:root {
  --header-offset: 122px; /* Desktop: header-top (68px) + mobile-nav-buttons (0px, hidden) + main-nav (52px) + 2px buffer */
}

body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding-top: var(--header-offset);
  background-color: #FFFFFF;
  color: #333333;
  line-height: 1.6;
  overflow-x: hidden;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  background-color: #FFFFFF; /* Default background for entire header */
}

.header-top {
  box-sizing: border-box;
  min-height: 68px;
  height: 68px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: #1A8ECF; /* 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; /* Adjusted padding */
}

.logo {
  font-size: 28px;
  font-weight: bold;
  color: #FFFFFF;
  text-decoration: none;
  display: block;
  padding: 0;
  line-height: 1;
}

.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: #F0F0F0; /* Light background for mobile buttons */
  border-bottom: 1px solid #E0E0E0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 5px;
  text-decoration: none;
  font-weight: bold;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.2s ease;
}

.btn-login {
  background-color: #EA7C07; /* Login button color */
  color: #FFFFFF;
  border: none;
}

.btn-login:hover {
  background-color: #D46A00;
  transform: translateY(-1px);
}

.btn-register {
  background-color: #26A9E0; /* Primary color for register */
  color: #FFFFFF;
  border: none;
}

.btn-register:hover {
  background-color: #1E8BC3;
  transform: translateY(-1px);
}

.hamburger-menu {
  display: none; /* Hidden by default on desktop */
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  z-index: 1001;
  position: relative;
  margin-left: 20px;
}

.main-nav {
  box-sizing: border-box;
  min-height: 52px;
  height: 52px;
  display: flex; /* Displayed by default on desktop */
  align-items: center;
  overflow: hidden;
  background-color: #26A9E0; /* Primary color for main-nav */
  width: 100%;
}

.main-nav .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;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 25px;
}

.main-nav ul li a {
  color: #FFFFFF;
  text-decoration: none;
  font-weight: bold;
  font-size: 15px;
  padding: 5px 0;
  transition: color 0.3s ease;
  white-space: nowrap;
}

.main-nav ul li a:hover,
.main-nav ul li a.active {
  color: #F0F0F0;
  border-bottom: 2px solid #F0F0F0;
}

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

/* Footer styles */
.site-footer {
  background-color: #1A8ECF; /* Darker blue for footer */
  color: #FFFFFF;
  padding: 40px 0 20px;
  font-size: 14px;
}

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

.footer-col h3 {
  color: #FFFFFF;
  font-size: 18px;
  margin-bottom: 15px;
}

.footer-logo {
  font-size: 28px;
  font-weight: bold;
  color: #FFFFFF;
  text-decoration: none;
  display: block;
  margin-bottom: 15px;
}

.footer-description {
  line-height: 1.8;
  margin-bottom: 15px;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

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

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

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

.footer-nav li a:hover {
  color: #F0F0F0;
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 30px 0;
}

.footer-bottom p {
  margin: 0;
}

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

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

  .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;
    position: relative; /* For absolute positioning of logo */
  }

  .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); /* Account for hamburger menu width */
  }

  .logo img {
    max-height: 56px !important;
  }

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

  .hamburger-menu {
    display: block;
    order: -1; /* Place it at the beginning */
    background-color: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1001;
  }

  .hamburger-menu .bar {
    background-color: #FFFFFF;
    width: 25px;
    height: 3px;
    margin: 4px 0;
    transition: 0.4s;
  }

  .hamburger-menu.active .bar:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
  }

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

  .hamburger-menu.active .bar:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
  }

  .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;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 0;
    max-width: calc(50% - 5px); /* 10px gap between two buttons */
    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 by JS */
    position: fixed;
    top: var(--header-offset); /* Position below fixed header and mobile buttons */
    left: 0;
    width: 80%; /* Adjust as needed */
    max-width: 300px;
    height: calc(100% - var(--header-offset));
    background-color: #26A9E0;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
    transform: translateX(-100%); /* Off-screen by default */
    transition: transform 0.3s ease-in-out;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    padding-top: 20px;
    overflow-y: auto;
    z-index: 1000;
  }

  .main-nav.active {
    display: flex; /* Must be flex for content to show */
    transform: translateX(0);
  }

  .main-nav .nav-container {
    flex-direction: column;
    align-items: flex-start;
    padding: 0 15px;
    width: 100%;
    max-width: none;
  }

  .main-nav ul {
    flex-direction: column;
    width: 100%;
    gap: 0;
  }

  .main-nav ul li {
    width: 100%;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  }

  .main-nav ul li:last-child {
    border-bottom: none;
  }

  .main-nav ul li a {
    padding: 15px 0;
    display: block;
    width: 100%;
    color: #FFFFFF;
    font-size: 16px;
    border-bottom: none;
  }

  .mobile-overlay.active {
    display: block;
  }

  .site-footer {
    padding: 30px 0 15px;
  }

  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 25px;
    padding: 0 15px;
    margin-bottom: 25px;
  }

  .footer-col h3 {
    margin-bottom: 10px;
  }

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

  /* Ensure images in page content are responsive */
  .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;
  }
}
/* 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;
}