style.css

*{
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    box-sizing: border-box;

}
body{

    background:  #262a2f;
}
.container{

    width: 400px;
    padding: 25px 35px;
    /* these move div in the center of web page */
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    background: #fff;
    border-radius: 10px;
}
.container p{
    font-weight: 600;
    font-size: 16px;
    margin-bottom: 8px;
}
.container input{
 width: 100%;
 height: 50px;
 border: 1px solid #494eea;
 outline: 0;
 padding: 10px;
 margin: 10px 0 20px;
 border-radius: 5px;


}

.container button{

    width: 100%;
    height: 50px;
    background: #494eea;
    color: #fff;
    border: 0;
    outline: 0;
    padding: 10px;
    box-shadow: 0 10px 10px rgba(0,0,0,0.1);
    cursor: pointer;
    margin: 20px 0;
    border-radius: 5px;
    font-weight: 500;
   

}

#imgbox{

    width: 200px;
    border-radius: 5px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 1s;
}

#imgbox img{

    width: 100%;
    padding: 10px;
}

#imgbox.show-img{
    max-height: 300px;
    margin: 10px auto;
    border: 1px solid #d1d1d1;

}

.error{
    animation: shake 0.1s linear 10;
}

@keyframes shake{


    0%{
        transform: translateX(0);
    }
    25%{
        transform: translateX(0=-2px);
    }
    50%{
        transform: translateX(0);
    }
    75%{
        transform: translateX(+2px);
    }
    100%{
        transform: translateX(0);
    }
}