/* ===== 基础 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --primary: #1f5fd6;
  --primary-dark: #16489f;
  --text: #2a2f3a;
  --muted: #6b7280;
  --bg-alt: #f4f7fb;
  --white: #ffffff;
}
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}
.container { width: 90%; max-width: 1140px; margin: 0 auto; }
a { text-decoration: none; color: inherit; }

/* ===== 导航 ===== */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0,0,0,.06);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 20px; font-weight: 700; color: var(--primary); }
.nav-menu { display: flex; gap: 28px; }
.nav-menu a { color: var(--text); font-size: 15px; transition: color .2s; }
.nav-menu a:hover { color: var(--primary); }
.nav-toggle { display: none; background: none; border: 0; font-size: 26px; color: var(--text); cursor: pointer; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block; padding: 12px 30px;
  background: var(--primary); color: #fff; border-radius: 6px;
  font-size: 15px; font-weight: 600; transition: background .2s;
  border: 0; cursor: pointer;
}
.btn:hover { background: var(--primary-dark); }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--primary), #3a7bf0);
  color: #fff; text-align: center;
  padding: 110px 0 120px;
}
.hero h1 { font-size: 44px; margin-bottom: 16px; }
.hero .slogan { font-size: 19px; opacity: .95; margin-bottom: 32px; }

/* ===== 区块 ===== */
.section { padding: 80px 0; }
.section-alt { background: var(--bg-alt); }
.section-title {
  text-align: center; font-size: 30px; margin-bottom: 40px;
  position: relative; padding-bottom: 14px;
}
.section-title::after {
  content: ""; position: absolute; left: 50%; bottom: 0;
  transform: translateX(-50%); width: 56px; height: 4px;
  background: var(--primary); border-radius: 2px;
}
.lead { font-size: 17px; color: #3c4453; max-width: 860px; margin: 0 auto 16px; text-align: center; }
.section p { text-align: center; color: var(--muted); }

/* 数据 */
.stats { display: flex; flex-wrap: wrap; justify-content: center; gap: 40px; margin-top: 40px; }
.stat { text-align: center; }
.stat .num { display: block; font-size: 34px; font-weight: 700; color: var(--primary); }
.stat .label { font-size: 14px; color: var(--muted); }

/* 产品卡片 */
.grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.card {
  background: #fff; border-radius: 10px; padding: 30px 22px;
  text-align: center; box-shadow: 0 4px 18px rgba(0,0,0,.05);
  transition: transform .2s, box-shadow .2s;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 10px 28px rgba(0,0,0,.1); }
.card-icon { font-size: 40px; margin-bottom: 14px; }
.card h3 { font-size: 18px; margin-bottom: 10px; color: var(--text); }
.card p { font-size: 14px; }

/* 服务列表 */
.service-list { max-width: 820px; margin: 0 auto; list-style: none; }
.service-list li {
  background: #fff; border-left: 4px solid var(--primary);
  padding: 16px 22px; margin-bottom: 14px; border-radius: 6px;
  box-shadow: 0 2px 10px rgba(0,0,0,.04); text-align: left; color: #3c4453;
}
.service-list strong { color: var(--primary); }

/* 联系 */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.contact-info p { text-align: left; font-size: 16px; margin-bottom: 12px; color: #3c4453; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 12px 14px; margin-bottom: 14px;
  border: 1px solid #d8dee8; border-radius: 6px; font-size: 15px;
  font-family: inherit; resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--primary); }
.contact-form .btn { width: 100%; }
.hint { font-size: 13px; color: var(--muted); text-align: left; margin-top: 8px; }

/* 页脚 */
.footer { background: #1c2430; color: #aeb6c2; padding: 26px 0; text-align: center; font-size: 14px; }

/* ===== 语言切换 ===== */
.nav-right { display: flex; align-items: center; gap: 14px; }
.lang-switch { display: flex; align-items: center; gap: 4px; font-size: 14px; }
.lang-switch .sep { color: var(--muted); }
.lang-switch button {
  background: none; border: 0; cursor: pointer; color: var(--muted);
  font-size: 14px; padding: 5px 8px; border-radius: 5px; transition: all .15s;
}
.lang-switch button.active { color: #fff; background: var(--primary); }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .nav-menu {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; background: #fff; padding: 14px 0;
    box-shadow: 0 6px 16px rgba(0,0,0,.08); gap: 0;
  }
  .nav-menu.open { display: flex; }
  .nav-menu a { padding: 12px 24px; }
  .hero h1 { font-size: 34px; }
  .grid { grid-template-columns: 1fr; }
  .section { padding: 56px 0; }
}