:root {
  --primary-color: #26A9E0;
  --secondary-color: #FFFFFF;
  --login-button-color: #C26500; /* Darker orange for AA contrast */
  --background-color: #FFFFFF;
  --text-color: #000000;
  --header-offset: 122px; /* Desktop: 68px (header-top) + 52px (main-nav) + 2px */
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  color: var(--text-color);
  background-color: var(--background-color);
  padding-top: var(--header-offset);
  overflow-x: hidden;
}

body.no-scroll {
  overflow: hidden;
}

/* Global link styles */
a {
  text-decoration: none;
  color: var(--primary-color);
}
a:hover {
  text-decoration: underline;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 5px;
  font-weight: bold;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.2s ease;
  color: var(--secondary-color); /* Default white text for buttons */
  background-color: var(--primary-color);
  border: none;
}
.btn:hover {
  transform: translateY(-2px);
  text-decoration: none;
  filter: brightness(1.1);
}
.btn-login {
  background-color: var(--login-button-color);
}
.btn-register {
  background-color: var(--primary-color);
}

/* Header styles */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  background-color: var(--secondary-color); /* Fallback, specific sections will override */
}

.header-top {
  box-sizing: border-box;
  min-height: 68px;
  height: 68px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: #0E74A8; /* Darker blue for header-top */
  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 30px; /* Padding for logo and buttons */
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: var(--secondary-color); /* White text for logo */
  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 {
  display: flex;
  gap: 12px;
  align-items: center;
}

.mobile-nav-buttons {
  box-sizing: border-box;
  display: none; /* Hidden by default on desktop */
  min-height: 48px;
  background-color: var(--secondary-color);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.main-nav {
  box-sizing: border-box;
  min-height: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--primary-color); /* Primary blue for main-nav */
  width: 100%;
}

.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(--secondary-color); /* White text for nav links */
  padding: 8px 15px;
  font-weight: bold;
  transition: background-color 0.3s ease;
  white-space: nowrap;
}
.nav-link:hover {
  background-color: rgba(255, 255, 255, 0.2);
  border-radius: 3px;
  text-decoration: none;
}

/* Hamburger menu for mobile */
.hamburger-menu {
  display: none; /* Hidden by default on desktop */
  width: 30px;
  height: 24px;
  position: relative;
  cursor: pointer;
  background: transparent;
  border: none;
  padding: 0;
  z-index: 1001;
}
.hamburger-menu span {
  display: block;
  width: 100%;
  height: 3px;
  background-color: var(--secondary-color); /* White lines */
  position: absolute;
  left: 0;
  transition: all 0.3s ease;
}
.hamburger-menu span:nth-child(1) { top: 0; }
.hamburger-menu span:nth-child(2) { top: 50%; transform: translateY(-50%); }
.hamburger-menu span:nth-child(3) { bottom: 0; }

.hamburger-menu.active span:nth-child(1) { top: 50%; transform: translateY(-50%) rotate(45deg); }
.hamburger-menu.active span:nth-child(2) { opacity: 0; }
.hamburger-menu.active span:nth-child(3) { bottom: 50%; transform: translateY(50%) rotate(-45deg); }

/* 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: 999;
  transition: opacity 0.3s ease;
  opacity: 0;
}
.overlay.active {
  display: block;
  opacity: 1;
}

/* Footer styles */
.site-footer {
  background-color: #333333; /* Dark background for footer */
  color: var(--secondary-color);
  padding: 40px 0 20px;
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.footer-col h3 {
  color: var(--primary-color); /* Primary blue for footer headings */
  font-size: 16px;
  margin-bottom: 15px;
}

.footer-logo {
  font-size: 20px;
  font-weight: bold;
  color: var(--secondary-color);
  margin-bottom: 15px;
  display: block;
}

.footer-description {
  line-height: 1.6;
  margin-bottom: 15px;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.footer-nav {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-nav li {
  margin-bottom: 8px;
}
.footer-nav a {
  color: var(--secondary-color);
  transition: color 0.3s ease;
}
.footer-nav a:hover {
  color: var(--primary-color);
  text-decoration: none;
}

.footer-bottom {
  text-align: center;
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.7);
}
.footer-bottom p {
  margin: 0;
}

/* Mobile styles */
@media (max-width: 768px) {
  :root {
    --header-offset: 110px; /* Mobile: 60px (header-top) + 48px (main-nav) + 2px */
  }
  body {
    padding-top: var(--header-offset);
  }

  .header-top {
    min-height: 60px !important;
    height: 60px !important;
    justify-content: space-between;
    padding-left: 15px;
    padding-right: 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;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    max-width: calc(100% - 100px); /* Leave space for hamburger */
  }
  .logo img {
    max-height: 56px !important;
  }

  .desktop-nav-buttons {
    display: none !important;
  }

  .hamburger-menu {
    display: block;
    order: -1;
    z-index: 1001;
    margin-right: auto;
  }
  .header-top .header-container .hamburger-menu {
    flex-shrink: 0;
  }

  .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-left: 15px; padding-right: 15px;
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    background-color: var(--secondary-color);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  }
  .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;
    position: fixed;
    top: var(--header-offset);
    left: 0;
    width: 80%;
    max-width: 300px;
    background-color: var(--primary-color);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    padding: 20px 0;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    display: none;
  }
  .main-nav.active {
    transform: translateX(0);
    display: flex;
  }

  .nav-container {
    width: 100%;
    max-width: none;
    padding: 0 15px;
    flex-direction: column;
    align-items: flex-start;
  }
  .nav-link {
    width: 100%;
    padding: 12px 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .nav-link:last-child {
    border-bottom: none;
  }

  .overlay.active {
    display: block;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    padding: 0 15px;
  }
  .footer-col {
    margin-bottom: 20px;
  }

  .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;
  }
}