// These variables help keep track of the input name and ID
// currentTab helps keep track of each individual input
- var currentTab = 1
// tabControlName is used as a unique identifier for the accordion
- var tabControlName = 'rad'
mixin tab(title, checked)
  li
    - var tabId = tabControlName + currentTab++
    // Using radio inputs means only one can be selected at a time
    // The ID must be unique so the label will point to the input
    input(id=tabId type='radio' name=tabControlName checked=checked)
    label(for=tabId): div=title
    .accslide
      .content
        block
    
ul
  +tab('Just keep going with longer text', true)
    h1 Just keep going with longer text
    p Lorem ipsum...
  +tab('Second panel')
    h1 Second panel
    p Lorem ipsum...
  +tab('Third panel')
    h1 Third panel
    p Lorem ipsum...
  +tab('Fourth panel')
    h1 Fourth panel
    p Lorem ipsum...
View Compiled
// Variables
// Only generate rules up to the max tabs desired
$max-tabs: 8;
$tab-width: 40px;

// Theming
@import url('https://fonts.googleapis.com/css?family=Open+Sans');

$clr-bg: #1C1F2B;
$clr-bg-light: lighten($clr-bg, 10%);
$clr-bg-lighter: lighten($clr-bg, 15%);
$clr-bg-dark: darken($clr-bg, 2.5%);
$clr-bg-darker: darken($clr-bg, 5%);
$clr-text: $clr-white;
$clr-text-hint: rgba($clr-text, .6);
$clr-primary: $clr-blue;

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
  background: $clr-bg;
  color: $clr-text;
  font-family: 'Open Sans', sans-serif;
}

/* LIST */
ul {
  list-style: none;
}

/* FORM */
// Hide the input
input {
  position: absolute;
  top: -9999px;
  left: -9999px;
}

// Make the label a vertical bar
label {
  display: block;
  float: left;
  height: 100vh;
  width: $tab-width;
  overflow: hidden;

  background: $clr-bg-light;
  text-align: center;
  font-size: 14px;
  line-height: $tab-width + 10;

  transition: background 300ms ease;
}

li:nth-child(even) > input + label {
  background: $clr-bg-lighter;
}

label:hover,
li:nth-child(even) > input + label:hover {
  background: $clr-primary;
  color: #fff;
  cursor: pointer;
}

input[type="radio"]:checked ~ label {
  background: $clr-primary;
  color: #fff;
  cursor: default !important;
}

/* SLIDES */
.accslide {
  display: block;
  height: 100%;
  width: 0px;
  padding: 10px 0;
  float: left;
  overflow-x: hidden;

  font-sizes: 12px;
  line-height: 1.5;

  transition: all 700ms ease;

  * { padding-left: 10px }
  img { margin-top: 10px  }
}

input[type="radio"]:not(:checked) ~ label > * {
  padding-left: 7px;
  font-size: 1.2em;
  white-space: nowrap;
	transform: rotate(90deg);
}

input[type="radio"]:checked ~ label > * {
  display: none;
}

@for $i from 2 through $max-tabs {
  @for $j from 1 through $i {
    li:nth-child(#{$j}):nth-last-child(#{$i - $j + 1}) input[type="radio"]:checked ~ .accslide {
      width: calc(100% - #{$i * $tab-width});
    }
  }
}
View Compiled
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External CSS

  1. https://raw.githubusercontent.com/mrmlnc/material-color/master/material-color.scss

External JavaScript

This Pen doesn't use any external JavaScript resources.