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HTML 

              
                <!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>

  <body>
    <p style="font-size: 25px; font-weightL">CSS Grid Equal Columns!</p>
    <p>1fr 1fr 1fr works, but there are some gotchas!</p>

    <div class="a container">
      <div>
        <span class="columnSize">1fr</span>
      </div>
      <div>
        <span class="columnSize">1fr</span>
      </div>
      <div>
        <span class="columnSize">1fr</span>
      </div>
    </div>

    <div class="b container">
      <div>
        <span class="columnSize">1fr</span>
      </div>
      <div>
        <span class="columnSize">1fr<br /></span>
        <p>
          I have more content in me, but since there are spaces I will wrap!
          Columns are still the same width
        </p>
      </div>
      <div>
        <span class="columnSize">1fr</span>
      </div>
    </div>

    <div class="c container">
      <div>
        <span class="columnSize">1fr<br /></span>
        But if something causes me to be larger - like an image. I'll take that
        space up before the fr (free space) is distributed.
        <img src="https://source.unsplash.com/random/600x50" alt="" />
      </div>
      <div>
        <span class="columnSize">1fr<br /></span>
      </div>
      <div>
        <span class="columnSize">1fr</span>
      </div>
    </div>
    <div class="c container">
      <div>
        <span class="columnSize">1fr<br /></span>
      </div>
      <div>
        <span class="columnSize">1fr<br /></span>
        <p>unbrokenTextCanAlsoCauseTheElementToGrowLargerAndLargerAndLarger</p>
      </div>

      <div>
        <span class="columnSize">1fr</span>
      </div>
    </div>

    <div class="d container">
      <div>
        <span class="columnSize">1fr<br /></span>
        <p class="fix">Fix:</p>
        max-width: 100%; on images
        <img src="https://source.unsplash.com/random/800x50" alt="" />
      </div>
      <div>
        <span class="columnSize">1fr<br /></span>
        <p class="fix">Fix:</p>
        <p>word-wrap or overflow scroll/hidden</p>
        <p>unbrokenTextCanAlsoCauseTheElementToGrowLargerAndLargerAndLarger</p>
      </div>
      <div>
        <span class="columnSize">1fr</span>
      </div>
    </div>

    <div class="e container">
      <div>
        <span class="columnSize">minmax(0, 1fr)<br /></span>
        minmax will ensure the columns stay equal, but the above fixes are still
        needed to account for larger content.
        <img src="https://source.unsplash.com/random/800x50" alt="" />
      </div>
      <div>
        <span class="columnSize">minmax(0, 1fr)<br /></span>
        <p>unbrokenTextCanAlsoCauseTheElementToGrowLargerAndLargerAndLarger</p>
      </div>
      <div>
        <span class="columnSize">minmax(0, 1fr)</span>
      </div>
    </div>
    <h2>repeat(3, minmax(0, 1fr));</h2>
    <div class="f container">
      <div>
        <span class="columnSize">minmax(0, 1fr)<br /></span>
        minmax will ensure the columns stay equal, but the above fixes are still
        needed to account for larger content.
        <img src="https://source.unsplash.com/random/800x50" alt="" />
      </div>
      <div>
        <span class="columnSize">minmax(0, 1fr)<br /></span>
        <p>unbrokenTextCanAlsoCauseTheElementToGrowLargerAndLargerAndLarger</p>
      </div>
      <div>
        <span class="columnSize">minmax(0, 1fr)</span>
      </div>
    </div>

    <h2>repeat(auto-fit, minmax(0, 1fr));</h2>
    <div class="i container">
      <div>
        <span class="columnSize"></span>
      </div>
      <div>
        <span class="columnSize">Longboyyyyyyyyyyyyyyyy</span>
      </div>
      <div>
        <span class="columnSize">autoFit</span>
      </div>
      <div>
        <span class="columnSize">autoFit</span>
        <img src="https://source.unsplash.com/random/800x50" alt="" />
      </div>
      <div>
        <span class="columnSize"> autoFit </span>
      </div>
      <div>
        <span class="columnSize">autoFit</span>
      </div>
    </div>

    <div class="g container">
      <div>
        <span class="columnSize">33.33%</span>
      </div>
      <div>
        <span class="columnSize">33.33%</span>
        <br />
        percentages work if you aren't using grid gap, but you go "over budget"
        if you add gap to 100% width. Just like adding margin.
      </div>
      <div>
        <span class="columnSize">33.33%</span>
      </div>
    </div>
    <div class="h container">
      <div>
        <span class="columnSize">calc(33% - 20px)<br /></span>
        What about CSS calc()?!
      </div>
      <div>
        <span class="columnSize">calc(33% - 20px)<br /></span>
        <p>Three columns, two gaps. Comes up short.</p>
      </div>
      <div>
        <span class="columnSize">calc(33% - 20px)</span>
        <p>
          Doing the math also assumes you know how many columns ahead of time
        </p>
      </div>
    </div>


  </body>
</html>
!

CSS 

              
                
      .columnSize {
        color: black;
        font-weight: 600;
        font-size: 20px;
      }

      body {
        font-family: "Operator Mono";
        font-weight: 200;
        font-size: 20px;
        text-align: center;
      }

      .container {
        position: relative;
        max-width: 1000px;
        margin: 0 auto;
      }
      .container:before,
      .container:after {
        content: "";
        display: block;
        width: 2px;
        height: 290%;
        position: absolute;
        left: -2px;
        top: -200px;
        /* border-left: 3px dashed #272727ee; */
        background: linear-gradient(to bottom, transparent 50%, #000000aa 50%);
        background-size: 100% 50px;
        z-index: 2;
        display: none;
      }
      .container:after {
        right: -2px;
        left: auto;
      }

      .container > div {
        border: 2px solid black;
        border-radius: 20px;
        text-align: center;
        padding: 10px;
        margin-bottom: 20px;
      }

      .container.a {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: 1fr 1fr 1fr;
      }

      .container.b {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: 1fr 1fr 1fr;
      }

      .container.c {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: 1fr 1fr 1fr;
      }

      .container.d {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: 1fr 1fr 1fr;
      }

      .d img {
        max-width: 100%;
      }

      .d {
        word-wrap: anywhere;
      }

      .container.e {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: repeat(3, minmax(0, 1fr));
      }

      .container.f {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: repeat(3, minmax(0, 1fr));
        word-wrap: anywhere;
      }

      .f > div {
        border-color: #ffc600;
        border-width: 4px;
      }

      .f img {
        max-width: 100%;
      }

      .container.g {
        display: grid;
        grid-gap: 20px;
        grid-template-columns: 33.33% 33.33% 33.33%;
      }

      .container.h {
        display: grid;
        grid-template-columns:
          calc(33% - 20px) calc(33% - 20px)
          calc(33% - 20px);
        gap: 20px;
      }
      .container.i {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(0, 1fr));
        gap: 20px;
      }

      .container.i > div {
        word-wrap: break-word;
        border-color: #ffc600;
        border-width: 4px;
        img {
          max-width: 100%;
        }
      }

      h2 {
        margin: 0;
        font-size: 20px;
      }

      /*
  Oh Hello!

  These are some base styles so that our tutorial looks good.

  Let's go through the important bits real quick
*/
      :root {
        --yellow: #ffc600;
        --black: #272727;
      }

      html {
        /* border-box box model allows us to add padding and border to our elements without increasing their size */
        box-sizing: border-box;
        /* A system font stack so things load nice and quick! */
        font-family: "Operator", -apple-system, BlinkMacSystemFont, "Segoe UI",
          Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji",
          "Segoe UI Emoji", "Segoe UI Symbol";
        font-weight: 900;
        font-size: 10px;
        color: var(--black);
        text-shadow: 0 2px 0 rgba(0, 0, 0, 0.07);
      }

      /*
  WAT IS THIS?!
  We inherit box-sizing: border-box; from our <html> selector
  Apparently this is a bit better than applying box-sizing: border-box; directly to the * selector
*/
      *,
      *:before,
      *:after {
        box-sizing: inherit;
      }

      body {
        /* background-image: url("./images/topography.svg"),
          linear-gradient(110deg, #f93d66, #6d47d9); */
        background-size: 340px, auto;
        min-height: calc(100vh - 100px);
        margin: 50px;
        /* background: white; */
        background-attachment: fixed;
        letter-spacing: -1px;
      }

      h1,
      h2,
      h3,
      h4,
      h5,
      h6 {
        margin: 0 0 5px 0;
      }

      /* Each item in our grid will contain numbers */
      .item {
        /* We center the contents of these items. You can also do this with flexbox too! */
        display: grid;
        justify-content: center;
        align-items: center;
        border: 5px solid rgba(0, 0, 0, 0.03);
        border-radius: 3px;
        font-size: 35px;
        background-color: var(--yellow);
        /* best colour */
      }

      .item p {
        margin: 0 0 5px 0;
      }

      .fix {
        margin: 0;
        font-weight: 900;
      }
!

JS
!
999px

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