:root {
  --header-offset: 166px;
  --primary: #113B7A;
  --secondary: #1D5FD1;
  --card-bg: #10233F;
  --text-main: #F3F8FF;
  --text-secondary: #AFC4E8;
  --border: #244D84;
  --glow: #4FA8FF;
  --gold: #F2C14E;
  --divider: #1B3357;
  --deep-navy: #08162B;
  --button-gradient: linear-gradient(180deg, #2B73F6 0%, #1144A6 100%);
}

body {
  padding-top: var(--header-offset);
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--deep-navy);
  color: var(--text-main);
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  background-color: var(--primary);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.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-left: 24px;
  padding-right: 24px;
  min-height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  font-size: 28px;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: 1px;
  transition: opacity 0.2s ease;
  text-transform: lowercase;
}

.logo:hover {
  opacity: 0.9;
}

.logo-text {
  color: var(--text-main);
}

.logo-text-accent {
  color: var(--gold);
  margin-left: 3px;
}

.desktop-nav-buttons {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 20px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: none;
  white-space: nowrap;
  transition: all 0.3s ease;
  line-height: 1.4;
  min-height: 36px;
  box-sizing: border-box;
}

.btn-login {
  background: linear-gradient(180deg, #2B73F6 0%, #1144A6 100%);
  color: var(--text-main);
  border: 1px solid rgba(255,255,255,0.1);
}

.btn-login:hover {
  box-shadow: 0 0 12px var(--glow);
  transform: translateY(-1px);
}

.btn-register {
  background: linear-gradient(180deg, #F2C14E 0%, #D4A032 100%);
  color: var(--deep-navy);
  font-weight: 700;
}

.btn-register:hover {
  box-shadow: 0 0 15px rgba(242, 193, 78, 0.6);
  transform: translateY(-1px);
}

.btn-download {
  background: linear-gradient(180deg, #2B73F6 0%, #1144A6 100%);
  color: var(--text-main);
  border: 1px solid var(--border);
}

.btn-download:hover {
  box-shadow: 0 0 12px var(--glow);
  transform: translateY(-1px);
}

.main-nav {
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--divider);
  width: 100%;
  display: flex;
  position: static;
  transform: none;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  padding-left: 24px;
  padding-right: 24px;
}

.nav-menu {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 0;
  flex-wrap: wrap;
  min-height: 52px;
}

.nav-item {
  margin: 0;
}

.nav-link {
  display: block;
  padding: 12px 18px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.3s ease, background-color 0.3s ease;
  border-radius: 4px;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--gold);
  background-color: rgba(79, 168, 255, 0.1);
}

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

.hamburger-menu {
  display: none;
}

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

@media (max-width: 768px) {
  :root {
    --header-offset: 146px;
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding-left: 15px;
    padding-right: 15px;
    min-height: 60px;
    flex-wrap: wrap;
  }

  .logo {
    font-size: 24px;
    order: 1;
    flex: 1;
    justify-content: center;
    display: flex;
  }

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

  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 8px 15px;
    background-color: var(--deep-navy);
    border-bottom: 1px solid var(--divider);
    min-height: 48px;
    width: 100%;
    box-sizing: border-box;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    max-width: 130px;
    padding: 8px 12px;
    font-size: 13px;
  }

  .main-nav {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 280px;
    max-width: 85vw;
    background-color: var(--card-bg);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    display: none;
    z-index: 1002;
    overflow-y: auto;
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.4);
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    padding: 20px 15px;
  }

  .nav-menu {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    overflow-y: auto;
  }

  .nav-item {
    width: 100%;
  }

  .nav-link {
    padding: 14px 15px;
    font-size: 15px;
    width: 100%;
    box-sizing: border-box;
    border-bottom: 1px solid var(--divider);
  }

  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    cursor: pointer;
    background: transparent;
    border: none;
    padding: 10px;
    z-index: 1003;
    order: 0;
    position: absolute;
    left: 15px;
    top: 18px;
  }

  .hamburger-menu .bar {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--text-main);
    transition: all 0.3s ease;
    border-radius: 2px;
  }

  .hamburger-menu.active .bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

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

  .hamburger-menu.active .bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease;
  }

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

  body.no-scroll {
    overflow: hidden;
  }

  body {
    overflow-x: hidden;
  }

  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }

  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
}

.site-footer {
  background-color: var(--deep-navy);
  border-top: 2px solid var(--divider);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  padding: 50px 0 30px;
  color: var(--text-secondary);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  justify-content: space-between;
}

.footer-brand-col {
  flex: 1;
  min-width: 260px;
  max-width: 350px;
}

.footer-logo {
  font-size: 28px;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
  letter-spacing: 1px;
  text-transform: lowercase;
  display: inline-block;
}

.footer-description {
  margin: 15px 0;
  line-height: 1.6;
  font-size: 14px;
  color: var(--text-secondary);
}

.footer-copyright {
  font-size: 13px;
  color: var(--text-secondary);
  opacity: 0.8;
}

.footer-links-col {
  min-width: 180px;
}

.footer-col-title {
  color: var(--gold);
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 15px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.footer-nav {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav li {
  margin: 0;
  padding: 0;
}

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s ease;
}

.footer-link:hover {
  color: var(--gold);
}

.footer-contact-col {
  min-width: 200px;
}

.footer-buttons {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-buttons .btn {
  width: 100%;
  max-width: 180px;
}

@media (max-width: 768px) {
  .footer-container {
    width: 100%;
    max-width: none;
    padding-left: 15px;
    padding-right: 15px;
  }

  .footer-grid {
    flex-direction: column;
    gap: 30px;
  }

  .footer-brand-col {
    min-width: 100%;
  }
}
/* 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;
}