problem description
1.
the environmental background of the problems and what methods you have tried
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related codes
 / / Please paste the code text below (do not replace the code with pictures) 
 subcomponent code 
 < template > 
<transition name="slider">
    <div class="about" ref="subtips">
        <m-header :canreturn=true :titleText="titleText" :type=8 :backType=2 @back="hide"></m-header>
        <div class="infobox">
            <slot>
            </slot>
        </div>
    </div>
</transition>< / template >
< style scoped lang= "stylus" rel= "stylesheet/stylus" >
.about {
position: fixed;
width: 100%;
top: 0;
bottom: 0;
background: -sharpffffff;
z-index: 5;
.infobox {
    padding: 0 15px;
    .title {
        color: red;
    }
}} 
 < / style > 
 parent component code 
 < tips > 
      <div class="title"></div>< / tips >
what result do you expect? What is the error message actually seen?
 inserts a title class= "title" in the slot; 
 also defines the css style of title in the subcomponent, but the style does not take effect 
