:root {
  --header-offset: 122px;
  --main-color: #2F6BFF;
  --accent-color: #6FA3FF;
  --btn-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  background: #F4F7FB;
  padding-top: var(--header-offset);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  color: #1F2D3D;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 4px 20px rgba(47, 107, 255, 0.15);
  background: #FFFFFF;
}
.header-top {
  background: #FFFFFF;
}
.header-container {
  max-width: 1200px;
  min-height: 68px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 30px;
}
.logo {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: #2F6BFF;
  text-decoration: none;
  letter-spacing: -0.5px;
  line-height: 1.2;
  text-shadow: 0 1px 2px rgba(47, 107, 255, 0.2);
}
.desktop-nav-buttons {
  display: flex;
  gap: 12px;
  align-items: center;
}
.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  color: #FFFFFF;
  background: var(--btn-gradient);
  border: 2px solid #2F6BFF;
  box-shadow: 0 2px 8px rgba(47, 107, 255, 0.3);
  transition: all 0.3s ease;
  text-align: center;
  cursor: pointer;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(47, 107, 255, 0.4);
  color: #FFFFFF;
  text-decoration: none;
}
.btn-download {
  background: #FFFFFF;
  color: #2F6BFF;
  border: 2px solid #2F6BFF;
}
.btn-download:hover {
  background: #F0F5FF;
  color: #2F6BFF;
}

.main-nav {
  width: 100%;
  min-height: 52px;
  display: flex;
  flex-direction: row;
  position: static;
  background: linear-gradient(90deg, #2F6BFF 0%, #6FA3FF 100%);
}
.nav-container {
  max-width: 1200px;
  min-height: 52px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
  padding: 8px 20px;
  width: 100%;
}
.nav-link {
  display: inline-block;
  color: #FFFFFF;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 4px;
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease;
  line-height: 1.2;
}
.nav-link:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
}

.mobile-menu-overlay {
  display: none;
}

.hamburger-menu {
  display: none;
}

.mobile-nav-buttons {
  display: none;
}

.site-footer {
  background: #1F2D3D;
  color: #FFFFFF;
  padding: 40px 20px 0;
  margin-top: 40px;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 30px;
  flex-wrap: wrap;
  padding-bottom: 30px;
}
.footer-column {
  flex: 1 1 200px;
}
.footer-brand {
  flex: 2 1 300px;
}
.footer-logo {
  font-size: 24px;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 12px;
}
.footer-description {
  font-size: 14px;
  color: #CCE0FF;
  line-height: 1.5;
  max-width: 320px;
}
.footer-heading {
  color: #6FA3FF;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 15px;
  text-transform: uppercase;
}
.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-link {
  font-size: 14px;
  color: #CCE0FF;
  text-decoration: none;
  transition: color 0.2s ease;
  padding: 2px 0;
}
.footer-link:hover {
  color: #FFFFFF;
  text-decoration: underline;
}
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding: 15px 0;
  text-align: center;
}
.copyright-text {
  font-size: 13px;
  color: #CCE0FF;
  line-height: 1.4;
}

@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }
  .header-container {
    width: 100%;
    max-width: none;
    min-height: 60px;
    padding: 8px 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
  }
  .logo {
    display: block;
    font-size: 22px;
    text-align: center;
    flex: 1;
    order: 2;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .hamburger-menu {
    display: flex;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
    margin: 0;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    order: 1;
    z-index: 1001;
  }
  .hamburger-line {
    display: block;
    width: 28px;
    height: 3px;
    background: #2F6BFF;
    border-radius: 3px;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }
  .hamburger-menu.active .hamburger-line:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }
  .hamburger-menu.active .hamburger-line:nth-child(2) {
    opacity: 0;
  }
  .hamburger-menu.active .hamburger-line:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }
  .mobile-nav-buttons {
    display: flex;
    width: 100%;
    background: #FFFFFF;
    padding: 6px 12px;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    border-top: 1px solid #D6E2FF;
  }
  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 120px;
    font-size: 12px;
    padding: 8px 12px;
    max-width: 180px;
  }
  .desktop-nav-buttons {
    display: none;
  }
  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 80%;
    max-width: 360px;
    min-height: 100vh;
    flex-direction: column;
    background: #FFFFFF;
    justify-content: flex-start;
    padding-top: 80px;
    padding-bottom: 30px;
    overflow-y: auto;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 1001;
    box-shadow: 2px 0 15px rgba(31, 45, 61, 0.1);
  }
  .main-nav.active {
    display: block;
    transform: translateX(0);
  }
  .nav-container {
    width: 100%;
    max-width: none;
    min-height: auto;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 0;
    padding: 10px;
    background: #FFFFFF;
  }
  .nav-link {
    color: #1F2D3D;
    font-size: 16px;
    padding: 12px 15px;
    width: 100%;
    border-bottom: 1px solid #D6E2FF;
    border-radius: 0;
  }
  .nav-link:hover {
    background: #F0F5FF;
    color: #2F6BFF;
  }
  .mobile-menu-overlay {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.55);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease;
  }
  .mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
  }
  .site-footer {
    padding: 30px 16px 0;
  }
  .footer-container {
    flex-direction: column;
    gap: 20px;
  }
  .footer-column {
    flex: 1 1 100%;
  }
  .footer-brand {
    text-align: left;
  }
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}

@media (max-width: 480px) {
  body {
    padding-top: 146px;
  }
  .mobile-nav-buttons .btn {
    min-width: 0;
    flex: 1 1 45%;
    padding: 8px 8px;
    font-size: 11px;
  }
  .logo {
    font-size: 18px;
  }
}
/* 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;
}