<div class="container">
  <div class="title">Lorem Ipsum</div>
  <div class="content">
    Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
  </div>
</div>

$bg-mask = "data:image/png;base64,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"
.container
  width 500px
  color white
  border-top-left-radius 20px
  border-top-right-radius 20px
  margin auto
  mask url($bg-mask) left -80px bottom/160px 30px no-repeat,
       url($bg-mask) right -80px bottom/160px 30px no-repeat,
       linear-gradient(to top, rgba(black,0) 30px, rgba(black,1) 30px),
       linear-gradient(to right, rgba(black,0) 80px, rgba(black,1) 80px, rgba(black,1) 50%, rgba(black,0) 50%),
       linear-gradient(to left, rgba(black,0) 80px, rgba(black,1) 80px, rgba(black,1) 50%, rgba(black,0) 50%)
  -webkit-mask @mask 
  filter drop-shadow(0 0 1px rgba(#26c8e7,.6))
  position relative
  .title
    font-size 20px
    position absolute
    top 20px
    left 20px
  .content
    font-size 15px
    line-height 1.4
    padding 50px 20px 30px
    filter drop-shadow(0 0 20px rgba(#26c8e7,.6))
    &:before
      content ''
      width @width
      height 100%
      background rgba(black,0.2)
      mask @mask
      -webkit-mask @mask 
      display block
      position absolute
      left 0
      top 0

body
  width 100vw
  height 100vh
  background black
  display flex