:root { --header-offset: 164px; --primary: #113B7A; --secondary: #1D5FD1; --primary-dark: #08162B; --primary-light: #1B3357; --button-bg: linear-gradient(180deg, #2B73F6 0%, #1144A6 100%); --card-bg: #10233F; --text-main: #F3F8FF; --text-secondary: #AFC4E8; --border-color: #244D84; --accent-glow: #4FA8FF; --accent-gold: #F2C14E; --divider: #1B3357; }
body { padding-top: var(--header-offset); margin: 0; font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif; background: #0a0e1a; color: var(--text-main); overflow-x: hidden; }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; background: var(--deep-navy, #0a0e1a); box-shadow: 0 4px 30px rgba(0, 0, 0, 0.55); border-bottom: 1px solid var(--border-color); min-height: auto; }
.header-top { background: var(--primary-dark, #08162B); border-bottom: 1px solid var(--divider); }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 8px 24px; min-height: 68px; box-sizing: border-box; }
.logo { display: inline-block; font-size: 28px; font-weight: 900; color: var(--text-main); text-decoration: none; letter-spacing: 1px; line-height: 1.2; white-space: nowrap; background: linear-gradient(135deg, var(--accent-gold, #F2C14E) 0%, var(--text-main, #F3F8FF) 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.logo:hover { opacity: 0.9; }
.desktop-nav-buttons { display: flex; gap: 10px; align-items: center; }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 22px; border-radius: 8px; font-weight: 700; font-size: 15px; line-height: 1.2; text-decoration: none; cursor: pointer; border: none; transition: all 0.25s ease; white-space: nowrap; min-height: 40px; }
.btn-login { background: transparent; color: var(--text-main); border: 1px solid var(--accent-glow, #4FA8FF); }
.btn-login:hover { background: rgba(79, 168, 255, 0.15); border-color: var(--text-main); }
.btn-register { background: var(--button-bg, linear-gradient(180deg, #2B73F6 0%, #1144A6 100%)); color: #fff; box-shadow: 0 4px 15px rgba(43, 115, 246, 0.4); }
.btn-register:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(43, 115, 246, 0.5); }
.main-nav { display: flex; width: 100%; background: var(--primary, #113B7A); min-height: 52px; align-items: center; border-top: 1px solid var(--divider); }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 16px; flex-wrap: wrap; width: 100%; box-sizing: border-box; gap: 4px; min-height: 52px; }
.nav-link { display: inline-block; padding: 8px 14px; color: var(--text-main); text-decoration: none; font-weight: 600; font-size: 15px; border-radius: 6px; transition: all 0.2s ease; white-space: nowrap; line-height: 1.4; border-bottom: 2px solid transparent; }
.nav-link:hover { background: rgba(255, 255, 255, 0.1); color: var(--accent-glow, #4FA8FF); border-bottom-color: var(--accent-gold, #F2C14E); }
.nav-link.active { color: var(--accent-gold, #F2C14E); border-bottom-color: var(--accent-gold, #F2C14E); }
.mobile-menu-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.5); z-index: 999; display: none; opacity: 0; transition: opacity 0.3s ease; }
.mobile-menu-overlay.active { display: block; opacity: 1; }
.mobile-nav-buttons { display: none; position: relative; z-index: 1000; }
.hamburger-menu { display: none; background: transparent; border: none; cursor: pointer; padding: 10px; margin-left: auto; position: relative; z-index: 1002; min-height: 44px; }
.hamburger-menu span { display: block; width: 26px; height: 3px; background: var(--text-main); margin: 5px 0; border-radius: 3px; transition: all 0.3s ease; }
.hamburger-menu.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger-menu.active span:nth-child(2) { opacity: 0; }
.hamburger-menu.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
.site-footer { background: var(--primary-dark, #08162B); border-top: 1px solid var(--border-color); padding: 50px 20px 20px; margin-top: 40px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; border-bottom: 1px solid var(--divider); }
.footer-logo { display: inline-block; font-size: 30px; font-weight: 900; color: var(--accent-gold, #F2C14E); text-decoration: none; margin-bottom: 15px; }
.footer-desc { color: var(--text-secondary); line-height: 1.8; font-size: 14px; margin: 0; }
.footer-heading { color: var(--text-main); font-size: 18px; font-weight: 700; margin: 0 0 18px; position: relative; padding-bottom: 8px; }
.footer-heading::after { content: ''; position: absolute; left: 0; bottom: 0; width: 30px; height: 3px; background: var(--accent-gold, #F2C14E); border-radius: 2px; }
.footer-nav { list-style: none; padding: 0; margin: 0; }
.footer-nav li { margin-bottom: 12px; }
.footer-nav a { color: var(--text-secondary); text-decoration: none; font-size: 14px; transition: all 0.2s ease; display: inline-flex; align-items: center; gap: 6px; }
.footer-nav a:hover { color: var(--accent-gold, #F2C14E); padding-left: 4px; }
.footer-bottom { max-width: 1200px; margin: 20px auto 0; text-align: center; color: var(--text-secondary); font-size: 13px; }
.footer-bottom p { margin: 0; line-height: 1.6; }
@media (max-width: 768px) {
  :root { --header-offset: 146px; }
  .header-container { width: 100%; max-width: none; min-height: 60px; padding: 6px 16px; }
  .header-top { min-height: 60px; }
  .desktop-nav-buttons { display: none; }
  .hamburger-menu { display: block; order: 1; margin-left: 0; }
  .site-header .header-container { justify-content: space-between; position: relative; }
  .site-header .logo { order: 2; position: absolute; left: 50%; transform: translateX(-50%); font-size: 24px; }
  .mobile-nav-buttons { display: flex; justify-content: center; align-items: center; gap: 8px; position: relative; z-index: 1000; background: var(--primary-dark, #08162B); padding: 6px 10px; box-sizing: border-box; border-top: 1px solid var(--divider); }
  .mobile-nav-buttons .btn { flex: 1; max-width: 140px; padding: 8px 12px; font-size: 13px; min-height: 36px; }
  .mobile-nav-buttons .hamburger-menu { flex: 0 0 44px; width: 44px; margin-left: auto; padding: 6px; }
  .main-nav { display: none; flex-direction: column; width: 270px; max-width: 85%; position: fixed; top: 0; left: 0; height: 100vh; height: 100dvh; background: var(--primary-dark, #08162B); z-index: 1001; transform: translateX(-100%); transition: transform 0.3s ease; box-shadow: 4px 0 15px rgba(0, 0, 0, 0.3); overflow-y: auto; border-top: none; align-items: flex-start; justify-content: flex-start; }
  .main-nav.active { display: flex; transform: translateX(0); }
  .nav-container { flex-direction: column; align-items: stretch; padding: 60px 10px 20px; gap: 2px; width: 100%; max-width: none; justify-content: flex-start; }
  .nav-link { display: block; width: calc(100% - 20px); padding: 12px 14px; color: var(--text-main); border-radius: 6px; border-bottom: 1px solid var(--divider); text-align: left; font-size: 15px; }
  .nav-link:hover { background: rgba(255, 255, 255, 0.1); padding-left: 18px; }
  .mobile-menu-overlay.active { z-index: 1000; }
  .site-footer { padding: 40px 15px 15px; }
  .footer-container { grid-template-columns: 1fr 1fr; gap: 25px; }
  .footer-brand { grid-column: 1 / -1; text-align: center; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; padding-top: 10px; }
  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;
}