body {
  margin: 0;
  font-family: 'Helvetica Neue', Helvetica, Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: #f7f8fa;
  color: #222;
}

header.utmb-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: 64px;
}
.logo img {
  height: 40px;
}
nav {
  display: flex;
  align-items: center;
  gap: 12px;
}
nav a {
  color: #fff;
  text-decoration: none;
  font-size: 1em;
  padding: 0 8px;
  transition: color 0.2s;
}
nav a:hover {
  color: var(--utmb-yellow);
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 12px 48px 12px;
}
.hero, .feature-hero, .activities-hero, .subscription-hero, .support-hero, .about-hero, .login-section, .signup-section {
  border-radius: 24px;
  margin-bottom: 32px;
  padding: 40px 24px;
  text-align: center;
}
.features, .feature-details, .activity-list, .subscription-options, .support-content, .about-content {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  justify-content: center;
}
.feature-list, .feature-details, .activity-list, .subscription-options {
  width: 100%;
  justify-content: space-around;
}
.feature-item, .feature-block, .activity-item, .subscription-plan, .support-block {
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 2px 8px rgba(28,28,245,0.06);
  padding: 24px 18px;
  min-width: 220px;
  max-width: 320px;
  flex: 1 1 220px;
  margin: 0 8px 16px 8px;
}
.subscription-plan.premium {
  border: 2px solid var(--utmb-accent);
  background: var(--utmb-yellow);
  color: #222;
}
.plan-price {
  display: block;
  font-size: 2em;
  font-weight: bold;
  margin: 16px 0;
}
.cta-section {
  text-align: center;
  margin: 48px 0 0 0;
}
footer {
  text-align: center;
  color: #888;
  padding: 32px 0 16px 0;
  font-size: 0.95em;
}
form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 340px;
  margin: 0 auto;
}
input[type="email"], input[type="password"], input[type="text"] {
  padding: 12px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 1em;
}
button, .cta-btn {
  font-size: 1em;
  padding: 12px 0;
  border-radius: 24px;
  border: none;
  font-weight: bold;
  cursor: pointer;
}
@media (max-width: 700px) {
  main {
    padding: 12px 2vw 32px 2vw;
  }
  .features, .feature-details, .activity-list, .subscription-options, .support-content, .about-content {
    flex-direction: column;
    gap: 12px;
    align-items: stretch;
  }
  .feature-item, .feature-block, .activity-item, .subscription-plan, .support-block {
    min-width: 0;
    max-width: 100%;
    margin: 0 0 16px 0;
  }
  header.utmb-header {
    flex-direction: column;
    height: auto;
    padding: 12px 0;
  }
  nav {
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
  }
  .logo img {
    height: 32px;
  }
}