:root {
  --primary-color: #26A9E0;
  --primary-dark: #1a7ba3;
  --primary-light: #e6f5fb;
  --secondary-color: #FFFFFF;
  --text-dark: #333333;
  --text-light: #666666;
  --text-white: #FFFFFF;
  --accent-warning: #EA7C07;
  --header-offset: 122px;
  --header-offset-mobile: 110px;
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #FFFFFF;
  padding-top: var(--header-offset);
  overflow-x: hidden;
}
a {
  text-decoration: none;
  color: inherit;
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background-color: var(--secondary-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  min-height: auto;
}
.header-top {
  background-color: var(--primary-dark);
  width: 100%;
  min-height: 68px;
  display: flex;
  align-items: center;
}
.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 30px;
  width: 100%;
  min-height: 68px;
}
.logo {
  display: inline-block;
  color: var(--secondary-color);
  font-size: 28px;
  font-weight: 800;
  letter-spacing: 1px;
  white-space: nowrap;
  text-transform: uppercase;
}
.logo:hover {
  color: rgba(255, 255, 255, 0.9);
}
.desktop-nav-buttons {
  display: flex;
  gap: 10px;
  align-items: center;
}
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 700;
  text-align: center;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  line-height: 1.4;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}
.btn-register {
  background: linear-gradient(135deg, #f7971e, #ffd200);
  color: var(--text-dark);
}
.btn-login {
  background: var(--accent-warning) !important;
  color: var(--text-white) !important;
}
.mobile-nav-buttons {
  display: none;
}
.main-nav {
  background-color: var(--primary-color);
  width: 100%;
  display: flex;
  flex-direction: row;
  position: static;
  z-index: 1001;
  min-height: 52px;
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 0;
  width: 100%;
  padding: 0 15px;
  flex-wrap: wrap;
}
.nav-link {
  display: inline-block;
  color: var(--text-white);
  font-size: 15px;
  font-weight: 600;
  padding: 15px 14px;
  transition: background-color 0.3s ease, color 0.3s ease;
  white-space: nowrap;
  line-height: 1.4;
}
.nav-link:hover {
  background-color: var(--primary-dark);
  color: var(--secondary-color);
}
.hamburger-menu {
  display: none;
}
.mobile-menu-overlay {
  display: none;
}
.site-footer {
  background-color: #2a2a3a;
  color: var(--text-white);
  margin-top: 60px;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 50px 30px 30px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 30px;
}
.footer-logo {
  display: inline-block;
  color: var(--secondary-color);
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 15px;
  text-transform: uppercase;
}
.footer-desc {
  color: #b0b0c0;
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 15px;
}
.footer-certificates {
  display: flex;
  gap: 12px;
}
.cert-item {
  display: inline-block;
  padding: 4px 12px;
  border: 1px solid var(--primary-color);
  border-radius: 4px;
  color: var(--primary-color);
  font-size: 12px;
  font-weight: 700;
}
.footer-title {
  color: var(--secondary-color);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 15px;
  position: relative;
  padding-bottom: 10px;
}
.footer-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 30px;
  height: 2px;
  background-color: var(--primary-color);
}
.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-nav a {
  color: #b0b0c0;
  font-size: 14px;
  transition: color 0.3s ease, padding-left 0.3s ease;
}
.footer-nav a:hover {
  color: var(--primary-color);
  padding-left: 5px;
}
.footer-bottom {
  background-color: #20202e;
  padding: 15px 0;
  width: 100%;
}
.footer-bottom-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding: 0 30px;
}
.copyright {
  color: #b0b0c0;
  font-size: 13px;
}
.footer-note {
  color: #888;
  font-size: 12px;
}
@media (max-width: 768px) {
  :root {
    --header-offset: var(--header-offset-mobile, 110px);
  }
  .header-top {
    min-height: 60px;
  }
  .header-container {
    width: 100%;
    max-width: none;
    padding: 0 15px;
    min-height: 60px;
  }
  .logo {
    font-size: 22px;
  }
  .main-nav {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 108px;
    left: 0;
    width: 280px;
    height: calc(100vh - 108px);
    background-color: var(--primary-color);
    transition: transform 0.3s ease;
    transform: translateX(-100%);
    overflow-y: auto;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.2);
  }
  .main-nav.active {
    display: block;
    transform: translateX(0);
  }
  .nav-container {
    width: 100%;
    max-width: none;
    padding: 20px 0;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
  }
  .nav-link {
    display: block;
    padding: 12px 20px;
    font-size: 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .nav-link:hover {
    background-color: rgba(0, 0, 0, 0.1);
    padding-left: 25px;
  }
  .hamburger-menu {
    display: block;
    position: absolute;
    top: 18px;
    left: 12px;
    z-index: 1003;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 5px;
    width: 40px;
    height: 40px;
  }
  .hamburger-menu span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--secondary-color);
    margin: 6px auto;
    transition: all 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);
  }
  .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;
  }
  .mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
  }
  .desktop-nav-buttons {
    display: none;
  }
  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    padding: 6px 15px;
    background: linear-gradient(90deg, var(--primary-dark) 0%, var(--primary-color) 50%, var(--primary-dark) 100%);
    min-height: 48px;
  }
  .mobile-nav-buttons .btn {
    padding: 8px 18px;
    font-size: 13px;
    width: auto;
    min-width: 90px;
  }
  .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;
}