.mce-btn[aria-label="Heading"] {
    border: solid 0px !important;
}

.mce-btn[aria-label="Heading"] button {
    width: 100px;
    height: 35px;
    margin-bottom: -10px;
    transform: translateY(-5px);
}

.mce-btn[aria-label="Heading"] button i {
    width: 100%;
    height: 100%;
    background-position: center;
    background-size: contain;
    background-repeat: no-repeat;
}

.mce-btn[aria-label="Heading"] button span {
    display: none;
}

.mce-btn[aria-label="Heading"] ~ .mce-btn[aria-label="Heading"] {
	display: none;
}