The length of first tab persists to be active - css

Question

My first tab longer than second one. In first tab there are links and images with anchor link.The problem is first tab's links are still active although I click on second tab and lays down on my tag cloud, so prevent them to be clickable. I would like to know why links of first tab are still clickable althoug they are not appearing?
fiddle
HTML
<section class="tabs">
<input id="tab-1" type="radio" name="radio-set" class="tab-selector-1" checked="checked" />
<label for="tab-1" class="tab-label-1">About</label>
<input id="tab-2" type="radio" name="radio-set" class="tab-selector-2" />
<label for="tab-2" class="tab-label-2">Services</label>
<input id="tab-3" type="radio" name="radio-set" class="tab-selector-3" />
<label for="tab-3" class="tab-label-3">Work</label>
<div class="clear-shadow"></div>
<div class="tab-content">
<div class="content-1">
Link
<a href="#" class="tab-thumb thumbnail" rel="bookmark" title="testing editor styles">
<img src="#" width="250" height="250"/></a>
Link
<a href="#" class="tab-thumb thumbnail" rel="bookmark" title="testing editor styles">
<img src="#" width="250" height="250"/></a>
Link
<a href="#" class="tab-thumb thumbnail" rel="bookmark" title="testing editor styles">
<img src="#" width="250" height="250"/></a>
Link
<a href="#" class="tab-thumb thumbnail" rel="bookmark" title="testing editor styles">
<img src="#" width="250" height="250"/></a>
</div>
<div class="content-2">
<h2>Most Commented</h2>
</div>
</div>
</section>
Link
CSS
.tabs {
position: relative;
margin: 40px auto;
width: 100%;
height: auto;
}
.tabs input {
position: absolute;
z-index: 1000;
width: 100px;
height: 40px;
left: 0px;
top: 0px;
opacity: 0;
-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
filter: alpha(opacity=0);
cursor: pointer;
}
.tabs input#tab-2{
left: 100px;
}
.tabs input#tab-3{
left: 220px;
}
.tabs input#tab-4{
left: 340px;
}
.tabs label {
background: #5ba4a4;
background: -moz-linear-gradient(top, #5ba4a4 0%, #4e8c8a 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#5ba4a4), color-stop(100%,#4e8c8a));
background: -webkit-linear-gradient(top, #5ba4a4 0%,#4e8c8a 100%);
background: -o-linear-gradient(top, #5ba4a4 0%,#4e8c8a 100%);
background: -ms-linear-gradient(top, #5ba4a4 0%,#4e8c8a 100%);
background: linear-gradient(top, #5ba4a4 0%,#4e8c8a 100%);
font-size: 15px;
line-height: 40px;
height: 40px;
position: relative;
padding: 0 12px;
float: left;
display: block;
width: 80px;
color: #385c5b;
letter-spacing: 1px;
text-transform: uppercase;
font-weight: bold;
text-align: center;
text-shadow: 1px 1px 1px rgba(255,255,255,0.3);
border-radius: 3px 3px 0 0;
box-shadow: 2px 0 2px rgba(0,0,0,0.1), -2px 0 2px rgba(0,0,0,0.1);
}
.tabs label:after {
content: '';
background: #fff;
position: absolute;
bottom: -2px;
left: 0;
width: 100%;
height: 2px;
display: block;
}
.tabs input:hover + label {
background: #5ba4a4;
}
.tabs label:first-of-type {
z-index: 4;
box-shadow: 2px 0 2px rgba(0,0,0,0.1);
}
.tab-label-2 {
z-index: 3;
}
.tab-label-3 {
z-index: 2;
}
.tabs input:checked + label {
background: #fff;
z-index: 6;
}
.clear-shadow {
clear: both;
}
.tab-content {
background: #fff;
position: relative;
width: 100%;
height: auto;
z-index: 5;
box-shadow: 0 -2px 3px -2px rgba(0,0,0,0.2), 0 2px 2px rgba(0,0,0,0.1);
border-radius: 0 3px 3px 3px;
}
.tab-content div {
position: absolute;
top: 0;
left: 0;
padding: 10px 40px;
z-index: 1;
opacity: 0;
-webkit-display: flex;
display: flex;
-webkit-flex-flow: column;
flex-flow: column;
-webkit-transition: opacity linear 0.1s;
-moz-transition: opacity linear 0.1s;
-o-transition: opacity linear 0.1s;
-ms-transition: opacity linear 0.1s;
transition: opacity linear 0.1s;
}
.tab-content div img { border: 1px solid #903; position: relative;
}
.tabs input.tab-selector-1:checked ~ .tab-content .content-1,
.tabs input.tab-selector-2:checked ~ .tab-content .content-2,
.tabs input.tab-selector-3:checked ~ .tab-content .content-3 {
z-index: 100;
-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
filter: alpha(opacity=100);
opacity: 1;
-webkit-transition: opacity ease-out 0.2s 0.1s;
-moz-transition: opacity ease-out 0.2s 0.1s;
-o-transition: opacity ease-out 0.2s 0.1s;
-ms-transition: opacity ease-out 0.2s 0.1s;
transition: opacity ease-out 0.2s 0.1s;
position:relative;
}
.tab-content div h2,
.tab-content div h3{
color: #398080;
}
.tab-content div p {
font-size: 14px;
line-height: 22px;
font-style: italic;
text-align: left;
margin: 0;
color: #777;
padding-left: 15px;
font-family: Cambria, Georgia, serif;
border-left: 8px solid rgba(63,148,148, 0.1);
}
.tab-content li {
overflow: hidden;
list-style: none;
border-bottom: 1px solid #f0f0f0;
margin: 0 0 8px;
padding: 0 0 6px;
}

Answer 1

Because opacity:0 does make your div transparent but it is still there. Change opacity:0 to display:none insteed
fiddle