:root {
  --primary: #2F6BFF;
  --primary-light: #6FA3FF;
  --button-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
  --card-bg: #FFFFFF;
  --bg-light: #F4F7FB;
  --text-main: #1F2D3D;
  --text-black: #000000;
  --border-color: #D6E2FF;
  --glow: #A5C4FF;
  --header-offset: 122px;
  --header-top-bg: #1F2D3D;
  --header-nav-bg: #FFFFFF;
  --header-top-mobile-bg: #1F2D3D;
  --header-nav-mobile-bg: #FFFFFF;
}

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

body {
  padding-top: var(--header-offset);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  color: var(--text-main);
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-height: auto;
  background: #FFFFFF;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
  border-bottom: 1px solid #EAEEF5;
}

.header-top {
  background-color: var(--header-top-bg);
  width: 100%;
  display: block;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-left: 24px;
  padding-right: 24px;
  min-height: 68px;
}

.logo {
  display: inline-block;
  font-size: 30px;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  letter-spacing: 1px;
  background: linear-gradient(135deg, #FFFFFF 0%, #A5C4FF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.desktop-nav-buttons {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  display: inline-block;
  text-decoration: none;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  padding: 10px 24px;
  border-radius: 50px;
  text-align: center;
  transition: all 0.3s ease;
  min-width: 110px;
}

.btn-register {
  background: var(--button-gradient);
  color: #FFFFFF;
  box-shadow: 0 4px 15px rgba(47, 107, 255, 0.4);
}

.btn-register:hover {
  box-shadow: 0 6px 20px rgba(47, 107, 255, 0.55);
  transform: translateY(-2px);
}

.btn-login {
  background: transparent;
  color: #FFFFFF;
  border: 2px solid rgba(255, 255, 255, 0.7);
}

.btn-login:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #FFFFFF;
}

.btn-download {
  background: #6FA3FF;
  color: #1F2D3D;
  box-shadow: 0 4px 15px rgba(111, 163, 255, 0.4);
}

.btn-download:hover {
  background: #4A8BFF;
  color: #FFFFFF;
  transform: translateY(-2px);
}

.main-nav {
  background-color: var(--header-nav-bg);
  width: 100%;
  display: flex;
  min-height: 52px;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 8px;
  padding: 8px 24px;
  width: 100%;
}

.nav-link {
  display: inline-block;
  color: #1F2D3D;
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 8px;
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
  line-height: 1.3;
}

.nav-link:hover {
  color: #2F6BFF;
  background-color: #F0F4FF;
}

.nav-link.active {
  color: #2F6BFF;
  font-weight: 700;
  background-color: #E8EEFF;
}

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

.hamburger-menu {
  display: none;
}

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

.site-footer {
  background-color: #1F2D3D;
  color: #FFFFFF;
  margin-top: 60px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr 0.8fr;
  gap: 40px;
  padding: 50px 24px 40px;
}

.footer-logo {
  font-size: 28px;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #FFFFFF 0%, #A5C4FF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-desc {
  font-size: 14px;
  color: #A0AEC0;
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 360px;
}

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

.cert-badge {
  display: inline-block;
  font-size: 12px;
  color: #6FA3FF;
  background: rgba(111, 163, 255, 0.1);
  border: 1px solid #6FA3FF;
  padding: 6px 14px;
  border-radius: 20px;
  width: fit-content;
}

.footer-column .footer-title {
  font-size: 16px;
  font-weight: 600;
  color: #FFFFFF;
  margin-bottom: 16px;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav a {
  color: #A0AEC0;
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s ease;
  padding: 4px 0;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding: 18px 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 14px;
  color: #A0AEC0;
}

@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding-left: 15px;
    padding-right: 15px;
    min-height: 60px;
  }

  .header-top {
    background-color: var(--header-top-mobile-bg);
  }

  .logo {
    font-size: 24px;
    color: #FFFFFF;
  }

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

  .main-nav {
    background-color: var(--header-nav-mobile-bg);
    display: none;
    flex-direction: column;
    position: fixed;
    top: 60px;
    left: 0;
    width: 86%;
    max-width: 280px;
    height: calc(100vh - 60px);
    overflow-y: auto;
    transform: translateX(-100%);
    transition: transform 0.3s ease-in-out;
    z-index: 1002;
    box-shadow: 4px 0 15px rgba(0, 0, 0, 0.1);
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    gap: 10px;
    padding: 24px 20px 20px;
  }

  .nav-link {
    width: 100%;
    font-size: 17px;
    font-weight: 600;
    color: #1F2D3D;
    padding: 12px 0;
    border-radius: 0;
    transition: color 0.2s ease;
    white-space: normal;
  }

  .nav-link.active {
    background-color: transparent;
    color: #2F6BFF;
    font-weight: 700;
  }

  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    background-color: #FFFFFF;
    padding: 8px 12px;
    border-bottom: 1px solid #EAEEF5;
    min-height: 48px;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 0;
    font-size: 13px;
    padding: 10px 10px;
  }

  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    position: fixed;
    top: 8px;
    left: 12px;
    z-index: 1003;
    border-radius: 8px;
  }

  .hamburger-menu .bar {
    display: block;
    width: 22px;
    height: 2.5px;
    background-color: #FFFFFF;
    margin: 3px 0;
    border-radius: 3px;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }

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

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

  .hamburger-menu.active .bar:nth-child(3) {
    transform: translateY(-8.5px) rotate(-45deg);
  }

  .mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
  }

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

  body.no-scroll {
    overflow: hidden;
  }

  .footer-container {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 36px 20px 30px;
  }

  .footer-desc {
    max-width: 100%;
  }

  .footer-nav {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 10px 18px;
  }

  .footer-nav a {
    font-size: 14px;
  }

  .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) {
  .hamburger-menu {
    display: none;
  }

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

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

@media (max-width: 480px) {
  .logo {
    font-size: 22px;
  }

  .footer-certification {
    flex-direction: row;
    flex-wrap: wrap;
  }
}
/* 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;
}