #fff; padding: 10px 20px; border-radius: 99px;
  font-weight: 500; box-shadow: 0 4px 12px rgba(0,0,0,0.2); transition: 0.25s ease; z-index: 999; opacity: 0; pointer-events: none;
}
.toast.show { transform: translateX(-50%) translateY(0); opacity: 1; }
.float-btn {
  position: fixed; right: 16px; bottom: 16px; background: #ef4444; color: #fff;
  padding: 10px 16px; border-radius: 99px; font-weight: 600; font-size: 0.9rem;
  display: flex; align-items: center; gap: 6px; box-shadow: 0 4px 12px rgba(239,68,68,0.3);
  transition: 0.2s; z-index: 98;
}
.float-btn:hover { transform: translateY(-2px); }
.float-btn span { display: none; }

/* 📐 响应式断点控制（严格 Mobile-First） */
@media (min-width: 640px) {
  .hero-inner { flex-direction: row; text-align: left; justify-content: space-between; }
  .hero-content { max-width: 55%; }
  .hero-actions { justify-content: flex-start; }
  .hero-stats { justify-content: flex-start; }
  .hero-visual { max-width: 280px; }
  .contact-qr img { width: 100px; height: 100px; }
}

@media (min-width: 768px) {
  .section { padding: 56px 0; }
  .contact-box { flex-direction: row; text-align: left; justify-content: center; padding: 24px; }
  .contact-info { text-align: left; }
  .wechat-row { justify-content: flex-start; }
  .contact-qr img { width: 110px; height: 110px; }
  .float-btn span { display: inline; }
  .steps-track::before { content: ''; position: absolute; top: 18px; left: 12%; right: 12%; height: 2px; background: #e5e7eb; z-index: 0; }
  .step { z-index: 1; }
}

@media (min-width: 1024px) {
  .container { padding: 0 24px; }
  .section { padding: 64px 0; }
  .contact-qr img { width: 120px; height: 120px; }
  .hero-visual { max-width: 320px; }
}