我需要更改 div 中元素的不透明度，使其比父元素的不透明度更高。在没有预处理器的情况下，如何提供.solid完全不透明度 ( ="1")？
.half-faded {
opacity:0.3;
border:1px solid black;
width:200px;
display:flex;
justify-content:space-around;
}
.solid {
opacity:1; /* doesn't help */
opacity:2; /* twice doesn't help */
}<div class="half-faded">
<span class="one">One</span>
<span class="two">Two</span>
<span class="solid">Solid</span>
<span class="four">Four</span>
</div>