estilo.css

html, body {
    margin: 0;
    height: 100%;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background: rgb(198,238,255);
    background: linear-gradient(51deg, rgba(198,238,255,1) 0%, rgba(96,150,255,1) 100%);
}

main{
    margin: 25px 0;
    width: 100%;
    height: 80%;
}

header{
    font-size: larger;
    width: 100%;
    padding: 20px 0;
    text-align: center;
}

.content{
    height: 75%;
    display: flex;
    justify-content: space-around;
}

.inputContainer, .outputContainer{
    width: 35%;
}

.content textarea{
    padding: 5px;
    height: 100%;
    width: 100%;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    font-size: medium;
    border: none;
    border-radius: 5px;
    resize: none;
    display: block;
}


textarea::placeholder{
    color: gray;
}

.buttonContainer{
    display: flex;
    justify-content: space-around;
    margin:0.3em 0.3em 0.3em 0;
    border-radius:0.15em;
    box-sizing: border-box;
    text-decoration:none;
    text-transform:uppercase;
    font-weight:400;
    text-align:center;
    position:relative;
}

.buttonContainer input{
    background-color: white;
    border-width: 2px;
    padding: 10px;
    border-radius:5px ;
}

footer{
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 10px;
    font-size: small;
    text-align: center;
}

footer img{
    margin-top: 7px;
    width: 15px;
}

@media only screen and (max-width:480px){
    .buttonContainer{
        display: inline-block;
    }

    .buttonContainer input{
        background-color: white;
        border-width: 2px;
        margin: 0 0 5px 0;
        padding: 5px;
        font-size: 12px;
        border-radius:5px ;
    }
}