Expanding rectangle

Images in top left and bottom right corners eventually

by katalin_2003

HTML

<div id="container">
  <div id="intro">
    <div id="small-container">
      <p>Hello!</p>
      <input type="text" value="PlaceHolderValue">
    </div>
  </div>
</div>

CSS

/* CSS Document */
html {
  height: 100%;
}

body {
  height: 100%;
  width: 100%;
  margin: 0;
  background-color: #f0f9ff;
  font-family: sans-serif;
}

#container {
  width: 700px;
  height: 350px;
  position: absolute;
  left: 50%;
  top: 50%;
  /*xmargin: -175px 0 0 -350px;*/
}

#intro {
  position: relative;
  width: 700px;
  height: 350px;
  border: 2px solid #ccc;
  border-radius: 4px;
  -moz-border-radius: 10px;
  background: #fff;
  animation: welcome 2s;
  animation-timing-function: linear;
  animation-play-state: running;
  -webkit-animation: welcome 2s;
  -webkit-animation-fill-mode: forwards;
  animation-fill-mode: forwards;
  /*Safari and Chrome*/
  -webkit-animation-timing-function: linear;
  -webkit-animation-play-state: running;
}

#small-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

p {
	position: relative;
	left: 0;
	top: 0;
}

@keyframes welcome {
  from {
    width: 0px;
    margin-left: 0;
    margin-top: 0;
    height: 0px;
  }

  to {
    width: 700px;
    margin-left: -350px;
    margin-top: -175px;
    height: 350px;
  }
}

/*Safari and Chrome*/
@-webkit-keyframes welcome {
  from {
    width: 0px;
    height: 0px;
    margin-left: 0;
    margin-top: 0;
  }

  to {
    width: 700px;
    height: 350px;
    margin-left: -350px;
    margin-top: -175px;
  }
}