WeVividWeVividBuild a CSS box-shadow visually with sliders for offset, blur, spread, colour and opacity, then copy the CSS.
box-shadow: 0px 8px 24px 0px rgba(21, 23, 28, 0.18);
A positive spread expands the shadow's edges outward from the box; negative shrinks it inward, before blur is applied.
A normal shadow appears outside the element; an inset shadow appears inside it, as if the element were pressed in.