Removing Box on Click

First, thanks for this plugin. I tried a few others first and I like this one the best.

On to my question: is there a way to remove the blue box that surrounds the title when the accordion is expanded? Here’s the current CSS I am working with:

.accordion {
  border-bottom: 1px solid #ccc;
  margin: 20px 0 50px;
}
.accordion-title {
  /* border-top: 1px solid #ccc; */
  margin: 0;
  padding: 15px 0;
  transition: 0.3s;
  cursor: pointer;
}
.accordion-content {
  padding-bottom: 15px;
}

.accordion-title:after {
    content: "+";
    float: right;
}

.accordion-title.open:after {
    content: "\2212";
}

Thanks in advance.