.site-header { position: fixed; top: 0; left: 0; width: 100%; display: flex; flex-direction: column; z-index: 1000; box-shadow: 0 4px 15px rgba(31, 45, 61, 0.15); background: #FFFFFF; }
.site-header .header-top { background: linear-gradient(180deg, #1B4BBF 0%, #2F6BFF 100%); width: 100%; }
.site-header .header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 14px 30px; }
.site-header .logo { display: inline-flex; align-items: center; font-size: 28px; font-weight: 800; color: #FFFFFF; text-decoration: none; letter-spacing: 0.5px; line-height: 1.2; text-shadow: 0 2px 6px rgba(0, 0, 0, 0.25); }
.site-header .desktop-nav-buttons { display: flex; align-items: center; gap: 12px; }
.site-header .btn { display: inline-flex; align-items: center; justify-content: center; padding: 12px 28px; border-radius: 50px; font-size: 15px; font-weight: 700; text-decoration: none; color: #FFFFFF; background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); border: 2px solid rgba(255, 255, 255, 0.25); box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2); transition: all 0.3s ease; cursor: pointer; white-space: nowrap; }
.site-header .btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3); border-color: #FFFFFF; }
.site-header .btn-register { background: linear-gradient(180deg, #FFD700 0%, #FFA500 100%); color: #1F2D3D; border-color: rgba(255, 255, 255, 0.5); }
.site-header .btn-download { background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); }
.site-header .main-nav { background: #FFFFFF; width: 100%; display: flex; border-bottom: 2px solid #D6E2FF; }
.site-header .nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 20px; min-height: 52px; gap: 4px; flex-wrap: wrap; }
.site-header .nav-link { display: inline-flex; align-items: center; padding: 8px 16px; font-size: 15px; font-weight: 600; color: #1F2D3D; text-decoration: none; border-radius: 6px; transition: color 0.3s, background 0.3s; white-space: nowrap; }
.site-header .nav-link:hover { color: #2F6BFF; background: #F4F7FB; }
.site-header .mobile-nav-buttons { display: none; }
.site-header .hamburger-menu { display: none; }
.site-header .mobile-menu-overlay { display: none; }
.site-footer { background: #1F2D3D; padding: 60px 0 0 0; color: #D6E2FF; }
.site-footer .footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; padding: 0 30px 40px; }
.site-footer .footer-logo { font-size: 26px; font-weight: 800; color: #FFFFFF; text-decoration: none; display: inline-block; margin-bottom: 18px; }
.site-footer .footer-description { font-size: 14px; line-height: 1.8; color: #A5C4FF; margin: 0 0 16px 0; }
.site-footer .footer-disclaimer { font-size: 13px; color: #6FA3FF; margin: 0; font-weight: 600; }
.site-footer .footer-heading { font-size: 17px; font-weight: 700; color: #FFFFFF; margin: 0 0 18px 0; position: relative; padding-bottom: 10px; }
.site-footer .footer-heading::after { content: ''; position: absolute; bottom: 0; left: 0; width: 32px; height: 3px; background: #2F6BFF; border-radius: 2px; }
.site-footer .footer-nav { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.site-footer .footer-nav a { color: #A5C4FF; text-decoration: none; font-size: 14px; transition: color 0.3s, padding-left 0.3s; line-height: 1.6; }
.site-footer .footer-nav a:hover { color: #FFFFFF; padding-left: 6px; }
.site-footer .footer-bottom { background: #152638; padding: 18px 30px; text-align: center; border-top: 1px solid rgba(214, 226, 255, 0.15); }
.site-footer .copyright { font-size: 14px; color: #A5C4FF; margin: 0; }
body { padding-top: var(--header-offset, 122px); }
:root { --header-offset: 122px; }
@media (max-width: 768px) {
  .site-header { background: #FFFFFF; }
  .site-header .header-container { width: 100%; max-width: none; padding: 10px 15px; }
  .site-header .logo { font-size: 20px; }
  .site-header .desktop-nav-buttons { display: none; }
  .site-header .main-nav { display: none; position: fixed; top: 0; left: 0; width: 280px; height: 100vh; flex-direction: column; justify-content: flex-start; background: #FFFFFF; box-shadow: 4px 0 20px rgba(0, 0, 0, 0.15); transform: translateX(-100%); transition: transform 0.3s ease, display 0s linear 0.3s; z-index: 1002; overflow-y: auto; padding-top: 70px; }
  .site-header .main-nav.active { display: flex; transform: translateX(0); transition: transform 0.3s ease; }
  .site-header .nav-container { flex-direction: column; align-items: flex-start; width: 100%; max-width: none; padding: 10px; gap: 0; }
  .site-header .nav-link { width: 100%; padding: 14px 18px; font-size: 16px; border-bottom: 1px solid #F4F7FB; border-radius: 0; color: #1F2D3D; }
  .site-header .nav-link:hover { background: #F4F7FB; color: #2F6BFF; }
  .site-header .mobile-nav-buttons { display: flex; justify-content: center; gap: 10px; padding: 8px 15px; background: #FFFFFF; border-bottom: 2px solid #F4F7FB; z-index: 998; }
  .site-header .hamburger-menu { display: flex; flex-direction: column; justify-content: center; align-items: center; width: 44px; height: 44px; background: transparent; border: none; cursor: pointer; z-index: 1003; position: absolute; left: 10px; top: 14px; padding: 0; }
  .site-header .hamburger-menu span { display: block; width: 24px; height: 3px; background: #FFFFFF; margin: 3px 0; border-radius: 2px; transition: transform 0.3s ease, opacity 0.3s ease, background 0.3s; }
  .site-header .hamburger-menu:hover span { background: #A5C4FF; }
  .site-header .hamburger-menu.active span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
  .site-header .hamburger-menu.active span:nth-child(2) { opacity: 0; }
  .site-header .hamburger-menu.active span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }
  .site-header .mobile-menu-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(31, 45, 61, 0.6); z-index: 1001; opacity: 0; transition: opacity 0.3s ease; }
  .site-header .mobile-menu-overlay.active { display: block; opacity: 1; }
  .site-footer .footer-container { grid-template-columns: 1fr 1fr; gap: 30px; padding: 0 20px 30px; }
  .site-footer .footer-bottom { padding: 15px 20px; }
  :root { --header-offset: 110px; }
  body { overflow-x: hidden; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; }
  body.no-scroll { overflow: hidden; position: fixed; width: 100%; }
}
@media (min-width: 769px) {
  .site-header .hamburger-menu { display: none; }
  .site-header .mobile-menu-overlay { display: none !important; }
  .site-header .mobile-nav-buttons { display: none !important; }
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}
/* 内容保护（系统追加，请勿删除） */
body {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
input, textarea, select, [contenteditable="true"] {
  -webkit-user-select: text;
  -moz-user-select: text;
  user-select: text;
}