body {
    font-family: Arial, sans-serif;
    margin: 20px;
    background-color: #f4f4f4;
    color: #333;
}

h1 {
    color: #007bff;
    text-align: center;
}

p#intro {
    font-size: 18px;
    margin-bottom: 20px;
}

form#addForm {
    margin-bottom: 20px;
    text-align: center;
}

input[type="text"] {
    padding: 10px;
    width: 200px;
    margin-right: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

button {
    padding: 10px 20px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background-color: #218838;
}

ul#itemList {
    list-style-type: none;
    padding: 0;
}

ul#itemList li {
    background-color: #fff;
    margin: 10px 0;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
}

ul#itemList li:hover {
    background-color: #f8f9fa;
}

.highlight {
    font-weight: bold;
    background-color: #ffffcc;
}

/* Media Queries for Responsiveness */
@media (max-width: 600px) {
    input[type="text"] {
        width: 100%;
        margin-bottom: 10px;
    }

    button {
        width: 100%;
    }
}