:root { --header-offset: 166px; --primary-color: #26A9E0; --secondary-color: #FFFFFF; --dark-color: #1a2a3a; --light-color: #f8f9fa; --text-color: #333333; --login-color: #EA7C07; }
body { padding-top: var(--header-offset); margin: 0; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; background-color: var(--secondary-color); box-shadow: 0 4px 12px rgba(0,0,0,0.12); }
.header-top { background: linear-gradient(90deg, #1a5276 0%, #1a6e8e 100%); width: 100%; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 10px 20px; min-height: 68px; }
.logo { color: #ffffff; text-decoration: none; font-size: 28px; font-weight: 800; letter-spacing: -0.5px; white-space: nowrap; text-shadow: 2px 2px 4px rgba(0,0,0,0.3); transition: all 0.3s ease; display: inline-block; }
.logo:hover { transform: scale(1.02); text-decoration: none; }
.desktop-nav-buttons { display: flex; gap: 10px; align-items: center; }
.btn { display: inline-block; padding: 10px 20px; border-radius: 25px; text-decoration: none; font-weight: 700; font-size: 14px; transition: all 0.3s ease; border: none; cursor: pointer; text-align: center; }
.btn:hover { text-decoration: none; transform: translateY(-2px); box-shadow: 0 6px 15px rgba(0,0,0,0.2); }
.btn-login { background-color: var(--login-color); color: #ffffff; box-shadow: 0 4px 8px rgba(234,124,7,0.4); }
.btn-register { background: linear-gradient(45deg, #ff9800, #ffb300); color: #ffffff; box-shadow: 0 4px 8px rgba(255,152,0,0.4); }
.btn-download { background-color: #ffffff; color: #1a5276; }
.main-nav { background-color: #ffffff; width: 100%; display: flex; min-height: 52px; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 20px; gap: 5px; flex-wrap: wrap; width: 100%; }
.nav-link { color: var(--text-color); text-decoration: none; font-size: 15px; font-weight: 600; padding: 16px 10px; text-align: center; transition: color 0.3s ease; border-bottom: 3px solid transparent; white-space: nowrap; display: inline-block; }
.nav-link:hover { color: var(--primary-color); text-decoration: none; border-bottom-color: var(--primary-color); }
.hamburger-menu { display: none; background: transparent; border: none; cursor: pointer; padding: 8px; z-index: 1002; }
.hamburger-line { display: block; width: 25px; height: 3px; background-color: #ffffff; margin: 5px 0; transition: all 0.3s ease; border-radius: 2px; }
.hamburger-menu.active .hamburger-line:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger-menu.active .hamburger-line:nth-child(2) { opacity: 0; }
.hamburger-menu.active .hamburger-line:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
.mobile-header-container { display: none; }
.mobile-nav-buttons { display: none; }
.mobile-menu-overlay { display: none; }
.site-footer { background-color: #1a2a3a; color: #ffffff; }
.footer-container { max-width: 1200px; margin: 0 auto; padding: 50px 20px 30px; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
.footer-brand { padding-right: 20px; }
.footer-logo { color: var(--primary-color); text-decoration: none; font-size: 24px; font-weight: 800; display: inline-block; margin-bottom: 15px; }
.footer-description { color: #a0a8b4; font-size: 14px; line-height: 1.7; margin: 0; }
.footer-title { color: #ffffff; font-size: 16px; font-weight: 700; margin-bottom: 20px; text-transform: uppercase; letter-spacing: 1px; position: relative; padding-bottom: 10px; }
.footer-title::after { content: ''; position: absolute; bottom: 0; left: 0; width: 30px; height: 2px; background-color: var(--primary-color); }
.footer-nav { display: flex; flex-direction: column; gap: 10px; }
.footer-link { color: #a0a8b4; text-decoration: none; font-size: 14px; padding: 5px 0; transition: color 0.3s ease, padding-left 0.3s ease; }
.footer-link:hover { color: var(--primary-color); text-decoration: none; padding-left: 5px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding: 20px; text-align: center; display: flex; justify-content: center; align-items: center; gap: 15px; max-width: 1200px; margin: 0 auto; }
.footer-bottom p { color: #a0a8b4; font-size: 14px; margin: 0; }
.footer-age-warning { color: #ff6b6b !important; font-weight: bold; border: 2px solid #ff6b6b; padding: 2px 8px; border-radius: 4px; }
@media (max-width: 768px) {
  :root { --header-offset: 146px; }
  body { overflow-x: hidden; }
  .header-container { width: 100%; max-width: none; padding-left: 10px; padding-right: 10px; min-height: 60px; }
  .logo { font-size: 22px; order: 2; margin: 0 auto; text-align: center; position: absolute; left: 50%; transform: translateX(-50%); }
  .hamburger-menu { display: block; order: 1; margin-right: auto; }
  .desktop-nav-buttons { display: none; }
  .header-top { position: relative; }
  .header-container { justify-content: flex-start; position: relative; }
  .mobile-header-container { display: block; background: linear-gradient(90deg, #1a5276 0%, #1a6e8e 100%); padding-top: 0; }
  .mobile-nav-buttons { display: flex; gap: 6px; justify-content: center; padding: 8px 10px; min-height: 48px; width: 100%; max-width: 100%; box-sizing: border-box; flex-wrap: wrap; }
  .mobile-nav-buttons .btn { flex: 1; padding: 8px 10px; font-size: 13px; min-width: 90px; max-width: 120px; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; width: 85%; max-width: 320px; height: 100vh; background-color: #ffffff; z-index: 1001; flex-direction: column; transform: translateX(-100%); transition: transform 0.3s ease; box-shadow: 2px 0 10px rgba(0,0,0,0.1); overflow-y: auto; }
  .main-nav.active { display: flex; transform: translateX(0); }
  .nav-container { flex-direction: column; align-items: flex-start; gap: 0; padding: 20px 15px; width: 100%; max-width: none; flex-wrap: nowrap; justify-content: flex-start; }
  .nav-link { display: block; width: 100%; padding: 12px 8px; font-size: 15px; text-align: left; border-bottom: 1px solid #eaeaea; }
  .nav-link:hover { background-color: #f5f5f5; border-bottom-color: #eaeaea; color: var(--primary-color); }
  .mobile-menu-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.5); z-index: 999; }
  .mobile-menu-overlay.active { display: block; }
  .site-footer { background-color: #1a2a3a; }
  .footer-container { grid-template-columns: 1fr; gap: 30px; padding: 30px 20px 20px; }
  .footer-brand { padding-right: 0; }
  .footer-logo { font-size: 22px; }
  .footer-title { font-size: 15px; margin-bottom: 15px; }
  .footer-link { font-size: 13px; }
  .footer-bottom { flex-direction: column; gap: 8px; padding: 15px 10px; }
  .footer-bottom p { font-size: 13px; }
  .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;
}