:root {
  --header-offset: 164px; 
  --primary: #113B7A;
  --secondary: #1D5FD1;
  --btn-gradient: linear-gradient(180deg, #2B73F6 0%, #1144A6 100%);
  --card-bg: #10233F;
  --text-main: #F3F8FF;
  --text-secondary: #AFC4E8;
  --border-color: #244D84;
  --glow: #4FA8FF;
  --gold: #F2C14E;
  --divider: #1B3357;
  --deep-navy: #08162B;
}
body {
  padding-top: var(--header-offset); 
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: linear-gradient(135deg, #0a1420 0%, #08162B 50%, #0d1f3a 100%);
  color: var(--text-main);
  overflow-x: hidden;
  line-height: 1.6;
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: var(--deep-navy);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  border-bottom: 2px solid var(--gold);
}
.header-top {
  background: linear-gradient(180deg, var(--primary) 0%, var(--deep-navy) 100%);
  border-bottom: 1px solid var(--divider);
  width: 100%;
}
.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 24px;
  width: auto;
}
.logo {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--gold);
  text-decoration: none;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}
.logo:hover {
  color: #ffffff;
  transition: color 0.3s ease;
}
.desktop-nav-buttons {
  display: flex;
  gap: 12px;
  align-items: center;
}
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 50px;
  color: #ffffff;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.5px;
  text-decoration: none;
  border: none;
  cursor: pointer;
  text-transform: uppercase;
  transition: all 0.3s ease;
  text-align: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}
.btn-register {
  background: var(--btn-gradient);
  border: 1px solid rgba(255, 255, 255, 0.2);
}
.btn-register:hover {
  background: linear-gradient(180deg, #3d85ff 0%, #1855c9 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(43, 115, 246, 0.4);
}
.btn-login {
  background: linear-gradient(180deg, var(--gold) 0%, #d4a422 100%);
  color: var(--deep-navy);
  border: 1px solid rgba(0, 0, 0, 0.1);
}
.btn-login:hover {
  background: linear-gradient(180deg, #fdd05e 0%, #e0b833 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(242, 193, 78, 0.4);
}
.main-nav {
  background: linear-gradient(180deg, rgba(17, 59, 122, 0.98) 0%, rgba(8, 22, 43, 0.98) 100%);
  width: 100%;
  display: flex;
  min-height: 52px;
  border-bottom: 1px solid rgba(242, 193, 78, 0.2);
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 6px 24px;
  width: 100%;
  position: relative;
}
.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 4px;
  justify-content: center;
  align-items: center;
  flex-wrap: nowrap;
}
.nav-menu li {
  position: relative;
}
.nav-link {
  display: inline-block;
  padding: 8px 12px;
  color: var(--text-main);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.3s ease;
  white-space: nowrap;
  text-transform: none;
  letter-spacing: 0.3px;
}
.nav-link:hover,
.nav-link.active {
  color: var(--gold);
  background-color: rgba(34, 93, 209, 0.2);
  box-shadow: 0 2px 8px rgba(79, 168, 255, 0.2);
}
.nav-link::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background-color: var(--gold);
  transition: width 0.3s ease;
}
.nav-link:hover::after,
.nav-link.active::after {
  width: 60%;
}
.hamburger-menu {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 10px;
  z-index: 1001;
}
.hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--gold);
  transition: all 0.3s ease;
}
.mobile-menu-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.7);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}
.mobile-menu-overlay.active {
  opacity: 1;
  visibility: visible;
}
.mobile-nav-buttons {
  display: none;
  position: fixed;
  top: 112px;
  left: 0;
  width: 100%;
  background: rgba(8, 22, 43, 0.95);
  padding: 12px 16px;
  justify-content: center;
  align-items: center;
  gap: 15px;
  z-index: 1000;
  border-bottom: 1px solid var(--divider);
}
.site-footer {
  background: var(--deep-navy);
  border-top: 3px solid var(--gold);
  padding: 60px 20px 20px;
  color: var(--text-main);
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 30px;
}
.footer-col h3.footer-title {
  font-size: 16px;
  color: var(--gold);
  margin-bottom: 15px;
  text-transform: uppercase;
  letter-spacing: 1px;
}
.footer-logo {
  font-size: 20px;
  color: var(--gold);
  text-decoration: none;
  font-weight: 700;
  margin-bottom: 15px;
  display: block;
}
.footer-brand p {
  font-size: 15px;
  line-height: 1.6;
  margin: 10px 0;
  color: var(--text-secondary);
}
.footer-nav {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-nav li {
  margin-bottom: 8px;
}
.footer-nav a {
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.3s;
}
.footer-nav a:hover {
  color: var(--gold);
  padding-left: 5px;
}
.footer-divider {
  border-top: 1px solid var(--divider);
  margin: 20px 0;
}
.footer-bottom {
  text-align: center;
}
.copyright {
  color: var(--text-secondary);
  font-size: 14px;
  margin: 0 0 10px;
}
.disclaimer {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.5;
  margin: 0 auto;
  max-width: 600px;
}
.footer-certification {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 20px;
}
.age-badge {
  background-color: var(--button-gradient, #42257c);
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  color: #ffffff;
  border-radius: 4px;
  background: var(--secondary);
}
.certification-text {
  font-size: 12px;
  color: var(--text-secondary);
}
@media (max-width: 768px) {
  :root {
    --header-offset: 146px; 
  }
  body {
    overflow-x: hidden;
  }
  .header-container {
    width: 100%;
    max-width: none;
    padding: 8px 15px;
    gap: 10px;
  }
  .nav-container {
    width: 100%;
    max-width: none;
    padding: 0;
    justify-content: flex-start;
  }
  .hamburger-menu {
    display: flex;
    margin-right: auto;
  }
  .logo {
    flex: 1;
    margin: 0;
    text-align: center;
  }
  .main-nav {
    background: var(--deep-navy);
    width: 280px;
    max-width: 85%;
    height: auto;
    min-height: 100vh;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
    padding-bottom: 20px;
    z-index: 1000;
  }
  .main-nav.active {
    display: block;
    transform: translateX(0);
  }
  .nav-menu {
    flex-direction: column;
    width: 100%;
    align-items: flex-start;
    justify-content: flex-start;
    padding: 25px 0 25px 15px;
    gap: 6px;
  }
  .nav-menu li {
    width: 100%;
    text-align: left;
  }
  .nav-link {
    display: block;
    padding: 10px 5px;
    width: 100%;
    color: var(--text-main);
    font-size: 14px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .mobile-nav-buttons {
    display: flex;
    width: 100%;
    max-width: none;
    top: 111px;
  }
  .mobile-menu-overlay.active {
    display: block;
    top: 0;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .site-footer {
    padding: 40px 16px 20px;
  }
  .footer-col {
    text-align: left;
  }
  .footer-logo {
    text-align: left;
  }
  .footer-certification {
    justify-content: flex-start;
  }
  .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 (max-width: 420px) {
  .mobile-nav-buttons {
    gap: 8px;
    padding: 8px 10px;
    top: 110px;
  }
  .btn {
    padding: 8px 14px;
    font-size: 12px;
  }
}
/* 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;
}