<div class="alert">
  <h2>Hey! Read Me...</h2>
  <p>This is an example of what you can do with pure css to style radio buttons or checkboxes. If you are looking a more flexible & mordern way to style radio buttons on forms, take a look at this <a target="_blank"  href="https://codepen.io/AngelaVelasquez/details/BWXbxP" title="SVG radio buttons">version with SVG icons</a>. I also wrote a <a target="_blank" href="https://codepen.io/AngelaVelasquez/post/css-styling-radio-button">post</a> about it.</p>
</div>

<div class="container">
  
  <h2>Your favorite thing in the world:</h2>
  
  <ul>
  <li>
    <input type="radio" id="f-option" name="selector">
    <label for="f-option">Pizza</label>
    
    <div class="check"></div>
  </li>
  
  <li>
    <input type="radio" id="s-option" name="selector">
    <label for="s-option">Bacon</label>
    
    <div class="check"><div class="inside"></div></div>
  </li>
  
  <li>
    <input type="radio" id="t-option" name="selector">
    <label for="t-option">Cats</label>
    
    <div class="check"><div class="inside"></div></div>
  </li>
</ul>
</div>

<div class="signature">
  <p>Made with <i class="much-heart"></i> by <a href="https://codepen.io/AngelaVelasquez">Angela Velasquez</a></p>
</div>

@import url('https://fonts.googleapis.com/css?family=Lato');

body, html{
  height: 100%;
  background: #222222;
  font-family: 'Lato', sans-serif;
}

.container{
  display: block;
  position: relative;
  margin: 40px auto;
  height: auto;
  width: 500px;
  padding: 20px;
}

h2 {
  color: #AAAAAA;
}

.container ul{
  list-style: none;
  margin: 0;
  padding: 0;
  overflow: auto;
}

ul li{
  color: #AAAAAA;
  display: block;
  position: relative;
  float: left;
  width: 100%;
  height: 100px;
  border-bottom: 1px solid #333;
}

ul li input[type=radio]{
  position: absolute;
  visibility: hidden;
}

ul li label{
  display: block;
  position: relative;
  font-weight: 300;
  font-size: 1.35em;
  padding: 25px 25px 25px 80px;
  margin: 10px auto;
  height: 30px;
  z-index: 9;
  cursor: pointer;
  -webkit-transition: all 0.25s linear;
}

ul li:hover label{
  color: #FFFFFF;
}

ul li .check{
  display: block;
  position: absolute;
  border: 5px solid #AAAAAA;
  border-radius: 100%;
  height: 25px;
  width: 25px;
  top: 30px;
  left: 20px;
  z-index: 5;
  transition: border .25s linear;
  -webkit-transition: border .25s linear;
}

ul li:hover .check {
  border: 5px solid #FFFFFF;
}

ul li .check::before {
  display: block;
  position: absolute;
  content: '';
  border-radius: 100%;
  height: 15px;
  width: 15px;
  top: 5px;
  left: 5px;
  margin: auto;
  transition: background 0.25s linear;
  -webkit-transition: background 0.25s linear;
}

input[type=radio]:checked ~ .check {
  border: 5px solid #0DFF92;
}

input[type=radio]:checked ~ .check::before{
  background: #0DFF92;
}

input[type=radio]:checked ~ label{
  color: #0DFF92;
}

.signature {
  margin: 10px auto;
  padding: 10px 0;
  width: 100%;
}

.signature p{
  text-align: center;
  font-family: Helvetica, Arial, Sans-Serif;
  font-size: 0.85em;
  color: #AAAAAA;
}

.signature .much-heart{
  display: inline-block;
  position: relative;
  margin: 0 4px;
  height: 10px;
  width: 10px;
  background: #AC1D3F;
  border-radius: 4px;
  -ms-transform: rotate(45deg);
    -webkit-transform: rotate(45deg);
    transform: rotate(45deg);
}

.signature .much-heart::before, 
.signature .much-heart::after {
    display: block;
  content: '';
  position: absolute;
  margin: auto;
  height: 10px;
  width: 10px;
  border-radius: 5px;
  background: #AC1D3F;
  top: -4px;
}

.signature .much-heart::after {
  bottom: 0;
  top: auto;
  left: -4px;
}

.signature a {
  color: #AAAAAA;
  text-decoration: none;
  font-weight: bold;
}


/* Styles for alert... 
by the way it is so weird when you look at your code a couple of years after you wrote it XD */

.alert {
  box-sizing: border-box;
  background-color: #BDFFE1;
  width: 100%;
  position: relative; 
  top: 0;
  left: 0;
  z-index: 300;
  padding: 20px 40px;
  color: #333;
}

.alert h2 {
  font-size: 22px;
  color: #232323;
  margin-top: 0;
}

.alert p {
  line-height: 1.6em;
  font-size:18px;
}

.alert a {
  color: #232323;
  font-weight: bold;
}