CSS - 透明的“玻璃”模式，其他一切都变暗了

Question

  

THE ANSWER: background-attachment

  

----- JSBin Example ----

答案是使用background-attachment

  

原始问题

我正在开展一个项目，在这个项目中，我们想要显示一个“透视”到背景的模态，但模态面板外的任何地方都会被轻微遮盖。

我已成功将border: 10000px rgba(0,0,0,0.3)与border-radius: 10010px一起使用，但这是一个黑客，我无法用box-shadow

概述模态

有没有标准方法可以做到这一点？如果您能想到将透明度滤镜渐变应用于图像的方法，则可以获得奖励积分。

Answer 1

我认为你在这里得到的最佳选择是有一个3行，其中中间的一行包含3列，而最上面的行和＆amp;左右列（中间一行）的背景变暗：

$(function() {
  $('button').click(function() {
    tpl = '<div class="modal-reverse-container"><div class="r1"></div><div class="r2"><div class="c1"></div><div class="c2"></div><div class="c3"></div></div><div class="r3"></div></div>'
    $('body').append($(tpl));
    $('.modal-reverse-container').width($(document).width());
    $('.modal-reverse-container').height($(document).height());
    $('.modal-reverse-container r1, .modal-reverse-container r2').height($(document).height());
  });
  $(document).on('click', '.modal-reverse-container', function() {
    $(this).remove();
  });
});

td {
  text-align: center;
  background: red;
}
.modal-reverse-container {
  position: absolute;
  top: 0;
  left: 0;
}
.modal-reverse-container .r1, .modal-reverse-container .r2, .modal-reverse-container .r3 {
  height: 33%;
}
.modal-reverse-container .r1, .modal-reverse-container .r3 {
  background: rgba(0, 0, 0, 0.7);
}
.modal-reverse-container .r2 .c1, .modal-reverse-container .r2 .c2, .modal-reverse-container .r2 .c3 {
  width: 33%;
  height: 100%;
  float: left;
}
.modal-reverse-container .r2 .c3 {
  float: right;
}
.modal-reverse-container .r2 .c1, .modal-reverse-container .r2 .c3 {
  background: rgba(0, 0, 0, 0.7);
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table width="100%">
  <tr>
    <td>1</td>
    <td>2</td>
    <td>3</td>
  </tr>
</table>
<img src="https://dummyimage.com/600x400/d950d9/fff" />
<div>
  Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32.
</div>
<button>Set reverse-modal</button>

Answer 2

  

---- JSBin Example ----

答案是使用background-attachment

background-attachment: fixed;
background-size: cover;
background-position: center center;
background-image: linear-gradient(rgba(0,0,0,0.4), rgba(0,0,0,0.4)), url(http://imgur.com/oVaQJ8F.png);

.modal-backdrop {
    background: url(myurl.png) center center / cover no-repeat fixed
}

.modal-panel {
    background: url(myurl.png) center center / cover no-repeat fixed
}

最佳值为fixed（并非所有设备都支持修复），因此您的背景和模态可以默认共享相同的视口X和Y (0, 0)

然后，您可以使用background-size百分比或cover

进行缩放

使用background:简写时，请务必使用/将background-position与background-scale金额分开

我在旧设备上遇到了一个错误，因此我使用local然后手动计算leftX和topY以排列背景和模板面板background-position at { {1}}在我的视口上。

然后我用相同的百分比缩放两个图像，以覆盖屏幕

我还使用了渐变，信用 - How to darken a background Image