Tooltip tick via pseudo-elements

styles.scss

.tooltip {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  max-width: 350px;
  padding: 0.5rem 1rem;
  background-color: #fff;
  border: 1px solid #000;
  border-radius: 4px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  font-size: 0.85rem;
  z-index: 1;

  &::before {
    --size: 8px;

    position: absolute;
    content: '';
    top: calc(var(--size) * -2);
    left: 0;
    right: 0;
    height: 0;
    width: 0;
    margin: auto;
    border-width: var(--size);
    border-style: solid;
    border-color: transparent transparent #fff;
  }
}