html, body, #app {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: 'Helvetica', sans-serif;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  padding: 0;
}

* {
  box-sizing: border-box;
}

html, body, #app {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: 'Helvetica', sans-serif;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  padding: 0;
}

Add box-sizing border box to EVERYTHING
Add box-sizing border box to EVERYTHING
