csscss-shapesbox-shadowcss-gradients

CSS "inverse border-radius" outside element's bounding box to create a mobile phone notch design


I'm trying to create something that looks like a mobile phone with HTML and CSS and I'd like the camera to have something like an "inverted border-radius" that connects it with the frame smoothly.

I can't just make it bigger and mask the unwanted area with a pseudoelement with a white background because the screen content might not always be white.

Also, I can't use mask-image on that same element because that "inverted border-radius" would actually extend past it's bounding box, so I would actually be adding more area rather than subtracting (plus support is really low).

I want to avoid using SVGs if possible.

body {
  position: relative;
  overflow: hidden;
  height: 100vh;
  margin: 0;
}

.phone {
  width: 420px;
  height: 800px;
  padding: 12px 12px 24px;
  position: absolute;
  top: 32px;
  left: 50%;
  transform: translate(-50%, 0);
  background: #000;
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, .125);
  border-radius: 16px;
}

.screen {
  height: 100%;
  overflow: hidden;
  position: relative;
  background: #FFF;
  border-radius: 8px;
}

.viewport {
  height: 100%;
  position: relative;
  overflow-x: hidden;
  overflow-y: scroll;
}

.notch {
  top: 12px;
  left: 50%;
  width: 24px;
  height: 12px;
  z-index: 10;
  position: absolute;
  transform: translate(-50%, 0);
  background: #000;
  border-bottom-left-radius: 1024px;
  border-bottom-right-radius: 1024px;
}

.camera {
  top: 0;
  left: 50%;
  width: 12px;
  border: 4px solid #33244A;
  height: 12px;
  position: absolute;
  transform: translate(-50%, -50%);
  background:  #304A58;
  border-radius: 1024px;
  box-sizing: border-box;
}
<div class="phone">
  <div class="notch">
    <div class="camera"></div>
  </div>

  <div class="screen">
    <div class="viewport"></div>
  </div>
</div>


Solution

  • There are four ways to do that, from simple to more complex:

    Here you can check the first 3 solutions:

    const notch = document.getElementById('notch');
    const button = document.getElementById('button');
    const xrayCheckbox = document.getElementById('xrayCheckbox');
    const xrayLabel = document.getElementById('xrayLabel');
    const label = document.getElementById('label');
    
    const solutions = [{
      name: 'pseudoelements + radial-gradient',
      classes: 'notch notch-gradient'
    }, {
      name: 'pseudoelements + box-shadow',
      classes: 'notch notch-shadow'
    }, {
      name: 'pseudoelements + mask-image',
      classes: 'notch notch-mask'
    }];
    
    let currentSolutionIndex = 0;
    let currentSolution = solutions[currentSolutionIndex];
    let xRayEnabled = false;
    
    button.onclick = () => {
      currentSolutionIndex = (currentSolutionIndex + 1) % solutions.length;
      currentSolution = solutions[currentSolutionIndex];
      
      updateLabels();
    };
    
    xrayCheckbox.onchange = () => {  
      xRayEnabled = xrayCheckbox.checked;
      
      updateLabels();
    };
    
    function updateLabels() {
      if (xRayEnabled) {
        notch.className = `${ currentSolution.classes }-xray`;
        label.innerText = `${ currentSolution.name } (X-Ray)`;
        xrayLabel.innerText = 'Disable X-Ray';
      } else {
        notch.className = currentSolution.classes;
        label.innerText = currentSolution.name;
        xrayLabel.innerText = 'Enable X-Ray';
      }
    }
    body {
      position: relative;
      overflow: hidden;
      height: 100vh;
      margin: 0;
    }
    
    .phone {
      width: 420px;
      height: 800px;
      padding: 12px 12px 24px;
      position: absolute;
      top: 32px;
      left: 50%;
      transform: translate(-50%, 0);
      background: #000;
      box-shadow: 0 8px 32px 0 rgba(0, 0, 0, .5);
      border-radius: 16px;
    }
    
    .screen {
      height: 100%;
      overflow: hidden;
      position: relative;
      background: #FFF;
      border-radius: 8px;
    }
    
    .viewport {
      height: 100%;
      position: relative;
      overflow-x: hidden;
      overflow-y: scroll;
    }
    
    .notch {
      top: 12px;
      left: 50%;
      width: 24px;
      height: 12px;
      z-index: 10;
      position: absolute;
      transform: translate(-50%, 0);
      background: #000;
      border-bottom-left-radius: 1024px;
      border-bottom-right-radius: 1024px;
    }
    
    .notch::before,
    .notch::after {
      top: 0;
      width: 8px;
      height: 8px;
      content: "";
      position: absolute;
    }
    
    .notch-gradient-xray,
    .notch-shadow-xray,
    .notch-mask-xray {
      background: red;
    }
    
    /* RADIAL GRADIENT SOLUTION */
    
    .notch-gradient::before {
      left: -6px;
      background: radial-gradient(circle at bottom left, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .notch-gradient::after {
      right: -6px;
      background: radial-gradient(circle at bottom right, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .notch-gradient-xray::before {
      left: -6px;
      background: green radial-gradient(circle at bottom left, transparent 0, transparent 70%, cyan 70%, cyan 100%);
    }
    
    .notch-gradient-xray::after {
      right: -6px;
      background: green radial-gradient(circle at bottom right, transparent 0, transparent 70%, cyan 70%, cyan 100%);
    }
    
    /* BOX-SHADOW SOLUTION */
    
    .notch-shadow::before {
      left: -6px;
      background: transparent;
      border-radius: 0 8px 0 0;
      box-shadow: 0 -4px 0 0 #000;
    }
    
    .notch-shadow::after {
      right: -6px;
      background: transparent;
      border-radius: 8px 0 0 0;
      box-shadow: 0 -4px 0 0 #000;
    }
    
    .notch-shadow-xray::before {
      left: -6px;
      background: green;
      border-radius: 0 8px 0 0;
      box-shadow: 0 -4px 0 0 cyan;
    }
    
    .notch-shadow-xray::after {
      right: -6px;
      background: green;
      border-radius: 8px 0 0 0;
      box-shadow: 0 -4px 0 0 cyan;
    }
    
    /* MASK SOLUTION */
    
    .notch-mask::before {
      left: -6px;
      background: #000;
      -webkit-mask-image: radial-gradient(circle at bottom left, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .notch-mask::after {
      right: -6px;
      background: #000;
      -webkit-mask-image: radial-gradient(circle at bottom right, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .notch-mask-xray::before {
      left: -6px;
      background: cyan;
      -webkit-mask-image: radial-gradient(circle at bottom left, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .notch-mask-xray::after {
      right: -6px;
      background: cyan;
      -webkit-mask-image: radial-gradient(circle at bottom right, transparent 0, transparent 70%, black 70%, black 100%);
    }
    
    .camera {
      top: 0;
      left: 50%;
      width: 12px;
      border: 4px solid #33244A;
      height: 12px;
      position: absolute;
      transform: translate(-50%, -50%);
      background:  #304A58;
      border-radius: 1024px;
      box-sizing: border-box;
    }
    
    #button {
      font-family: monospace;
      font-size: 16px;
      padding: 8px 16px;
      margin: 32px auto 16px;
      background: transparent;
      border: 2px solid black;
      display: block;
      border-radius: 2px;
    }
    
    #xray {
      font-family: monospace;
      font-size: 16px;
      padding: 0 16px;
      text-align: center;
      display: block;
      margin: 0 0 16px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    #xrayCheckbox {
      margin: 0 8px 0 0;
    }
    
    #label {
      font-family: monospace;
      font-size: 16px;
      padding: 0 16px;
      text-align: center;
    }
    <div class="phone">
      <div id="notch" class="notch notch-gradient">
        <div class="camera"></div>
      </div>
    
      <div class="screen">
        <div class="viewport">
          <button id="button">Change Solution</button>
          
          <label id="xray">
            <input id="xrayCheckbox" type="checkbox" />
            <span id="xrayLabel">Enable X-Ray</span>
          </label>
          
          <div id="label">pseudoelements + radial-gradient</div>
        </div>
      </div>
    </div>