:root {
  --header-offset: 122px; /* 68px (header-top) + 52px (main-nav) + 2px safety */
}
body {
  font-family: 'Arial', sans-serif;
  margin: 0;
  padding-top: var(--header-offset);
  color: #333333; /* Text Main */
  background-color: #F5F7FA; /* Background */
  line-height: 1.6;
  direction: ltr;
  overflow-x: hidden;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  background-color: #E53935; /* Primary color, for fixed header */
}

.header-top {
  box-sizing: border-box;
  min-height: 68px;
  height: 68px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: #E53935; /* Primary color */
  width: 100%;
  color: #FFFFFF;
}

.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;
}

.hamburger-menu {
  display: none; /* Hidden on desktop */
  width: 30px;
  height: 24px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  position: relative;
  z-index: 1001; /* Above header content */
}

.hamburger-menu .bar {
  display: block;
  width: 100%;
  height: 3px;
  background-color: #FFFFFF;
  margin: 5px 0;
  transition: all 0.3s ease;
}

.hamburger-menu.active .bar:nth-child(2) {
  opacity: 0;
}

.hamburger-menu.active .bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger-menu.active .bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

.logo {
  font-size: 28px;
  font-weight: bold;
  color: #FFFFFF; /* White text on primary background */
  text-decoration: none;
  display: flex;
  align-items: center;
}
.logo img {
  display: block;
  max-height: 60px; /* Desktop max-height */
  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 on desktop */
  min-height: 48px;
  background-color: #E53935; /* Same as header-top for consistency */
}

.main-nav {
  box-sizing: border-box;
  min-height: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: #F5F7FA; /* Background color, different from header-top */
  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: #333333; /* Text Main */
  text-decoration: none;
  padding: 10px 15px;
  font-weight: bold;
  white-space: nowrap;
  transition: color 0.3s ease, background-color 0.3s ease;
}

.nav-link:hover, .nav-link.active {
  color: #E53935; /* Primary color on hover/active */
}

/* Buttons */
.btn {
  padding: 10px 20px;
  border-radius: 5px;
  text-decoration: none;
  font-weight: bold;
  transition: all 0.3s ease;
  color: #FFFFFF;
  text-align: center;
  white-space: nowrap;
  cursor: pointer;
}

.btn-register {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%); /* Button gradient */
}

.btn-register:hover {
  opacity: 0.9;
}

.btn-login {
  background-color: #FF5A4F; /* Accent color */
}

.btn-login:hover {
  opacity: 0.9;
}

/* Overlay for mobile menu */
.overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 998;
}

.overlay.active {
  display: block;
}

/* Footer */
.site-footer {
  background-color: #333333; /* Dark background for footer */
  color: #FFFFFF;
  padding: 40px 20px 20px;
  font-size: 14px;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  max-width: 1200px;
  margin: 0 auto 30px;
}

.footer-col h3 {
  font-size: 18px;
  margin-bottom: 15px;
  color: #FF5A4F; /* Accent color for footer headings */
}

.footer-col p {
  margin-bottom: 10px;
  line-height: 1.8;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.footer-logo {
  font-size: 24px;
  font-weight: bold;
  color: #FFFFFF;
  text-decoration: none;
  margin-bottom: 15px;
  display: block;
}

.footer-nav {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-nav li {
  margin-bottom: 8px;
}

.footer-nav a {
  color: #FFFFFF;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-nav a:hover {
  color: #FF5A4F; /* Accent color on hover */
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  max-width: 1200px;
  margin: 0 auto;
}

.footer-bottom p {
  margin: 0;
}

/* Mobile styles */
@media (max-width: 768px) {
  :root {
    --header-offset: 110px; /* 60px (header-top) + 48px (mobile-nav-buttons) + 2px safety */
  }

  body {
    padding-top: var(--header-offset);
    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, 0.2);
  }

  .header-top {
    min-height: 60px;
    height: 60px;
  }

  .header-container {
    padding: 0 15px;
    justify-content: flex-start; /* Adjust for hamburger */
    max-width: none; /* No max-width on mobile */
  }

  .hamburger-menu {
    display: block; /* Show on mobile */
    margin-right: 15px;
  }

  .logo {
    flex: 1 !important;
    display: flex !important;
    justify-content: center !important;
    align-items: center !important;
    font-size: 24px;
    margin-right: 0;
    max-width: calc(100% - 60px); /* Account for hamburger menu width */
  }
  .logo img {
    max-height: 56px !important; /* Mobile max-height */
  }

  .desktop-nav-buttons {
    display: none !important; /* Hide desktop buttons on mobile */
  }

  .mobile-nav-buttons {
    display: flex !important; /* Show mobile buttons on mobile */
    min-height: 48px;
    align-items: center;
    justify-content: center; /* Center buttons */
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    padding: 0 15px;
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    background-color: #E53935; /* Same as header-top */
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 0;
    max-width: calc(50% - 5px); /* For two buttons with 10px gap */
    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 for mobile menu */
    position: fixed;
    top: var(--header-offset); /* Position below fixed header */
    left: 0;
    width: 70%; /* Adjust as needed */
    height: calc(100% - var(--header-offset));
    background-color: #FFFFFF; /* White background for mobile menu */
    flex-direction: column;
    padding: 20px 0;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
    transform: translateX(-100%); /* Start off-screen */
    transition: transform 0.3s ease, display 0.3s ease; /* Added display transition */
    z-index: 999; /* Below overlay */
    overflow-y: auto; /* Allow scrolling for long menus */
    box-sizing: border-box;
  }

  .main-nav.active {
    display: flex; /* Show when active */
    transform: translateX(0); /* Slide in */
  }

  .nav-container {
    flex-direction: column;
    padding: 0;
    max-width: none;
    width: 100%;
    height: auto;
    align-items: flex-start;
  }

  .nav-link {
    width: 100%;
    padding: 12px 20px;
    border-bottom: 1px solid #E0E0E0; /* Border for menu items */
    color: #333333;
  }
  .nav-link:last-child {
    border-bottom: none;
  }

  .overlay.active {
    display: block;
  }

  .footer-top-grid {
    grid-template-columns: 1fr; /* Single column on mobile */
    gap: 20px;
  }

  .footer-col h3 {
    margin-top: 20px;
  }

  .footer-col:first-child h3 {
    margin-top: 0;
  }

  .footer-logo {
    margin-bottom: 10px;
  }

  .site-footer {
    padding: 30px 15px 15px;
  }
}
/* 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;
  }
}