@wordpress/block-library/build-style/tabs/editor.css

Block library for the WordPress editor.

.wp-block-tabs.wp-block .wp-block-tabs__tab-item__inserter {
  height: 100%;
  display: flex;
  align-items: center;
}
.wp-block-tabs.wp-block .wp-block-tab.wp-block {
  display: flex;
  flex-direction: column;
  gap: var(--wp--style--unstable-tabs-gap);
}
.wp-block-tabs.wp-block .wp-block-tab.wp-block > section {
  flex-grow: 1;
}
.wp-block-tabs.wp-block .wp-block-tab.wp-block > section > .wp-block:first-child {
  margin-top: 0;
}
.wp-block-tabs.wp-block .wp-block-tab.wp-block > section > .wp-block:last-child {
  margin-bottom: 0;
}
.wp-block-tabs.wp-block.is-vertical > .wp-block-tab.wp-block {
  flex-direction: row;
}
.wp-block-tabs.wp-block.is-vertical .wp-block-tabs__tab-item__inserter {
  align-items: flex-start;
  margin-right: -1px;
}