/* 全局基础样式 */
:root {
  --color-primary: #0a4f8c;
  --color-primary-dark: #06345c;
  --color-accent: #e85d04;
  --color-text: #1a1a1a;
  --color-muted: #5c5c5c;
  --color-bg: #f5f7fa;
  --color-card: #ffffff;
  --font-sans: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 24px rgba(10, 79, 140, 0.12);
  --radius: 10px;
  --header-h: 72px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.page-main {
  min-height: calc(100vh - var(--header-h) - 200px);
  padding-top: var(--header-h);
}

.container {
  width: min(1120px, 100% - 32px);
  margin-left: auto;
  margin-right: auto;
}

.section {
  padding: 56px 0;
}

.section--alt {
  background: #fff;
}

.section-title {
  margin: 0 0 12px;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-primary-dark);
}

.section-lead {
  margin: 0 0 32px;
  color: var(--color-muted);
  max-width: 640px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}

.btn--primary {
  background: linear-gradient(135deg, var(--color-primary), #1568b8);
  color: #fff;
}

.btn--primary:hover {
  background: var(--color-primary-dark);
  text-decoration: none;
}

.btn--outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn--outline:hover {
  background: rgba(10, 79, 140, 0.06);
  text-decoration: none;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--color-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card__body {
  padding: 20px;
}

.card__title {
  margin: 0 0 8px;
  font-size: 1.125rem;
}

.card__text {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--color-muted);
}

/* 页脚（由 nav.js 注入结构） */
#site-footer {
  background: var(--color-primary-dark);
  color: #e8eef5;
  margin-top: 48px;
}

.footer-inner {
  width: min(1120px, 100% - 32px);
  margin: 0 auto;
  padding: 40px 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

@media (max-width: 720px) {
  .footer-inner {
    grid-template-columns: 1fr;
  }
}

.footer-brand strong {
  font-size: 1.125rem;
}

.footer-tagline {
  margin: 8px 0 0;
  opacity: 0.9;
  font-size: 0.9375rem;
}

.footer-contact p {
  margin: 0 0 8px;
  font-size: 0.9375rem;
}

.footer-contact a {
  color: #fff;
}

.footer-icp {
  margin-top: 12px;
  font-size: 0.8125rem;
  opacity: 0.85;
}

.footer-copy {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: 16px;
  text-align: center;
  font-size: 0.8125rem;
  opacity: 0.85;
}