<div class="title">Lorem ipsum</div>

*, *::before {
  box-sizing: border-box;
}

.title {
  position: relative;
  text-align: center;
  overflow: hidden;
  padding: 10px 60px;
  color: #fff;
  font-family: sans-serif;
}

.title::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  width: calc((100% - 60px * 2) * 0.7071);
  padding-bottom: calc((100% - 60px * 2) * 0.7071);
  background-color: #f00;
  transform: translate(-50%, -50%) rotate(45deg);
  box-shadow: 
    calc(-20px * 0.7071) calc(20px * 0.7071) 0 rgba(255, 0, 0, 0.2),
    calc(-40px * 0.7071) calc(40px * 0.7071) 0 rgba(255, 0, 0, 0.2),
    calc(-60px * 0.7071) calc(60px * 0.7071) 0 rgba(255, 0, 0, 0.2),
    calc(20px * 0.7071) calc(-20px * 0.7071) 0 rgba(255, 0, 0, 0.2),
    calc(40px * 0.7071) calc(-40px * 0.7071) 0 rgba(255, 0, 0, 0.2),
    calc(60px * 0.7071) calc(-60px * 0.7071) 0 rgba(255, 0, 0, 0.2);
  z-index: -1;
}