:root { --primary: #2F6BFF; --primary-light: #6FA3FF; --btn-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); --bg-color: #F4F7FB; --white: #FFFFFF; --text-main: #1F2D3D; --text-dark: #000000; --border-color: #D6E2FF; --glow: #A5C4FF; --header-offset: 122px; --header-top-bg: #1e3f96; --main-nav-bg: #2F6BFF; --nav-item-color: #ffffff; --nav-item-hover-bg: #1e4fbf; --nav-item-hover-color: #ffffff; }
* { margin: 0; padding: 0; box-sizing: border-box; }
body { padding-top: var(--header-offset); font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: var(--bg-color); }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; background-color: var(--white); box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15); }
.header-top { background-color: var(--header-top-bg); width: 100%; }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 12px 30px; min-height: 68px; }
.logo { display: inline-flex; align-items: center; justify-content: center; font-size: 32px; font-weight: 900; color: var(--white); text-decoration: none; letter-spacing: 1px; line-height: 1; text-shadow: 2px 2px 6px rgba(0, 0, 0, 0.25); transition: color 0.3s ease; }
.logo:hover { color: var(--glow); }
.desktop-nav-buttons { display: flex; align-items: center; gap: 12px; }
.btn { display: inline-block; padding: 10px 24px; border-radius: 30px; text-decoration: none; font-weight: 700; font-size: 14px; line-height: 1.2; cursor: pointer; transition: all 0.35s ease; min-height: 40px; text-align: center; }
.btn-register { background: var(--btn-gradient); color: #ffffff; border: none; box-shadow: 0 4px 12px rgba(47, 107, 255, 0.35); }
.btn-register:hover { transform: translateY(-2px); box-shadow: 0 6px 18px rgba(47, 107, 255, 0.5); }
.btn-login { background: transparent; color: #ffffff; border: 2px solid var(--glow); }
.btn-login:hover { background: var(--primary-light); border-color: var(--primary-light); transform: translateY(-2px); }
.main-nav { background-color: var(--main-nav-bg); width: 100%; display: flex; min-height: 52px; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; align-items: center; padding: 0 20px; width: 100%; }
.nav-menu { list-style-type: none; display: flex; flex-direction: row; align-items: center; justify-content: center; gap: 2px; flex: 1; }
.nav-menu li a { display: block; padding: 12px 16px; color: var(--nav-item-color); text-decoration: none; font-size: 14px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; border-radius: 4px; transition: background-color 0.3s ease, color 0.3s ease; line-height: 1.2; }
.nav-menu li a:hover { background-color: var(--nav-item-hover-bg); color: var(--nav-item-hover-color); }
.mobile-nav-header { display: none; }
.hamburger-menu { display: none; background: none; border: none; cursor: pointer; padding: 12px; z-index: 1001; }
.hamburger-menu span { display: block; width: 26px; height: 3px; background-color: var(--white); margin: 5px 0; border-radius: 3px; transition: all 0.3s ease; }
.mobile-menu-overlay { display: none; }
.mobile-logo { display: none; }
.mobile-nav-buttons { display: none; }
.site-footer { background-color: var(--text-dark); color: #e0e0e0; padding-top: 50px; font-size: 14px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 40px; padding: 0 30px 40px; }
.footer-logo { display: inline-block; font-size: 30px; font-weight: 900; color: var(--white); text-decoration: none; margin-bottom: 16px; }
.footer-desc { color: #b0b0b0; line-height: 1.7; }
.footer-title { color: var(--white); font-size: 18px; margin-bottom: 16px; font-weight: 700; position: relative; padding-bottom: 10px; }
.footer-title::after { content: ''; position: absolute; bottom: 0; left: 0; width: 34px; height: 3px; background: var(--btn-gradient); border-radius: 4px; }
.footer-nav ul { list-style-type: none; }
.footer-nav ul li { margin-bottom: 10px; }
.footer-nav ul li a { color: #b0b0b0; text-decoration: none; transition: color 0.3s ease, padding-left 0.3s ease; }
.footer-nav ul li a:hover { color: var(--primary-light); padding-left: 8px; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.08); padding: 22px; text-align: center; color: #888; }
.footer-bottom a { color: var(--primary-light); text-decoration: none; }
@media (max-width: 768px) { :root { --header-offset: 146px; }
  body { padding-top: var(--header-offset); overflow-x: hidden; }
  .header-container { max-width: none; width: 100%; position: relative; display: flex; justify-content: center; align-items: center; min-height: 60px; padding: 8px 15px; }
  .header-top .logo { font-size: 28px; }
  .desktop-nav-buttons { display: none; }
  .hamburger-menu { display: block; position: absolute; left: 10px; top: 50%; transform: translateY(-50%); }
  .hamburger-menu span { background-color: var(--white); }
  .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); }
  .main-nav { min-height: auto; display: none; position: fixed; top: 60px; left: 0; width: 100%; transform: translateX(-100%); transition: transform 0.3s ease-in-out; flex-direction: column; background-color: var(--white); box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1); z-index: 1000; }
  .main-nav.active { display: flex; transform: translateX(0); height: auto; max-height: calc(100vh - 60px); overflow-y: auto; }
  .main-nav.open { display: flex; transform: translateX(0); }
  .nav-container { max-width: none; width: 100%; flex-direction: column; align-items: stretch; padding: 0; }
  .mobile-nav-header { display: flex; justify-content: center; align-items: center; padding: 10px; border-bottom: 1px solid var(--border-color); position: relative; }
  .mobile-logo { display: block; }
  .nav-menu { flex-direction: column; align-items: center; width: 100%; gap: 0; }
  .nav-menu li { width: 100%; }
  .nav-menu li a { padding: 14px 30px; color: var(--text-main); text-transform: none; font-size: 16px; border-bottom: 1px solid var(--border-color); text-align: center; font-weight: 600; }
  .nav-menu li a:hover { background-color: var(--bg-color); color: var(--primary); }
  .mobile-nav-buttons { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; min-height: 48px; padding: 12px 15px; width: 100%; background: var(--bg-color); }
  .mobile-nav-buttons .btn { flex: 1; max-width: 180px; text-align: center; color: #ffffff; }
  .mobile-menu-overlay { display: none; position: fixed; top: 60px; left: 0; bottom: 0; width: 100%; background-color: rgba(0, 0, 0, 0.6); z-index: 999; transition: opacity 0.3s ease; }
  .mobile-menu-overlay.active { display: block; }
  .footer-container { grid-template-columns: 1fr; text-align: center; padding: 40px 20px; gap: 30px; }
  .footer-title::after { left: 50%; transform: translateX(-50%); }
  .footer-bottom { 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;
}