body,
h1,
h2,
h3,
h4,
h5,
h6,
hr,
p,
blockquote,
dl,
dt,
dd,
ul,
ol,
li,
pre,
fieldset,
lengend,
button,
input,
textarea,
th,
td {
  /* table elements 表格元素 */
  margin: 0;
  padding: 0;
}
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: #2c3e50;
}