ss.css

body{
   margin: 0;
    padding: 0;
    background: url(background.jpg);
    background-size: cover;
    font-family: monospace;
}
.box
{
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    width: 350px;
    height: 420px;
    padding: 50px;
    border-radius: 10px;
    box-sizing: border-box;
    background: rgba(0,0,0,.5);
}
.user{
    width: 100px;
    height: 100px;
    border-radius: 50%;
    overflow: hidden;
    position: absolute;
    top: calc(-100px/2 );
    left:calc(50% - 50px);
  
    
    
}

h2{
    margin: 0;
    padding: 10px 0 20px;
    color: #80ff33;
    text-align: center;
}

.box p
{
    margin: 0;
    padding: 0;
    font-weight: bold;
    color: #fff;
}

.box input{
    width: 100%;
    margin-bottom: 20px;
}
.box input[type="text"],
.box input[type="password"]{
    border: none;
    border-bottom: 1px solid #fff;
    background: transparent;
    outline: none;
    height: 40px;
    color: #fff;
    font-size: 16px;
}
::placeholder{
    color: rgba(255,255,255,.6);
    
}
.box input[type="submit"]{
    border: none;
    outline: none;
    height: 40px;
    color: #fff;
    font-size: 16px;
    background: #80ff33;
    cursor: pointer;
    border-radius: 20px;
}
.box input[type="submit"]:hover
{
    background: #33ffb8;
    letter-spacing: 3px;
}
.box a
{
    color:#fff;
    font-size: 14px;
    font-weight: bold;
    text-decoration: none;
}