style.css

body {
    background-image: url(./image/back.jpg);
    background-size: cover;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    font-family: 'Black Han Sans', sans-serif;
}

.container {
    border:5px solid white;
    border-radius: 20px;
    text-align: center;
    background-color: rgba(247,243,242,0.7);

    width: 50%;
    padding-right: 15px;
    padding-left: 15px;
    padding-bottom: 5px;
    margin-right: auto;
    margin-left: auto;
    margin-bottom: 5px;
}

.main-img {
    width: 20vw;
    height: 20vh;
}

.form-control {
    width: 70%;
    font-size: 3w;
    margin-right: 20px;
    border: 1px solid #ced4da;
    border-radius: 0.25rem;
    text-align: center;
}

.input-box{
    display: flex;
}