使用混合混合模式的暗模式：差异不起作用

Question

Okay, so i've been trying to implement a dark mode feature on my website. I have made a widget that appears at the bottom right of the page. I have the whole website enclosed within a div called- test. Upon clicking the widget, it toggles and adds the class dark-mode-screen to the test div.

However, only the color of the text and the widget changes while the background remains the same.

CSS

        .box {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            border: 1px solid #333;
            padding: 10px 20px;
            font-family: sans-serif;
            mix-blend-mode: normal;
            transition: mix-blend-mode 0.7s ease-in;
        }

        .dark-button {
            position: absolute;
            right: 20px;
            bottom: 20px;
            border-radius: 50px;
            height: 60px;
            width: 60px;
            border: 1px solid steelblue;
            background: steelblue;
            outline: none;
        }

        .dark-mode-screen {
          width: 100vw;
          height: 100%;
          position: fixed;
          top: 0;
          left: 0;
          background: white;
          overflow-y: scroll;
        }

        .test {
            background: #fff;
            transition: all 0.7s ease-in;
        }

HTML:

    <div class="test">
    <div class="container" style="background: #fff; mix-blend-mode: difference;">

        <div class="box">
            <h3>My Paragraph</h3>
            <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
            tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
            quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
            consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
            cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
            proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
        </div>

        <button class="dark-button"></button>

    </div>
    </div>

JavaScript:

        const darkModeToggle = document.querySelector('.dark-button');
        darkModeToggle.onclick = function() {
            document.querySelector('.test').classList.toggle('dark-mode-screen');
        }

Answer 1

You could set background-color CSS property to white mix-blend-mode isn't provided with anything to subtract with:

.box {
  ...
  background-color: white;
}

 const darkModeToggle = document.querySelector('.dark-button'); darkModeToggle.onclick = function() { document.querySelector('.test').classList.toggle('dark-mode-screen'); }

 .box { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); border: 1px solid #333; padding: 10px 20px; font-family: sans-serif; mix-blend-mode: normal; transition: mix-blend-mode 0.7s ease-in; background-color: white; }.dark-button { position: absolute; right: 20px; bottom: 20px; border-radius: 50px; height: 60px; width: 60px; border: 1px solid steelblue; background: steelblue; outline: none; }.dark-mode-screen { width: 100vw; height: 100%; position: fixed; top: 0; left: 0; background: white; overflow-y: scroll; }.test { background: #fff; transition: all 0.7s ease-in; }

 <div class="test"> <div class="container" style="background: #fff; mix-blend-mode: difference;"> <div class="box"> <h3>My Paragraph</h3> <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p> </div> <button class="dark-button"></button> </div> </div>