primevue-mirror/src/components/button/Button.css

.p-button {
    margin: 0;
    display: inline-flex;
    cursor: pointer;
    user-select: none;
    align-items: center;
    vertical-align: bottom;
    text-align: center;
    overflow: hidden;
    position: relative;
}

.p-button-text {
    flex: 1 1 auto;
}

.p-button-icon-right {
    order: 1;
}

.p-button:disabled {
    cursor: default;
}

.p-button-icon-only {
    justify-content: center;
}

.p-button-icon-only .p-button-text {
    visibility: hidden;
    width: 0;
    flex: 0 0 auto;
}

.p-button-vertical {
    flex-direction: column;
}

.p-button-icon-bottom {
    order: 2;
}

.p-buttonset .p-button {
    margin: 0;
}

.p-buttonset .p-button:not(:last-child) {
    border-right: 0 none;
}

.p-buttonset .p-button:not(:first-of-type):not(:last-of-type) {
    border-radius: 0;
}

.p-buttonset .p-button:first-of-type {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.p-buttonset .p-button:last-of-type {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}

.p-buttonset .p-button:focus {
    position: relative;
}