body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

code {
  font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New", monospace;
}

html,
body {
  width: 100%;
  height: 100%;
  font-family: "lucida grande", "lucida sans unicode", lucida, helvetica, "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
}
.fullScreen {
  width: 100%;
  height: 100%;
}

/* 居中设置 */
.flex {
  display: flex;
}

.main-center {
  justify-content: center;
}

.across-center {
  align-items: center;
}