/* 全局样式 */
* {
  box-sizing: border-box;
}

html {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: #122244;
  background-color: #f6f8fb;
  line-height: 1.6;
}

img {
  max-width: 100%;
  display: block;
}

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

button,
input,
textarea {
  font: inherit;
}

/* 容器 */
.container {
  width: min(1120px, calc(100% - 32px));
  margin: 50px auto 0 auto;
}

/* 头部导航 */
.site-header {
  background-color: #ffffff;
  border-bottom: 1px solid #e4ecf7;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 16px 0;
}

.brand {
  font-size: 1.3rem;
  font-weight: 700;
  color: #0f3256;
}

.nav-menu {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-link {
  color: #1d3d72;
  font-size: 0.95rem;
  transition: color 0.25s ease;
}

.nav-link:hover,
.nav-link.active {
  color: #0a66c2;
}

.nav-toggle {
  display: none;
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle .bar {
  display: block;
  width: 24px;
  height: 2px;
  margin: 4px 0;
  background-color: #0f3256;
  transition: transform 0.3s ease;
}

/* 英雄区 */
.hero {
  background: linear-gradient(135deg, #eef6ff 0%, #f9fbff 100%);
  padding: 80px 0 64px;
}

.hero-content {
  max-width: 720px;
}

.eyebrow {
  color: #0a66c2;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 3.5rem);
  margin: 0 0 20px;
  line-height: 1.05;
}

.hero-text {
  font-size: 1.05rem;
  color: #455880;
  max-width: 720px;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 24px;
  border-radius: 999px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background-color: #0a66c2;
  color: #ffffff;
  border: 1px solid transparent;
}

.btn-secondary {
  background-color: #ffffff;
  color: #0f3256;
  border: 1px solid #dbe3ef;
}

/* 分区 */
.section {
  padding: 64px 0;
}

.section-light {
  background-color: #ffffff;
}

.section-dark {
  background-color: #0f3256;
  color: #ffffff;
}

.section-title {
  max-width: 680px;
  margin-bottom: 40px;
}

.section-title h2 {
  font-size: 2rem;
  margin-bottom: 12px;
}

.section-title p {
  color: #5b6d89;
  margin: 0;
}

.white-title p {
  color: rgba(255, 255, 255, 0.82);
}

.card-grid,
.product-grid,
.metrics-grid,
.news-list,
.contact-grid {
  display: grid;
  gap: 24px;
}

.card,
.product-card,
.news-item,
.metric-card {
  background-color: #f8fbff;
  border: 1px solid #e7eff9;
  border-radius: 16px;
  padding: 28px;
}

.section-dark .card,
.section-dark .product-card,
.section-dark .metric-card {
  background-color: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.16);
}

.card h3,
.product-card h3,
.news-item h3,
.metric-card h3 {
  margin-top: 0;
  margin-bottom: 12px;
}

.card p,
.product-card p,
.news-item p,
.metric-card p {
  margin: 0;
  color: inherit;
}

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.feature-list li {
  margin-bottom: 14px;
  padding-left: 18px;
  position: relative;
}

.feature-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #0a66c2;
}

.split-layout {
  display: grid;
  gap: 32px;
  align-items: center;
  grid-template-columns: 1.1fr 0.9fr;
}

.feature-image,
.about-image {
  min-height: 320px;
  background: linear-gradient(180deg, rgba(10, 102, 194, 0.18) 0%, rgba(15, 50, 86, 0.05) 100%);
  border-radius: 24px;
}

.metrics-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.news-list {
  grid-template-columns: 1fr;
}

.news-item {
  padding: 28px;
}

.news-date {
  display: inline-block;
  margin-top: 18px;
  color: #0a66c2;
  font-size: 0.95rem;
}

.contact-grid {
  grid-template-columns: 1fr 1.1fr;
}

.contact-info {
  padding: 28px;
  border-radius: 16px;
  background-color: #eef4ff;
  border: 1px solid #d9e4f6;
}

.contact-info h3 {
  margin-top: 0;
}

.contact-form {
  display: grid;
  gap: 18px;
}

.contact-form label {
  font-weight: 600;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid #d9e4f6;
  border-radius: 12px;
  padding: 14px 16px;
  background-color: #ffffff;
  color: #162a44;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: 2px solid rgba(10, 102, 194, 0.24);
  border-color: #0a66c2;
}

footer {
  background-color: #ffffff;
  border-top: 1px solid #e4ecf7;
  padding: 24px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-links a {
  color: #1d3d72;
}

@media (max-width: 900px) {
  .split-layout,
  .contact-grid,
  .metrics-grid {
    grid-template-columns: 1fr;
  }

  .header-inner {
    flex-wrap: wrap;
  }
}

@media (max-width: 720px) {
  .container {
    width: calc(100% - 24px);
  }

  .hero {
    padding-top: 56px;
  }

  .nav-menu {
    position: absolute;
    inset: 64px 16px auto auto;
    flex-direction: column;
    background-color: #ffffff;
    border: 1px solid #e4ecf7;
    border-radius: 16px;
    padding: 16px;
    width: calc(100% - 32px);
    max-width: 320px;
    box-shadow: 0 16px 36px rgba(15, 50, 86, 0.12);
    transform: translateY(-20px);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s ease, opacity 0.25s ease;
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-link {
    padding: 10px 0;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
}