:root { --header-offset: 166px; --primary-color: #2F6BFF; --secondary-color: #6FA3FF; --btn-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); --text-main: #1F2D3D; --bg-color: #F4F7FB; --card-bg: #FFFFFF; --border-color: #D6E2FF; --glow-color: #A5C4FF; }
body { padding-top: var(--header-offset); margin: 0; font-family: Arial, Helvetica, sans-serif; background-color: var(--bg-color); color: var(--text-main); }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 2px 10px rgba(0,0,0,0.15); }
.header-top { background-color: #1A3E8C; width: 100%; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 10px 20px; min-height: 48px; }
.logo { display: inline-block; font-size: 2rem; font-weight: 900; color: #FFFFFF; text-decoration: none; letter-spacing: 2px; text-transform: uppercase; }
.logo:hover { color: var(--glow-color); }
.desktop-nav-buttons { display: flex; gap: 10px; }
.btn { display: inline-block; padding: 10px 20px; border-radius: 4px; font-weight: 600; text-decoration: none; font-size: 0.95rem; min-height: 40px; text-align: center; border: none; cursor: pointer; transition: all 0.3s ease; }
.btn:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.3); }
.btn-register { background: var(--btn-gradient); color: #FFFFFF; }
.btn-login { background-color: transparent; color: #FFFFFF; border: 2px solid #FFFFFF; }
.btn-login:hover { background-color: #FFFFFF; color: var(--primary-color); }
.main-nav { background-color: var(--primary-color); width: 100%; display: flex; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; flex-wrap: wrap; padding: 0 20px; min-height: 44px; gap: 4px; }
.nav-link { display: block; padding: 10px 12px; color: #FFFFFF; text-decoration: none; font-size: 0.95rem; font-weight: 400; border-radius: 3px; line-height: 1.2; }
.nav-link:hover { background-color: rgba(255,255,255,0.15); text-decoration: none; }
.nav-link.active { background-color: rgba(255,255,255,0.2); font-weight: 600; }
.mobile-actions { display: none; }
.hamburger-menu { display: none; }
.mobile-menu-overlay { display: none; }
.site-footer { background-color: #16233A; color: #FFFFFF; margin-top: 40px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 30px; padding: 40px 20px 30px; }
.footer-column { flex: 1 1 200px; min-width: 180px; }
.footer-brand .footer-logo { font-size: 1.8rem; font-weight: 900; color: #FFFFFF; text-decoration: none; text-transform: uppercase; }
.footer-description { font-size: 0.9rem; color: #B0C4DE; line-height: 1.6; margin-top: 10px; }
.footer-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 15px; color: #FFFFFF; border-bottom: 2px solid var(--primary-color); padding-bottom: 8px; display: inline-block; }
.footer-links { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer-links a { color: #B0C4DE; text-decoration: none; transition: color 0.3s; font-size: 0.9rem; }
.footer-links a:hover { color: var(--glow-color); text-decoration: none; }
.footer-bottom { background-color: #0D1520; padding: 15px 20px; text-align: center; }
.copyright-text { color: #B0C4DE; font-size: 0.9rem; margin: 0; }
@media (max-width: 768px) {
:root { --header-offset: 146px; }
.header-container { width: 100%; max-width: none; padding: 10px 15px; flex-wrap: wrap; }
.header-top { background-color: #1A3E8C; }
.main-nav { display: none; flex-direction: column; position: fixed; top: 0; left: 0; width: 78%; max-width: 320px; height: 100vh; background-color: var(--primary-color); transform: translateX(-100%); transition: transform 0.3s ease; overflow-y: auto; padding-top: 20px; padding-bottom: 20px; z-index: 1002; }
.main-nav.active { display: flex; transform: translateX(0); }
.nav-container { flex-direction: column; align-items: stretch; padding: 0; justify-content: flex-start; max-width: none; }
.nav-link { padding: 15px 20px; font-size: 1rem; text-align: left; border-bottom: 1px solid rgba(255,255,255,0.1); }
.logo { display: block; font-size: 1.8rem; }
.desktop-nav-buttons { display: none; }
.mobile-actions { display: block; background-color: var(--bg-color); }
.mobile-nav-buttons { display: flex; justify-content: center; gap: 10px; padding: 10px 15px; background-color: var(--bg-color); position: relative; z-index: 1000; min-height: 48px; flex-wrap: wrap; }
.mobile-nav-buttons .btn { flex: 1; max-width: 180px; padding: 8px 12px; }
.hamburger-menu { display: block; position: fixed; top: 10px; left: 15px; z-index: 1003; cursor: pointer; }
.bar { display: block; width: 24px; height: 3px; background-color: #FFFFFF; margin: 5px 0; transition: all 0.4s ease; border-radius: 2px; }
.hamburger-menu.active .bar:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger-menu.active .bar:nth-child(2) { opacity: 0; }
.hamburger-menu.active .bar: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(0,0,0,0.5); z-index: 1001; }
.mobile-menu-overlay.active { display: block; }
.page-content img { max-width: 100% !important; height: auto !important; display: block; }
.page-content { overflow-x: hidden; max-width: 100%; }
body { overflow-x: hidden; }
.footer-container { flex-direction: column; gap: 20px; padding: 30px 15px; }
.footer-column { flex: 1 1 auto; }
}
@media (max-width: 768px) {
.footer-container { flex-direction: column; gap: 20px; padding: 30px 15px; }
.footer-column { flex: 1 1 auto; }
.site-header { padding-bottom: 0; }
}
/* 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;
}