styles.css

body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f3efef;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    background-color: #313131;
    color: #ffffff;
    padding: 20px;
    text-align: center;
    width: 100%;
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    width: 80%;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    margin-bottom: 20px;
    width: 100%;
}

label {
    margin: 10px;
}

.preview {
    display: flex;
    width: 100%;
    height: 300px;
    border: 2px solid #313131;
    background-color: #fff;
    overflow: auto;
}

.box {
    background-color: #291bee;
    color: #ffffff;
    padding: 20px;
    margin: 5px;
    text-align: center;
    flex: 1;
}

footer {
    background-color: #313131;
    color: #ffffff;
    text-align: center;
    font-weight: bold;
    padding: 5px 0;
    width: 100%;
    position: fixed;
    bottom: 0;
}