body {
  background: url(dist/img/sekolah.gif) no-repeat;
  /* Keep the inherited background full size. */
  background-attachment: fixed; 
  background-size: cover;
  display: grid;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.blur {
  width: 63rem;
  height: 26rem;
  box-shadow: 0 0 1rem 0 rgba(0, 0, 0, .2); 
  border-radius: 15px;
  position: relative;
  z-index: 1;
  background: inherit;
  overflow: hidden;
}

.blur:before {
  content: "";
  position: absolute;
  background: inherit;
  z-index: -1;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  box-shadow: inset 0 0 2000px rgba(255, 255, 255, .5);
  filter: blur(10px);
  margin: -20px;
}