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CSS

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JavaScript

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HTML 

              
                <div id="speech-bubble">
  <p contenteditable>Inspired by the awesome NES.css!<br>With editable text!</p> 
</div>
!

CSS 

              
                @import url('https://fonts.googleapis.com/css?family=Press+Start+2P');

body {
  background-color: red;
  padding: 50px;
}

#speech-bubble {
  width: auto;
  max-width: 75%;
  height: auto;
  background-color: #fff;
  padding: 25px;
  display: inline-block;
  margin: 30px 30px 70px;
  position: relative;
  
  box-shadow:
    0 -10px 0 #fff, //top
    0 -20px 0 #000,
    -10px 0 0 #fff, //left
    -20px 0 0 #000,
    0 10px 0 #fff, //bottom
    0 20px 0 #000,
    10px 0 0 #fff, //right
    20px 0 0 #000,
    -10px -10px 0 #000, //top-left corner
    10px 10px 0 #000, //top-right corner
    -10px 10px 0 #000, //bottom-left corner
    10px -10px 0 #000 //bottom-right corner
}

#speech-bubble:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 5%;
  width: 10px;
  height: 10px;
  margin-bottom: -20px;
  background-color: #fff;
  
  box-shadow:
    10px 0 0 #fff,
    20px 0 0 #fff,
    30px 0 0 #fff,
    40px 0 0 #fff,
    50px 0 0 #fff,
    -10px 10px 0 #000,
    0px 10px 0 #fff,
    10px 10px 0 #fff,
    20px 10px 0 #fff,
    30px 10px 0 #fff,
    40px 10px 0 #fff,
    50px 10px 0 #000,
    -30px 20px 0 #000,
    -20px 20px 0 #000,
    -10px 20px 0 #fff,
    0px 20px 0 #fff,
    10px 20px 0 #fff,
    20px 20px 0 #fff,
    30px 20px 0 #000,
    40px 20px 0 #000,
    -40px 30px 0 #000,
    -30px 30px 0 #fff,
    -20px 30px 0 #fff,
    -10px 30px 0 #fff,
    0px 30px 0 #fff,
    10px 30px 0 #000,
    20px 30px 0 #000,
    -40px 40px 0 #000,
    -30px 40px 0 #000,
    -20px 40px 0 #000,
    -10px 40px 0 #000,
    0px 40px 0 #000
}

p {
  min-width: 25px;
  display: inline-block;
  margin: 0;
  font-size: 1.4em;
  font-family: 'Press Start 2P', cursive;
  line-height: 1.5em;
  position: relative;
}

p:empty:before {
  content: 'Inspired by the awesome NES.css';
  color: #555;
  border: 1px solid #ccc;
}

p:empty:focus:before {
  content: '';
  width: 25px;
  height: 1em;
  display: inline-block;
  border: 1px solid #ccc;
  border-bottom: 5px solid #000;
}

p:focus {
  outline: none;
  // caret-color: transparent;
  
  &:after {
    display: none;
  }
}

p:after {
  content: '';
  height: 20px;
  width: 10px;
  margin-top: 5px;
  margin-left: 10px;
  background-color: #000;
  border: 0;
  display: inline-block;
  position: absolute;
  animation: blink 1000ms infinite;
}

@keyframes blink {
  0% {
    background-color: #000;
  }
  49.99999% {
    background-color: #000;
  }
  50% {
    background-color: #fff;
  }
  100% {
    background-color: #fff;
  }
}
!

JS 

              
                // Taking decades of human achievement in web technologies and reverting it all back to the 80's. Playing with box-shadow properties to achieve cool pixelated effect. No real intent to produce anything substantial out of this. Just done for fun.
// Inspired by the awesome NES.css
// https://nostalgic-css.github.io/NES.css/
!
999px

Console