html, body {
  margin: 0;
  padding: 0;
  line-height: 1.5;
  font-size: 18px;
  font-family: "Microsoft YaHei", sans-serif;
}

img {
  max-width: 100%;
  height: auto;
}

/* learnt from github */
pre, code {
  font-family: Consolas, "Liberation Mono", Courier, monospace;
  background-color: #f8f8f8;
  border: 1px solid #ddd;
  border-radius: 3px;
}
pre {
  padding: 6px 10px;
  overflow: auto;
  font-size: 60%;
  line-height: 160%;
}
code {
  padding: 2px 5px;
  margin: 0 2px;
}
pre > code {
  border: none;
  background-color: inherit;
  padding: 0;
  margin: 0;
}
table {
  font-size: 80%;
  width: 100%;
  overflow: auto;
  display: block;
  margin: 15px 0;
  border-collapse: collapse;
  border-spacing: 0;
}
table th, table td {
  border: 1px solid #ddd;
  padding: 6px 13px;
}
table tr {
  border-top: 1px solid #ccc;
  background-color: #fff;
}
table tr:nth-child(2n) {
  background-color: #f8f8f8;
}
blockquote {
  margin: 15px 0;
  border-left: 4px solid #DDD;
  padding: 0 15px;
  color: #777;
}

/* TODO: be responsive, use grid instead of absolute */
.sidebar {
  color: #fff;
  background-color: #2a2a2a;
}
.sidebar-inner {
  padding: 2% 5%;
}
.sidebar a {
  color: #fff;
}
.sidebar h1 a {
  text-decoration: none;
}
.sidebar blockquote {
  color: #999;
}

.main-inner {
  padding: 2% 5% 6%;
}
.main-page {
  padding-bottom: 3%;
}

.img-holder {
  position: absolute;
  top: -9999px;
  left: -9999px;
}

@media (min-width: 640px) {
  pre {
    font-size: 80%;
  }
  table {
    font-size: 100%;
  }

  .sidebar-inner {
    padding: 2% 10%;
  }

  .main-inner {
    padding-left: 10%;
    padding-right: 10%;
  }
}

@media (min-width: 990px) {
  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: 25%;
  }
  .sidebar-inner {
    padding: 15%;
  }

  .main {
    margin-left: 25%;
    width: 75%;
  }
}