/**
 * Float Up — lightweight CSS (no external fonts)
 */
.float-up-button {
    position: fixed;
    bottom: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--float-up-size, 50px);
    height: var(--float-up-size, 50px);
    border-radius: 50%;
    background-color: var(--float-up-bg-color, #40454b);
    color: var(--float-up-icon-color, #ffffff);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
    transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
    opacity: 0;
    visibility: hidden;
    border: none;
    cursor: pointer;
    z-index: 99999;
    outline: none;
    padding: 0;
    margin: 0;
    -webkit-tap-highlight-color: transparent;
}

.float-up-button:focus-visible {
    box-shadow: 0 0 0 3px rgba(64, 69, 75, 0.35);
}

.float-up-button--bottom-left {
    left: 30px;
}

.float-up-button--bottom-right {
    right: 30px;
}

.float-up-button--visible {
    opacity: 1;
    visibility: visible;
}

.float-up-button:hover {
    transform: scale(1.08);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

.float-up-button__icon {
    width: calc(var(--float-up-size, 50px) * 0.5);
    height: calc(var(--float-up-size, 50px) * 0.5);
    color: var(--float-up-icon-color, #ffffff);
    display: block;
    flex-shrink: 0;
}

.float-up-button__img {
    width: calc(var(--float-up-size, 50px) * 0.65);
    height: calc(var(--float-up-size, 50px) * 0.65);
    object-fit: contain;
    display: block;
}