:root {
  --portal-color: #0dcaf0;
  --portal-color-dark: #0aa2c0;
  --secondary-color: #6c757d;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --warning-color: #ffc107;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  background-color: #f8f9fa;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

.navbar {
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar-brand {
  font-weight: 600;
  font-size: 1.25rem;
}

.card {
  border-radius: 12px;
  border: none;
  transition: all 0.3s ease;
}

.module-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.12) !important;
}

.card-header {
  font-weight: 600;
  border-radius: 12px 12px 0 0 !important;
}

.btn {
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 1.05rem;
}

.btn:active {
  transform: scale(0.98);
}

.form-control,
.form-select {
  border-radius: 8px;
  border: 1px solid #ced4da;
  padding: 10px 14px;
  font-size: 1rem;
}

.form-control:focus,
.form-select:focus {
  border-color: var(--portal-color);
  box-shadow: 0 0 0 0.2rem rgba(13, 202, 240, 0.25);
}

.form-control-lg {
  padding: 12px 16px;
  font-size: 1.05rem;
}

.alert {
  border-radius: 10px;
  border: none;
}

.footer {
  background-color: #f8f9fa;
  border-top: 1px solid #dee2e6;
  margin-top: auto;
}

#install-banner,
#ios-banner {
  animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Mobile optimizations */
@media (max-width: 768px) {
  .container-fluid {
    padding-left: 12px;
    padding-right: 12px;
  }

  .card-body {
    padding: 1rem;
  }

  h2 {
    font-size: 1.4rem;
  }

  h4 {
    font-size: 1.15rem;
  }

  .btn-lg {
    padding: 10px 20px;
    font-size: 1rem;
  }

  .form-control-lg {
    padding: 10px 14px;
    font-size: 1rem;
  }
}

@media (max-width: 576px) {
  .navbar-brand {
    font-size: 1rem;
  }

  .card-body i[style*="font-size: 3rem"] {
    font-size: 2.2rem !important;
  }

  h5.card-title {
    font-size: 0.95rem;
  }
}