<section class="form">
  <p>Subscribe Our Newsletter</p>
  <input type="text" placeholder="Email Address">
  <input type="submit" value="Subscribe">
</section>
@import url('https://fonts.googleapis.com/css?family=Bree+Serif');

:root{
  --bg: #290454;
  --btn: #4B0899;
  --text: #ffffff;
  --width: 25em;
  --font: 'Bree Serif', serif;
}
body{
  background: var(--bg);
}
input[type="submit"]{
  background: var(--btn);
  color: var(--text);
  width: 100%;
  border: none;
  outline: none;
  margin-bottom: calc(var(--width)/11);
  font-family: var(--font);
}
input[type="text"]{
  background: var(--text);
  border: none;
}
input{
  padding: calc(var(--width)/24) calc(var(--width)/22);
  width: 100%;
  margin: auto;
  display: inline-block;
  margin-top: 30px;
  box-sizing: border-box;
  font-size: calc(var(--width)/24);
}
section.form{
  border: 0.5em solid var(--text);
  padding: calc(var(--width)/11) calc(var(--width)/11);
  width: var(--width);
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
}
section p{
  display: block;
  width: 100%;
  font-size: calc(var(--width)/12);
  text-align: center;
  color: var(--text);
  font-family: var(--font);
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.