wp-calypso/client/blocks/conversation-follow-button/style.scss

.conversation-follow-button,
button.conversation-follow-button {
	border: 0;
	padding: 0;

	.reader-follow-conversation {
		pointer-events: auto;

		path {
			fill: var(--color-primary);
		}
	}

	.conversation-follow-button__label {
		color: var(--color-primary);
		position: relative;
	}

	&:hover,
	&:focus {
		color: var(--color-primary);
	}

	&.popover__menu-item {
		&:hover,
		&:focus {
			.conversation-follow-button__label {
				color: var(--color-text-inverted);
			}

			.gridicon {
				fill: var(--color-text-inverted);
				g {
					fill: var(--studio-white);
					stroke: var(--color-success);
				}
			}
		}
	}

	&:focus {
		box-shadow: none;
	}

	// Hides Following icon by default
	.reader-following-conversation {
		display: none;
		pointer-events: none;
	}

	&.is-following {
		.reader-following-conversation {
			display: inline-block;
			pointer-events: auto;
			fill: var(--color-success);
		}

		.conversation-follow-button__label {
			color: var(--color-success);
		}

		// Hides Follow icon if already following
		.reader-follow-conversation {
			display: none;
			pointer-events: none;
		}

		&:hover,
		&:focus {
			color: var(--color-success);

			.reader-following-conversation {
				fill: var(--color-success);
			}
		}

		&.popover__menu-item {
			&:hover,
			&:focus {
				color: var(--color-text-inverted);

				.gridicon,
				.reader-follow-conversation,
				.reader-following-conversation {
					color: var(--color-text-inverted);
				}

				svg.reader-external path {
					fill: var(--color-text-inverted);
				}

				svg.reader-follow-conversation path,
				svg.reader-following-conversation path {
					fill: var(--color-text-inverted);

					&.status {
						fill: none;
					}
				}
			}
		}
	}

	.gridicon {
		height: 18px;
		top: 5px;
		width: 18px;
	}
}

.conversation-follow-button__label {
	@include breakpoint-deprecated( "<660px" ) {
		display: none;
	}
}