body {
  padding-top: 15px;
  background-color: #1a1a1a;
}

h1 {
  color: #ffffff;
  font-family: 'Poppins', sans-serif;
  letter-spacing: 
  font-weight: 600;
}

.container {
  padding: 1.8em 0 8.8em 0;
  margin: 10px auto;
  width: 580px;
  background: url('http://www.mendera.de/BWbilder/Leder.jpg');
  background-color: darkgrey;
  border-radius: 40px;
  border: 3px outset #eeeeee;
  box-shadow: 0px 15px 20px rgba(0, 0, 0, .6);

    flex-flow: row wrap;
}

.converter-wrapper {
  margin: 0 auto;
  width: 100%;
  max-width: 550px;
  text-align: center;
  padding: 15px;
  box-sizing: border-box;
}

.converter-wrapper input {
  font-family: 'Open Sans', sans-serif;
  font-size: 1em;
  width: 100%;
  text-align: center;
  margin-top: 15px;
  height: 40px;
  box-sizing: border-box;
}

.converter-wrapper span {
  position: relative;
  display: inline-block;
  vertical-align: middle;
  width: 100%;
}

.converter-wrapper span select {
  background-color: #f6b831;
  color: #111111;
  font-size: inherit;
  padding: 10px;
  width: 100%;
  border: 0;
  margin: 0;
  border-radius: 0px;
  text-indent: 0.01px;
  text-overflow: '';
  -webkit-appearance: none; /* hide default arrow in chrome OSX */
}

.converter-wrapper span::before,
.converter-wrapper span::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.converter-wrapper span::after { /*  Custom dropdown arrow */
  content: "\25BC";
  height: 1em;
  font-size: .625em;
  line-height: 1;
  right: 1.5em;
  top: 50%;
  margin-top: -.5em;
  color: #111;
}

.converter-wrapper span::before { /*  Custom dropdown arrow cover */
  width: 2.5em;
  right: 0;
  top: 0;
  bottom: 0;
  border-radius: 5;
  background-color: #bed60d;
}

.converter-side-a,
.converter-side-b {
  float: left;
  margin-top: 10px;
  box-sizing: border-box;
  width: 45%;
}

.converter-equals {
  float: left;
  box-sizing: border-box;
  width: 10%;
  color: #FFF;
  font-size: 2.4em;
  line-height: 0;
  text-align: center;
}

.converter-side-a {
  padding-right: 10px;
}

.converter-side-b {
  padding-left: 10px;
}