:root { --header-offset: 122px; --primary-color: #26A9E0; --secondary-color: #FFFFFF; --login-color: #EA7C07; --header-top-bg: #0b253a; --main-nav-bg: #ffffff; --nav-link-color: #333333; --nav-link-hover-bg: #26A9E0; --nav-link-hover-color: #ffffff; --btn-radius: 6px; }
* { margin: 0; padding: 0; box-sizing: border-box; }
body { padding-top: var(--header-offset); font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; margin: 0; background-color: #f5f5f5; }
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; background-color: var(--header-top-bg); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2); min-height: auto; }
.header-top { background-color: var(--header-top-bg); width: 100%; color: var(--secondary-color); }
.header-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding-left: 30px; padding-right: 30px; min-height: 68px; gap: 15px; }
.logo { font-size: 32px; font-weight: 800; color: #ffffff; text-decoration: none; letter-spacing: 1px; display: block; line-height: 1.2; text-transform: uppercase; flex-shrink: 0; }
.logo:hover { color: #e0f2fe; }
.desktop-nav-buttons { display: flex; align-items: center; gap: 10px; justify-content: flex-end; }
.mobile-nav-buttons { display: none; }
.btn { display: inline-block; padding: 8px 18px; border-radius: var(--btn-radius); text-decoration: none; font-weight: 600; font-size: 14px; border: none; cursor: pointer; transition: all 0.3s ease; text-align: center; line-height: 1.5; }
.btn-login { background-color: var(--login-color); color: #ffffff; }
.btn-login:hover { background-color: #c96a05; transform: translateY(-1px); }
.btn-register { background: linear-gradient(135deg, #26A9E0 0%, #1a7fb8 100%); color: #ffffff; }
.btn-register:hover { background: linear-gradient(135deg, #1a7fb8 0%, #145d8a 100%); transform: translateY(-1px); }
.btn-download { background: linear-gradient(135deg, #34c759 0%, #28a745 100%); color: #ffffff; }
.btn-download:hover { background: linear-gradient(135deg, #28a745 0%, #1e7e34 100%); transform: translateY(-1px); }
.main-nav { background-color: var(--main-nav-bg); width: 100%; display: flex; box-shadow: inset 0 1px 0 #e9ecef, inset 0 -1px 0 #e9ecef; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; flex-wrap: wrap; padding-left: 20px; padding-right: 20px; min-height: 52px; gap: 0; }
.nav-link { display: inline-block; padding: 10px 17px; color: var(--nav-link-color); text-decoration: none; font-size: 14px; font-weight: 600; text-transform: uppercase; transition: background-color 0.3s ease, color 0.3s ease; border-radius: 4px 4px 0 0; margin: 0; }
.nav-link:hover { background-color: var(--nav-link-hover-bg); color: var(--nav-link-hover-color); }
.hamburger-menu { display: none; position: fixed; top: 15px; left: 15px; z-index: 1002; background: transparent; border: none; cursor: pointer; padding: 8px; border-radius: 4px; transition: all 0.3s ease; }
.hamburger-menu span { display: block; width: 25px; height: 2px; background-color: #ffffff; margin: 6px 0; transition: transform 0.3s ease, opacity 0.3s ease; border-radius: 2px; }
.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); }
.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: 998; opacity: 0; visibility: hidden; transition: opacity 0.3s ease;
}
.mobile-menu-overlay.active { display: block; opacity: 1; visibility: visible; }
.site-footer { background-color: #f8f9fa; border-top: 1px solid #e9ecef; padding-top: 40px; width: 100%; }
.footer-container { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 20px; padding: 0 30px;
}
.footer-brand { display: flex; flex-direction: column; }
.footer-logo { font-size: 28px; font-weight: 800; color: #0b253a; text-decoration: none; letter-spacing: 1px; text-transform: uppercase; margin-bottom: 10px; }
.footer-desc { font-size: 13px; color: #6c757d; line-height: 1.6; margin: 0; }
.footer-heading { font-size: 16px; font-weight: 700; color: #0b253a; margin-bottom: 12px; border-bottom: 2px solid var(--primary-color); display: inline-block; padding-bottom: 4px; }
.footer-nav { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 6px; }
.footer-nav a { color: #495057; text-decoration: none; font-size: 14px; transition: color 0.3s ease; }
.footer-nav a:hover { color: var(--primary-color); text-decoration: underline; }
.footer-col { min-width: 140px; }
.footer-bottom { background-color: #e9ecef; text-align: center; margin-top: 30px; padding: 15px 20px; font-size: 14px; color: #495057; }
.footer-bottom p { margin: 0; }
.footer-bottom a { color: #0b253a; text-decoration: none; }
@media (min-width: 769px) {
  .footer-container { grid-template-columns: 2fr 1fr 1fr; }
}
@media (max-width: 768px) {
  :root { --header-offset: 110px; }
  body { overflow-x: hidden; }
  .page-content img { max-width: 100% !important; height: auto !important; display: block; }
  .page-content { overflow-x: hidden; max-width: 100%; }
  .header-container { width: 100%; max-width: none; padding-left: 15px; padding-right: 15px; min-height: 60px; justify-content: center; gap: 0; }
  .header-top { width: 100%; padding-top: 0; }
  .header-container { flex-direction: row; }
  .logo { font-size: 24px; margin: 0 auto; padding-left: 45px; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; width: 80%; min-width: 280px; height: 100vh; background-color: #ffffff; flex-direction: column; box-shadow: 2px 0 20px rgba(0, 0, 0, 0.3); transform: translateX(-100%); transition: transform 0.3s ease; overflow-y: auto; z-index: 999; border-radius: 0 12px 12px 0; padding-top: 80px; }
  .main-nav.active { display: block; transform: translateX(0); }
  .nav-container { width: 100%; max-width: none; flex-direction: column; justify-content: flex-start; align-items: stretch; padding: 0; gap: 0; }
  .nav-link { padding: 14px 24px; text-align: center; border-bottom: 1px solid #f1f3f5; color: #0b253a; }
  .nav-link:hover { background-color: #26A9E0; color: #ffffff; }
  .nav-link:last-child { border-bottom: none; }
  .desktop-nav-buttons { display: none; }
  .mobile-nav-buttons { display: flex; flex-direction: row; justify-content: center; align-items: center; gap: 8px; background-color: #ffffff; padding: 7px 15px; width: 100%; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1); min-height: 48px; }
  .mobile-nav-buttons .btn { flex: 1; padding: 8px 12px; font-size: 13px; }
  .hamburger-menu { display: block; top: 16px; left: 15px; }
  .mobile-menu-overlay.active { display: block; }
  .footer-container { width: 100%; max-width: none; grid-template-columns: 1fr 1fr; gap: 15px; padding: 0 20px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-heading { font-size: 15px; margin-bottom: 10px; }
  .footer-nav a { font-size: 13px; }
  .footer-col { min-width: 0; }
}
@media (max-width: 480px) {
  .mobile-nav-buttons .btn { padding: 6px 8px; font-size: 12px; }
  .logo { font-size: 22px; padding-left: 45px; }
  .footer-container { grid-template-columns: 1fr; }
  .footer-brand { grid-column: auto; }
  .btn-register, .btn-login, .btn-download { letter-spacing: 0.2px; }
  .footer-bottom { 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;
}