:root { --header-offset: 122px; --primary-color: #2F6BFF; --secondary-color: #6FA3FF; --text-main: #1F2D3D; --card-bg: #FFFFFF; --bg-color: #F4F7FB; --button-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); --border-color: #D6E2FF; --glow-color: #A5C4FF; }

body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; margin: 0; padding-top: var(--header-offset); background-color: var(--bg-color); color: var(--text-main); overflow-x: hidden; }

/* Site Header */
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1); background-color: var(--card-bg); }

.header-top { box-sizing: border-box; min-height: 68px; height: 68px; display: flex; align-items: center; overflow: hidden; background-color: #1A4BCC; width: 100%; }
.header-container { box-sizing: border-box; width: 100%; height: 100%; max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 0 20px; }

.logo { color: var(--card-bg); font-size: 28px; font-weight: bold; text-decoration: none; padding: 0; display: flex; align-items: center; white-space: nowrap; }
.logo img { display: block; max-height: 60px; height: auto; width: auto; max-width: 280px; object-fit: contain; }

.desktop-nav-buttons { display: flex; gap: 12px; align-items: center; }
.mobile-nav-buttons { box-sizing: border-box; display: none; min-height: 48px; background-color: var(--secondary-color); padding: 0 20px; }

.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 20px; border-radius: 8px; font-weight: bold; text-decoration: none; cursor: pointer; transition: all 0.3s ease; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; border: none; }
.btn-primary { background: var(--button-gradient); color: var(--card-bg); box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3); }
.btn-secondary { background-color: var(--card-bg); color: var(--primary-color); border: 2px solid var(--primary-color); }
.btn-secondary:hover { background-color: var(--primary-color); color: var(--card-bg); }

.main-nav { box-sizing: border-box; min-height: 52px; height: 52px; display: flex; align-items: center; overflow: hidden; background-color: var(--primary-color); width: 100%; transition: transform 0.3s ease; }
.nav-container { box-sizing: border-box; height: 100%; max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 20px; }
.nav-link { color: var(--card-bg); text-decoration: none; padding: 0 15px; font-weight: 500; font-size: 15px; transition: color 0.3s ease; white-space: nowrap; }
.nav-link:hover, .nav-link.active { color: var(--secondary-color); }

.hamburger-menu { display: none; background: none; border: none; cursor: pointer; padding: 10px; z-index: 1001; position: absolute; left: 15px; top: 50%; transform: translateY(-50%); }
.hamburger-menu .bar { display: block; width: 25px; height: 3px; background-color: var(--card-bg); margin: 5px auto; transition: all 0.3s ease; }
.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); }

.overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.5); z-index: 999; }
.overlay.active { display: block; }

/* Site Footer */
.site-footer { background-color: var(--primary-color); color: var(--card-bg); padding: 40px 20px 20px; font-size: 14px; line-height: 1.6; }
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; max-width: 1200px; margin: 0 auto 30px; }
.footer-col h3 { color: var(--card-bg); font-size: 18px; margin-bottom: 15px; }
.footer-col a { color: var(--card-bg); text-decoration: none; transition: color 0.3s ease; }
.footer-col a:hover { color: var(--secondary-color); }
.footer-col .footer-nav { list-style: none; padding: 0; margin: 0; }
.footer-col .footer-nav li { margin-bottom: 8px; }

.footer-logo { color: var(--card-bg); font-size: 24px; font-weight: bold; text-decoration: none; display: block; margin-bottom: 15px; }
.footer-description { color: rgba(255, 255, 255, 0.8); word-wrap: break-word; overflow-wrap: break-word; }

.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.2); padding-top: 20px; text-align: center; color: rgba(255, 255, 255, 0.8); max-width: 1200px; margin: 0 auto; }
.footer-bottom p { margin: 0; }

/* Mobile Responsive */
@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-top { min-height: 60px !important; height: 60px !important; }
  .header-container { width: 100%; max-width: none; padding: 0 15px; position: relative; }
  
  .logo { flex: 1 !important; display: flex !important; justify-content: center !important; align-items: center !important; position: absolute; left: 50%; transform: translateX(-50%); width: calc(100% - 100px); }
  .logo img { max-height: 56px !important; }

  .desktop-nav-buttons { display: none !important; }
  .mobile-nav-buttons {
    display: flex !important;
    min-height: 48px;
    align-items: center;
    width: 100%; max-width: 100%;
    box-sizing: border-box;
    padding-left: 15px; padding-right: 15px;
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    justify-content: center;
  }
  .mobile-nav-buttons .btn {
    flex: 1; min-width: 0;
    max-width: calc(50% - 5px);
    box-sizing: border-box;
    padding: 8px 12px;
    font-size: 13px;
    white-space: normal;
    word-wrap: break-word;
    overflow-wrap: break-word;
  }

  .main-nav {
    min-height: 48px !important; height: auto !important; /* height auto for content */
    position: fixed; top: var(--header-offset); left: 0;
    width: 280px; height: 100vh; /* Full viewport height */
    max-width: 80%; /* Limit width on larger mobile screens */
    background-color: var(--card-bg); /* White background for mobile menu */
    flex-direction: column; justify-content: flex-start; align-items: flex-start;
    padding: 20px;
    transform: translateX(-100%);
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    display: none; /* Default hidden state */
  }
  .main-nav.active { display: flex; transform: translateX(0); }
  .nav-container { flex-direction: column; align-items: flex-start; width: 100%; max-width: none; padding: 0; }
  .nav-link { color: var(--text-main); padding: 10px 0; width: 100%; text-align: left; border-bottom: 1px solid var(--border-color); }
  .nav-link:last-child { border-bottom: none; }

  .hamburger-menu { display: block; }

  .footer-grid { grid-template-columns: 1fr; margin-bottom: 20px; }
  .footer-col { text-align: center; margin-bottom: 20px; }
  .footer-col:last-child { margin-bottom: 0; }
  .footer-col h3 { margin-top: 20px; }
  .footer-col .footer-nav { text-align: center; }
  .footer-col .footer-nav li { display: inline-block; margin: 0 8px 8px; }
  .footer-logo { text-align: center; }
  .footer-description { text-align: center; }
}
/* 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;
}