* {
  font-family: "Hiragino Sans GB", "Helvetica Neue", "microsoft yahei", serif;
  margin: 0;
  padding: 0;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 100;
}
h1 {
  font-size: 30px;
}
h2 {
  font-size: 24px;
}
h3 {
  font-size: 16px;
}
h4 {
  font-size: 14px;
}
h5 {
  font-size: 12px;
}
h6 {
  font-size: 10px;
}
h3,
h4,
h5 {
  margin-top: 5px;
  font-weight: 600;
}
html {
  margin: 0;
  height: 100%;
}
body {
  background-color: #f0f0f0;
  margin: 0;
  padding: 0;
}
nav {
  width: 265px;
  min-height: 1000px;
  height: 100%;
  position: fixed;
  margin: 0;
  padding: 0;
  overflow: hidden;
}
button {
  height: 30px;
  color: #333;
  border: none;
}