@import url('https://fonts.googleapis.com/css?family=Open+Sans:400,600,700');
@import url('https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css');

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

html, body {
  height: 100vh;
}

body {
  font: 14px/1 'Open Sans', sans-serif;
  color: #555;
  background: #fafafa;
}

h1 {
  padding: 30px 0;
  font-weight: 400;
  text-align: center;
}

p {
  margin: 0 0 20px;
  line-height: 1.5;
}

main {
  min-width: 320px;
  max-width: 800px;
  padding: 30px;
  margin: 1 auto;
  background: #fafafa;
}

section {
  display: none;
  padding: 20px 0 0;
  border-top: 1px solid #ddd;
  
}

input {
  display: none;
}

label {
  display: inline-block;
  margin: 0 0 -1px;
  padding: 15px 25px;
  font-weight: 600;
  text-align: center;
  color: #bbb;
  border: 1px solid transparent;
}

label:before {
  font-family: fontawesome;
  font-weight: normal;
  margin-right: 10px;
}

label[for*='1']:before { content: '\f1cb'; }
label[for*='2']:before { content: '\f17d'; }
label[for*='3']:before { content: '\f16b'; }
label[for*='4']:before { content: '\f1a9'; }

label:hover {
  color: #000;
  cursor: pointer;
}

input:checked + label {
  color: #000;
  border: 1px solid #ddd;
  border-top: 4px solid blue;
  border-bottom: 4px solid #f0f0f0;
}

#tab1:checked ~ #content1,
#tab2:checked ~ #content2,
#tab3:checked ~ #content3,
#tab4:checked ~ #content4 {
  display: block;
}

@media screen and (max-width: 650px) {
  label {
    font-size: 0;
  }
  label:before {
    margin: 0;
    font-size: 18px;
  }
}

@media screen and (max-width: 400px) {
  label {
    padding: 15px;
  }
}