css backdrop-filter

backdrop-filter: none;

/* SVG 필터를 가리키는 URL */
backdrop-filter: url(commonfilters.svg#filter);

/* <filter-function> 값 */
backdrop-filter: blur(2px);
backdrop-filter: brightness(60%);
backdrop-filter: contrast(40%);
backdrop-filter: drop-shadow(4px 4px 10px blue);
backdrop-filter: grayscale(30%);
backdrop-filter: hue-rotate(120deg);
backdrop-filter: invert(70%);
backdrop-filter: opacity(20%);
backdrop-filter: sepia(90%);
backdrop-filter: saturate(80%);

/* 다중 필터 */
backdrop-filter: url(filters.svg#filter) blur(4px) saturate(150%);

/* 전역 값 */
backdrop-filter: inherit;
backdrop-filter: initial;
backdrop-filter: unset;

 

.title-back {
  ...
  background: rgb(229,229,229,.7); 
  backdrop-filter: saturate(80%) blur(3px);
}