.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 2px 15px rgba(31, 45, 61, 0.1); background-color: #FFFFFF; min-height: auto; }
.header-top { background-color: #1F2D3D; width: 100%; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding-left: 30px; padding-right: 30px; min-height: 68px; gap: 20px; }
.logo { display: block; color: #FFFFFF; font-size: 22px; font-weight: 800; text-decoration: none; letter-spacing: -0.5px; line-height: 1.2; }
.logo:hover { color: #FFFFFF; text-decoration: none; }
.desktop-nav-buttons { display: flex; align-items: center; gap: 10px; }
.btn { display: inline-block; padding: 10px 20px; border-radius: 8px; font-size: 14px; font-weight: 700; text-decoration: none !important; text-align: center; transition: all 0.3s ease; cursor: pointer; border: none; }
.btn-register { background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); color: #FFFFFF !important; box-shadow: 0 4px 12px rgba(47, 107, 255, 0.3); }
.btn-register:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(47, 107, 255, 0.4); }
.btn-login { background: #FFFFFF; color: #1F2D3D !important; border: 2px solid #2F6BFF; }
.btn-login:hover { background: #2F6BFF; color: #FFFFFF !important; }
.btn-download { background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); color: #FFFFFF !important; }
.btn-download:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(47, 107, 255, 0.4); }
.main-nav { display: flex; background-color: #FFFFFF; width: 100%; border-bottom: 2px solid #D6E2FF; }
.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: 0; flex-wrap: nowrap; }
.nav-link { display: inline-block; color: #1F2D3D; font-size: 14px; font-weight: 600; text-decoration: none; padding: 12px 14px; transition: color 0.3s ease; white-space: nowrap; }
.nav-link:hover { color: #2F6BFF; text-decoration: none; }
.hamburger-menu { display: none; background: none; border: none; cursor: pointer; padding: 8px; margin-left: 0; }
.mobile-menu-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(31, 45, 61, 0.6); z-index: 998; opacity: 0; transition: opacity 0.3s ease; }
.site-footer { background-color: #1F2D3D; color: #FFFFFF; padding: 50px 0 0 0; margin-top: 60px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; padding: 0 30px 40px 30px; }
.footer-logo { display: inline-block; color: #FFFFFF; font-size: 20px; font-weight: 800; text-decoration: none; margin-bottom: 15px; }
.footer-logo:hover { color: #6FA3FF; text-decoration: none; }
.footer-description { color: #B0B8C4; font-size: 14px; line-height: 1.6; }
.footer-title { color: #FFFFFF; font-size: 16px; font-weight: 700; margin-bottom: 20px; position: relative; padding-bottom: 10px; }
.footer-title::after { content: ''; position: absolute; bottom: 0; left: 0; width: 30px; height: 3px; background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); border-radius: 2px; }
.footer-links { list-style: none; padding: 0; margin: 0; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: #B0B8C4; font-size: 14px; text-decoration: none; transition: color 0.3s ease; }
.footer-links a:hover { color: #6FA3FF; text-decoration: none; }
.footer-note { color: #B0B8C4; font-size: 13px; margin-top: 20px; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.1); padding: 20px 0; text-align: center; }
.copyright { color: #B0B8C4; font-size: 13px; margin: 0; }
:root { --header-offset: 122px; }
body { padding-top: var(--header-offset); }
@media (max-width: 768px) {
  :root { --header-offset: 146px; }
  .header-container { width: 100%; max-width: none; padding-left: 15px; padding-right: 15px; min-height: 60px; gap: 10px; }
  .logo { font-size: 17px; order: 2; flex: 1; text-align: center; }
  .hamburger-menu { display: flex; order: 1; flex-direction: column; justify-content: center; align-items: center; width: 40px; height: 40px; padding: 8px; background: transparent; border: none; cursor: pointer; }
  .hamburger-menu span { display: block; width: 22px; height: 2px; background-color: #FFFFFF; margin: 3px 0; transition: all 0.3s ease; }
  .hamburger-menu.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .hamburger-menu.active span:nth-child(2) { opacity: 0; }
  .hamburger-menu.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
  .desktop-nav-buttons { display: flex; order: 3; gap: 6px; }
  .btn { padding: 8px 12px; font-size: 13px; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; width: 75%; max-width: 320px; height: 100vh; background-color: #FFFFFF; flex-direction: column; justify-content: flex-start; transform: translateX(-100%); transition: transform 0.3s ease; z-index: 1001; overflow-y: auto; padding-top: 70px; border-right: 2px solid #D6E2FF; }
  .main-nav.active { display: block; transform: translateX(0); }
  .nav-container { width: 100%; max-width: none; flex-direction: column; align-items: stretch; padding: 0; min-height: auto; }
  .nav-link { display: block; color: #1F2D3D; font-size: 15px; font-weight: 600; text-decoration: none; padding: 14px 20px; border-bottom: 1px solid #F0F4F8; }
  .nav-link:hover { color: #2F6BFF; background-color: #F4F7FB; }
  .mobile-menu-overlay.active { display: block; opacity: 1; }
  .site-footer { padding-top: 40px; }
  .footer-container { grid-template-columns: 1fr; gap: 30px; padding: 0 20px 30px 20px; }
  .footer-column { text-align: left; }
}
@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; }
}
/* 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;
}