html {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 14pt;
    line-height: 1.3;
}
  
body {
    width: 800px;
    max-width: 90%;
    margin: 5rem auto;
}
  
article {
    margin: 5rem 0;
}
  
section {
    margin: 3rem 0;
}
  
h1, h2, h3, h4, h5, h6 {
    font-weight: normal;
}
  
article > h1 {
    font-weight: bold;
}
  
samp {
    display: block;
    margin: 1em 0;
}
  
code, kbd {
    color: steelblue;
    font-style: normal;
    font-weight: normal;
}
  
code.tag::before {
    content: "<";
}
  
code.tag::after {
    content: ">";
}
  
ol.instructions {
    background-color: #f2f2f2;
    padding: 1rem 1rem 1rem 2rem;
    color: #666666;
    font-style: italic;
    font-size: 0.8rem;
    line-height: 1.2;
}
  
ol.instructions > li {
    margin: 0.4rem 0;
}
  
ol.instructions > li:first-child { margin-top: 0; }
ol.instructions > li:last-child { margin-bottom: 0; }
  
aside {
    padding: 1rem 2rem;
    color: white;
    background-color: gray;
    font-size: 0.8rem;
    margin: 1em 0;
}
  
.overflow-example {
    padding: 1rem;
    border: 1px solid gray;
}
  
.portrait {
    width: 125px;
}
  
.positioned-element {
    width: 50px;
    height: 50px;
    background-color: #ccc;
}
  
.static-example,
.relative-example,
.absolute-example,
.fixed-example,
.sticky-example {
    border: 1px solid #999;
    padding: 0 1rem;
}

.box-layers {
    background-color: #eeeeee;
    padding: 2rem 1rem 4rem 1rem;
    border-top: 10px solid #dddddd;
    margin: 4rem 0;
}

.h2-wrapper {
    border: 1px solid black;
}

.box-sizing-example {
    background-color: #eeeeee;
    padding: 2rem;
    border: 10px solid #dddddd;
    width: 100%;
    box-sizing: border-box;
}

.overflow-example {
    width: 50%;
    height: 300px;
    overflow: hidden;
    overflow: auto;
}