6 margin:
0 25px
50px
25px;
7 background-color: lightyellow;
10 <!-- Positive spread does not increase border radii. -->
12 -webkit-box-shadow: black 0 100px 0 20px;
13 -webkit-border-radius: 10px;
15 <!-- It uses the actual radii (in this case, 25px after scaling
16 to fit in a total side length of 50px) not the specified radii. -->
18 -webkit-box-shadow: black 0 100px 0 20px;
19 -webkit-border-radius: 50px;
21 <!-- Negative spread decreases the radii. -->
23 -webkit-box-shadow: black 0 100px 0 -10px;
24 -webkit-border-radius: 20px;