:root {
  --header-offset: 122px;
}

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

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-height: 100px;
  background-color: #FFFFFF;
  z-index: 1000;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  display: flex;
  flex-direction: column;
}

.header-top {
  width: 100%;
  background-color: #26A9E0;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 30px;
  min-height: 68px;
}

.logo {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  font-size: 2.2rem;
  font-weight: 900;
  color: #FFFFFF;
  text-decoration: none;
  line-height: 1;
  display: block;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
  letter-spacing: 1px;
}

.logo:hover {
  color: #FFFFFF;
  opacity: 0.9;
}

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

.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 700;
  color: #FFFFFF;
  background-color: #000000;
  text-decoration: none;
  text-align: center;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  min-width: 80px;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  opacity: 0.94;
  color: #FFFFFF;
}

.btn-login {
  background-color: #EA7C07;
}

.btn-login:hover {
  background-color: #d46e06;
}

.btn-register {
  background-color: #000000;
}

.btn-register:hover {
  background-color: #333333;
}

.btn-download {
  background-color: #26A9E0;
}

.btn-download:hover {
  background-color: #1d93c4;
}

.main-nav {
  width: 100%;
  background-color: #f8f9fa;
  display: flex;
  border-top: 2px solid #26A9E0;
  min-height: 52px;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 8px 20px;
  width: 100%;
}

.nav-link {
  color: #333333;
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 9px;
  margin: 0 1px;
  border-radius: 4px;
  transition: color 0.3s ease, background-color 0.3s ease;
  text-transform: capitalize;
  white-space: nowrap;
}

.nav-link:hover {
  color: #26A9E0;
  background-color: rgba(38, 169, 224, 0.1);
}

.nav-link.active {
  color: #26A9E0;
  font-weight: 800;
}

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

.hamburger-menu {
  display: none;
}

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

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

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

.site-footer {
  background-color: #f8f9fa;
  border-top: 4px solid #26A9E0;
  margin-top: 40px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 50px 30px 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand {
  padding-right: 20px;
}

.footer-logo {
  font-size: 2rem;
  font-weight: 900;
  color: #26A9E0;
  text-decoration: none;
  line-height: 1;
  display: block;
  margin-bottom: 15px;
}

.footer-logo:hover {
  color: #26A9E0;
  text-decoration: none;
  opacity: 0.85;
}

.footer-description {
  color: #333333;
  font-size: 0.9rem;
  line-height: 1.7;
  margin: 0;
}

.footer-nav h4 {
  color: #333333;
  font-size: 1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid #26A9E0;
  display: inline-block;
}

.footer-nav ul {
  list-style: none;
  padding: 0;
}

.footer-nav ul li {
  margin-bottom: 10px;
}

.footer-nav ul li a {
  color: #666666;
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.6;
  transition: color 0.3s ease, padding-left 0.3s ease;
  display: inline-block;
}

.footer-nav ul li a:hover {
  color: #26A9E0;
  text-decoration: none;
  padding-left: 6px;
}

.footer-bottom {
  border-top: 1px solid #dddddd;
  padding-top: 20px;
  margin-top: 40px;
  text-align: center;
}

.footer-bottom p {
  color: #888888;
  font-size: 0.9rem;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  margin: 0;
}

.copyright-year {
  font-weight: 600;
  color: #333333;
}

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

  .header-container {
    width: 100%;
    max-width: none;
    padding: 8px 15px;
    justify-content: center;
    min-height: 60px;
  }

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

  .site-header {
    min-height: 60px;
  }

  .header-top {
    order: 1;
    background-color: #26A9E0;
  }

  .mobile-header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 4px 15px;
    background-color: #26A9E0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: relative;
    z-index: 1002;
    order: 0;
  }

  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 48px;
    cursor: pointer;
    background: transparent;
    border: none;
    padding: 8px;
    z-index: 1003;
    gap: 6px;
  }

  .hamburger-menu span {
    display: block;
    width: 26px;
    height: 3px;
    background-color: #FFFFFF;
    border-radius: 2px;
    transition: all 0.3s ease;
  }

  .hamburger-menu.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }

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

  .hamburger-menu.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }

  .mobile-logo {
    font-size: 1.8rem;
    font-weight: 900;
    color: #FFFFFF;
    text-decoration: none;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    flex: 1;
    line-height: 1;
    pointer-events: auto;
  }

  .mobile-header-spacer {
    display: block;
    width: 40px;
    flex-shrink: 0;
  }

  .main-nav {
    display: none;
    position: fixed;
    top: 108px;
    left: 0;
    width: 280px;
    max-width: 85%;
    height: auto;
    max-height: calc(100vh - 120px);
    background: #FFFFFF;
    padding: 10px 0 40px 0;
    box-shadow: 2px 0 30px rgba(0, 0, 0, 0.2);
    border-top: none;
    z-index: 1001;
    overflow-y: auto;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    order: 3;
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    align-items: flex-start;
    padding: 0;
    margin: 0;
  }

  .nav-link {
    color: #333333;
    padding: 13px 20px;
    border-bottom: 1px solid #f0f0f0;
    font-size: 0.95rem;
    width: 100%;
  }

  .nav-link:hover {
    background-color: rgba(38, 169, 224, 0.08);
    color: #26A9E0;
  }

  .mobile-nav-buttons {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px;
    width: 100%;
    padding: 12px 15px;
    background-color: #F0F8FC;
    border-top: 1px solid #D6EEF7;
    order: 2;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    min-width: 0;
    max-width: 160px;
    padding: 10px 15px;
    font-size: 0.75rem;
  }

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

  .mobile-menu-overlay.active,
  .mobile-menu-overlay.visible {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
  }

  body.no-scroll {
    overflow: hidden;
  }

  .site-footer {
    margin-top: 30px;
  }

  .footer-container {
    padding: 30px 20px 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .footer-brand {
    padding-right: 0;
    text-align: center;
  }

  .footer-logo {
    display: inline-block;
    margin-bottom: 10px;
  }

  .footer-nav {
    text-align: center;
  }

  .footer-nav h4 {
    display: inline-block;
    margin-bottom: 12px;
  }

  .footer-bottom {
    margin-top: 25px;
    padding-top: 15px;
  }

  .footer-bottom p {
    flex-direction: column;
    gap: 2px;
    font-size: 0.8rem;
  }

  .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) {
  .site-header {
    min-height: 120px;
  }

  .page-content {
    padding-top: 10px;
  }
}
/* 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;
}