html - 是否有可能让一个元素透明并透过他的父不透明背景看到

Question

您好，我正在设计一个表单 (HTML/CSS/JS)，当用户想要订阅或登录时，该表单会在内容上弹出。整个表单背景是纯色不透明，但我希望输入具有透明背景，以便我们可以通过它看到表单背后的内容。将输入设置为透明没有任何问题，但我不知道如何让它们“通过”它们的父背景颜色。我开始认为仅使用 CSS 是不可能的。我可以共享代码，但这更像是一个通用问题。谢谢

Answer 1

您可以通过使用更多元素和一点创意使您的输入看起来像是一个切口来作弊...

Working Example

$('.wrap').draggable();// demo only, used to show off cutout effect. Not necessary 

.wrap {
    position:absolute;
}
.top, .bottom {
    background:grey;
}
input, .top, .bottom {
    width: 100%;
    border: 30px solid grey;
}
input {
    background: transparent;
    color: red;
    border: 29px solid grey;
    outline: none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="http://code.jquery.com/ui/1.11.4/jquery-ui.min.js"></script>
<div class="wrap">
    <div class="top">This may be cheating, but it works...</div>
    <input type="text" placeholder="testing"/>
    <div class="bottom"></div>
</div>
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