/* ===========================================================
   header-footer.css — 全局统一导航栏与页脚样式
   所有页面共享，与 index.html 保持完全一致
   =========================================================== */

/* --- 固定导航栏 --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: var(--bg-header);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-header-alt);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 4rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.header-inner .logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-primary);
  background: none;
  -webkit-text-fill-color: var(--text-primary);
  background-clip: unset;
}

/* 桌面端导航 */
.nav-desktop {
  display: none;
  flex: 1;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
}
.nav-desktop a {
  text-decoration: none;
  font-size: 0.875rem;
  color: var(--text-footer);
  transition: color 0.2s ease;
  padding: 0;
  background: none;
  border-radius: 0;
}
.nav-desktop a:hover { color: var(--accent-dark); }
.nav-desktop a.active { color: var(--text-primary); }

/* 移动端汉堡按钮 */
.mobile-menu-btn {
  display: block;
  color: var(--text-primary);
  font-size: 1.25rem;
  padding: 0.25rem;
  background: none;
  border: none;
  cursor: pointer;
}

/* 移动端下拉菜单 */
.mobile-menu {
  display: none;
  padding: 0 1.5rem 1rem;
  background: var(--bg-header);
}
.mobile-menu.open { display: block; }
.mobile-menu a {
  display: block;
  padding: 0.5rem 0;
  font-size: 0.875rem;
  text-decoration: none;
  color: var(--text-footer);
  transition: color 0.2s ease;
}
.mobile-menu a:hover { color: var(--accent-dark); }

@media (min-width: 768px) {
  .mobile-menu-btn { display: none; }
  .mobile-menu { display: none !important; }
  .nav-desktop { display: flex; }
}

/* ===========================================================
   页脚
   =========================================================== */
.site-footer {
  background: var(--bg-footer);
  border-top: 1px solid var(--border-footer);
}
.footer-inner {
  max-width: 72rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-bottom: 2rem;
}
@media (min-width: 768px) {
  .footer-grid { grid-template-columns: repeat(4, 1fr); }
}
.footer-col h4 {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}
.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-col ul li { margin-bottom: 0.5rem; }
.footer-col ul li a {
  color: var(--text-footer);
  font-size: 0.75rem;
  text-decoration: none;
  transition: color 0.2s ease;
}
.footer-col ul li a:hover { color: var(--accent-dark); }
.footer-divider {
  height: 1px;
  background: var(--border-footer);
  margin-bottom: 1.5rem;
}
.footer-copy {
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-footer);
}
.footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-footer);
}
.footer-links a {
  color: var(--text-footer);
  text-decoration: none;
  transition: color 0.2s ease;
}
.footer-links a:hover { color: var(--accent-dark); }
.footer-links .sep { color: var(--text-footer-sep); }