/* =====================================================
   全站基础样式：首页 / 通用按钮 / 布局
   ===================================================== */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
  background: #fff;
  color: #333;
}

a { text-decoration: none; color: inherit; }

/* ---------------- 顶部导航 ---------------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 28px;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #f0e4d8;
}
.logo { font-size: 20px; font-weight: 700; color: #b03a2e; letter-spacing: 1px; }
.site-header nav { display: flex; gap: 10px; }

/* ---------------- 按钮 ---------------- */
.btn {
  display: inline-block; padding: 10px 22px; border-radius: 24px;
  font-size: 15px; cursor: pointer; border: none; text-align: center;
  transition: all .25s; font-family: inherit;
}
.btn.primary { background: linear-gradient(135deg, #b03a2e, #d24a3c); color: #fff; box-shadow: 0 4px 14px rgba(176, 58, 46, .3); }
.btn.primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(176, 58, 46, .4); }
.btn.ghost { background: #fff; color: #b03a2e; border: 1.5px solid #d9a441; }
.btn.ghost:hover { background: #fff8f0; }
.btn.big { padding: 13px 34px; font-size: 16px; }
.nav-btn { padding: 8px 18px; border-radius: 20px; font-size: 14px; }

/* ---------------- 首页 Hero ---------------- */
.hero {
  position: relative; min-height: 92vh; display: flex; align-items: center; justify-content: center;
  background: #1f2b3a center/cover no-repeat;
  color: #fff; text-align: center; padding: 90px 20px 60px;
}
.hero-mask {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(31, 43, 58, .55), rgba(31, 43, 58, .78));
}
.hero-inner { position: relative; z-index: 1; max-width: 760px; }
.hero h1 { font-size: clamp(32px, 6vw, 56px); line-height: 1.35; letter-spacing: 3px; margin-bottom: 22px; }
.hero p { font-size: 16px; line-height: 2; opacity: .92; margin-bottom: 34px; }
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn.light { color: #fff; border-color: rgba(255,255,255,.8); background: rgba(255,255,255,.12); }
.btn.light:hover { background: rgba(255,255,255,.22); }

/* ---------------- 功能卡片 ---------------- */
.features {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px; max-width: 1080px; margin: -40px auto 0; padding: 0 20px; position: relative; z-index: 2;
}
.feature-card {
  background: #fff; border-radius: 16px; padding: 30px 22px; text-align: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .08); transition: transform .3s;
}
.feature-card:hover { transform: translateY(-6px); }
.f-ico { font-size: 38px; margin-bottom: 14px; }
.feature-card h3 { font-size: 18px; margin-bottom: 10px; color: #b03a2e; }
.feature-card p { font-size: 14px; line-height: 1.8; color: #777; }

/* ---------------- 步骤 ---------------- */
.how { max-width: 1080px; margin: 70px auto; padding: 0 20px; text-align: center; }
.how h2 { font-size: 28px; letter-spacing: 2px; margin-bottom: 40px; color: #5c3a1e; }
.steps { display: flex; justify-content: center; gap: 30px; flex-wrap: wrap; }
.step { flex: 1; min-width: 200px; max-width: 260px; background: #fff8f0; border-radius: 16px; padding: 30px 20px; }
.step b {
  display: inline-flex; align-items: center; justify-content: center;
  width: 46px; height: 46px; border-radius: 50%;
  background: linear-gradient(135deg, #b03a2e, #d9a441); color: #fff; font-size: 20px; margin-bottom: 14px;
}
.step p { font-size: 14px; line-height: 1.9; color: #666; }

/* ---------------- 页脚 ---------------- */
.site-footer { text-align: center; padding: 40px 20px; color: #aaa; font-size: 13px; border-top: 1px solid #f4ece2; }

@media (max-width: 640px) {
  .site-header { padding: 12px 16px; }
  .hero { min-height: 78vh; padding-top: 110px; }
}