style.css

body{
    margin:0;
    padding:0;
    background:url(technology.jpg);
    background-size: cover;
    background-blend-mode: darken;
    font-family: sans-serif;
}
.Loginbox{
    width: 520px;
    height: 320px;
    background: rgba(0, 0, 0, 0.5);
    color:#fff;
    top: 50%;
    left: 50%;
    position: absolute;
    transform: translate(-50%,-50%);
    box-sizing: border-box;
    padding: 70px 30px;
}
.avatar{
    width: 200px;
    height: 200px;
    border-radius: 50%;
    position: absolute;
    top: -80px;
    left: calc(50% - 100px)
}
h1{
    margin: 0;
    padding: 0 0 20px;
    text-align: center;
    font-size: 22px;
}
.Loginbox p{
    margin: 0;
    padding: 0;
    font-weight: bold;
    }

.Loginbox input[type="text"]{
    border: none;
    border-bottom: 1px solid black;
    background: transparent;
    outline: none;
    height: 40px;
    color: rgb(243, 225, 225);
    font-size: 14px;
}
.Loginbox input[type="submit"]
{
    border: none;
    outline: none;
    height: 40px;
    width: 90px;
    background: #0a4b5c;
    color: #fff;
    font-size: 18px;
    border-radius: 20px;
}
.Loginbox input[type="submit"]:hover{
    cursor: pointer;
    background:#39dc79;
    color: #000;
}