1, upper triangle type
div { width: 0; height: 0; < /span>border: 40px solid; border-color: transparent transparent red; }
2, lower triangle type
div { width: 0 ; height: 0; border: 40px solid; border-color: red transparent transparent; < span class="token punctu ation">} span>
< span class="token property">and so on. . span>