style.css

@import url('https://fonts.googleapis.com/css2?family=Acme&display=swap');
* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'Acme', sans-serif;
}

.mainDiv {
    width: 100%;
    height: 100vh;
    position: relative;
    background: #3498DB;
}

.centerDiv {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

h1 {
    text-transform: capitalize;
    text-align: center;
    margin-bottom: 30px;
    color: #ECF0F1;
    text-shadow: 1px 2px 3px #2980B9;
    font-size: 2.1rem;
}

h2 {
    text-align: center;
}

textarea {
    background-color: #444;
    box-shadow: 0 0 1px rgba(0, 0, 0, 0.2);
    border-radius: 10px 10px 0 0;
    border: 20px solid #34495E;
    color: white;
    font-size: 1.3rem;
}

.mainbtn {
    padding: 10px 20px;
    border-radius: 20px;
    border: 5px solid #2980B9;
    background: #ECF0F1;
    font-size: 1rem;
    margin-top: 20px;
}