
body {
  background-color: #64ceaa;
  color: white;
  font-family: sans-serif;
}

kbd {
  border: 1px solid white;
  margin: 2px;
  padding: 2px;
}

.header, .app, #bpm {
  text-align: center;
}

.header {
  margin-top: 4em;
}

.output {
  margin: 2em;
}

input#bpm {
  font-size: 1em;
  font-weight: bold;
  padding: 1em;
  width: 5.25em;
}

button#toggle {
  background-color: white;
  font-size: 1em;
  font-weight: bold;
  padding: 1em;
}

#flash {
  fill: white;
  stroke-width: 10;
}

#flash.active {
  stroke: white;
}


body {
  background-color: #64ceaa;
  color: white;
  font-family: sans-serif;
}

kbd {
  border: 1px solid white;
  margin: 2px;
  padding: 2px;
}

.header, .app, #bpm {
  text-align: center;
}

.header {
  margin-top: 4em;
}

.output {
  margin: 2em;
}

input#bpm {
  font-size: 1em;
  font-weight: bold;
  margin: .3em;
  padding: 1.5em;
  width: 5.25em;
}

button#toggle {
  background-color: white;
  font-size: 1em;
  font-weight: bold;
  margin: .3em;
  padding: 1.5em;
}

#flash {
  fill: white;
  stroke-width: 10;
}

#flash.active {
  stroke: white;
}

Increase input / button size
Increase input / button size
