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htmlcssbackgroundlinear-gradientsmix-blend-mode

CSS: how to have transparent background with the blend mode only affecting/being clipped to the (text) content?


Here is the code I have. I think it's fairly obvious what I am trying to achieve - I want to remove the black background behind the text, however, when I simply remove the black background css, the gradient layer just shows, since it's not clipped to the text.

body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background:url('https://wallpapersite.com/images/pages/pic_w/16658.jpg') no-repeat center center fixed;
    background-size: cover;
}

.neon {
    position: relative;
    overflow: hidden;
    filter: brightness(200%);
}

.text {
    background-color: black;
    color: white;
    font-size: 100px;
    font-weight: bold;
    font-family: sans-serif;
    text-transform: uppercase;
    position: relative;
    user-select: none;
}

.text::before {
    content: attr(data-text);
    position: absolute;
    color: white;
    filter: blur(0.02em);
    mix-blend-mode: difference;
}

.gradient {
    position: absolute;
    background: linear-gradient(45deg, #00f7ff, #f545d7, #0085ff, #6945f5, #005aff);
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    mix-blend-mode: multiply;
}

.spotlight {
    position: absolute;
    top: -100%;
    left: -100%;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(
            circle,
            white,
            transparent 25%
        ) center / 25% 25%,
        radial-gradient(
            circle,
            white,
            black 25%
        ) center / 12.5% 12.5%;
    animation: light 5s linear infinite;
    mix-blend-mode: color-dodge;
}

@keyframes light {
    to {
        transform: translate(50%, 50%);
    }
}
<div class="neon">
  <span class="text" data-text="NIGHT SKY">NIGHT SKY</span>
  <span class="gradient"></span>
  <span class="spotlight"></span>
</div>

Anyway, I have tried a few things like messing around with some of the mix-blend-modes, adding some clipping paths etc, but couldn't get anything close to working. I think it should (?) be possible, but if it isn't, I will try some other methods tomorrow (like converting the text to a png and using the background-clip property)


Solution

  • Another mix-blend-mode will fix it. Use lighten in this case to remove the black part you don't want:

    html {
      background:#fff; /* this is needed to make sure the blending works fine (any color will do the trick) */
    }
    
    body {
      margin: 0;
      height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      background: url('https://wallpapersite.com/images/pages/pic_w/16658.jpg') no-repeat center center fixed;
      background-size: cover;
    }
    
    .neon {
      position: relative;
      overflow: hidden;
      filter: brightness(200%);
      mix-blend-mode:lighten; /* here */
    }
    
    .text {
      background-color: black;
      color: white;
      font-size: 100px;
      font-weight: bold;
      font-family: sans-serif;
      text-transform: uppercase;
      position: relative;
      user-select: none;
    }
    
    .text::before {
      content: attr(data-text);
      position: absolute;
      color: white;
      filter: blur(0.02em);
      mix-blend-mode: difference;
    }
    
    .gradient {
      position: absolute;
      background: linear-gradient(45deg, #00f7ff, #f545d7, #0085ff, #6945f5, #005aff);
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      mix-blend-mode: multiply;
    }
    
    .spotlight {
      position: absolute;
      top: -100%;
      left: -100%;
      right: 0;
      bottom: 0;
      background: radial-gradient( circle, white, transparent 25%) center / 25% 25%, radial-gradient( circle, white, black 25%) center / 12.5% 12.5%;
      animation: light 5s linear infinite;
      mix-blend-mode: color-dodge;
    }
    
    @keyframes light {
      to {
        transform: translate(50%, 50%);
      }
    }
    <div class="neon">
      <span class="text" data-text="NIGHT SKY">NIGHT SKY</span>
      <span class="gradient"></span>
      <span class="spotlight"></span>
    </div>