style.css

html {
    background: #95a5a6;
    background-image: url(http://subtlepatterns2015.subtlepatterns.netdna-cdn.com/patterns/dark_embroidery.png);
    font-family: 'Helvetica Neue', Arial, Sans-Serif;
}
* { box-sizing: border-box; margin: 0; padding:0; }
header{
    background: chocolate;
    border: black solid 1px;
    margin: 10px;
    padding-left: 10px;
}
#par2{

}
#Ex1 ,#Ex4 {
    margin: 10px;
    background: azure;
    border: black solid 1px;
    padding: 10px;

}
#Ex2 {
    margin: 10px;
    background:antiquewhite;
    border: black solid 1px;
    padding: 10px;

}
#Ex3 {
    margin: 10px;
    background:beige;
    border: black solid 1px;
    padding: 10px;

}
#box {
    margin-top: 10px;
    background:blue;
    border: black solid 1px;
    padding: 10px;


}
.btn{
    background-color: #4CAF50; /* Green */
    border: none;
    color: white;
    padding: 10px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
}
.login-wrap {
    position: relative;
    margin: 0 auto;
    background: #ecf0f1;
    width: 0px;
    border-radius: 5px;
    box-shadow: 3px 3px 10px #333;
    padding: 15px;

}

h2 ,a {
    text-align: center;
    font-weight: 200;
    font-size: 2em;
    margin-top: 10px;
    color: #34495e;
    display: none;
}

.form {
    padding-top: 20px;
}

input[type="text"], input[type="password"], #btn9 {

    outline: 0;
    -moz-outline-style: none;
    display: none;
}