:root {
  --primary-color: #2F6BFF;
  --secondary-color: #6FA3FF;
  --header-top-bg: #1A3B8F;
  --main-nav-bg: #FFFFFF;
  --button-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
  --text-dark: #1F2D3D;
  --border-color: #D6E2FF;
  --glow-color: #A5C4FF;
  --header-offset: 164px;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-height: auto;
  background-color: #FFFFFF;
  box-shadow: 0 4px 20px rgba(47, 107, 255, 0.15);
  z-index: 1000;
  font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
}

.header-top {
  background-color: var(--primary-color);
  background-image: linear-gradient(135deg, #1A3B8F 0%, #2F6BFF 100%);
  width: 100%;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 40px;
  min-height: 68px;
}

.logo {
  font-size: 1.9rem;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  letter-spacing: 1px;
  display: inline-block;
  line-height: 1.2;
  position: relative;
}

.logo:hover {
  text-decoration: none;
  opacity: 0.9;
}

.hamburger-menu {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  border-radius: 8px;
  min-width: 44px;
  min-height: 44px;
  margin-right: 10px;
}

.hamburger-line {
  display: block;
  width: 24px;
  height: 2.5px;
  background-color: #FFFFFF;
  border-radius: 2px;
  transition: transform 0.3s ease-in-out, opacity 0.2s ease;
}

.hamburger-menu.active .hamburger-line:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
}

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

.hamburger-menu.active .hamburger-line:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 40px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  line-height: 1.2;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(47, 107, 255, 0.4);
}

.btn-primary {
  background-color: #FFFFFF;
  color: var(--primary-color);
  border: 2px solid #FFFFFF;
}

.btn-primary:hover {
  background-color: transparent;
  color: #FFFFFF;
}

.btn-highlight {
  background: var(--button-gradient);
  color: #FFFFFF;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-highlight:hover {
  box-shadow: 0 0 18px rgba(165, 196, 255, 0.9);
}

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

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 0px 20px;
  width: 100%;
  min-height: 52px;
}

.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 0px;
  margin: 0;
  padding: 0;
  width: 100%;
  flex-wrap: wrap;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  padding: 14px 18px;
  color: var(--text-dark);
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  border-radius: 0px;
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--primary-color);
  background-color: #F0F6FF;
  text-decoration: none;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 60%;
  height: 3px;
  background-color: var(--primary-color);
  border-radius: 4px;
  transition: transform 0.2s ease;
}

.nav-link:hover::after {
  transform: translateX(-50%) scaleX(1);
}

.header-actions-mobile {
  display: none;
}

.mobile-menu-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.55);
  z-index: 999;
  transition: opacity 0.3s ease;
  opacity: 0;
  visibility: hidden;
}

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

body {
  padding-top: var(--header-offset);
  overflow-x: hidden;
  margin: 0;
}

.site-footer {
  background-color: #1B2B45;
  color: #C8D6E5;
  padding: 45px 0 0 0;
  margin-top: 50px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 25px;
}

.footer-top {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: flex-start;
  gap: 60px;
  padding-bottom: 40px;
}

.footer-info {
  flex: 1 1 50%;
}

.footer-logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  letter-spacing: 0.5px;
  display: inline-block;
  margin-bottom: 15px;
}

.footer-logo:hover {
  text-decoration: none;
  color: #A5C4FF;
}

.footer-description {
  font-size: 0.95rem;
  line-height: 1.6;
  color: #C8D6E5;
  margin: 0;
  max-width: 500px;
}

.footer-nav-wrapper {
  flex: 1 1 40%;
}

.footer-title {
  color: #FFFFFF;
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 18px 0;
  position: relative;
  padding-bottom: 10px;
}

.footer-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background-color: #4A8BFF;
  border-radius: 3px;
}

.footer-nav {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 36px;
  row-gap: 10px;
}

.footer-nav li a {
  display: inline-block;
  padding: 4px 0;
  color: #A8C0D9;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-nav li a:hover {
  color: #FFFFFF;
  text-decoration: none;
  transform: translateX(3px);
}

.footer-bottom {
  border-top: 1px solid #2E4567;
  padding: 25px 0;
  text-align: center;
}

.copyright-text {
  margin: 0 0 8px 0;
  font-size: 0.9rem;
  color: #A8C0D9;
}

.footer-disclaimer {
  margin: 0;
  font-size: 0.85rem;
  color: #7B94B0;
}

@media (max-width: 768px) {
  :root {
    --header-offset: 148px;
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding: 10px 15px;
    min-height: 60px;
  }

  .hamburger-menu {
    display: flex;
    order: 0;
  }

  .logo {
    display: block;
    order: 1;
    flex: 1;
    text-align: center;
    font-size: 1.6rem;
    margin-left: 0;
  }

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

  .header-actions-mobile {
    display: block;
    background-color: var(--primary-color);
  }

  .mobile-nav-buttons {
    width: 100%;
    max-width: none;
    margin: 0 auto;
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    min-height: 48px;
    background-color: #1A3B8F;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    max-width: 180px;
    padding: 10px 12px;
    font-size: 0.9rem;
  }

  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 80%;
    max-width: 360px;
    height: 100vh;
    background-color: #FFFFFF;
    flex-direction: column;
    overflow-y: auto;
    z-index: 1001;
    transform: translateX(-100%);
    transition: transform 0.35s ease-in-out;
    box-shadow: inset -2px 0 15px rgba(0, 0, 0, 0.05);
    padding-bottom: 30px;
  }

  .main-nav.active {
    display: block;
    transform: translateX(0);
    box-shadow: 6px 6px 30px rgba(0, 0, 0, 0.25);
  }

  .nav-container {
    width: 100%;
    max-width: none;
    padding: 0;
    margin: 0;
    display: block;
  }

  .nav-menu {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    width: 100%;
    padding: 20px 0 30px;
    margin: 0;
  }

  .nav-item {
    border-bottom: 1px solid #F0F5FE;
  }

  .nav-link {
    display: block;
    width: 100%;
    padding: 16px 30px;
    font-size: 1.15rem;
    color: var(--text-dark);
    text-align: left;
    font-weight: 600;
  }

  .nav-link::after,
  .nav-link:hover::after {
    content: none;
  }

  .nav-link:hover {
    background-color: #F1F7FF;
    color: var(--primary-color);
  }

  .mobile-nav-buttons .btn-login {
    order: 0;
  }

  .mobile-nav-buttons .btn-register {
    order: 1;
  }

  .footer-top {
    flex-direction: column;
    gap: 35px;
  }

  .footer-info,
  .footer-nav-wrapper {
    width: 100%;
    flex: none;
  }

  .footer-nav {
    grid-template-columns: 1fr 1fr;
    column-gap: 20px;
  }

  .footer-container {
    padding: 0 20px;
  }

  .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) {
  .main-nav {
    display: flex !important;
    flex-direction: row;
    position: static;
    transform: none;
  }

  .nav-menu {
    display: flex !important;
    flex-direction: row;
  }

  .mobile-menu-overlay {
    display: none !important;
  }
}
/* 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;
}