body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: #fff;
    padding: 15px;
    text-align: center;
}

header .logo h1 {
    margin: 0;
}

header nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
}

header nav ul li {
    display: inline;
    margin-right: 15px;
}

header nav ul li a {
    color: #fff;
    text-decoration: none;
}

.hero {
    text-align: center;
    padding: 50px;
    background-color: #e0f7fa;
}

.search-by-sickness, .categories {
    padding: 20px;
    text-align: center;
}

button, .button {
    background-color: #007bff;
    color: #fff;
    padding: 10px 20px;
    border: none;
    text-decoration: none;
    display: inline-block;
    margin-top: 10px;
}

.category-grid {
    display: flex;
    justify-content: space-around;
}

.category-item {
    width: 30%;
    background-color: #fff;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 8px;
}

footer {
    text-align: center;
    padding: 20px;
    background-color: #333;
    color: #fff;
    position: absolute;
    width: 100%;
    bottom: 0;
}