ul {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
  }

  li {
    border: 1px solid #ccc;
    border-radius: 8px;
    padding: 10px;
    width: 180px;
    box-shadow: 2px 2px 5px #ccc;
    text-align: center;
    background: #fff;
  }

  li img {
    width: 150px;
    height: auto;
    margin-bottom: 8px;
  }

.category-heading {
    width: 100%;
    font-size: 1.2em;
    font-weight: bold;
    margin: 30px 0 10px;
    border-bottom: 2px solid #666;
  }

.back-to-top {
  margin-top: 30px;
  text-align: center;
}

.back-to-top a {
  text-decoration: none;
  color: #333;
  font-weight: bold;
  border: 1px solid #ccc;
  padding: 8px 16px;
  border-radius: 8px;
  background-color: #f0f0f0;
  transition: background-color 0.3s;
}

.back-to-top a:hover {
  background-color: #e0e0e0;
}

nav ul.nav {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

nav ul.nav li {
  background-color: #fff;
  border: 1px solid #aaa;
  border-radius: 10px;
  padding: 10px 20px;
  cursor: pointer;
  box-shadow: 2px 2px 5px rgba(0,0,0,0.1);
  transition: all 0.2s;
}

nav ul.nav li:hover {
  background-color: #f0f0f0;
}

nav ul.nav li a {
  display: block;
  text-decoration: none;
  color: #333;
  font-weight: bold;
}

nav ul.nav li.active {
  background-color: #ffe0e0;
  border-color: #d66;
}


@media screen and (max-width: 480px) {
  ul {
    justify-content: center;
    padding: 10px;
  }

  li {
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
  }

 .nav {
    overflow-x: auto;
    white-space: nowrap;
    flex-wrap: nowrap;
    padding: 10px;
    gap: 8px;
  }

  .nav li {
    display: inline-block;
  }
}