styles.css

* {
    margin: 0;
}

body {
    margin: 0;
}

.blog_wrapper h2, h3, h4{
    font-family: "Roboto";
}

.blog_wrapper h3{
    color: #3d4552;
}

.blog_wrapper h4{
    color: #5b677a;
}

.blog_wrapper p{
    font-family: "Open Sans";
}

.blog_wrapper{
    display: flex;
    flex-direction: column;
    margin:auto;
    width:700px;
}

.blog_wrapper p{
    padding-top: 7px;
    padding-bottom: 8px;
}

.content{
    overflow: hidden;
    transition: height 200ms;
    font-family: "Open Sans";
    font-size:14px;
}

.collapsible {
	margin-left:50%;
    transform: translate(-50%);
    font-size:13px;
    padding: 7px 78px;
    background: #fff;
    border: none;
    box-shadow: inset 0px -3px 5px #e8e8e8;
    border-radius: 4px;
}

.collapsible:hover {
    background: #c5e2f0;
    box-shadow: inset 0px -3px 5px #caeafa;
}

.collapsible:active {
    position: relative;
    margin-top: 1px;
}

.content{
    padding: 20px 20px 20px 20px;
    width: 95%;
    margin: auto;
    background: #e3e3e3;
    margin-top: 10px;
    margin-bottom: 20px;
    border-radius: 4px;
}

.isolating_pixel{
    padding-top: 20px;
    padding-bottom: 30px;
}

.linear_algebra_class{
    padding-top: 25px;
}

.linear_algebra_class h3{
    padding-top: 10px;
}

.linear_algebra_class h4{
    padding-top: 5px;
}

.matrix_wrapper input{
    width:30px;
    margin: 5px 5px 5px 5px;
}

.apply_matrix_arrow_wrapper{
    font-family: Open Sans;
}