I am using the link code below to create a one-button fold transition effect, but I can not avoid the background button in the upper left corner of the button. What class could you use to leave that part transparent and thus show the yellow color, what is the background of the main DIV?
<div class="back">
<a href="#" class="button curl-top-left">BUTTON EFFECT</a>
</div>
.back {
background: #fc0;
}
.button {
display: inline-block;
padding: 1em;
margin: 1em;
background-color:#007E9F;
text-decoration: none;
color: white;
}
.curl-top-left {
display: inline-block;
position: relative;
-webkit-transform: translateZ(0);
transform: translateZ(0);
box-shadow: 0 0 1px rgba(0, 0, 0, 0);
}
.curl-top-left:before {
pointer-events: none;
position: absolute;
content: '';
height: 0;
width: 0;
top: 0;
left: 0;
/* IE9 */
background: linear-gradient(135deg, white 45%, #aaaaaa 50%, #cccccc 56%, white 80%);
filter: progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr='#ffffff', endColorstr='#000000');
/*For IE7-8-9*/
z-index: 1000;
box-shadow: 1px 1px 1px rgba(0, 0, 0, 0.4);
-webkit-transition-duration: 0.3s;
transition-duration: 0.3s;
-webkit-transition-property: width, height;
transition-property: width, height;
}
.curl-top-left:hover:before,
.curl-top-left:focus:before,
.curl-top-left:active:before {
width: 40px;
height: 40px;
}