html {
  background-color: #f0f0f0;
}

body {
  background: #fff;
  padding: 50px 16px;
  /* clear default body 8px margin and 
  center block horizontally with margins */
  margin: 0px auto;
  width: 80vw;
  max-width: 500px;
  /*  cover at least full height */
  min-height: 100%;
  min-height: calc(100vh - 100px);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

main {
  width: 100%;
  margin: 0 auto;
  padding: 0;
}

section {
  /* Make them sit in same line, and account 
  for prettier adding new lines to src */
  width: 100%;
  display: block;
  border-style: dotted;
  margin: 1em auto;
  box-sizing: border-box;
}

h1,
h2 {
  text-align: center;
}

hr {
  width: 95%;
}

img {
  width: 100%;
  display: block;
  margin: 0 auto;
  border-bottom: 3px solid black;
}

li {
  line-height: 1.5em;
}