nav {
    background: #20A759;
    color: #fff;
    padding: 10px;
}
nav a{
    color: #fff;
    text-decoration: none;
    padding: 10px 20px;
}
nav .active,
nav a:hover{
    background: #0B6B3A;
}

body {
    background: #a8dcf4;
}
/* id selector */
#intro {
    background: #418fb1;
    border: 1px solid #099249;
    min-height: 100px;
    padding: 10px;
    box-shadow: 2px 2px 5px black;
}
#intro h1{
    text-align: left;
    border: 0;
    color: #fff;
}

/* class selector */
.button{
    padding: 15px 20px;
    background: #bebcbd;
    color: #fff;
    display: inline-block;
    margin: 10px;
    text-decoration: none;
    border-radius: 10px;
}
.btn-primary{
    background: #E42A42;
}