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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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Adding Classes

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About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

!
Insecure Resource

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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Packages

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HTML 

              
                //- inspiration = https://isotope.metafizzy.co
- 
  const elements = [
    { name: "Nitrogen", abbr: "N", float: "14.007", index: "7", tags: "" },
    { name: "Sodium", abbr: "Na", float: "22.99", index: "11", tags: "metal ium" },
    { name: "Argon", abbr: "Ar", float: "39.948", index: "18", tags: "" },
    { name: "Potassium", abbr: "K", float: "39.0983", index: "19", tags: "metal ium" },
    { name: "Calcium", abbr: "Ca", float: "40.078", index: "20", tags: "metal ium" },
    { name: "Cobalt", abbr: "Co", float: "58.933", index: "27", tags: "metal transition" },
    { name: "Cadmium", abbr: "Cd", float: "112.411", index: "48", tags: "metal transition ium" },
    { name: "Antimony", abbr: "Sb", float: "121.76", index: "51", tags: "" },
    { name: "Tellurium", abbr: "Te", float: "127.6", index: "52", tags: "ium" },
    { name: "Ytterbium", abbr: "Yb", float: "173.054", index: "70", tags: "metal ium" },
    { name: "Rhenium", abbr: "Re", float: "186.207", index: "75", tags: "metal transition ium" },
    { name: "Gold", abbr: "Au", float: "196.967", index: "79", tags: "metal transition" },
    { name: "Mercury", abbr: "Hg", float: "200.59", index: "80", tags: "metal transition" },
    { name: "Thallium", abbr: "Tl", float: "204.383", index: "81", tags: "metal ium" },
    { name: "Lead", abbr: "Pb", float: "207.2", index: "82", tags: "metal" },
    { name: "Bismuth", abbr: "Bi", float: "208.980", index: "83", tags: "metal" },
    { name: "Uranium", abbr: "U", float: "238.029", index: "92", tags: "metal ium" },
    { name: "Plutonium", abbr: "Pu", float: "244", index: "94", tags: "metal ium" },
  ].sort((a, b) => a.name.localeCompare(b.name))

.controls
  fieldset#filterelements
    legend Filter
    label
      input(type="radio" name="filter" value="all" checked)
      | show all
    label
      input(type="radio" name="filter" value="metal")
      | metal
    label
      input(type="radio" name="filter" value="transition")
      | transition
    label
      input(type="radio" name="filter" value="ium")
      | -ium

  fieldset#sortelements
    legend Sort
    label
      input(type="radio" name="sort" value="name" checked)
      | name
    label
      input(type="radio" name="sort" value="symbol")
      | symbol
    label
      input(type="radio" name="sort" value="number")
      | number

.container
  each element, i in elements
    .box(style=`--pos: ${i};` class=`${element.tags} box-${i}`)
      style.
        @media (prefers-reduced-motion: no-preference) {
          .box-#{i} {
            view-transition-name: box-#{i};
          }
        
          /* :only-child here makes the animation only fire if there's no pair for it */
          ::view-transition-old(box-#{i}):only-child {
            animation: scale-out .25s ease-out forwards;
          }

          ::view-transition-new(box-#{i}):only-child {
            opacity: 0;
            animation: 
              fade-in .01s ease-in forwards,
              scale-out .4s ease-in reverse;
          }
        }
          
        ::view-transition-group(box-#{i}) {
          animation-delay: #{i * 20}ms;
        }
      .number= element.index
      .symbol= element.abbr
      .name= element.name
      .float= element.float
!

CSS 

              
                @keyframes scale-out {
  to { scale: 0 }
}

@keyframes fade-in {
  to { opacity: 1 }
}

@media (prefers-reduced-motion: no-preference) {
  ::view-transition-group(*) {
    animation-duration: 1.3s;
    animation-timing-function: linear(
      0, 0.009, 0.035 2.1%, 0.141, 0.281 6.7%, 0.723 12.9%, 0.938 16.7%, 1.017,
      1.077, 1.121, 1.149 24.3%, 1.159, 1.163, 1.161, 1.154 29.9%, 1.129 32.8%,
      1.051 39.6%, 1.017 43.1%, 0.991, 0.977 51%, 0.974 53.8%, 0.975 57.1%,
      0.997 69.8%, 1.003 76.9%, 1.004 83.8%, 1
    );
  }
}

@layer demo {
  .box {
    --hue: calc(var(--pos) * 20);
    background: oklch(65% .3 var(--hue));
    color: oklch(10% .3 var(--hue));
  }
  
  /*  
    further view-transition CSS is 
    inline with the pug templates so staggering
    and individual customizations can be done easier
  */
  
  html {
    /* optimization: */
    /* tell page you arent transitioning the whole page */
    view-transition-name: none;
  }
  
  /* allow interrupting the view transition with mouse */
  ::view-transition {
    pointer-events: none;
  }
}

@layer demo.support {
  * {
    box-sizing: border-box;
    margin: 0;
  }

  html {
    block-size: 100%;
    color-scheme: dark light;
  }

  body {
    min-block-size: 100%;
    font-family: system-ui, sans-serif;

    display: grid;
    align-content: start;
    padding: 1rem;
    gap: 1rem;
  }
  
  .number {
    text-align: end;
  }
  
  .symbol {
    color: Canvas;
    font-size: 60cqi;
    font-weight: bolder;
  }
  
  .float {
    font-size: .75em;
  }
  
  .container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(15ch, 1fr));
    gap: 2ch;
  }
  
  .box {
    container-type: inline-size;
    display: grid;
    align-content: space-between;
    aspect-ratio: 1;
    padding: 1rem;
    font-size: 1.25rem;
  }
  
  .controls {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem 6rem;
  }
  
  fieldset {
    display: inline-flex;
    flex-wrap: wrap;
    gap: 2ch;
    max-inline-size: max-content;
    border: none;
    padding: 0;
  }
  
  legend {
    padding: 0;
    font-weight: bolder;
    margin-block-end: .5ch;
  }
  
  label {
    display: flex;
    align-items: center;
    gap: .5ch;
    text-transform: capitalize;
  }
  
  label:has(:checked) {
    color: Highlight;
    color: AccentColor;
    text-decoration: underline Highlight;
  }
  
  @media (prefers-color-scheme: light) {
    label:has(:checked) {
      color: LinkText;
      color: AccentColor;
    }
  }
}
!

JS 

              
                const boxes = document.querySelectorAll('.box')

window.filterelements.oninput = e => {
  e.target.value === 'all'
    ? viewTransition(showAll) 
    : viewTransition(filterBy, e.target.value)
}

window.sortelements.oninput = e => {
  viewTransition(sortBy, e.target.value)
}

function viewTransition(fn, params) {
  if (document?.startViewTransition) {
    document.startViewTransition(() => {
      fn(params)
    })
  }
  else fn(params)
}

function showAll() {
  boxes.forEach(box => box.style.display = null)
}

function filterBy(classname) {
  boxes.forEach(box =>
    box.style.display = box.classList.contains(classname) ? null : 'none')
}

function sortBy(classname) {
  const parent = boxes[0].parentNode
  parent.innerHTML = ''

  Array.from(boxes).sort((a, b) => {
    const nameA = a.querySelector(`.${classname}`).innerText
    const nameB = b.querySelector(`.${classname}`).innerText
    return nameA.localeCompare(nameB)
  }).forEach(box => {
    parent.appendChild(box)
  })
}

// animating display: none || block
function modifyDom() {
  document.querySelectorAll('.box').forEach(box => {
    box.style.display = Math.random() >= .5 ? null : 'none'
  })
}
!
999px

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