Please use the following trees' rules for future changes in CSS to maintain its structure:

```
.cssClass {

/* Positioning */
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
z-index: 100;


/* Block model */
display: block;
float: right;
width: 100px;
height: 100px;
margin: 10px;
padding: 10px;


/* Typography */
font: normal 13px/1.5 "Arial", sans-serif;
font-style: normal;
font-size: 13px;
line-height: 1.5;
font-family: "Arial", sans-serif;
text-align: center;
color: #333333;


/* Layout */
background-color: #f5f5f5;
border: 1px solid #e5e5e5;
border-radius: 3px;
opacity: 1;


/* Animation */
transition: color 1s;


/* Others */
will-change: auto;
}
```
