:root { --primary-color: #26A9E0; --secondary-color: #FFFFFF; --header-offset: 122px; }
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #FFFFFF; color: #333333; padding-top: var(--header-offset); overflow-x: hidden; }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 2px 10px rgba(0,0,0,0.15); background-color: #FFFFFF; border-bottom: 3px solid var(--primary-color); }
.header-top { background-color: #FFFFFF; width: 100%; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 10px 30px; min-height: 68px; }
.logo { font-size: 28px; font-weight: 800; text-decoration: none; color: #000000; text-transform: lowercase; letter-spacing: 1px; display: inline-block; white-space: nowrap; }
.logo:hover { color: var(--primary-color); }
.desktop-nav-buttons { display: flex; align-items: center; gap: 10px; }
.btn { display: inline-block; padding: 10px 22px; border-radius: 8px; text-decoration: none; font-size: 14px; font-weight: 700; text-align: center; transition: transform 0.2s, box-shadow 0.2s; cursor: pointer; border: none; white-space: nowrap; }
.btn:hover { transform: translateY(-2px); box-shadow: 0 5px 15px rgba(0,0,0,0.2); text-decoration: none; }
.btn-login { background: #EA7C07; color: #FFFFFF; }
.btn-register { background: linear-gradient(135deg, var(--primary-color), #1a8fc0); color: #FFFFFF; }
.main-nav { background-color: #f0f8fc; width: 100%; display: flex; border-top: 1px solid #e0e0e0; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 20px; width: 100%; }
.nav-link { display: inline-block; padding: 14px 18px; color: #333333; text-decoration: none; font-size: 15px; font-weight: 600; transition: color 0.3s, background-color 0.3s; white-space: nowrap; }
.nav-link:hover { color: var(--primary-color); background-color: rgba(38,169,224,0.1); text-decoration: none; }
.nav-link.active { color: var(--primary-color); border-bottom: 2px solid var(--primary-color); }
.hamburger-menu { display: none; }
.mobile-menu-overlay { display: none; }
.mobile-nav-buttons { display: none; }
.site-footer { background-color: #1a2733; color: #ffffff; padding: 50px 20px 30px; margin-top: 60px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; }
.footer-brand .footer-logo { font-size: 26px; font-weight: 800; color: #ffffff; text-decoration: none; display: inline-block; margin-bottom: 15px; }
.footer-brand .footer-logo:hover { color: var(--primary-color); }
.footer-desc { font-size: 14px; line-height: 1.6; color: #b0bec5; margin-bottom: 25px; }
.footer-copyright { font-size: 13px; color: #8899a6; margin-top: 10px; }
.footer-heading { font-size: 16px; font-weight: 700; color: #ffffff; margin-bottom: 20px; text-transform: uppercase; letter-spacing: 0.5px; }
.footer-nav { display: flex; flex-direction: column; gap: 12px; }
.footer-nav a { color: #b0bec5; text-decoration: none; font-size: 14px; transition: color 0.3s; }
.footer-nav a:hover { color: var(--primary-color); text-decoration: underline; }
@media (max-width: 768px) {
  :root { --header-offset: 110px; }
  .site-header { border-bottom: 2px solid var(--primary-color); }
  .header-top { background-color: #FFFFFF; }
  .header-container { width: 100%; max-width: none; padding: 8px 15px; min-height: 60px; justify-content: space-between; align-items: center; }
  .header-container .logo { font-size: 22px; position: absolute; left: 50%; transform: translateX(-50%); }
  .desktop-nav-buttons { display: none; }
  .hamburger-menu { display: flex; flex-direction: column; justify-content: center; align-items: center; width: 40px; height: 40px; background: none; border: none; cursor: pointer; gap: 5px; z-index: 1001; position: relative; }
  .hamburger-menu span { display: block; width: 22px; height: 2px; background-color: #333; transition: all 0.3s ease; border-radius: 2px; }
  .hamburger-menu.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .hamburger-menu.active span:nth-child(2) { opacity: 0; }
  .hamburger-menu.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .main-nav { display: none; position: fixed; top: 60px; left: 0; width: 280px; height: 100vh; background-color: #FFFFFF; flex-direction: column; z-index: 1000; transform: translateX(-100%); transition: transform 0.3s ease; border-right: 2px solid var(--primary-color); }
  .main-nav.active { display: block; transform: translateX(0); }
  .nav-container { width: 100%; max-width: none; display: flex; flex-direction: column; align-items: flex-start; padding: 0; }
  .nav-link { display: block; width: 100%; padding: 14px 20px; font-size: 15px; color: #333; border-bottom: 1px solid #f0f0f0; }
  .nav-link:hover { background-color: rgba(38,169,224,0.1); color: var(--primary-color); }
  .mobile-nav-buttons { display: flex; width: 100%; padding: 8px 15px; background-color: #FFFFFF; border-bottom: 1px solid #e0e0e0; gap: 10px; z-index: 999; min-height: 48px; }
  .mobile-nav-buttons .btn { flex: 1; font-size: 13px; padding: 9px 12px; }
  .mobile-menu-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.5); z-index: 999; opacity: 0; pointer-events: none; transition: opacity 0.3s ease; }
  .mobile-menu-overlay.active { opacity: 1; pointer-events: auto; }
  .footer-container { grid-template-columns: 1fr; gap: 30px; }
  .footer-heading { margin-bottom: 15px; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; }
  body { overflow-x: hidden; }
}
/* 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;
}