.browser
  .parent(style="overflow: hidden")
    .children.is__sticky Parent with overflow: hidden
    .children

  .parent
    .children.is__sticky Parent with overflow: visible
    .children

.parent {
  width: calc(100% / 2 - 10px);
  box-shadow: inset 0 0 1px #000;
  margin: 50px 0;
}

.children {
  height: 600px;
  padding: 10px;
  font-size: 16px;
  text-align: center;
  color: rgba(26, 115, 232);
}

.is__sticky {
  position: sticky;
  top: 10px;
  height: auto;
  background: rgba(26, 115, 232, 0.15);
}

.browser {
  overflow: scroll;
  height: 380px;
  margin: 10px;
  border: 1px solid rgba(0,0,0,.08);
  border-radius: 4px;
  border-top-width: 25px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
}

.browser::after {
  content: '↓ Scroll inside ↓';
  position: absolute;
  top: 13px;
  left: 0;
  width: 100%;
  font-size: 16px;
  text-align: center;
  color: #000;
  opacity: .4;
}