Here are 2 types of triangles to use when styling. The first will add an element of color choice additively into the design (triangle + content). The latter is seemingly destructive/inset (triangle - content).
//type 1 - Content + Triangle
&:before {
content: '';
width: 30px;
height: 30px;
transform: rotate(45deg) translateX(-50%);
position: absolute;
// top: 0;
left: 50%;
background-color: white;
}
//type 2 - Content - Triangle
&:before {
content: "";
display: block;
position: absolute;
left: 0;
right: 0;
z-index: 1;
bottom: 0;
height: 50px;
background-color: white;
clip-path: polygon(0 0, calc(50% - 30px) 0, 50% 50%, calc(50% + 30px) 0, 100% 0, 100% 100%, 0 100%);
}