* {
      box-sizing: border-box;
    }
    img {
      max-width: 100%;
      height: auto;
    }
    .siteshell {
      max-width: 800px;
      margin: 0 auto;
      padding: 0 15px;
    }
    header {
      text-align: center;
    }
    nav {
      padding: 15px 0;
    }
    nav a {
      display: inline-block;
      margin-right: 10px;
    }
.alignleft, img.alignleft {
	margin-right: 1.5em;
	display: inline;
	float: left;
	}
.alignright, img.alignright {
	margin-left: 1.5em;
	display: inline;
	float: right;
	}
.aligncenter, img.aligncenter {
	margin-right: auto;
	margin-left: auto;
	display: block;
	clear: both;
	}
.alignnone, img.alignnone {
	}