Pen Settings

HTML

About HTML Preprocessors

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.

Learn more · Versions

Adding Classes

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

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

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

CSS

About CSS Preprocessors

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

Learn more · Versions

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).

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

Powered by Algolia
About External Resources

You can apply CSS to your Pen from any stylesheet on the web. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself.

You can also link to another Pen here (use the .css URL Extension) and we'll pull the CSS from that Pen and include it. If it's using a matching preprocessor, use the appropriate URL Extension and we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

JavaScript

About JavaScript Preprocessors

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

Learn more · Versions

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Powered by Algolia
About External Resources

You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

You can also link to another Pen here, and we'll pull the JavaScript from that Pen and include it. If it's using a matching preprocessor, we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Powered by Algolia
About Packages

Using packages here is powered by Skypack, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ES6 import usage.

All packages are different, so refer to their docs for how they work.

If you're using React / ReactDOM, make sure to turn on Babel for the JSX processing.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML 

              
                - var categories = ['alkali-metals','alkaline-earth-metals','lanthanoids','actinoids','transition-metals','post-transition-metals','metalloids','other-nonmetals','noble-gasses','unknown']

// ELEMENT MIXIN TEMPLATE
mixin element(number, symbol, name, mass, weight, material, column, row)
  .element(class=material)(class='c'+column)(class='r'+row)
    input.activate(type='radio', name='elements')
    input.deactivate(type='radio', name='elements')
    .overlay
    .square
      .model
        each item in weight.reverse()
          .orbital
            - for (var i = 0; i < item; i++)
              .electron
      .atomic-number= number
      .label
        .symbol= symbol
        .name= name
      .atomic-mass= mass
      ul.atomic-weight
        each item in weight.reverse()
          li= item


// PLACEHOLDER MIXIN TEMPLATE
mixin placeholder(number, material, column, row)
  .placeholder(class=material)(class='c'+column)(class='r'+row)
    .square= number


.wrapper
  each item in categories
    input.category-toggle(type='radio', id=item, name='categories')
    input.category-cancel(type='radio', id='cancel' name='categories')
  .periodic-table
    +element(1, 'H', 'Hydrogen', 1.008, [1], 'other-nonmetal', 1, 1)
    +element(2, 'He', 'Helium', 4.0026, [2], 'noble-gas', 18, 1)
    +element(3, 'Li', 'Lithium', 6.94, [3], 'alkali-metal', 1, 2)
    +element(4, 'Be', 'Beryllium', 9.0122, [2,2], 'alkaline-earth-metal', 2, 2)
    +element(5, 'B', 'Boron', 10.81, [2,3], 'metalloid', 13, 2)
    +element(6, 'C', 'Carbon', 12.011, [2,4], 'other-nonmetal', 14, 2)
    +element(7, 'N', 'Nitrogen', 14.007, [2,5], 'other-nonmetal', 15, 2)
    +element(8, 'O', 'Oxygen', 15.999, [2,6], 'other-nonmetal', 16, 2)
    +element(9, 'F', 'Flourine', 18.998, [2,7], 'other-nonmetal', 17, 2)
    +element(10, 'Ne', 'Neon', 20.180, [2,8], 'noble-gas', 18, 2)
    +element(11, 'Na', 'Sodium', 22.990, [2,8,1], 'alkali-metal', 1, 3)
    +element(12, 'Mg', 'Magnesium', 24.305, [2,8,2], 'alkaline-earth-metal', 2, 3)
    +element(13, 'Al', 'Aluminium', 26.982, [2,8,3], 'post-transition-metal', 13, 3)
    +element(14, 'Si', 'Silicon', 28.085, [2,8,4], 'metalloid', 14, 3)
    +element(15, 'P', 'Phosphorus', 30.974, [2,8,5], 'other-nonmetal', 15, 3)
    +element(16, 'S', 'Sulfur', 32.06, [2,8,6], 'other-nonmetal', 16, 3)
    +element(17, 'Cl', 'Chlorine', 35.45, [2,8,7], 'other-nonmetal', 17, 3)
    +element(18, 'Ar', 'Argon', 39.948, [2,8,8], 'noble-gas', 18, 3)
    +element(19, 'K', 'Potassium', 39.098, [2,8,8,1], 'alkali-metal', 1, 4)
    +element(20, 'Ca', 'Calcium', 40.078, [2,8,8,2], 'alkaline-earth-metal', 2, 4)
    +element(21, 'Sc', 'Scandium', 44.956, [2,8,9,2], 'transition-metal', 3, 4)
    +element(22, 'Ti', 'Titanium', 47.867, [2,8,10,2], 'transition-metal', 4, 4)
    +element(23, 'V', 'Vanadium', 50.942, [2,8,11,2], 'transition-metal', 5, 4)
    +element(24, 'Cr', 'Chromium', 51.996, [2,8,13,1], 'transition-metal', 6, 4)
    +element(25, 'Mn', 'Manganese', 54.938, [2,8,13,2], 'transition-metal', 7, 4)
    +element(26, 'Fe', 'Iron', 55.845, [2,8,14,2], 'transition-metal', 8, 4)
    +element(27, 'Co', 'Cobalt', 58.933, [2,8,15,2], 'transition-metal', 9, 4)
    +element(28, 'Ni', 'Nickel', 58.693, [2,8,16,2], 'transition-metal', 10, 4)
    +element(29, 'Cu', 'Copper', 63.546, [2,8,18,1], 'transition-metal', 11, 4)
    +element(30, 'Zn', 'Zinc', 65.38, [2,8,18,2], 'transition-metal', 12, 4)
    +element(31, 'Ga', 'Gallium', 69.723, [2,8,18,3], 'post-transition-metal', 13, 4)
    +element(32, 'Ge', 'Germanium', 72.630, [2,8,18,4], 'metalloid', 14, 4)
    +element(33, 'As', 'Arsenic', 74.922, [2,8,18,5], 'metalloid', 15, 4)
    +element(34, 'Se', 'Selenium', 78.971, [2,8,18,6], 'other-nonmetal', 16, 4)
    +element(35, 'Br', 'Bromine', 79.904, [2,8,18,7], 'other-nonmetal', 17, 4)
    +element(36, 'Kr', 'Krypton', 83.798, [2,8,18,8], 'noble-gas', 18, 4)
    +element(37, 'Rb', 'Rubidium', 85.468, [2,8,18,8,1], 'alkali-metal', 1, 5)
    +element(38, 'Sr', 'Strontium', 87.62, [2,8,18,8,2], 'alkaline-earth-metal', 2, 5)
    +element(39, 'Y', 'Yttrium', 88.906, [2,8,18,9,2], 'transition-metal', 3, 5)
    +element(40, 'Zr', 'Zirconium', 91.224, [2,8,18,10,2], 'transition-metal', 4, 5)
    +element(41, 'Nb', 'Niobium', 92.906, [2,8,18,12,1], 'transition-metal', 5, 5)
    +element(42, 'Mo', 'Molybdenum', 95.95, [2,8,18,13,1], 'transition-metal', 6, 5)
    +element(43, 'Tc', 'Technetium', '(98)', [2,8,18,13,2], 'transition-metal', 7, 5)
    +element(44, 'Ru', 'Ruthenium', 101.07, [2,8,18,15,1], 'transition-metal', 8, 5)
    +element(45, 'Rh', 'Rhodium', 102.91, [2,8,18,16,1], 'transition-metal', 9, 5)
    +element(46, 'Pd', 'Palladium', 106.42, [2,8,18,18], 'transition-metal', 10, 5)
    +element(47, 'Ag', 'Silver', 107.87, [2,8,18,18,1], 'transition-metal', 11, 5)
    +element(48, 'Cd', 'Cadmium', 112.41, [2,8,18,18,2], 'transition-metal', 12, 5)
    +element(49, 'In', 'Indium', 114.82, [2,8,18,18,3], 'post-transition-metal', 13, 5)
    +element(50, 'Sn', 'Tin', 204.38, [2,8,18,18,4], 'post-transition-metal', 14, 5)
    +element(51, 'Sb', 'Antimony', 121.76, [2,8,18,18,5], 'metalloid', 15, 5)
    +element(52, 'Te', 'Tellurium', 127.60, [2,8,18,18,6], 'metalloid', 16, 5)
    +element(53, 'I', 'Iodine', 126.90, [2,8,18,18,7], 'other-nonmetal', 17, 5)
    +element(54, 'Xe', 'Xenon', 131.29, [2,8,18,18,8], 'noble-gas', 18, 5)
    +element(55, 'Cs', 'Caesium', 132.91, [2,8,18,18,8,1], 'alkali-metal', 1, 6)
    +element(56, 'Ba', 'Barium', 137.33, [2,8,18,18,8,2], 'alkaline-earth-metal', 2, 6)
    +element(57, 'La', 'Lanthanum', 138.91, [2,8,18,18,9,2], 'lanthanoid', 4, 9)
    +element(58, 'Ce', 'Cerium', 140.12, [2,8,18,19,9,2], 'lanthanoid', 5, 9)
    +element(59, 'Pr', 'Praseodymium', 140.91, [2,8,18,21,8,2], 'lanthanoid', 6, 9)
    +element(60, 'Nd', 'Neodymium', 144.24, [2,8,18,22,8,2], 'lanthanoid', 7, 9)
    +element(61, 'Pm', 'Promethium', 144.24, [2,8,18,23,8,2], 'lanthanoid', 8, 9)
    +element(62, 'Sm', 'Samarium', 150.36, [2,8,18,24,8,2], 'lanthanoid', 9, 9)
    +element(63, 'Eu', 'Europium', 151.96, [2,8,18,25,8,2], 'lanthanoid', 10, 9)
    +element(64, 'Gd', 'Gadolinium', 157.25, [2,8,18,25,9,2], 'lanthanoid', 11, 9)
    +element(65, 'Tb', 'Terbium', 158.93, [2,8,18,27,8,2], 'lanthanoid', 12, 9)
    +element(66, 'Dy', 'Dysprosium', 162.50, [2,8,18,28,8,2], 'lanthanoid', 13, 9)
    +element(67, 'Ho', 'Holmium', 164.93, [2,8,18,29,8,2], 'lanthanoid', 14, 9)
    +element(68, 'Er', 'Erbium', 167.26, [2,8,18,30,8,2], 'lanthanoid', 15, 9)
    +element(69, 'Tm', 'Thulium', 168.93, [2,8,18,31,8,2], 'lanthanoid', 16, 9)
    +element(70, 'Yb', 'Ytterbium', 173.05, [2,8,18,32,8,2], 'lanthanoid', 17, 9)
    +element(71, 'Lu', 'Lutetium', 174.97, [2,8,18,32,9,2], 'lanthanoid', 18, 9)
    +element(72, 'Hf', 'Hafnium', 178.49, [2,8,18,32,10,2], 'transition-metal', 4, 6)
    +element(73, 'Ta', 'Tantalum', 180.95, [2,8,18,32,11,2], 'transition-metal', 5, 6)
    +element(74, 'W', 'Tungsten', 183.84, [2,8,18,32,12,2], 'transition-metal', 6, 6)
    +element(75, 'Re', 'Rhenium', 186.21, [2,8,18,32,13,2], 'transition-metal', 7, 6)
    +element(76, 'Os', 'Osmium', 190.23, [2,8,18,32,14,2], 'transition-metal', 8, 6)
    +element(77, 'Ir', 'Iridium', 192.22, [2,8,18,32,15,2], 'transition-metal', 9, 6)
    +element(78, 'Pt', 'Platinum', 195.08, [2,8,18,32,17,1], 'transition-metal', 10, 6)
    +element(79, 'Au', 'Gold', 196.97, [2,8,18,32,18,1], 'transition-metal', 11, 6)
    +element(80, 'Hg', 'Mercury', 200.59, [2,8,18,32,18,2], 'transition-metal', 12, 6)
    +element(81, 'Tl', 'Thallium', 204.38, [2,8,18,32,18,3], 'post-transition-metal', 13, 6)
    +element(82, 'Pb', 'Lead', 207.2, [2,8,18,32,18,4], 'post-transition-metal', 14, 6)
    +element(83, 'Bi', 'Bismuth', 208.98, [2,8,18,32,18,5], 'post-transition-metal', 15, 6)
    +element(84, 'Po', 'Polonium', '(209)', [2,8,18,32,18,6], 'post-transition-metal', 16, 6)
    +element(85, 'At', 'Astatine', '(210)', [2,8,18,32,18,7], 'metalloid', 17, 6)
    +element(86, 'Rn', 'Radon', '(222)', [2,8,18,32,18,8], 'noble-gas', 18, 6)
    +element(87, 'Fr', 'Francium', '(223)', [2,8,18,32,18,8,1], 'alkali-metal', 1, 7)
    +element(88, 'Ra', 'Radium', '(226)', [2,8,18,32,18,8,2], 'alkaline-earth-metal', 2, 7)
    +element(89, 'Ac', 'Actinium', '(227)', [2,8,18,32,18,9,2], 'actinoid', 4, 10)
    +element(90, 'Th', 'Thorium', 232.04, [2,8,18,32,18,10,2], 'actinoid', 5, 10)
    +element(91, 'Pa', 'Protactinium', 231.04, [2,8,18,32,20,9,2], 'actinoid', 6, 10)
    +element(92, 'U', 'Uranium', 238.03, [2,8,18,32,21,9,2], 'actinoid', 7, 10)
    +element(93, 'Np', 'Neptunium', '(237)', [2,8,18,32,22,9,2], 'actinoid', 8, 10)
    +element(94, 'Pu', 'Plutonium', '(244)', [2,8,18,32,24,8,2], 'actinoid', 9, 10)
    +element(95, 'Am', 'Americium', '(243)', [2,8,18,32,25,8,2], 'actinoid', 10, 10)
    +element(96, 'Cm', 'Curium', '(247)', [2,8,18,32,25,9,2], 'actinoid', 11, 10)
    +element(97, 'Bk', 'Berkelium', '(247)', [2,8,18,32,27,8,2], 'actinoid', 12, 10)
    +element(98, 'Cf', 'Californium', '(251)', [2,8,18,32,28,8,2], 'actinoid', 13, 10)
    +element(99, 'Es', 'Einsteinium', '(252)', [2,8,18,32,29,8,2], 'actinoid', 14, 10)
    +element(100, 'Fm', 'Fermium', '(257)', [2,8,18,32,30,8,2], 'actinoid', 15, 10)
    +element(101, 'Md', 'Mendelevium', '(258)', [2,8,18,32,31,8,2], 'actinoid', 16, 10)
    +element(102, 'No', 'Nobelium', '(259)', [2,8,18,32,32,8,2], 'actinoid', 17, 10)
    +element(103, 'Lr', 'Lawrencium', '(266)', [2,8,18,32,32,8,3], 'actinoid', 18, 10)
    +element(104, 'Rf', 'Rutherfordium', '(267)', [2,8,18,32,32,10,2], 'transition-metal', 4, 7)
    +element(105, 'Db', 'Dubnium', '(268)', [2,8,18,32,32,11,2], 'transition-metal', 5, 7)
    +element(106, 'Sg', 'Seaborgium', '(269)', [2,8,18,32,32,12,2], 'transition-metal', 6, 7)
    +element(107, 'Bh', 'Bohrium', '(270)', [2,8,18,32,32,13,2], 'transition-metal', 7, 7)
    +element(108, 'Hs', 'Hassium', '(277)', [2,8,18,32,32,14,2], 'transition-metal', 8, 7)
    +element(109, 'Mt', 'Meitnerium', '(278)', [2,8,18,32,32,15,2], 'unknown', 9, 7)
    +element(110, 'Ds', 'Darmstadtium', '(281)', [2,8,18,32,32,17,1], 'unknown', 10, 7)
    +element(111, 'Rg', 'Roentgenium', '(282)', [2,8,18,32,32,17,2], 'unknown', 11, 7)
    +element(112, 'Cn', 'Copernicium', '(282)', [2,8,18,32,32,18,2], 'transition-metal', 12, 7)
    +element(113, 'Nh', 'Nihonium', '(286)', [2,8,18,32,32,18,3], 'unknown', 13, 7)
    +element(114, 'Fl', 'Flerovium', '(289)', [2,8,18,32,32,18,4], 'post-transition-metal', 14, 7)
    +element(115, 'Mc', 'Moscovium', '(290)', [2,8,18,32,32,18,5], 'unknown', 15, 7)
    +element(116, 'Lv', 'Livermorium', '(293)', [2,8,18,32,32,18,6], 'unknown', 16, 7)
    +element(117, 'Ts', 'Tennessine', '(294)', [2,8,18,32,32,18,7], 'unknown', 17, 7)
    +element(118, 'Og', 'Oganesson', '(294)', [2,8,18,32,32,18,8], 'unknown', 18, 7)
    
    +placeholder('57-71', 'lanthanoid', 3, 6)
    +placeholder('89-103', 'actinoid', 3, 7)
    
    .gap.c3.r8
    
    .key
      .row
        label.alkali-metal(for='alkali-metals') Alkali Metals
        label.alkaline-earth-metal(for='alkaline-earth-metals') Alkaline Earth Metals
        label.lanthanoid(for='lanthanoids') Lanthanoids
        label.actinoid(for='actinoids') Aktinoids
        label.transition-metal(for='transition-metals') Transition Metals
        label.post-transition-metal(for='post-transition-metals') Post-Transition Metals
        label.metalloid(for='metalloids') Metalloids
        label.other-nonmetal(for='other-nonmetals') Other Nonmetals
        label.noble-gas(for='noble-gasses') Noble Gasses
        label.unknown(for='unknown') Unknown
!

CSS 

              
                $bgColor: #101318
$gridGap: 5px

$alkaliMetalColor: #ecbe59
$alkalineEarthMetalColor: #dee955
$lanthanoidColor: #ec77a3
$actinoidColor: #c686cc
$transitionMetalColor: #fd8572
$postTransitionMetalColor: #4cddf3
$metalloidColor: #3aefb6
$otherNonmetalColor: #52ee61
$nobleGasColor: #759fff
$unknownColor: #cccccc

body
  background: $bgColor
  text-shadow: 0 0 0.4vw currentColor

.wrapper
  position: relative
  overflow: hidden
  padding: 2%
  
  > input
    -webkit-appearance: none
    position: fixed
    left: 0
    top: 0
    width: 100%
    height: 100%
    visibility: hidden
    opacity: 0
    pointer-events: none

.periodic-table
  display: grid
  grid-gap: $gridGap
  grid-template-columns: repeat(18, 1fr)



// --------------------------------------
// ELEMENT
.element
  position: relative
  font-size: 0.5vw
  padding-bottom: 100%
  cursor: pointer
  color: #fff
  transition: 500ms
  
  .overlay
    position: fixed
    z-index: 1
    left: 0
    right: 0
    top: 0
    bottom: 0
    background-color: $bgColor
    opacity: 0
    pointer-events: none
    transition: 500ms
  
  .square
    position: absolute
    left: 0
    top: 0
    width: 100%
    height: 100%
    border: 2px solid
    box-sizing: border-box
    background: $bgColor
    display: flex
    flex-direction: column
    justify-content: center
    align-items: center
    transition-property: transform, z-index, left, right, top, bottom
    transition-duration: 100ms, 0ms, 200ms, 200ms, 200ms, 200ms
    transition-delay: 0ms, 100ms, 0ms, 0ms, 0ms, 0ms

  .atomic-number
    position: absolute
    left: 0
    top: 0
    padding: 2px

  .label
    text-align: center
    transition: 200ms

  .symbol
    font-size: 1.7vw

  .name
    font-size: 0.7vw

  .atomic-mass
    position: absolute
    left: 0
    right: 0
    bottom: 0
    padding: 2px
    text-align: center

  .atomic-weight
    position: absolute
    right: 0
    top: 0
    list-style: none
    margin: 0
    padding: 2px
    opacity: 0
    transition: 200ms
    text-align: right
  
  .model
    display: none
    position: absolute
    left: -500%
    right: -500%
    top: -500%
    bottom: -500%
    transform: scale(0.1)
    
    .orbital
      position: absolute
      left: 0
      right: 0
      top: 0
      bottom: 0
      border: 5px solid
      border-radius: 50%
      opacity: 0.25
      
      @for $i from 1 through 7
        &:nth-child(#{$i})
          margin: 10% + 5.5 * ($i - 1)
          animation-duration: 40s - 6 * ($i - 1)
      
      .electron
        position: absolute
        left: 0
        right: 0
        top: 0
        bottom: 0

        &::before
          content: ""
          position: absolute
          left: calc(50% - 0.7vw)
          top: -0.7vw
          width: 1.4vw
          height: 1.4vw
          background-color: currentColor
          border-radius: 50%
          opacity: 0.75

        @for $i from 1 through 32
          @for $a from 1 through $i
            &:nth-last-child(#{$i}):first-child ~ .electron:nth-child(#{$a})
              transform: rotate((360deg/$i)*($a - 1))

  input[type="radio"]
    -webkit-appearance: none
    position: absolute
    z-index: 2
    left: 0
    top: 0
    width: 100%
    height: 100%
    opacity: 0
    cursor: pointer
    outline: none
    
    &.activate
      &:hover ~ .square
        z-index: 2
        transform: scale(1.35)
        transition-delay: 0ms
        outline: none
        pointer-events: none
    
      &:checked + input[type="radio"].deactivate
        z-index: 3
        pointer-events: all
      
      &:checked ~ .overlay
        opacity: 0.75

      &:checked ~ .square
        z-index: 3
        transform: scale(3)
        transition-duration: 500ms, 0ms, 200ms, 200ms, 200ms, 200ms
        transition-delay: 0ms
        outline: none
        cursor: auto
        
        .label
          transition-duration: 500ms
          transform: scale(0.75)

        .atomic-weight
          opacity: 1
          transition: 500ms

        .model
          display: block
          animation: fade-in
          animation-duration: 1s
          
        .orbital
          animation-name: rotate
          animation-timing-function: linear
          animation-iteration-count: infinite
    
    &.deactivate
      position: fixed
      display: block
      z-index: 1
      opacity: 0
      pointer-events: none 
    
      &:checked ~ .square
        z-index: 1

        
// --------------------------------------
// PLACEHOLDER     
.placeholder
  position: relative
  z-index: -1
  font-size: 1vw
  padding-bottom: 100%
  color: #fff
  transition: 500ms
  
  .square
    position: absolute
    left: 0
    top: 0
    width: 100%
    height: 100%
    border: 2px solid
    box-sizing: border-box
    display: flex
    flex-direction: column
    justify-content: center
    align-items: center
    opacity: 0.5


// --------------------------------------
// GAP     
.gap
  position: relative
  padding-bottom: 100%
  transition: 500ms
  
  &::before
    content: ""
    position: absolute
    left: 50%
    top: 0
    width: 50%
    height: calc(200% + #{$gridGap} * 2 - 4px)
    border-width: 0 0 2px 2px
    border-style: solid
    margin-left: -1px
    color: #fff
    opacity: 0.2
    

  
// --------------------------------------
// COLORS
.alkali-metal
  color: $alkaliMetalColor

.alkaline-earth-metal
  color: $alkalineEarthMetalColor

.lanthanoid
  color: $lanthanoidColor

.actinoid
  color: $actinoidColor
  
.transition-metal
  color: $transitionMetalColor

.post-transition-metal
  color: $postTransitionMetalColor

.metalloid
  color: $metalloidColor

.other-nonmetal
  color: $otherNonmetalColor

.noble-gas
  color: $nobleGasColor

.unknown
  color: $unknownColor



// --------------------------------------
// ROWS & COLUMNS
@for $i from 1 through 10
  .r#{$i}
    grid-row: $i

@for $i from 1 through 18
  .c#{$i}
    grid-column: $i



// --------------------------------------
// SHIFT EDGE ELEMENTS ON ZOOM
.r1 input[type="radio"].activate:checked ~ .square
  top: 100%

.r10 input[type="radio"].activate:checked ~ .square
  top: -100%

.c1 input[type="radio"].activate:checked ~ .square
  left: 100%

.c18 input[type="radio"].activate:checked ~ .square
  left: -100%



// --------------------------------------
// ANIMATIONS
@keyframes rotate
  from
    transform: rotate(0deg)
  to
    transform: rotate(360deg)

@keyframes fade-in
  from
    opacity: 0
  to
    opacity: 1

@keyframes noise
  0%, 100%
    background-position: 0 0
  10%
    background-position: -5% -10%
  20%
    background-position: -15% 5%
  30%
    background-position: 7% -25%
  40%
    background-position: 20% 25%
  50%
    background-position: -25% 10%
  60%
    background-position: 15% 5%
  70%
    background-position: 0% 15%
  80%
    background-position: 25% 35%
  90%
    background-position: -10% 10%



// --------------------------------------
// KEY
.key
  position: relative
  z-index: 1
  grid-row: 1
  grid-column-start: 3
  grid-column-end: 17
  font-size: 0.8vw
  line-height: 1.5
  display: flex
  align-items: center
  pointer-events: none
  user-select: none
  
  .row
    position: relative
    display: flex
    width: 100%
    justify-content: space-between
    
    label
      opacity: 0.85
      cursor: pointer
      transition: 120ms
      pointer-events: all
      
      &:hover
        opacity: 1 !important


// --------------------------------------
// CATEGORY TOGGLES
#alkali-metals:checked ~ .periodic-table .element:not(.alkali-metal),
#alkaline-earth-metals:checked ~ .periodic-table .element:not(.alkaline-earth-metal),
#lanthanoids:checked ~ .periodic-table .element:not(.lanthanoid),
#actinoids:checked ~ .periodic-table .element:not(.actinoid),
#transition-metals:checked ~ .periodic-table .element:not(.transition-metal),
#post-transition-metals:checked ~ .periodic-table .element:not(.post-transition-metal),
#metalloids:checked ~ .periodic-table .element:not(.metalloid),
#other-nonmetals:checked ~ .periodic-table .element:not(.other-nonmetal),
#noble-gasses:checked ~ .periodic-table .element:not(.noble-gas),
#unknown:checked ~ .periodic-table .element:not(.unknown),
#alkali-metals:checked ~ .periodic-table .placeholder,
#alkaline-earth-metals:checked ~ .periodic-table .placeholder,
#lanthanoids:checked ~ .periodic-table .placeholder:not(.lanthanoid),
#actinoids:checked ~ .periodic-table .placeholder:not(.actinoid),
#transition-metals:checked ~ .periodic-table .placeholder,
#post-transition-metals:checked ~ .periodic-table .placeholder,
#metalloids:checked ~ .periodic-table .placeholder,
#other-nonmetals:checked ~ .periodic-table .placeholder,
#noble-gasses:checked ~ .periodic-table .placeholder,
#unknown:checked ~ .periodic-table .placeholder
  opacity: 0.15
  pointer-events: none

#alkali-metals:checked ~ .periodic-table .key label:not(.alkali-metal),
#alkaline-earth-metals:checked ~ .periodic-table .key label:not(.alkaline-earth-metal),
#lanthanoids:checked ~ .periodic-table .key label:not(.lanthanoid),
#actinoids:checked ~ .periodic-table .key label:not(.actinoid),
#transition-metals:checked ~ .periodic-table .key label:not(.transition-metal),
#post-transition-metals:checked ~ .periodic-table .key label:not(.post-transition-metal),
#metalloids:checked ~ .periodic-table .key label:not(.metalloid),
#other-nonmetals:checked ~ .periodic-table .key label:not(.other-nonmetal),
#noble-gasses:checked ~ .periodic-table .key label:not(.noble-gas),
#unknown:checked ~ .periodic-table .key label:not(.unknown)
  opacity: 0.65

.category-toggle:not(#lanthanoids):not(#actinoids):checked ~ .periodic-table .gap
  opacity: 0.5

.category-toggle:checked ~ .category-cancel
  visibility: visible
  pointer-events: all
  cursor: pointer
!

JS 

              
                // ¯\_(ツ)_/¯
!
999px

Console