To change Video Pagination arrow size, you can use these CSS codes.
#1. All Videos
You can use this CSS code
.lesson-item-pagination-link .lesson-item-pagination-icon svg {
width: 30px;
height: 50px;
}
#2. Specific Video item
First, find Video Item ID.
In my example, it is: #item-67b8436e4b42897e5a091db7
You can use this CSS code
#item-67b8436e4b42897e5a091db7 {
.lesson-item-pagination-link .lesson-item-pagination-icon svg {
width: 30px;
height: 50px;
}