Edit on
.preload.login--container
  .login--form
    .login--username-container
      %label Username
      %input(type="text" placeholder="Username" autofocus)

    .login--password-container
      %label Password
      %input(type="password" placeholder="Password")
      %button.js-toggle-login.login--login-submit Login
 
  .login--toggle-container
    %small Hey you,
    .js-toggle-login Login
    %small already

    
    
    
%footer
  %a(href="https://twitter.com/code_dependant" class="twitter-follow-button" data-show-count="false")
    Follow @code_dependant
  %script !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');
  
View Compiled
@import compass

$background-color: #F15A5C  
$easing-function: cubic-bezier(.06,.63,0,1)
$animation-duration: 1s

*
  margin: 0
  padding: 0
  box-sizing: border-box
  
html, body 
  height: 100%
  background-color: $background-color
  font-family: 'Roboto Slab', serif
  color: white
// see https://css-tricks.com/transitions-only-after-page-load/
.preload *
  transition: none !important
    
label
  display: block
  font-weight: bold
  font-size: small
  text-transform: uppercase
  font-size: 0.7em
  margin-bottom: 0.35em

    
input[type="text"], input[type="password"]
  width: 100%
  border: none
  padding: 0.5em
  border-radius: 2px
  margin-bottom: 0.5em
  color: #333
  &:focus
    outline: none
    box-shadow: inset -1px -1px 3px rgba(0, 0, 0, .3)
  
button
  padding-left: 1.5em
  padding-right: 1.5em
  padding-bottom: 0.5em
  padding-top: 0.5em
  border: none
  border-radius: 2px
  background-color: #7E5AF1
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.25)
  color: white
  box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.45)
    

small
  font-size: 1em
  

.login--login-submit
  float: right

.login--container
  width: 600px
  background-color: $background-color
  margin: 0 auto
  position: relative
  top: 25%
  
.login--toggle-container
  position: absolute
  background-color: $background-color
  right: 0
  line-height: 2.5em
  width: 50%
  height: 120px
  text-align: right
  cursor: pointer
  transform: perspective(1000px) translateZ(1px)
  transform-origin: 0% 0%
  transition: all $animation-duration $easing-function
  backface-visibility: hidden
  //border: 1px solid black
  .js-toggle-login
    font-size: 4em
    text-decoration: underline

  .login--active &
    transform: perspective(1000px) rotateY(180deg)
    background-color: darken($background-color, 25%)
    

.login--username-container, .login--password-container
  float: left
  background-color: $background-color
  width: 50%
  height: 120px
  padding: .5em
  
    
    
.login--username-container
  transform-origin: 100% 0%
  transform: perspective(1000px) rotateY(180deg)
  transition: all $animation-duration $easing-function
  background-color:  darken($background-color, 25%)
  backface-visibility: hidden
    
  .login--active &
    transform: perspective(1000px) rotateY(0deg)
  
    background-color: $background-color


footer
  position: absolute
  bottom: 12px
  left: 20px
    
View Compiled
$ ->
  $(".login--container").removeClass("preload")
  @timer = window.setTimeout =>
    $(".login--container").toggleClass("login--active")
  , 2000

  $(".js-toggle-login").click =>
    window.clearTimeout(@timer)
    $(".login--container").toggleClass("login--active")
    $(".login--username-container input").focus()
    
View Compiled
Rerun