:root {
  --primary: #26A9E0;
  --primary-dark: #1a7a9e;
  --secondary: #FFFFFF;
  --login-btn: #EA7C07;
  --bg: #FFFFFF;
  --black: #000000;
  --header-offset: 122px;
}
body {
  padding-top: var(--header-offset);
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg);
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: #ffffff;
  box-shadow: 0 2px 15px rgba(0,0,0,0.15);
  z-index: 1000;
}
.header-top {
  background: #f0f8ff;
  width: 100%;
}
.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 20px;
}
.logo {
  font-size: 28px;
  font-weight: 900;
  color: var(--primary);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 1px;
  transition: color 0.3s;
}
.logo:hover {
  color: var(--primary-dark);
}
.header-actions {
  display: flex;
  gap: 10px;
}
.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 50px;
  font-weight: bold;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
  font-size: 14px;
  text-align: center;
  border: none;
  cursor: pointer;
}
.btn-login {
  background: var(--login-btn);
  color: #fff;
  box-shadow: 0 4px 8px rgba(234,124,7,0.3);
}
.btn-login:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(234,124,7,0.4);
}
.btn-register {
  background: linear-gradient(135deg, #26A9E0 0%, #1a7a9e 100%);
  color: #fff;
  box-shadow: 0 4px 8px rgba(38,169,224,0.3);
}
.btn-register:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(38,169,224,0.4);
}
.btn-download {
  background: linear-gradient(135deg, #28a745 0%, #1e7e34 100%);
  color: #fff;
  box-shadow: 0 4px 8px rgba(40,167,69,0.3);
}
.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(40,167,69,0.4);
}
.main-nav {
  background: #e6f4fa;
  width: 100%;
  display: flex;
  justify-content: center;
  border-top: 1px solid #d1e7f0;
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  padding: 8px 20px;
  gap: 4px;
}
.nav-link {
  padding: 8px 12px;
  color: #1a5f7a;
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  border-radius: 20px;
  transition: background 0.3s, color 0.3s;
  white-space: nowrap;
}
.nav-link:hover,
.nav-link.active {
  background: var(--primary);
  color: #fff;
}
.hamburger-menu {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 1001;
  position: absolute;
  top: 15px;
  left: 15px;
  padding: 5px;
}
.hamburger-menu span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--primary);
  margin: 5px 0;
  transition: all 0.3s;
}
.mobile-menu-overlay {
  display: none;
}
.mobile-nav-buttons {
  display: none;
}
@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }
  .site-header {
    min-height: 108px;
  }
  .header-top {
    background: #f0f8ff;
    padding: 5px 0;
  }
  .header-container {
    width: 100%;
    max-width: none;
    padding: 8px 15px;
    justify-content: space-between;
    align-items: center;
  }
  .logo {
    font-size: 24px;
    margin: 0 auto;
    order: 2;
  }
  .header-actions {
    display: none;
  }
  .hamburger-menu {
    display: block;
    order: 1;
  }
  .hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
  }
  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 280px;
    background: #fff;
    box-shadow: 2px 0 10px rgba(0,0,0,0.1);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 1000;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    padding-top: 60px;
  }
  .main-nav.active {
    display: block;
    transform: translateX(0);
  }
  .nav-container {
    width: 100%;
    max-width: none;
    padding: 10px;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
  }
  .nav-link {
    display: block;
    padding: 12px 20px;
    border-bottom: 1px solid #f0f0f0;
    font-size: 16px;
    width: 100%;
    box-sizing: border-box;
  }
  .nav-link:hover,
  .nav-link.active {
    background: var(--primary);
    color: #fff;
  }
  .mobile-menu-overlay {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s;
    z-index: 999;
  }
  .mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
  }
  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 8px 10px;
    background: #f8f9fa;
    border-bottom: 1px solid #e9ecef;
  }
  .mobile-nav-buttons .btn {
    flex: 1;
    padding: 10px 8px;
    font-size: 12px;
  }
}
.site-footer {
  background: #1a1a2e;
  color: #fff;
  padding: 30px 20px 10px;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
  justify-content: space-between;
}
.footer-info {
  flex: 1 1 250px;
}
.footer-logo {
  font-size: 24px;
  color: var(--primary);
  margin-bottom: 10px;
}
.footer-links,
.footer-contact {
  flex: 1 1 150px;
}
.footer-links h4,
.footer-contact h4 {
  color: #fff;
  font-size: 16px;
  margin-bottom: 10px;
}
.footer-nav,
.footer-contact ul {
  list-style: none;
  padding: 0;
}
.footer-nav li,
.footer-contact li {
  margin-bottom: 8px;
}
.footer-nav a,
.footer-contact a {
  color: #ccc;
  text-decoration: none;
  transition: color 0.3s;
}
.footer-nav a:hover,
.footer-contact a:hover {
  color: var(--primary);
}
.footer-bottom {
  text-align: center;
  border-top: 1px solid #333;
  padding-top: 10px;
  margin-top: 20px;
  font-size: 14px;
  color: #aaa;
}
@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;
  }
}
/* 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;
}