JezK

Edit File: style.css

:where(.wp-block-tab-list button) { box-sizing: border-box; color: inherit; display: block; width: -moz-max-content; width: max-content; text-decoration: none; cursor: pointer; flex-basis: inherit !important; flex-grow: inherit !important; position: relative; border: none; background: none; -moz-appearance: none; appearance: none; -webkit-appearance: none; margin: 0; padding: var(--wp--preset--spacing--20, 0.5em) var(--wp--preset--spacing--30, 1em); font-size: inherit; font-family: inherit; font-weight: inherit; line-height: inherit; letter-spacing: inherit; text-transform: inherit; text-align: inherit; } :where(.wp-block-tab-list button)[aria-selected=true]::before { content: ""; position: absolute; border-bottom: 2px solid currentColor; pointer-events: none; left: 0; width: 100%; bottom: 0; }