Question: I want to trim this column character. For example this is the column data 55.30000000000000004. Now want to display data 55.3 like this. Could you help me give simple C# windows application code?

Answer: 
Here is one way to do it:

* Define the background in the common `#btn-menu span` style element
* Set the background size to match the button size
* For each span, set `background-position-y` to the appropriate vertical offset

In the code snippet below, I showed 3 colors in the gradient to make the effect more obvious. The same example is shown in [this jsfiddle](https://jsfiddle.net/ConnorsFan/8o3t64rr/).

```css
#btn-menu {
  float: left;
  width: 150px;
  height: 150px;
  position: relative;
  background: none;
  border: none;
  z-index: 5000;
  position: relative;
}

#btn-menu span {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 15px;
  background-image: linear-gradient(45deg, red 20%, yellow 60%, blue 100%);
  background-size: 150px 150px;
}

#btn-menu span:nth-child(1) {
  top: 0;
  background-position-y: 0px;
}

#btn-menu span:nth-child(2) {
  top: 65px;
  background-position-y: -65px;
}

#btn-menu span:nth-child(3) {
  bottom: 0;
  background-position-y: -135px;
}

#gradient {
  float: left;
  margin-left: 50px;
  width: 150px;
  height: 150px;
  background-image: linear-gradient(45deg, red 20%, yellow 60%, blue 100%);
}
```

```html
<button type="button" id="btn-menu">
  <span></span>
  <span></span>
  <span></span>
</button>

<div id="gradient"></div>
```
I updated your js fiddle with [my solution](https://jsfiddle.net/spacyad6/1/).

The idea is to use span not to display the color but to hide it.

Relevant part of the changes :

```
<div id="gradient">
  <span></span>
  <span></span>
</div>

#gradient {
  position : relative;
}

#gradient span {
  position: absolute;
  left: 0;
  width: 100%;
  height: calc((150px - 45px)/2);
  background-color : #f3f5f6;
}

#gradient span:nth-child(1) {
  top: 15px;
}

#gradient span:nth-child(2) {
  bottom: 15px;
}

```

For this solution you need to know :

* The background color hex
* The height of your button
* The height of the span you want

Which should not be a problem for a normal use.

Downside :

* Need hardcoded values as explained before
* Good luck for making a border-radius or something like that for those fake spans now