layout.css

body {
  font-size: 18px;
  font-weight: 300;
  font-family: Palatino, Optima, "Source Han Sans CN", "Hiragino Sans GB" Georgia, serif;
  min-width: 800px;
}

.clearfix::before,
.clearfix::after {
  content:".";
  display:block;
  height: 0;
  visibility: hidden;
}
.clearfix::after {
  clear:both;
}
.clearfix {
  zoom:1; /* For IE 6/7 (trigger hasLayout) */
}

.float-left {
  float: left;
}

.float-right {
  float: right;
}

.expanded {
  margin: 0;
  padding: 0;
}

a, a:link, a:visited, a:hover, a:active {
  color: #1abc9c;
  text-decoration: none;
}

.container {
  width: 900px;
  margin: 0 auto;
}

header {
  height: 300px;
  padding-top: 50px;
  text-align: center;
  background: #2D2D2D;
  overflow: hidden;
}

.fixed-top {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1;
}

nav {
  height: 40px;
  line-height: 40px;
  background: #222222;
  box-shadow: 0 0 5px rgba(0,0,0,0.5);
}

nav span a {
  color: #ecf0f1 !important;
}

.nav-links {
  margin: 0;
  list-style: none;
}

.nav-link {
  margin: 0 10px;
}

.nav-link a {
  display: inline;
  color: #ecf0f1;
}

nav a:hover {
  text-decoration: underline;
}

.banner {
  color: #00D8FF;
}

.hide {
  visibility: hidden;
}

.btn {
  display: block;
  height: 50px;
  width: 350px;
  line-height: 50px;
  margin: 0 auto;
  background: #e74c3c;
  color: #ecf0f1 !important;
  border-radius: 3px;
}

.btn:hover {
  background: #c0392b;
}

.title-wrapper {
  position: relative;
  left: 50%;
  margin-top: 20px;
}

.logo, .main-title {
  position: relative;
  left: -50%;
}

.main-title {
  display: inline-block;
  *display: inline;
  margin: 60px;
  font-size: 60px;
  font-weight: 200;
  color: #ecf0f1;
}

.logo {
  display: inline-block;
  *display: inline;
}

footer {
  background: #1D2027;
  font-size: 15px;
  padding: 30px 0;
}

.footer-info {
  margin-right: 15px;
}

.footer-info a {
  color: #ecf0f1;
}

.footer-author, .footer-author a {
  color: #8D8D8E;
}

.footer-author a:hover {
  text-decoration: underline;
}

section {
  clear: both;
  position: relative;
  padding-top: 30px;
}

section h2 {
  color: #7f8c8d;
  font-size: 30px;
}

.sticky {
  position: sticky;
  top: 10px;

}

.content {
  width: 450px;
}

.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.links {
  list-style: none;
}

.link {
  margin-bottom: 20px;
}