Wavy Section Border on 7.1

Site URL: https://www.methodistpreschools.org

Hi guys,

I wonder if there's a better way to tackle this. I've used this code to insert a wavy bottom border onto my sections (image: yellow background)

2 things:

1. When I add a background image to the section, the wavy border disappears. When I tried to insert a background that included the wavy bottom border, you can see the white behind it and it doesn't overlap with the next section (image: teal background). Is there a way around this? 
2. My data-section-id list is getting pretty long. Is there a way I can ID a section so the border applies to only those?

Thanks!

section[data-section-id="60ecfb9536a7a57c1cedde3f"] {  
    /* Desktop Only */
@media only screen and (min-width: 951px) {
.content {
      margin-top: 2.5em;
  }}
  .section-background {
    top: 10;
    overflow: visible;
      &:after {
  content:'';
  width: 101%;
  height: 100%;
  background-image: url(https://static1.squarespace.com/static/5fe9e26f8d20536a3fc01415/t/61064558a23b887eab808753/1627800920685/Group+35.png);
  position: absolute;
  background-size: 100%;
  background-repeat: no-repeat;
  left: -1;
  bottom: 0; 
  transform: translateY(100%);

  margin-bottom: 1px;
  z-index: 1;
}}}

.section