类优先级CSS H1

Question

您能解释为什么h1.smaller-20不优先于.hm-share h1吗？ 怎样在我的网站上将所有h1.smaller-20设置为相同大小？

<hm-logo-bar left-cb="ctrl.skip()" left-name="'Passer'"></hm-logo-bar>
<ion-content  scroll="false" class="hm-share">
  <div ng-if="ctrl.step == 1">
    <div class="hm-container">
      <h1>{{'share.0' | translate}}</h1>
      <h1>{{'share.1' | translate}}</h1>
      <h1 class="smaller-20">{{'share.2' | translate}}</h3>
    </div>
    ...