:root { --primary-color: #E53935; --secondary-color: #FF5A4F; --bg-color: #F5F7FA; --card-bg: #FFFFFF; --text-main: #333333; --border-color: #E0E0E0; --header-offset: 122px; --header-bg-top: #1a1a2e; --header-bg-nav: #FFFFFF; --nav-text: #333333; --nav-text-hover: #E53935; }
body { padding-top: var(--header-offset); margin: 0; font-family: 'Segoe UI', Roboto, Arial, 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 4px 12px rgba(0, 0, 0, 0.15); }
.header-top { background-color: var(--header-bg-top); width: 100%; border-bottom: 2px solid var(--secondary-color); }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding-left: 20px; padding-right: 20px; min-height: 68px; }
.logo { display: inline-block; font-size: 28px; font-weight: 800; color: #FFFFFF; text-decoration: none; line-height: 1.2; padding: 5px 0; letter-spacing: 1px; }
.logo:hover { color: var(--secondary-color); }
.desktop-nav-buttons { display: flex; gap: 10px; align-items: center; }
.btn { display: inline-block; padding: 10px 24px; border-radius: 25px; font-size: 14px; font-weight: 700; text-decoration: none; transition: all 0.3s ease; border: none; cursor: pointer; line-height: 1.4; }
.btn-register { background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%); color: #FFFFFF; box-shadow: 0 2px 8px rgba(229, 57, 53, 0.4); }
.btn-register:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(229, 57, 53, 0.5); }
.btn-login { background: #FFFFFF; color: #E53935; border: 2px solid #E53935; }
.btn-login:hover { background: var(--primary-color); color: #FFFFFF; }
.main-nav { background-color: var(--header-bg-nav); width: 100%; display: flex; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1); }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding-left: 20px; padding-right: 20px; }
.nav-link { color: var(--nav-text); text-decoration: none; font-size: 15px; font-weight: 600; padding: 14px 18px; position: relative; transition: color 0.3s ease; border-bottom: 3px solid transparent; }
.nav-link:hover { color: var(--nav-text-hover); border-bottom-color: var(--primary-color); }
.mobile-nav-header, .mobile-nav-close, .mobile-nav-buttons { display: none; }
.mobile-header-bar, .mobile-action-buttons { display: none; }
.mobile-nav-overlay { display: none; }
@media (max-width: 768px) {
  :root { --header-offset: 110px; }
  .site-header { box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15); }
  .header-top { display: none; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; width: 85%; max-width: 320px; height: 100vh; background: var(--header-bg-nav); z-index: 1002; flex-direction: column; transform: translateX(-100%); transition: transform 0.4s ease; box-shadow: 4px 0 15px rgba(0, 0, 0, 0.2); overflow-y: auto; }
  .main-nav.active { display: block; transform: translateX(0); }
  .nav-container { width: 100%; max-width: none; padding-left: 0; padding-right: 0; flex-direction: column; align-items: flex-start; justify-content: flex-start; }
  .nav-link { width: 100%; padding: 15px 24px; color: var(--nav-text); font-size: 16px; border-bottom: 1px solid var(--border-color); border-left: 4px solid transparent; box-sizing: border-box; }
  .nav-link:hover { color: var(--primary-color); background: #F5F7FA; border-left-color: var(--primary-color); }
  .mobile-nav-header { display: flex; justify-content: space-between; align-items: center; padding: 16px 20px; background: var(--primary-color); color: #fff; }
  .mobile-nav-title { font-size: 16px; font-weight: 700; }
  .mobile-nav-close { display: block; background: transparent; border: none; color: #fff; font-size: 24px; cursor: pointer; line-height: 1; padding: 0; }
  .mobile-nav-buttons { display: flex; gap: 10px; padding: 15px 20px; border-top: 1px solid var(--border-color); flex-direction: column; }
  .mobile-nav-buttons .btn { display: block; width: 100%; text-align: center; }
  .mobile-header-bar { display: flex; align-items: center; justify-content: space-between; background: #1a1a2e; padding: 10px 15px; position: relative; min-height: 60px; }
  .mobile-header-bar .logo { display: block; font-size: 26px; }
  .hamburger-menu { display: flex; flex-direction: column; justify-content: center; align-items: center; width: 42px; height: 42px; background: transparent; border: none; cursor: pointer; padding: 0; z-index: 1100; position: relative; }
  .hamburger-menu span { display: block; width: 24px; height: 2px; background: #FFFFFF; margin: 3px 0; transition: all 0.3s ease; border-radius: 2px; }
  .hamburger-menu.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .hamburger-menu.active span:nth-child(2) { opacity: 0; }
  .hamburger-menu.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
  .mobile-action-buttons { display: flex; gap: 8px; justify-content: center; padding: 8px 15px; background: #1a1a2e; border-top: 1px solid rgba(255, 255, 255, 0.1); position: relative; z-index: 1001; min-height: 48px; }
  .mobile-action-buttons .btn { flex: 1; padding: 8px 12px; font-size: 13px; text-align: center; max-width: 160px; }
  .mobile-nav-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.5); z-index: 1001; opacity: 0; transition: opacity 0.3s ease; }
  .mobile-nav-overlay.active { display: block; opacity: 1; }
  .header-container { max-width: none; width: 100%; }
  .nav-container { max-width: none; width: 100%; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; }
  body { overflow-x: hidden; }
  body.no-scroll { overflow: hidden; }
}
.site-footer { background-color: #1a1a2e; color: #ffffff; padding: 50px 0 0; margin-top: 50px; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; padding: 0 20px 40px; }
.footer-logo { color: #ffffff; font-size: 26px; font-weight: 800; text-decoration: none; display: inline-block; margin-bottom: 12px; }
.footer-logo:hover { color: var(--secondary-color); }
.footer-description { color: #b0b0b8; font-size: 14px; line-height: 1.6; margin-bottom: 16px; }
.footer-certifications { display: flex; flex-wrap: wrap; gap: 8px; }
.cert-badge { background: #2a2a4a; border: 1px solid rgba(255, 255, 255, 0.2); border-radius: 4px; padding: 4px 10px; font-size: 11px; color: #d0d0d8; }
.footer-heading { color: #ffffff; font-size: 16px; font-weight: 600; margin-bottom: 16px; border-bottom: 2px solid var(--primary-color); padding-bottom: 8px; display: inline-block; }
.footer-nav { list-style: none; padding: 0; margin: 0; }
.footer-nav li { margin-bottom: 10px; }
.footer-nav a { color: #b0b0b8; text-decoration: none; font-size: 14px; transition: color 0.3s; }
.footer-nav a:hover { color: var(--secondary-color); text-decoration: underline; }
.footer-contact-list { list-style: none; padding: 0; margin: 0; color: #b0b0b8; }
.footer-contact-list li { margin-bottom: 10px; font-size: 14px; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.1); text-align: center; padding: 15px 20px; }
.footer-copyright { color: #b0b0b8; font-size: 13px; }
@media (max-width: 768px) {
  .footer-container { grid-template-columns: 1fr; gap: 30px; padding: 20px 15px 30px; }
  .footer-about { text-align: center; }
  .footer-contact-list { line-height: 1.8; }
}
/* 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;
}