.promo-open {
    position: fixed;
    bottom: 20px;
    left: 20px;
    z-index: 100;
    padding: 10px 18px;
    border: 1px solid #fff;
    border-radius: 6px;
    background: #666;
    color: #fff;
    font: inherit;
    cursor: pointer;
}

.promo-open[hidden] {
    display: none;
}

/* Bootstrap displays dialog elements even when they are closed. */
.promo-dialog:not([open]) {
    display: none;
}

.promo-dialog {
    margin: auto;
    padding: 0;
    border: 0;
    border-radius: 8px;
    width: max-content;
    max-width: calc(100vw - 24px);
    max-height: calc(100vh - 24px);
    max-height: calc(100dvh - 24px);
    background: #fff;
    box-shadow: 0 12px 48px rgba(0, 0, 0, .35);
}

.promo-dialog::backdrop {
    background: rgba(0, 0, 0, .7);
}

.promo-toolbar {
    position: absolute;
    top: 10px;
    right: 10px;
    z-index: 1;
}

.promo-close {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid rgba(255, 255, 255, .7);
    border-radius: 50%;
    background: rgba(25, 25, 25, .8);
    color: #fff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, .3);
    font: 30px/1 Arial, sans-serif;
    cursor: pointer;
    transition: background-color .15s ease;
}

.promo-image {
    display: block;
    width: auto;
    height: auto;
    max-width: 100%;
    max-height: calc(100vh - 24px);
    max-height: calc(100dvh - 24px);
    object-fit: contain;
}

.promo-open:hover {
    background: #444;
}

.promo-close:hover {
    background: #b72b17;
}

.promo-open:focus-visible,
.promo-close:focus-visible {
    outline: 3px solid #b72b17;
    outline-offset: -3px;
}

html.promo-active {
    overflow: hidden;
}