* {
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

.group:after {
  visibility: hidden;
  display: block;
  content: "";
  clear: both;
  height: 0;
}

body {
  font: 13px/1.4 sans-serif; 
  background: #ccc;
}
a {
  text-decoration: none;
}
h1 {
  font-size: 50px;
  letter-spacing: -2px;
  line-height: 1;
  margin: 0 0 10px 0;
}

h1~p {
  margin: 0 0 20px 0;
}

p.cssregions, p.no-cssregions { display: none; }
.cssregions-test p.cssregions { color: green; display: block; }
.no-cssregions-test p.no-cssregions { color: red; display: block; }

article {
  margin: 0 0 30px 0;
}
.date-bubble {
  color: #777;
}

.page-wrap {
  width: 80%;
  margin: 0 auto;
  background: #eee;
  overflow: hidden;
}

.main-content, aside {
  padding: 80px 20px 20px 20px;
}

.main-content {
  float: left;
  width: 70%;
}

aside {
  float: right;
  width: 30%;
}

#ad-source img { /* the selector is always the source, not the element it flows into */
  width: 100%;
  max-width: 200px;
  height: auto;
  float: right;
  margin: 0 0 10px 0;
}

@media (max-width: 800px) {
  .main-content [class^='ad-region'] {
    display: block;
  }
    .main-content [class^='ad-region']:last-child {
    height: 300px; /* I wish height auto worked */
  }
  aside {
    display: none;
  }

  #ad-source img {
    float: left;
    width: auto;
    margin-right: 10px;
  }
  .main-content {
    width: 100%;
  }
}