CSS Layout

Great for navbars, list items, card rows, and centering content.

css
.row {
  display: flex;
  align-items: center;       /* cross axis */
  justify-content: space-between; /* main axis */
  gap: 1rem;
  flex-wrap: wrap;
}

.item-grow { flex: 1; }              /* take the remaining space */
.item-fixed { flex: 0 0 200px; }     /* fixed 200px */

Great for dashboards, galleries, and complex page layouts.

css
/* Auto responsive grid — no media query needed */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

/* Holy grail */
.app {
  display: grid;
  grid-template:
    "header header" auto
    "side   main"   1fr
    "footer footer" auto / 240px 1fr;
  min-height: 100dvh;
}
.header { grid-area: header; }
.side   { grid-area: side; }
.main   { grid-area: main; }
.footer { grid-area: footer; }

css
/* Tooltip / dropdown */
.parent { position: relative; }
.tooltip {
  position: absolute;
  inset-inline-start: 0;
  top: calc(100% + 4px);
}

/* Sticky header */
.header { position: sticky; top: 0; z-index: 10; }

/* Modal overlay */
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,.5); }

Flex   → 1 axis, content-driven (navbar, button group, list)
Grid   → 2 axes, layout-driven (dashboard, gallery, full-page)
Position → element floating above the flow (modal, tooltip, badge, sticky)