style.css

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;600&display=swap');

* {
    box-sizing: border-box;
}

:root {
    --cadetblue2: #8EE5EE;
    --black: #000000;
    --width-break: 600px;
}

body {
    background-image: url('images/avatar-dekstop.jpg');
    /* height: 100%; */
    width: 100%;
    height: auto;
    background-position: center;
    background-repeat: no-repeat;
    margin: 0;
    font-family: 'Montserrat', sans-serif;
    color: var(--black);
    /* background-size: 100% 100%; */
    /* background-size: cover; */
    /* background-color:whitesmoke; */
}

/* @media only screen and (min-device-width: 250) {
    body {
        background-image: url('images/avatar-mobile.jpg');
    }
} */

nav {
    background-color: var(--cadetblue2);
    text-align: center;
}

div {
    margin: auto;
    padding: 1rem;
    max-width: var(--width-break);
}

textarea {
    box-sizing: border-box;
    display: block;
    width: 100%;
    min-height: 20vh;
    margin-top: 2rem;
    font-size: large;
    font-family: inherit;
    border: 2px solid var(--black);
    border-radius: 0.2rem;
    background-color: transparent;
    padding: 1rem;
    font-weight: bold;
}

button {
    background-color: var(--cadetblue2);
    margin: 1rem 0rem;
    padding: 0.5rem 1rem;
    font-family: 'Montserrat', sans-serif;
    font-size: large;
    border-radius: 0.2rem;
    cursor: pointer;
}

#translate-output {
    box-sizing: border-box;
    width: 100%;
    min-height: 15vh;
    max-height: 20vh;
    /* overflow:scroll; */
    border: 2px solid var(--black);
    border-radius: 0.2rem;
    font-weight: bold;
    background-color: transparent;
}

footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    padding: 1rem;
    background-color: var(--cadetblue2);
    text-align: center;
}

footer p {
    max-width: var(--width-break);
    margin: auto;
}