:root {
  --primary-color: #2F6BFF;
  --secondary-color: #6FA3FF;
  --button-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
  --card-bg: #FFFFFF;
  --page-bg: #F4F7FB;
  --text-main: #1F2D3D;
  --text-secondary: #000000;
  --border-color: #D6E2FF;
  --glow-color: #A5C4FF;
  --header-offset: 164px;
  --desktop-header-top-h: 68px;
  --desktop-main-nav-h: 52px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--page-bg);
  color: var(--text-main);
  padding-top: var(--header-offset);
}

body.no-scroll {
  overflow: hidden;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: var(--card-bg);
  box-shadow: 0 2px 8px rgba(31, 45, 61, 0.08);
  z-index: 1000;
  padding: 0;
  margin: 0;
}

.header-top {
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  width: 100%;
  min-height: var(--desktop-header-top-h);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 40px;
  min-height: var(--desktop-header-top-h);
}

.logo {
  display: inline-flex;
  align-items: center;
  font-size: 28px;
  font-weight: 800;
  text-decoration: none;
  color: var(--primary-color);
  letter-spacing: -0.5px;
  line-height: 1.2;
  white-space: nowrap;
}

.logo:hover {
  text-decoration: none;
  opacity: 0.8;
}

.main-nav {
  display: flex;
  flex-direction: row;
  position: static;
  background-color: var(--card-bg);
  width: 100%;
  min-height: var(--desktop-main-nav-h);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  min-height: var(--desktop-main-nav-h);
  padding: 0 16px;
  gap: 4px;
}

.nav-link {
  display: inline-block;
  padding: 8px 12px;
  text-decoration: none;
  color: var(--text-main);
  font-size: 14px;
  font-weight: 600;
  border-radius: 4px;
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--card-bg);
  background-color: var(--primary-color);
  text-decoration: none;
}

.desktop-nav-buttons {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, filter 0.2s ease;
  box-shadow: 0 2px 4px rgba(47, 107, 255, 0.2);
  line-height: 1.2;
}

.btn:hover {
  transform: translateY(-2px);
  text-decoration: none;
  box-shadow: 0 4px 8px rgba(47, 107, 255, 0.4);
  filter: brightness(1.05);
}

.btn-primary {
  background: var(--button-gradient);
  color: var(--card-bg);
}

.btn-secondary {
  background: var(--card-bg);
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

.btn-download {
  background: linear-gradient(180deg, #6FA3FF, #2F6BFF);
  color: var(--card-bg);
}

.hamburger-menu {
  display: none;
}

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

.site-footer {
  background-color: var(--text-main);
  color: var(--card-bg);
  padding: 0;
  margin-top: 40px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 20px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr 0.9fr 1fr;
  gap: 32px;
}

.footer-column {
  display: flex;
  flex-direction: column;
}

.footer-logo-link {
  font-size: 28px;
  font-weight: 800;
  text-decoration: none;
  color: var(--secondary-color);
}

.footer-logo-link:hover {
  text-decoration: none;
  opacity: 0.8;
}

.footer-description {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.85);
}

.footer-certifications {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.certification-badge {
  background-color: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(165, 196, 255, 0.3);
  color: var(--glow-color);
  padding: 4px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
  white-space: nowrap;
}

.footer-heading {
  color: var(--glow-color);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: flex-start;
}

.footer-link {
  color: rgba(255, 255, 255, 0.9);
  text-decoration: none;
  font-size: 14px;
  padding: 4px 0;
  transition: color 0.2s ease;
  line-height: 1.4;
}

.footer-link:hover {
  color: var(--secondary-color);
  text-decoration: none;
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-contact-item {
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  line-height: 1.4;
  display: flex;
  align-items: center;
  gap: 8px;
}

.contact-icon {
  font-size: 14px;
  flex-shrink: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  padding: 16px 24px;
}

.footer-copyright {
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
}

.footer-license-text {
  color: rgba(255, 255, 255, 0.5);
  font-size: 12px;
  margin-top: 4px;
}

@media (max-width: 768px) {
  :root {
    --header-offset: 146px;
  }

  .site-header {
    position: fixed;
    top: 0;
    width: 100%;
  }

  .header-top {
    min-height: auto;
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding: 0 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 60px;
    gap: 8px;
  }

  .logo {
    order: 1;
    flex: 1;
    justify-content: center;
    text-align: center;
    font-size: 24px;
    margin: 0;
    display: inline-flex;
    min-width: 0;
  }

  .hamburger-menu {
    display: flex;
    order: 0;
    flex-direction: column;
    justify-content: center;
    width: 44px;
    height: 44px;
    border: none;
    background: transparent;
    padding: 8px;
    cursor: pointer;
    gap: 5px;
    z-index: 1101;
    position: relative;
  }

  .hamburger-menu span {
    display: block;
    width: 100%;
    height: 3px;
    background-color: var(--text-main);
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease, background-color 0.3s ease;
  }

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

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

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

  .desktop-nav-buttons {
    display: flex;
    justify-content: center;
    order: 2;
    padding: 10px 12px;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    gap: 8px;
    flex-wrap: nowrap;
  }

  .btn {
    padding: 10px 16px;
    font-size: 14px;
    white-space: nowrap;
  }

  .main-nav {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 116px;
    left: 0;
    width: 280px;
    background-color: var(--card-bg);
    border-right: 1px solid var(--border-color);
    border-top: none;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.15);
    padding: 20px;
    z-index: 1005;
    transform: translateX(-110%);
    transition: transform 0.3s ease-in-out;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
    border-radius: 0 12px 12px 0;
    min-height: 0;
  }

  .main-nav.active {
    display: flex;
    transform: translateX(0);
  }

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 0;
    justify-content: flex-start;
  }

  .nav-link {
    display: block;
    width: 100%;
    padding: 12px 16px;
    font-size: 15px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
    text-align: left;
  }

  .nav-link:hover,
  .nav-link.active {
    background-color: var(--primary-color);
    color: var(--card-bg);
  }

  .mobile-menu-overlay {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1002;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease;
    backdrop-filter: blur(2px);
  }

  .mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
  }

  .site-footer {
    margin-top: 24px;
  }

  .footer-container {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 20px 16px;
  }

  .footer-nav-column {
    width: 100%;
  }

  .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 (min-width: 769px) and (max-width: 1024px) {
  .header-container {
    padding: 0 24px;
  }
  .nav-container {
    gap: 2px;
  }
  .nav-link {
    padding: 8px 8px;
    font-size: 13px;
  }
  .btn {
    padding: 8px 14px;
    font-size: 13px;
  }
}
/* 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;
}