Here is the code snippet:
/* header */
.header {
display: flex;
justify-content: center;
position: fixed;
color: var(--font-color);
backdrop-filter: blur(10px); //the line that is not applying correctly
height: 50px;
width: 100vw;
max-height: 3cm;
box-shadow: 0 -1px 4px 0 rgb(26 26 26 / 8%), 0 4px 8px 0 rgb(26 26 26 / 12%);
}
Therefore, the placeholder should also have a blurred effect.