/* JS disabled styles */
.no-js nav li:hover ul { display:block; }

/* base nav styles */
nav { display:block; margin:0 auto 20px; border:1px solid #222; position:relative; background-color:#6a6a6a; font:16px Tahoma, Sans-serif; z-index: 5;}
nav ul { padding:0; margin:0; }
nav li { position:relative; float:left; list-style-type:none; }
nav ul:after { content:"."; display:block; height:0; clear:both; visibility:hidden; }
nav li a { display:block; padding:10px 20px; border-left:1px solid #999; border-right:1px solid #222; color:#eee; text-decoration:none; }
nav li a:focus { outline:none; text-decoration:underline; }
nav li:first-child a { border-left:none; }
nav li.last a { border-right:none; }
nav a span { display:block; float:right; margin-left:5px; }
nav ul ul { display:none; width:250px; position:absolute; left:0; background:#6a6a6a; }
nav ul ul li { float:none; }
nav ul ul a { padding:5px 10px; border-left:none; border-right:none; font-size:14px; }
nav ul ul a:hover { background-color:#555; }

/* CSS3 */
.borderradius nav { -moz-border-radius:4px; -webkit-border-radius:4px; border-radius:4px; }
.cssgradients nav { background-image:-moz-linear-gradient(0% 22px 90deg, #222, #999); background-image:-webkit-gradient(linear, 0% 0%, 0% 70%, from(#999), to(#222)); }
.boxshadow.rgba nav { -moz-box-shadow:2px 2px 2px rgba(0,0,0,.75); -webkit-box-shadow:2px 2px 2px rgba(0,0,0,.75); box-shadow:2px 2px 2px rgba(0,0,0,.75); }
.cssgradients nav li:hover { background-image:-moz-linear-gradient(0% 100px 90deg, #999, #222); background-image:-webkit-gradient(linear, 0% 0%, 0% 100%, from(#222), to(#555)); }
.borderradius nav ul ul { -moz-border-radius-bottomleft:4px; -moz-border-radius-bottomright:4px; -webkit-border-bottom-left-radius:4px; -webkit-border-bottom-right-radius:4px; border-bottom-left-radius:4px; border-bottom-right-radius:4px; }
.boxshadow.rgba nav ul ul { background-color:rgba(0,0,0,0.8); -moz-box-shadow:2px 2px 2px rgba(0,0,0,.8); -webkit-box-shadow:2px 2px 2px rgba(0,0,0,.8); box-shadow:2px 2px 2px rgba(0,0,0,.8); }
.rgba nav ul ul li { border-left:1px solid rgba(0,0,0,0.1); border-right:1px solid rgba(0,0,0,0.1); }
.rgba nav ul ul a:hover { background-color:rgba(85,85,85,.9); }
.borderradius.rgba nav ul ul li.last { border-left:1px solid rgba(0,0,0,0.1); border-bottom:1px solid rgba(0,0,0,0.1); -moz-border-radius-bottomleft:4px; -moz-border-radius-bottomright:4px; -webkit-border-bottom-left-radius:4px; -webkit-border-bottom-right-radius:4px; border-bottom-left-radius:4px; border-bottom-right-radius:4px; }
.csstransforms ul a span { -moz-transform:rotate(-180deg);-webkit-transform:rotate(-180deg); }  

/* fallbacks */
.no-cssgradients nav, .no-js nav { padding-bottom:4px; border:none; background:url(../fallback/navBG.gif) repeat-x 0 0; }
.no-borderradius nav ul, .no-js nav ul { background:url(../fallback/navRight.gif) no-repeat 100% 0; }
.no-borderradius nav ul ul, .no-js nav ul ul { background:none; }
.no-borderradius nav li, .no-js nav li { height:44px; }
.no-cssgradients nav li:hover, .no-js nav li:hover { background:url(../fallback/navOverBG.gif) repeat-x 0 0; }
.no-borderradius nav li li, .no-js nav li li { height:auto; width:98%; left:-2px; }
.no-borderradius nav li:first-child, .no-js nav li:first-child { background:url(../fallback/navLeft.gif) no-repeat 0 0; }
.no-borderradius nav li:first-child:hover, .no-js nav li:first-child:hover { background:url(../fallback/navOverLeft.gif) no-repeat 0 0; }
.no-borderradius nav li li:first-child, .no-js nav li li:first-child { background:none; }
.no-rgba nav ul ul, .no-js nav ul ul { left:1px; padding-left:2px; background:url(../fallback/subnavBG.png) no-repeat 100% 100%; }
.no-rgba nav ul ul a, .no-js nav ul ul a { left:3px; }
.no-rgba nav ul ul a:hover { background:url(../fallback/subOverBG.png) repeat 0 0; }
.no-csstransforms ul a span { height:7px; width:12px; margin-top:8px; text-indent:-5000px; overflow:hidden; background:url(../fallback/indicator.png) no-repeat 0 0; }
.no-borderradius ul ul li.last { margin-bottom:10px; }
.no-cssgradients.boxshadow nav { box-shadow:none; }


.btn {
  background: #eeff00;
  background-image: -webkit-linear-gradient(top, #eeff00, #ffb700);
  background-image: -moz-linear-gradient(top, #eeff00, #ffb700);
  background-image: -ms-linear-gradient(top, #eeff00, #ffb700);
  background-image: -o-linear-gradient(top, #eeff00, #ffb700);
  background-image: linear-gradient(to bottom, #eeff00, #ffb700);
  -webkit-border-radius: 28;
  -moz-border-radius: 28;
  border-radius: 28px;
  font-family: Arial;
  color: #5c5c5c;
  font-size: 20px;
  padding: 10px 20px 10px 20px;
  text-decoration: none;
}

.btn:hover {
  background: #ffb700;
  background-image: -webkit-linear-gradient(top, #ffb700, #ff6600);
  background-image: -moz-linear-gradient(top, #ffb700, #ff6600);
  background-image: -ms-linear-gradient(top, #ffb700, #ff6600);
  background-image: -o-linear-gradient(top, #ffb700, #ff6600);
  background-image: linear-gradient(to bottom, #ffb700, #ff6600);
  text-decoration: none;
}


.control-group {
	display: inline-block;
	width: 200px;
	height: 100px;
	margin: 10px;
	padding: 30px;
	text-align: left;
	vertical-align: top;
	background: #fff;
	box-shadow: 0 1px 2px rgba(0,0,0,.1);
}
.control__indicator {
	position: absolute;
	top: 2px;
	left: 0;
	width: 20px;
	height: 20px;
	background: #e6e6e6;
}

.control--radio .control__indicator {
	border-radius: 50%;
}
For the purpose of this tutorial, I have styled the checkboxes and radio buttons similarly - the only modification here being border-radius: 50%; to make the radio buttons circular. Now I am aware that some of the following selectors are rather scary looking; bear with me, and try to follow the comments.
/* Hover and focus states */
.control:hover input ~ .control__indicator,
.control input:focus ~ .control__indicator {
	background: #ccc;
}

/* Checked state */
.control input:checked ~ .control__indicator {
	background: #2aa1c0;
}

/* Hover state whilst checked */
.control:hover input:not([disabled]):checked ~ .control__indicator,
.control input:checked:focus ~ .control__indicator {
	background: #0e647d;
}

/* Disabled state */
.control input:disabled ~ .control__indicator {
	pointer-events: none;
	opacity: .6;
	background: #e6e6e6;
}

/* Check mark */
.control__indicator:after {
	position: absolute;
	display: none;
	content: '';
}

/* Show check mark */
.control input:checked ~ .control__indicator:after {
	display: block;
}

/* Checkbox tick */
.control--checkbox .control__indicator:after {
	top: 4px;
	left: 8px;
	width: 3px;
	height: 8px;
	transform: rotate(45deg);
	border: solid #fff;
	border-width: 0 2px 2px 0;
}

/* Disabled tick colour */
.control--checkbox input:disabled ~ .control__indicator:after {
	border-color: #7b7b7b;
}

/* Radio button inner circle */
.control--radio .control__indicator:after {
	top: 7px;
	left: 7px;
	width: 6px;
	height: 6px;
	border-radius: 50%;
	background: #fff;
}

.control {
	font-size: 18px;
	position: relative;
	display: block;
	margin-bottom: 15px;
	padding-left: 30px;
	cursor: pointer;
}

.control input {
	position: absolute;
	z-index: -1;
	opacity: 0;
}
/* Disabled circle colour */
.control--radio input:disabled ~ .control__indicator:after {
	background: #7b7b7b;
}
.select {
	position: relative;
	display: inline-block;
	width: 100%;
	margin-bottom: 15px;
}

.select select {
	display: inline-block;
	width: 100%;
	padding: 10px 15px;
	cursor: pointer;
	color: #7b7b7b;
	border: 0;
	border-radius: 0;
	outline: 0;
	background: #e6e6e6;
	appearance: none;
	-webkit-appearance: none;
	-moz-appearance: none;
}

.select select::-ms-expand {
	display: none;
}
 .select select:hover,
.select select:focus {
	color: #000;
	background: #ccc;
}

.select select:disabled {
	pointer-events: none;
	opacity: .5;
}

.select__arrow {
	position: absolute;
	top: 16px;
	right: 15px;
	width: 0;
	height: 0;
	pointer-events: none;
	border-width: 8px 5px 0 5px;
	border-style: solid;
	border-color: #7b7b7b transparent transparent transparent;
}
.select select:hover ~ .select__arrow,
.select select:focus ~ .select__arrow {
	border-top-color: #000;
}

.select select:disabled ~ .select__arrow {
	border-top-color: #ccc;
}


::-webkit-input-placeholder { /* Chrome/Opera/Safari */
  color: pink;
}
::-moz-placeholder { /* Firefox 19+ */
  color: pink;
}
:-ms-input-placeholder { /* IE 10+ */
  color: pink;
}
:-moz-placeholder { /* Firefox 18- */
  color: pink;
}