style.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

#container {
    width: 100vw;
    height: 100vh;
    background: rgb(0, 0, 0);
    color: white;
    display: flex;
    justify-content: center;
    text-transform: capitalize;
    font-size: 1.2rem;
}

#container h3 {
    font-size: 1.5rem;
    text-align: center;
    line-height: 4;
}

#container input {
    font: italic 500 1.2rem '';
    letter-spacing: 0.05rem;
    width: 90vw;
    height: 40px;
    padding: 0 0.5rem;
    border: 0;
    border-radius: 1rem 0.5rem;
    text-transform: capitalize;
}

#container input::placeholder {
    text-transform: lowercase;
    color: rgba(0, 0, 0, 0.911);
}

@media screen and (min-width: 500px) {
    #container h3 {
        font-size: 2.3rem;
    }

    #container input {
        width: 400px;
        font-size: 1.5rem;
    }
}