themes-wordpress/seedlet/assets/sass/blocks/file/_editor.scss

.wp-block-file {
	.wp-block-file__textlink {
		color: var(--global--color-primary);
		text-decoration: underline; 
		text-decoration-thickness: 1px; // Not yet supported in Chrome
		text-underline-offset: 3px;  // Not yet supported in Chrome
		text-decoration-color: var(--global--color-secondary);
	}

	.wp-block-file__button-richtext-wrapper {
		display: block;
		margin-left: 0;
	}

	.wp-block-file__button {
		// Extend button style
		@include button-style;

		display: inline-block;
		margin: calc( 0.5 * var(--global--spacing-unit) ) 0 0 0;
		padding: calc(0.5 * var(--button--padding-vertical)) calc(0.5 * var(--button--padding-horizontal));
	}
}