:root { --header-offset: 122px; --color-primary: #2F6BFF; --color-secondary: #6FA3FF; --color-btn-grad-start: #4A8BFF; --color-btn-grad-end: #2F6BFF; --color-card-bg: #FFFFFF; --color-bg: #F4F7FB; --color-text-main: #1F2D3D; --color-text-black: #000000; --color-border: #D6E2FF; --color-glow: #A5C4FF; }
html { scroll-behavior: smooth; }
body { padding-top: var(--header-offset); margin: 0; font-family: 'Segoe UI', Roboto, Arial, sans-serif; background-color: var(--color-bg); color: var(--color-text-main); overflow-x: hidden; }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 4px 12px rgba(0,0,0,0.15); min-height: auto; background-color: transparent; }
.header-top { background: linear-gradient(135deg, #1F3FAF 0%, var(--color-primary) 100%); width: 100%; padding: 0; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 10px 20px; min-height: 68px; box-sizing: border-box; }
.logo { font-size: 28px; font-weight: 800; color: #ffffff; text-decoration: none; text-transform: uppercase; letter-spacing: 1px; display: inline-block; order: 0; text-shadow: 2px 2px 4px rgba(0,0,0,0.3); }
.logo:hover { color: var(--color-glow); transform: scale(1.03); transition: all 0.3s ease; }
.desktop-nav-buttons { display: flex; gap: 12px; align-items: center; }
.btn { display: inline-block; padding: 10px 24px; border-radius: 25px; font-size: 15px; font-weight: 700; text-decoration: none; text-align: center; transition: all 0.3s ease; border: none; cursor: pointer; box-shadow: 0 2px 6px rgba(0,0,0,0.15); color: #ffffff; line-height: 1.2; }
.btn:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.25); filter: brightness(1.1); }
.btn-register { background: linear-gradient(180deg, #FF6B35 0%, #FF4500 100%); }
.btn-login { background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); }
.main-nav { width: 100%; background-color: var(--color-card-bg); display: flex; align-items: center; justify-content: center; border-bottom: 2px solid var(--color-border); }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; gap: 5px; padding: 5px 20px; flex-wrap: wrap; width: 100%; box-sizing: border-box; }
.nav-link { display: block; padding: 8px 14px; font-size: 16px; font-weight: 600; color: var(--color-text-main); text-decoration: none; white-space: nowrap; border-radius: 4px; transition: background-color 0.2s ease, color 0.2s ease; line-height: 1.4; }
.nav-link:hover { background-color: var(--color-bg); color: var(--color-primary); text-decoration: none; }
.hamburger-menu { display: none; }
.mobile-menu-overlay { display: none; }
.mobile-nav-buttons { display: none; }
.site-footer { background-color: var(--color-text-main); color: #ffffff; padding: 40px 0 0 0; margin-top: 40px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px; padding: 40px 20px 20px 20px; }
.footer-logo { font-size: 24px; font-weight: 800; color: #ffffff; text-decoration: none; text-transform: uppercase; letter-spacing: 1px; }
.footer-desc { font-size: 14px; line-height: 1.6; margin-top: 12px; color: #cccccc; }
.footer-heading { font-size: 16px; font-weight: 700; margin-bottom: 16px; color: #ffffff; text-transform: uppercase; position: relative; padding-bottom: 8px; }
.footer-heading::after { content: ''; position: absolute; bottom: 0; left: 0; width: 40px; 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: 8px; }
.footer-links a { color: #cccccc; text-decoration: none; font-size: 14px; line-height: 1.5; transition: all 0.3s ease; }
.footer-links a:hover { color: #ffffff; padding-left: 6px; text-decoration: underline; }
.footer-info { font-size: 14px; line-height: 1.8; color: #cccccc; }
.footer-bottom { background-color: rgba(0,0,0,0.25); text-align: center; padding: 16px 20px; margin-top: 20px; }
.footer-bottom p { margin: 0; font-size: 14px; color: #888888; }
@media (max-width: 768px) {
  :root { --header-offset: 110px; }
  body { padding-top: var(--header-offset); overflow-x: hidden; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; }
  .header-top { background: linear-gradient(135deg, #1F3FAF 0%, var(--color-primary) 100%); padding: 0; }
  .header-container { width: 100%; max-width: none; padding: 8px 15px; min-height: 60px; box-sizing: border-box; justify-content: center; }
  .logo { position: absolute; left: 50%; transform: translateX(-50%); font-size: 24px; text-align: center; }
  .desktop-nav-buttons { display: none; }
  .hamburger-menu { display: flex; position: absolute; left: 15px; top: 8px; z-index: 1001; background: transparent; border: none; cursor: pointer; padding: 8px; flex-direction: column; align-items: center; justify-content: center; width: 40px; height: 40px; }
  .hamburger-line { display: block; width: 22px; height: 2px; background-color: #ffffff; margin: 3px 0; border-radius: 2px; transition: all 0.3s ease; }
  .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-menu-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.6); z-index: 999; opacity: 0; transition: opacity 0.3s ease; }
  .mobile-menu-overlay.active { display: block; opacity: 1; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; width: 280px; height: 100%; background-color: var(--color-card-bg); border-right: 2px solid var(--color-border); transform: translateX(-100%); transition: transform 0.3s ease; z-index: 1000; overflow-y: auto; justify-content: flex-start; border-bottom: none; }
  .main-nav.active { display: flex; transform: translateX(0); }
  .nav-container { width: 100%; max-width: none; flex-direction: column; align-items: stretch; padding: 60px 20px 20px 20px; gap: 0; }
  .nav-link { padding: 10px 12px; font-size: 16px; text-align: left; border-bottom: 1px solid #f0f0f0; }
  .nav-link:hover { background-color: var(--color-bg); }
  .mobile-nav-buttons { display: flex; position: fixed; top: 60px; left: 0; width: 100%; padding: 8px 15px; background-color: var(--color-primary); gap: 10px; z-index: 800; justify-content: center; box-shadow: 0 2px 6px rgba(0,0,0,0.15); min-height: 48px; box-sizing: border-box; }
  .mobile-nav-buttons .btn { padding: 8px 20px; font-size: 14px; flex: 0 1 auto; min-width: 120px; }
  .site-footer { padding-top: 30px; }
  .footer-container { width: 100%; max-width: none; grid-template-columns: 1fr 1fr; gap: 20px; padding: 30px 15px 20px 15px; box-sizing: border-box; }
  .footer-column { grid-column: auto; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { padding: 14px 15px; }
}
@media (max-width: 480px) {
  .footer-container { grid-template-columns: 1fr; }
  .mobile-nav-buttons .btn { padding: 8px 15px; font-size: 13px; }
}
/* 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;
}