Block hover higher another block - css

Question

In yellow square I have a hover effect, but when hover display the higher the green block. I need what would be the hover effect of only at yellow square.
I tried to use z-index - did not help.
What am I doing wrong?
*{
padding: 0;
margin: 0;
}
.wrapper {
border:2px solid black;
margin-top: 20px;
padding: 20px 20px;
height: 100%;
}
.block__one {
background-color:green;
z-index:5;
position: relative;
}
.item {
padding: 10px;
margin: 0;
text-align:center;
}
.list {
display: inline-block;
width: 50px;
height: 40px;
background-color:yellow;
position: relative;
z-index:10;
}
.list:hover .list__hover {
opacity:1;
bottom:0;
}
.list__hover {
width: 100%;
height: 50%;
background-color: #fff;
position: absolute;
bottom:-50px;
transition: bottom 0.5s;
opacity:0;
z-index:4;
}
.block__two {
background-color:red;
width: 100%;
height: 200px;
z-index:5;
position: relative;
}
<div class="wrapper">
<div class="block__one">
<ul class="item">
<li class="list">
<div class="list__hover"></div>
</li>
<li class="list">
<div class="list__hover"></div>
</ul>
</div>
<div class="block__two"></div>
</div>

Answer 1

I'm not certain I've 100% understood your post, but I believe that all you need is to add
overflow:hidden
to the .list class
Check if the snippet is doing what you want:
*{
padding: 0;
margin: 0;
}
.wrapper {
border:2px solid black;
margin-top: 20px;
padding: 20px 20px;
height: 100%;
}
.block__one {
background-color:green;
z-index:5;
position: relative;
}
.item {
padding: 10px;
margin: 0;
text-align:center;
}
.list {
display: inline-block;
width: 50px;
height: 40px;
background-color:yellow;
position: relative;
z-index:10;
overflow:hidden;
}
.list:hover .list__hover {
opacity:1;
bottom:0;
}
.list__hover {
width: 100%;
height: 50%;
background-color: #fff;
position: absolute;
bottom:-50px;
transition: bottom 0.5s;
opacity:0;
z-index:4;
}
.block__two {
background-color:red;
width: 100%;
height: 200px;
z-index:5;
position: relative;
}
<div class="wrapper">
<div class="block__one">
<ul class="item">
<li class="list">
<div class="list__hover"></div>
</li>
<li class="list">
<div class="list__hover"></div>
</ul>
</div>
<div class="block__two"></div>
</div>

Answer 2

Here's another solution using first height of 0% and then transitioning it to 50%. Also check your code, there's a few mistakes in it. You could, for example, use W3 validator.
* {
padding: 0;
margin: 0;
}
.wrapper {
border: 2px solid black;
margin-top: 20px;
padding: 20px 20px;
height: 100%;
}
.block__one {
background-color: green;
z-index: 5;
position: relative;
}
.item {
padding: 10px;
margin: 0;
text-align: center;
}
.list {
display: inline-block;
width: 50px;
height: 40px;
background-color: yellow;
position: relative;
z-index: 10;
}
.list:hover .list__hover {
opacity: 1;
bottom: 0px;
height: 50%;
transition: linear .5s;
}
.list__hover {
width: 100%;
height: 0%;
background-color: #fff;
position: absolute;
bottom: 0px;
opacity: 0;
z-index: 4;
}
.block__two {
background-color: red;
width: 100%;
height: 200px;
z-index: 5;
position: relative;
}
<div class="wrapper">
<div class="block__one">
<ul class="item">
<li class="list">
<div class="list__hover"></div>
</li>
<li class="list">
<div class="list__hover"></div>
</li>
</ul>
</div>
<div class="block__two"></div>
</div>