```
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--secondary);
  color: #333;
}

header {
  background-color: var(--dark);
  color: var(--light);
  padding: 1.5rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav {
  margin-top: 1rem;
}

nav a {
  color: var(--light);
  text-decoration: none;
  margin: 0 1rem;
  font-weight: bold;
}

.hero {
  background: linear-gradient(45deg, #1e73be, #0073aa);
  color: white;
  text-align: center;
  padding: 4rem 2rem;
  animation: fadeIn 1s ease-in-out;
}

.hero h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

.hero a.cta {
  background: white;
  color: #1e73be;
  padding: 0.75rem 1.5rem;
  font-weight: bold;
  text-decoration: none;
  border-radius: 5px;
  transition: 0.3s;
}

.hero a.cta:hover {
  background: #f1f1f1;
}

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

.slideshow-container {
  max-width: 100%;
  position: relative;
  margin: auto;
}

.mySlides {
  display: none;
}

.mySlides img {
  width: 100%;
  height: auto;
}

#catalog {
  padding: 2rem;
  background-color: var(--light);
}

.product-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
  gap: 2rem;
}

.product-card {
  background: var(--light);
  border-radius: 10px;
  padding: 1rem;
  width: 250px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  text-align: center;
}

.product-card img {
  width: 100%;
  height: auto;
  border-radius: 5px;
}

section {
  padding: 2rem;
}

.upload-form {
  text-align: center;
  margin: 2rem auto;
  background-color: var(--light);
  padding: 1rem;
  border-radius: 10px;
  max-width: 400px;
}

.upload-form input[type="file"] {
  display: block;
  margin: 1rem auto;
}

footer {
  background-color: var(--dark);
  color: var(--light);
  text-align: center;
  padding: 1rem;
  margin-top: 2rem;
}
```

how to add it to my website