为什么元素选择器击败类选择器

Question

我希望li元素的字体大小为20px

html和CSS在这里 https://jsfiddle.net/15m9tsq6/

div {
  font-family: Tahoma, Arial, Helvetica, Sans-serif;
  color: #2c3e49;
  font-size: 12px;
} 

.kk-wrapper {
    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;
    font-size: 20px;
    font-style: normal;
    font-variant: normal;
}