body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 20px;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 600px;
    margin: auto;
    background: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    transition: color 0.3s;
}

input {
    width: calc(100% - 100px);
    padding: 10px;
    margin-right: 10px;
}

button {
    padding: 10px;
}

select {
    padding: 10px;
    margin-right: 10px;
}

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

li {
    padding: 10px;
    border-bottom: 1px solid #ddd;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

li span {
    flex-grow: 1;
}

.category-container {
    margin-top: 20px;
}

.hidden {
    display: none;
}

.category-container {
    margin-top: 20px;
    border: 1px solid #ddd;
    padding: 10px;
    border-radius: 5px;
}

.category-container button {
    margin-top: 10px;
}