:root {
  --primary-color: #ff6b6b;
  --primary-hover-color: #ff5252;
  --background-color: #f8f9fa;
  --footer-color: #343a40;
  --text-color: white;
  --transition-duration: 0.3s;
}

body {
  font-family: 'Poppins', sans-serif;
  background-color: var(--background-color);
  color: #333;
  line-height: 1.6;
}

.header, .footer {
  color: var(--text-color);
  padding: 2rem 0;
}

.header {
  background-color: var(--primary-color);
  margin-bottom: 2rem;
}

.header h1 {
  font-weight: 600;
}

.footer {
  background-color: var(--footer-color);
  margin-top: 2rem;
}

.donut-card {
  transition: transform var(--transition-duration) ease-in-out,
              box-shadow var(--transition-duration) ease-in-out;
  background-color: white;
  border-radius: 8px;
  overflow: hidden;
}

.donut-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.donut-card img {
  height: 200px;
  object-fit: cover;
  width: 100%;
}

.zero-quantity img {
  filter: grayscale(100%);
  opacity: 0.7;
  transition: filter var(--transition-duration) ease,
              opacity var(--transition-duration) ease;
}

.zero-quantity:hover img {
  filter: grayscale(0%);
  opacity: 1;
}

.btn-custom {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
  color: var(--text-color);
  transition: background-color var(--transition-duration) ease,
              border-color var(--transition-duration) ease;
}

.btn-custom:hover {
  background-color: var(--primary-hover-color);
  border-color: var(--primary-hover-color);
}

.image-preview {
  max-width: 200px;
  max-height: 200px;
  object-fit: cover;
}

@media (max-width: 768px) {
  .header, .footer {
    padding: 1rem 0;
  }
  
  .donut-card img {
    height: 150px;
  }
}