/* ===== 顶部导航 ===== */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 48px;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  display: flex;
  align-items: center;
}
.site-nav .container {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.site-nav .brand {
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
}
.site-nav .brand:hover { text-decoration: none; }
.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  font-size: 14px;
  color: var(--text);
  opacity: 0.85;
  transition: opacity 0.2s ease;
}
.nav-links a:hover { opacity: 1; text-decoration: none; }
.nav-toggle { display: none; }

@media (max-width: 640px) {
  .nav-links {
    position: absolute;
    top: 48px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--nav-bg);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 8px 24px;
    display: none;
  }
  .nav-toggle:checked ~ .nav-links { display: flex; }
  .nav-links a { padding: 12px 0; }
  .nav-toggle-label {
    display: block;
    font-size: 20px;
    cursor: pointer;
    color: var(--text);
  }
}
@media (min-width: 641px) {
  .nav-toggle-label { display: none; }
}

/* ===== 页面主体 ===== */
main {
  padding-top: 48px; /* 导航高度 */
  min-height: calc(100vh - 48px);
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--bg-soft);
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  margin-top: 80px;
  font-size: 14px;
  color: var(--text-soft);
}
.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border);
}
.footer-top h4 {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.footer-top ul { list-style: none; padding: 0; margin: 0; }
.footer-top li { margin-bottom: 8px; }
.footer-top a { color: var(--text-soft); }
.footer-top a:hover { color: var(--text); text-decoration: none; }
.beian {
  padding-top: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  text-align: center;
}
.beian a { color: var(--text-soft); }
.beian a:hover { color: var(--accent); }
.beian p {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 6px;
}
.beian img { display: inline-block; }

@media (max-width: 768px) {
  .footer-top { grid-template-columns: 1fr; gap: 24px; }
}

/* ===== Hero ===== */
.hero {
  padding: 120px 0 80px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
}
.hero h1 {
  font-size: 72px;
  margin-bottom: 16px;
}
.hero .subtitle {
  font-size: 22px;
  color: var(--text-soft);
  margin-bottom: 32px;
}
.hero-ctas {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}
@media (max-width: 768px) {
  .hero { padding: 80px 0 60px; }
  .hero h1 { font-size: 44px; }
  .hero .subtitle { font-size: 18px; }
}

/* ===== Section ===== */
.section {
  padding: 80px 0;
}
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 32px;
}
.section-head h2 { margin: 0; }
.section-head a { font-size: 15px; }