.container
  .box
  .container-forms
    .container-info
      .info-item
        .table
          .table-cell
            p Have an account?
            .btn Log in
      .info-item
        .table
          .table-cell
            p Don't have an account? 
            .btn Sign up
    .container-form
      .form-item.log-in
        .table
          .table-cell
            input type="text" name="Username" placeholder="Username"
            input type="Password" name="Password" placeholder="Password"
            .btn Log in
      .form-item.sign-up
        .table
          .table-cell
            input type="text" name="email" placeholder="Email"
            input type="text" name="fullName" placeholder="Full Name"
            input type="text" name="Username" placeholder="Username"
            input type="Password" name="Password" placeholder="Password"
            .btn Sign up
a.box-item href="https://codepen.io/Anna_Batura/" target="_blank"
  svg class="rabbit" viewBox="0 0 600 600" version="1.2"
    path id="rabbit" d="m 335.94313,30.576451 c -9.79312,-0.146115 -17.39091,4.439466 -17.39091,13.789758 0,11.508038 -2.91019,60.415461 1.40532,76.238951 4.31553,15.82355 21.58583,38.97215 34.51834,54.67597 10.06946,12.22726 4.34772,41.69626 4.34772,56.0813 0,14.38499 -2.89751,25.9107 -8.65153,25.9107 -5.75402,0 -14.35971,5.75217 -20.11373,11.50612 -5.75395,5.75402 -11.51588,12.95631 -18.70841,7.20229 -7.19251,-5.75402 -20.15388,-11.49441 -43.16987,-15.80992 -23.01609,-4.31551 -61.84129,-0.0234 -86.29583,8.60763 -24.45458,8.63104 -76.25857,56.11061 -90.643535,77.6882 -14.385056,21.5775 -15.799189,87.73247 -14.36068,97.80193 1.438509,10.06953 -2.908267,17.28255 -10.100778,8.65153 -7.192459,-8.63104 -12.911438,-4.30381 -12.911438,-4.30381 0,0 -7.202292,14.37045 -7.202292,21.56298 0,7.19244 2.854564,14.36068 2.854564,14.36068 0,0 -11.506099,8.65056 -11.506099,14.40458 0,5.75397 11.515881,15.83044 18.708391,24.46146 7.192546,8.63097 31.651182,25.89997 41.720624,24.46148 10.069543,-1.43851 28.775063,-0.0121 35.967573,4.3038 7.19253,4.31551 24.44687,10.06761 46.02443,11.5061 21.57752,1.43851 81.97845,5.75307 97.80193,5.75307 15.82357,0 20.1675,-2.86435 27.35996,-10.05688 7.19253,-7.19245 -5.78527,-15.84115 -10.10079,-25.9107 -4.31551,-10.06946 14.40363,-7.16912 20.15765,-8.60763 5.75402,-1.43849 21.59424,-11.5061 31.66376,-11.5061 10.06953,0 8.6165,10.05589 21.56298,15.80993 12.94654,5.75393 31.63939,24.43902 46.02443,27.31602 14.38497,2.87695 47.47173,0.0121 58.97979,-4.30381 11.50797,-4.31551 10.06946,-14.37044 0,-21.56297 -10.06955,-7.19244 -34.50663,-20.16742 -38.82214,-27.35994 -4.31551,-7.19246 -5.74329,-15.81969 1.44924,-23.01224 7.19251,-7.19252 14.35876,-4.30292 25.86678,-10.05685 11.50806,-5.75402 15.80992,-23.04354 15.80992,-33.11301 0,-10.06953 1.36928,-21.01352 5.75307,-27.31602 3.67345,-5.28128 5.10015,-22.13212 5.30499,-33.64009 0.21874,-12.28864 -5.29329,-15.24871 -9.60881,-22.44122 -4.31543,-7.19246 4.30285,-17.25917 10.05687,-17.25917 5.75402,0 31.65108,-4.33602 41.72062,-8.65153 10.06946,-4.31546 20.16744,-23.03273 27.35995,-31.66377 7.19246,-8.63095 1.41799,-27.31512 -8.65154,-33.06907 -10.06954,-5.75402 -10.07746,-21.59431 -18.70841,-31.66377 -8.63103,-10.06953 -18.68507,-31.62961 -27.31604,-38.82213 -8.63101,-7.19253 -28.77502,-12.95535 -35.96755,-12.95535 -7.19253,0 -11.50612,9e-4 -11.50612,-5.75306 0,-5.75402 -1.44924,-12.9203 -1.44924,-25.86678 0,-12.94655 -16.24344,-68.464566 -37.3729,-102.149659 -4.40799,-7.027282 -11.5581,-5.405316 -20.15765,-2.898485 -5.69412,1.659863 -8.60761,4.35564 -8.60761,23.056136 0,18.700566 -11.50515,-0.03133 -17.25917,-10.100794 -5.75403,-10.069512 -15.86265,-21.58444 -28.80918,-24.461458 -2.42749,-0.539415 -4.76669,-0.800692 -7.02665,-0.834399 z"
View Compiled
@import "compass/css3"
@import url(https://fonts.googleapis.com/css?family=Oswald|Roboto)
$width: 600px
$height: 320px
$padding: 10px 15px
body
  position: absolute
  left: 0
  top: 0
  width: 100%
  height: 100%
  font-family: 'Roboto', sans-serif
  background-color: #5356ad
  overflow: hidden
.table
  display: table
  width: 100%
  height: 100%
.table-cell
  display: table-cell
  vertical-align: middle
  @include transition(all 0.5s)
.container
  position: relative
  width: $width
  margin: 30px auto 0
  height: $height
  background-color: #999ede
  top: 50%
  margin-top: -160px
  @include transition(all 0.5s)
  .box
    position: absolute
    left: 0
    top: 0
    width: 100%
    height: 100%
    overflow: hidden
    &:before, &:after
      content: " "
      position: absolute
      left: 152px
      top: 50px
      background-color: #9297e0
      transform: rotateX(52deg) rotateY(15deg) rotateZ(-38deg)
      width: 300px
      height: 285px
      @include transition(all 0.5s)
    &:after
      background-color: #a5aae4
      top: -10px
      left: 80px
      width: 320px
      height: 180px
  .container-forms
    position: relative
  .btn
    cursor: pointer
    text-align: center
    margin: 0 auto
    width: 60px
    color: #fff
    background-color: #ff73b3
    opacity: 1
    @include transition(all 0.5s)
    &:hover
      opacity: 0.7
      
  .btn, input
    padding: $padding
  input
    margin: 0 auto 15px
    display: block
    width: $width/2-80px
    @include transition(all 0.3s)
  .container-forms
    .container-info
      text-align: left
      font-size: 0
      .info-item
        text-align: center
        font-size: 16px
        width: $width/2
        height: $height
        display: inline-block
        vertical-align: top
        color: #fff
        opacity: 1
        @include transition(all 0.3s)
        p
          font-size: 20px
          margin: 20px
        .btn
          background-color: transparent
          border: 1px solid #fff
        .table-cell
          padding-right: 35px
        &:nth-child(2)
          .table-cell
            padding-left: 35px
            padding-right: 0
            
  .container-form
    overflow: hidden
    position: absolute
    left: 30px
    top: -30px
    width: 305px
    height: $height + 60px
    background-color: #fff
    box-shadow: 0 0 15px 0 rgba(0, 0, 0, 0.2)
    @include transition(all 0.5s)
    &:before
      content: "✔"
      position: absolute
      left: 160px
      top: -50px
      color: #5356ad
      font-size: 130px
      opacity: 0
      @include transition(all 0.5s)
    .btn
      position: relative
      box-shadow: 0 0 10px 1px #ff73b3
      margin-top: 30px
  .form-item
    position: absolute
    left: 0
    top: 0
    width: 100%
    height: 100%
    opacity: 1
    @include transition(all 0.5s)
    &.sign-up
      position: absolute
      left: -100%
      opacity: 0
  &.log-in
    .box
      &:before
        position: absolute
        left: 180px
        top: 62px
        height: 265px
      &:after
        top: 22px
        left: 192px
        width: 324px
        height: 220px
    .container-form
      left: 265px
      .form-item
        &.sign-up
          left: 0
          opacity: 1
        &.log-in
          left: -100%
          opacity: 0
  &.active
    width: 260px
    height: 140px
    margin-top: -70px
    .container-form
      left: 30px
      width: 200px
      height: 200px
      &:before
        content: "✔"
        position: absolute
        left: 51px
        top: 5px
        color: #5356ad
        font-size: 130px
        opacity: 1
    input, .btn, .info-item
      display: none
      opacity: 0
      padding: 0px
      margin: 0 auto
      height: 0
    .form-item
      height: 100%
    .container-forms
      .container-info
        .info-item
          height: 0%
          opacity: 0
.rabbit
  width: 50px
  height: 50px
  position: absolute
  bottom: 20px
  right: 20px
  z-index: 3
  fill: #fff
View Compiled
$(".info-item .btn").click(function(){
  $(".container").toggleClass("log-in");
});
$(".container-form .btn").click(function(){
  $(".container").addClass("active");
});
Run Pen

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://code.jquery.com/jquery-2.2.4.min.js