html { scroll-behavior: smooth; }
body { margin: 0; font-family: 'Arial', sans-serif; line-height: 1.6; color: #1F2D3D; background-color: #F4F7FB; padding-top: var(--header-offset); }

/* Header Offset */
:root { --header-offset: 122px; }

/* Site Header */
.site-header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1); box-sizing: border-box; }

/* Header Top */
.header-top { background-color: #1C4EBF; min-height: 68px; height: 68px; display: flex; align-items: center; overflow: hidden; width: 100%; box-sizing: border-box; }
.header-container { width: 100%; height: 100%; max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 0 20px; box-sizing: border-box; }

/* Logo */
.logo { color: #FFFFFF; font-size: 28px; font-weight: bold; text-decoration: none; display: block; white-space: nowrap; }
.logo img { display: block; max-height: 60px; height: auto; width: auto; max-width: 280px; object-fit: contain; }

/* Desktop Nav Buttons */
.desktop-nav-buttons { display: flex; gap: 12px; align-items: center; }

/* Buttons */
.btn { display: inline-block; padding: 10px 20px; border-radius: 25px; text-decoration: none; font-weight: bold; text-align: center; white-space: nowrap; cursor: pointer; transition: all 0.3s ease; color: #FFFFFF; background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%); border: none; box-sizing: border-box; }
.btn:hover { opacity: 0.9; transform: translateY(-1px); box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2); }

/* Hamburger Menu */
.hamburger-menu { display: none; flex-direction: column; justify-content: space-around; width: 30px; height: 25px; cursor: pointer; z-index: 1001; padding: 5px; box-sizing: border-box; }
.hamburger-menu span { display: block; width: 100%; height: 3px; background-color: #FFFFFF; border-radius: 3px; transition: all 0.3s ease; }
.hamburger-menu.active span:nth-child(1) { transform: translateY(11px) rotate(45deg); }
.hamburger-menu.active span:nth-child(2) { opacity: 0; }
.hamburger-menu.active span:nth-child(3) { transform: translateY(-11px) rotate(-45deg); }

/* Main Navigation */
.main-nav { background-color: #6FA3FF; min-height: 52px; height: 52px; display: flex; align-items: center; overflow: hidden; width: 100%; box-sizing: border-box; }
.nav-container { width: 100%; height: 100%; max-width: 1200px; margin: 0 auto; display: flex; flex-direction: row; justify-content: center; align-items: center; padding: 0 20px; box-sizing: border-box; }
.nav-link { color: #1F2D3D; text-decoration: none; padding: 8px 15px; font-weight: bold; transition: color 0.3s ease, background-color 0.3s ease; white-space: nowrap; font-size: 15px; }
.nav-link:hover { color: #FFFFFF; background-color: rgba(0, 0, 0, 0.1); border-radius: 5px; }

/* Overlay for 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; }
.overlay.active { display: block; }

/* Footer */
.site-footer { background-color: #F4F7FB; padding: 40px 20px; color: #1F2D3D; box-sizing: border-box; }
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; max-width: 1200px; margin: 0 auto; }
.footer-col { margin-bottom: 20px; }
.footer-logo { color: #1F2D3D; font-size: 24px; font-weight: bold; text-decoration: none; margin-bottom: 15px; display: inline-block; }
.footer-description { font-size: 14px; line-height: 1.8; color: #1F2D3D; word-wrap: break-word; overflow-wrap: break-word; }
.footer-title { font-size: 18px; font-weight: bold; margin-bottom: 15px; color: #1F2D3D; }
.footer-nav { list-style: none; padding: 0; margin: 0; }
.footer-nav li { margin-bottom: 8px; }
.footer-nav a { color: #1F2D3D; text-decoration: none; font-size: 14px; transition: color 0.3s ease; }
.footer-nav a:hover { color: #2F6BFF; }
.footer-bottom { text-align: center; margin-top: 40px; padding-top: 20px; border-top: 1px solid #D6E2FF; font-size: 13px; color: #1F2D3D; }
.footer-bottom a { text-decoration: none; color: #1F2D3D; }

/* Mobile Nav Buttons (Desktop Hidden) */
.mobile-nav-buttons { box-sizing: border-box; display: none; min-height: 48px; }

/* Anchor Slot Styling (Ensuring visibility) */
.footer-slot-anchor-inner { min-height: 1px; }

/* Responsive Styles */
@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%; }

  .site-header { box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1); }

  .header-top { min-height: 60px !important; height: 60px !important; padding: 0 15px; }
  .header-container { width: 100%; max-width: none; padding: 0; position: relative; }
  .logo { flex: 1 !important; display: flex !important; justify-content: center !important; align-items: center !important; font-size: 24px; }
  .logo img { max-height: 56px !important; max-width: 100%; height: auto; }
  .desktop-nav-buttons { display: none !important; }
  .hamburger-menu { display: flex; margin-right: auto; position: relative; z-index: 1001; }

  .mobile-nav-buttons {
    display: flex !important;
    min-height: 48px;
    align-items: center;
    justify-content: center;
    width: 100%; max-width: 100%;
    box-sizing: border-box;
    padding: 0 15px;
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    background-color: #6FA3FF; /* Match main-nav color for continuity */
  }
  .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 {
    display: none; /* Hidden by default, shown with JS */
    position: fixed; top: var(--header-offset); left: 0; width: 80%; max-width: 300px; height: calc(100% - var(--header-offset));
    background-color: #FFFFFF; /* White for mobile menu */
    flex-direction: column;
    align-items: flex-start;
    padding: 20px;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
    transform: translateX(-100%); /* Start off-screen */
    transition: transform 0.3s ease;
    z-index: 999;
    box-sizing: border-box;
    overflow-y: auto;
    min-height: auto !important; /* Override fixed height for scrollable menu */
    height: auto !important;
  }
  .main-nav.active {
    display: flex; /* Show when active */
    transform: translateX(0); /* Slide in */
  }
  .nav-container { flex-direction: column; align-items: flex-start; padding: 0; width: 100%; max-width: none; }
  .nav-link { width: 100%; padding: 12px 0; border-bottom: 1px solid #eee; font-size: 16px; }
  .nav-link:last-child { border-bottom: none; }

  .site-footer { padding: 30px 15px; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .footer-logo { font-size: 22px; }
  .footer-description { font-size: 13px; }
  .footer-title { font-size: 16px; }
  .footer-nav a { font-size: 13px; }
  .footer-bottom { margin-top: 30px; font-size: 12px; }
}
/* 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;
}