archivo inicial css

style.css

html,body{
  width: 100%;
  height: 100%;
  font-family: 'Open Sans', sans-serif
}

*, *:after, *:before{
  box-sizing: border-box;
  margin: 0px;
  padding: 0px;
}

article,aside,figure,footer,header,nav,section,details,summary{
  display:block;
}

ul, li {
  list-style: none;
}

a:link, a:hover, a:visited, a:active{
  text-decoration:none;
}

img,object,video,embed{
  max-width:100%;
}
/* Los botones deben tener un min-width=48px; min-height=48px */
.button {
  min-width: 48px;
  min-width: 48px;
}