/* 認証ページ共通スタイル */
body {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.auth-container {
  width: 100%;
  max-width: 440px;
  padding: 15px;
}

.auth-card {
  background: white;
  border-radius: 16px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
  overflow: hidden;
}

.auth-header {
  background: linear-gradient(135deg, #2d3748 0%, #1a202c 100%);
  color: white;
  padding: 2.5rem 2rem;
  text-align: center;
}

.auth-header h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.auth-header p {
  font-size: 0.95rem;
  opacity: 0.9;
  margin-bottom: 0;
}

.auth-body {
  padding: 2.5rem 2rem;
}

.google-btn {
  width: 100%;
  padding: 0.875rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  background: white;
  color: #333;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  transition: all 0.3s ease;
  text-decoration: none;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  white-space: nowrap;
}

.google-btn:hover {
  background: #f8f9fa;
  border-color: #4a5568;
  color: #2d3748;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(74, 85, 104, 0.2);
}

.google-icon {
  width: 24px;
  height: 24px;
}

.features {
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid #e0e0e0;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  color: #666;
  font-size: 0.9rem;
}

.feature-item i {
  color: #4a5568;
  font-size: 1.2rem;
}

.footer-note {
  text-align: center;
  margin-top: 2rem;
  color: white;
  font-size: 0.85rem;
}

.footer-note a {
  color: white;
  text-decoration: underline;
}

/* エラーページ用の追加スタイル */
.error-icon {
  font-size: 4rem;
  color: #4a5568;
  margin-bottom: 1rem;
}

.btn-home {
  width: 100%;
  padding: 0.875rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  color: white;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-block;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn-home:hover {
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(74, 85, 104, 0.3);
}

@media (max-width: 576px) {
  .auth-header {
    padding: 2rem 1.5rem;
  }

  .auth-header h1 {
    font-size: 1.75rem;
  }

  .auth-body {
    padding: 2rem 1.5rem;
  }

  .error-icon {
    font-size: 3rem;
  }
}