switching/style/main.css

html, body {
    height: 100%;
}

.mainContainer {
    width: 85%;
    margin: auto;
    min-height: 100%;
}

.button {
    border-radius: 5px;
    display: block;
    padding: 20px;
    background-color:  #cde6ea;
    box-sizing: content-box;
    text-decoration: none;
    font-weight: bold;
    color: inherit;
    text-align: center;
    float: right;
    font-size: 18px;
    transition: background-color 0.2s ease;
}





nav {
    display: flex;
    overflow: hidden;
    background-color: #93ff83;
}

nav > a {
    padding: 20px;
    flex: auto;
    display: block;
    box-sizing: content-box;
    text-decoration: none;
    font-weight: bold;
    color: inherit;
    text-align: center;
    background-color: transparent;
    font-size: 18px;

    transition: background-color 0.2s ease;
}

nav > a.current {
    background-color: #5db9ef;
}

nav > a:hover,
.button:hover {
    background-color: rgba(0, 0, 0, 0.2);
}

nav > a.current:hover {
    background-color: #5397ca;
}

nav > a:visited {
    color: inherit;
}

nav > a > div {
    position: relative;
    top: 50%;
    transform: translateY(-50%);
    overflow: hidden;
}


@media only screen and (max-width : 640px) {
	nav {
	    display: block;
	    overflow: hidden;
	    background-color: #93ff83;
	}

	nav > a {
	    padding: 20px;
	    flex: auto;
	    display: block;
	    box-sizing: content-box;
	    text-decoration: none;
	    font-weight: bold;
	    color: inherit;
	    text-align: center;
	    background-color: transparent;
	    font-size: 18px;

	    transition: background-color 0.2s ease;
	}

	nav > a.current {
	    background-color: #5db9ef;
	}

	nav > a:hover,
	.button:hover {
	    background-color: rgba(0, 0, 0, 0.2);
	}

	nav > a.current:hover {
	    background-color: #5397ca;
	}

	nav > a:visited {
	    color: inherit;
	}

	nav > a > div {
	    position: relative;
	    top: 50%;
	    transform: translateY(-50%);
	    overflow: hidden;
	}
}

.mainContainer {
    font-size: 14px;
    color: #333;
    text-align: left;
}

.mainContainer h1 {
    text-align: center;
    margin: 10px 0 5px 0;
    font-size: 24px;
    font-weight: 600;
    color: #000;
}

.mainContainer h2 {
    margin: 10px 0 5px 0;
    font-size: 22px;
    font-weight: 600;
    color: #000;
}

.mainContainer h3 {
    margin: 10px 0 5px 0;
    font-size: 18px;
    font-weight: 600;
    color: #000;
}

.mainContainer h4 {
    margin: 10px 0 5px 0;

    font-size: 14px;
    font-weight: 600;
    color: #000;
}

.mainContainer p {
    margin: 5px 5px 0 10px;

}

.mainContainer strong {
    font-weight: 600;
}

.mainContainer ul,
.mainContainer ol {
    margin: 5px 5px 10px 10px;

    list-style-position: outside;
}

.mainContainer ul li {
    margin: 5px 5px 0 15px;
}

.mainContainer img,
.mainContainer iframe {
    margin: 15px 0 15px 15px;
}

.c1 {
    color: aliceblue;
    background-color: darkred;
}

.c2 {
    color: aliceblue;
    background-color: midnightblue;
}

.c3 {
    color: aliceblue;
    background-color: indigo;
}

.c4 {
    color: aliceblue;
    background-color: seagreen;
}

.clearfix {
    *zoom: 1;
}

.clearfix:before,
.clearfix:after {
    content: '';
    display: table;
    line-height: 0;
}

.clearfix:after {
    clear: both;
}

.content {
    padding: 10px;
}

.footer {
	width: 100%;
	min-height: 30px;

	padding: 10px 20px;

	background-color: rgba(10, 10, 10, .1);

	font-size: 14px;
	color: #777;

	text-align: left;
  	box-sizing: border-box;
}