:root {
  --primary-color: #26A9E0;
  --primary-dark: #1a8ab8;
  --primary-light: #e8f4fb;
  --white: #FFFFFF;
  --black: #000000;
  --login: #EA7C07;
  --header-offset: 122px;
  --header-top-height: 68px;
  --nav-height: 52px;
  --mobile-header-top-height: 60px;
  --mobile-nav-height: 48px;
  --mobile-buttons-height: 48px;
}
body {
  padding-top: var(--header-offset);
  margin: 0;
  font-family: 'Segoe UI', Arial, sans-serif;
  background: var(--white);
  color: #333;
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-height: var(--header-top-height);
  z-index: 1000;
  background: var(--white);
  box-shadow: 0 2px 12px rgba(0,0,0,0.15);
  border-bottom: 2px solid var(--primary-color);
  flex-direction: row;
  flex-wrap: wrap;
}
.header-top {
  background: var(--primary-dark);
  width: 100%;
}
.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: var(--header-top-height);
  padding: 0 30px;
}
.logo {
  display: inline-block;
  font-size: 26px;
  font-weight: 800;
  color: var(--white);
  text-decoration: none;
  line-height: 1.2;
  padding: 8px 0;
  text-transform: uppercase;
  letter-spacing: 1px;
  order: 1;
}
.logo:hover {
  color: var(--white);
  text-decoration: none;
}
.desktop-nav-buttons {
  margin-left: auto;
  display: flex;
  gap: 12px;
  order: 2;
}
.btn {
  display: inline-block;
  padding: 8px 22px;
  font-size: 15px;
  font-weight: 700;
  border-radius: 6px;
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
  text-align: center;
}
.btn-login {
  background: var(--login);
  color: var(--white);
}
.btn-login:hover {
  background: #d66a00;
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(234, 124, 7, 0.3);
}
.btn-register {
  background: var(--white);
  color: var(--primary-dark);
  border: 2px solid var(--primary-dark);
}
.btn-register:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(26, 138, 184, 0.3);
}
.main-nav {
  background: var(--white);
  width: 100%;
  min-height: var(--nav-height);
  display: flex;
  border-top: 1px solid #e0e0e0;
  flex-direction: row;
  position: static;
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 5px;
  padding: 0 20px;
  width: 100%;
}
.nav-link {
  color: #333;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 4px;
  white-space: nowrap;
  transition: color 0.3s, background 0.3s;
  line-height: 1.4;
}
.nav-link:hover {
  color: var(--primary-color);
  background: var(--primary-light);
  text-decoration: none;
}
.nav-link.active {
  color: var(--primary-color);
  background: var(--primary-light);
  font-weight: 700;
}
.mobile-nav-buttons {
  display: none;
}
.hamburger-menu {
  display: none;
}
.mobile-menu-overlay {
  display: none;
}
.site-footer {
  background: var(--primary-dark);
  color: var(--white);
  width: 100%;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px 20px;
}
.footer-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 30px;
}
.footer-info {
  flex: 1;
  min-width: 280px;
  max-width: 400px;
}
.footer-logo {
  font-size: 24px;
  font-weight: 800;
  color: var(--white);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 1px;
}
.footer-logo:hover {
  color: var(--white);
  text-decoration: none;
  opacity: 0.9;
}
.footer-desc {
  margin-top: 15px;
  color: #b3d9ea;
  font-size: 14px;
  line-height: 1.6;
  max-width: 100%;
}
.footer-column {
  flex: 1;
  min-width: 220px;
  max-width: 320px;
}
.footer-heading {
  color: var(--white);
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 15px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary-color);
}
.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-nav a {
  color: #d9eef8;
  font-size: 14px;
  text-decoration: none;
  transition: color 0.3s, padding-left 0.3s;
  line-height: 1.5;
}
.footer-nav a:hover {
  color: var(--white);
  padding-left: 6px;
  text-decoration: underline;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: 15px;
  margin-top: 30px;
  text-align: center;
}
.copyright {
  font-size: 14px;
  color: #b3d9ea;
  margin: 0;
}
.footer-copyright-link {
  color: var(--white);
  text-decoration: none;
  font-weight: 600;
}
.footer-copyright-link:hover {
  text-decoration: underline;
  color: var(--white);
}
@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }
  .header-container {
    width: 100%;
    max-width: none;
    padding: 0 15px;
    min-height: var(--mobile-header-top-height);
  }
  .nav-container {
    width: 100%;
    max-width: none;
    padding: 0;
    flex-direction: column;
    align-items: flex-start;
  }
  .header-top {
    background: var(--primary-dark);
  }
  .desktop-nav-buttons {
    display: none;
  }
  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background: var(--white);
    box-shadow: 2px 0 12px rgba(0,0,0,0.2);
    z-index: 1001;
    overflow-y: auto;
    padding-top: var(--mobile-header-top-height);
    padding-bottom: 20px;
    flex-direction: column;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    border-top: none;
  }
  .main-nav.active {
    display: flex;
    transform: translateX(0);
  }
  .main-nav .nav-link {
    display: block;
    padding: 14px 16px;
    font-size: 16px;
    border-bottom: 1px solid #f0f0f0;
    color: #333;
    width: 100%;
    text-align: left;
    box-sizing: border-box;
  }
  .main-nav .nav-link:hover {
    background: var(--primary-light);
    border-radius: 0;
    color: var(--primary-color);
  }
  .mobile-nav-buttons {
    display: flex;
    flex-direction: row;
    justify-content: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--primary-light);
    width: 100%;
    box-sizing: border-box;
    min-height: var(--mobile-buttons-height);
    align-items: center;
    z-index: 1000;
  }
  .mobile-nav-buttons .btn {
    flex: 1;
    max-width: 160px;
    font-size: 14px;
    padding: 8px 14px;
    text-align: center;
  }
  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    cursor: pointer;
    background: transparent;
    border: none;
    z-index: 1002;
    position: fixed;
    top: 8px;
    left: 12px;
    padding: 10px;
  }
  .hamburger-menu span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--white);
    margin: 3px 0;
    border-radius: 2px;
    transition: all 0.3s ease;
  }
  .hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
  }
  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
  .mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
  }
  .mobile-menu-overlay.active {
    display: block;
  }
  .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;
}