:root {
  --primary-color: #26A9E0;
  --secondary-color: #FFFFFF;
  --btn-login-color: #EA7C07;
  --text-color-dark: #333333;
  --text-color-light: #FFFFFF;
  --header-offset: 122px; /* Desktop: header-top (68px) + main-nav (52px) + 2px buffer */
}

body {
  margin: 0;
  font-family: 'Arial', sans-serif;
  line-height: 1.6;
  color: var(--text-color-dark);
  padding-top: var(--header-offset);
  overflow-x: hidden; /* Prevent body overflow on desktop as well */
}

/* --- 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);
}

.header-top {
  box-sizing: border-box;
  min-height: 68px;
  height: 68px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--primary-color); /* Primary color 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 20px;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: var(--text-color-light);
  text-decoration: none;
  display: flex; /* For potential image logo alignment */
  align-items: center;
  height: 100%;
}

.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); /* Secondary color for mobile buttons */
  width: 100%;
  padding: 0 15px; /* Added padding for mobile buttons */
  align-items: center;
  justify-content: center;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 5px;
  text-decoration: none;
  font-weight: bold;
  text-align: center;
  white-space: nowrap; /* Prevent wrapping on desktop */
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.2s ease;
  color: var(--text-color-light);
  background-color: var(--btn-login-color); /* Default button color */
  border: none;
  line-height: 1.2; /* Adjust line height for button text */
  font-size: 14px;
}

.btn:hover {
  transform: translateY(-1px);
  opacity: 0.9;
}

.btn-register {
  background-color: var(--btn-login-color);
}

.btn-download {
  background-color: #007bff; /* Example secondary button color, ensuring contrast */
}

.main-nav {
  box-sizing: border-box;
  min-height: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: var(--secondary-color); /* Secondary color for main-nav */
  width: 100%;
  border-top: 1px solid rgba(0, 0, 0, 0.05); /* Subtle separator */
}

.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 {
  display: block;
  padding: 10px 15px;
  color: var(--text-color-dark);
  text-decoration: none;
  font-weight: 600;
  white-space: nowrap;
  transition: color 0.3s ease, background-color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-color);
  background-color: rgba(0, 0, 0, 0.05);
  border-radius: 3px;
}

.hamburger-menu {
  display: none; /* Hidden on desktop */
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  position: relative;
  z-index: 1001;
}

.hamburger-icon {
  display: block;
  width: 25px;
  height: 3px;
  background-color: var(--text-color-light);
  position: relative;
  transition: background-color 0.3s ease;
}

.hamburger-icon::before,
.hamburger-icon::after {
  content: '';
  display: block;
  width: 100%;
  height: 3px;
  background-color: var(--text-color-light);
  position: absolute;
  left: 0;
  transition: transform 0.3s ease;
}

.hamburger-icon::before {
  top: -8px;
}

.hamburger-icon::after {
  top: 8px;
}

.hamburger-menu.active .hamburger-icon {
  background-color: transparent;
}

.hamburger-menu.active .hamburger-icon::before {
  transform: translateY(8px) rotate(45deg);
}

.hamburger-menu.active .hamburger-icon::after {
  transform: translateY(-8px) rotate(-45deg);
}

.overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 998;
}

/* --- Footer Styles --- */
.site-footer {
  background-color: #f8f8f8;
  color: var(--text-color-dark);
  padding: 40px 20px;
  font-size: 14px;
}

.footer-slot-anchor-outer { /* For top_row_1, mid_1, mid_2, bottom_1 */
  margin-bottom: 20px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto 40px auto;
}

.footer-col h3 {
  color: var(--primary-color);
  font-size: 16px;
  margin-bottom: 15px;
}

.footer-logo {
  font-size: 22px;
  font-weight: bold;
  color: var(--primary-color);
  text-decoration: none;
  display: block;
  margin-bottom: 15px;
}

.footer-description {
  line-height: 1.8;
  color: #555;
  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(--text-color-dark);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-nav a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #eee;
  color: #777;
  max-width: 1200px;
  margin: 0 auto;
}

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

  /* Header */
  .header-top {
    min-height: 60px !important;
    height: 60px !important;
    padding: 0 15px; /* Adjust padding for mobile */
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding: 0;
    justify-content: space-between; /* Hamburger left, Logo center */
  }

  .logo {
    flex: 1 !important; /* Allow logo to take available space */
    display: flex !important;
    justify-content: center !important;
    align-items: center !important;
    font-size: 20px;
  }

  .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: 8px 15px; /* Reduced padding for mobile buttons */
    overflow: hidden;
    gap: 10px;
    flex-wrap: nowrap;
    justify-content: center; /* Center buttons if less than 2 */
    background-color: var(--secondary-color); /* Ensure background color */
    border-bottom: 1px solid rgba(0, 0, 0, 0.05); /* Separator for mobile buttons */
  }

  .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; /* Reduced padding */
    font-size: 13px; /* Reduced font size */
    white-space: normal;
    word-wrap: break-word;
    overflow-wrap: break-word;
  }

  .hamburger-menu {
    display: block;
    order: -1; /* Place hamburger first */
    margin-right: auto; /* Push logo to center */
    color: var(--text-color-light); /* Hamburger icon color */
  }

  .hamburger-menu .hamburger-icon,
  .hamburger-menu .hamburger-icon::before,
  .hamburger-menu .hamburger-icon::after {
    background-color: var(--text-color-light);
  }

  .main-nav {
    display: none; /* Hidden by default */
    flex-direction: column;
    position: fixed;
    top: var(--header-offset); /* Start below header */
    left: 0;
    width: 280px; /* Sidebar width */
    height: calc(100% - var(--header-offset));
    background-color: var(--secondary-color);
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
    transform: translateX(-100%); /* Off-screen */
    transition: transform 0.3s ease;
    overflow-y: auto;
    align-items: flex-start; /* Align menu items to left */
    border-top: none; /* Remove desktop border */
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    align-items: flex-start;
    padding: 10px 0;
  }

  .nav-link {
    width: 100%;
    padding: 12px 20px;
    text-align: left;
    border-bottom: 1px solid #eee;
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  .overlay.active {
    display: block;
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    max-width: 100%;
    padding: 0 15px;
  }

  .footer-col {
    margin-bottom: 20px;
  }

  .footer-bottom {
    padding: 20px 15px 0 15px;
  }

  /* Mobile content overflow prevention */
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}

.no-scroll {
  overflow: 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;
  }
}