:root {
  --primary: #2F6BFF;
  --secondary: #6FA3FF;
  --bg: #F4F7FB;
  --card-bg: #FFFFFF;
  --text-main: #1F2D3D;
  --border: #D6E2FF;
  --glow: #A5C4FF;
  --header-offset: 122px;
}

body {
  padding-top: var(--header-offset);
  margin: 0;
  font-family: 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text-main);
}

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: #FFFFFF;
  box-shadow: 0 2px 15px rgba(47, 107, 255, 0.15);
  border-bottom: 2px solid var(--border);
  min-height: auto;
}

.header-top {
  background: linear-gradient(180deg, #1A3D8F 0%, #2F6BFF 100%);
  width: 100%;
}

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

.logo {
  display: inline-block;
  color: #FFFFFF;
  font-size: 24px;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 1px;
  text-transform: uppercase;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

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

.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 25px;
  text-decoration: none;
  font-weight: bold;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  text-align: center;
}

.btn-register {
  background: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
  color: #FFFFFF;
  box-shadow: 0 4px 15px rgba(47, 107, 255, 0.3);
}

.btn-register:hover {
  box-shadow: 0 6px 20px rgba(47, 107, 255, 0.4);
  transform: translateY(-2px);
}

.btn-login {
  background: linear-gradient(180deg, #FFD700 0%, #FFA500 100%);
  color: #1F2D3D;
  box-shadow: 0 4px 15px rgba(255, 165, 0, 0.3);
}

.btn-login:hover {
  box-shadow: 0 6px 20px rgba(255, 165, 0, 0.4);
  transform: translateY(-2px);
}

/* ===== Navigation ===== */
.main-nav {
  background: #FFFFFF;
  width: 100%;
  display: flex;
  border-top: 1px solid var(--border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 10px 15px;
  gap: 5px;
  flex-wrap: wrap;
}

.nav-link {
  color: var(--text-main);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 6px;
  transition: all 0.3s ease;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--primary);
  background: rgba(47, 107, 255, 0.1);
}

/* ===== Mobile elements (hidden on desktop) ===== */
.hamburger-menu,
.mobile-menu-overlay,
.mobile-nav-buttons {
  display: none;
}

/* ===== Footer ===== */
.site-footer {
  background: linear-gradient(180deg, #1A3D8F 0%, #2F6BFF 100%);
  color: #FFFFFF;
  padding-top: 50px;
  margin-top: 0;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 0 30px 30px;
  gap: 30px;
}

.footer-column {
  flex: 1;
  min-width: 200px;
}

.footer-brand {
  flex: 1.5;
}

.footer-logo {
  display: inline-block;
  color: #FFFFFF;
  font-size: 22px;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
  margin-bottom: 15px;
}

.footer-description {
  color: rgba(255,255,255,0.8);
  font-size: 14px;
  line-height: 1.6;
  max-width: 350px;
}

.footer-title {
  color: #FFFFFF;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

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

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

.footer-nav a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s;
}

.footer-nav a:hover {
  color: #FFFFFF;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.2);
  padding: 20px 0;
  text-align: center;
}

.footer-bottom p {
  color: rgba(255,255,255,0.8);
  font-size: 14px;
  margin: 0;
}

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

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

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

  .logo {
    font-size: 18px;
    margin: 0 auto;
  }

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

  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 320px;
    height: 100vh;
    background: #FFFFFF;
    z-index: 1001;
    flex-direction: column;
    border-right: 2px solid var(--border);
    transform: translateX(-100%);
    transition: transform 0.3s ease, display 0s 0.3s;
    overflow-y: auto;
    padding-top: 80px;
    box-shadow: 4px 0 20px rgba(0,0,0,0.2);
  }

  .main-nav.active {
    display: flex;
    transform: translateX(0);
    transition: transform 0.3s ease, display 0s 0s;
  }

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px 20px;
    gap: 5px;
  }

  .nav-link {
    padding: 12px 15px;
    font-size: 16px;
    border-radius: 8px;
    text-align: left;
    border-bottom: 1px solid var(--border);
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  .mobile-nav-buttons {
    display: flex;
    background: #FFFFFF;
    border-bottom: 2px solid var(--border);
    padding: 10px 0;
  }

  .mobile-buttons-container {
    width: 100%;
    max-width: none;
    display: flex;
    justify-content: center;
    gap: 12px;
    padding: 0 15px;
  }

  .mobile-buttons-container .btn {
    flex: 1;
    max-width: 160px;
    padding: 10px 12px;
    font-size: 13px;
    white-space: nowrap;
  }

  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    cursor: pointer;
    position: fixed;
    top: 10px;
    left: 15px;
    z-index: 1002;
    background: transparent;
    border: none;
    padding: 0;
  }

  .hamburger-menu span {
    display: block;
    width: 24px;
    height: 2px;
    background: #FFFFFF;
    border-radius: 2px;
    transition: all 0.3s ease;
  }

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

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

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

  .mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease;
  }

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

  body.no-scroll {
    overflow: hidden;
  }

  .footer-container {
    width: 100%;
    max-width: none;
    padding: 0 20px 30px;
    flex-direction: column;
    gap: 25px;
  }

  .footer-column {
    min-width: 100%;
  }

  .footer-brand {
    order: 1;
  }

  .footer-links:nth-of-type(1) {
    order: 2;
  }

  .footer-links:nth-of-type(2) {
    order: 3;
  }

  .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;
}