.scroll-top {
    position: fixed;
    top: 50%;
    right: 0;
    z-index: 70;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 14px 8px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-right: 0;
    border-radius: 12px 0 0 12px;
    background-color: rgba(15, 23, 42, 0.92);
    color: #fff;
    font-family: 'Inter', sans-serif;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    cursor: pointer;
    box-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.5);
    opacity: 0;
    transform: translate(100%, -50%);
    transition: opacity 0.25s ease, transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), background-color 0.2s ease;
}

.scroll-top[hidden] {
    display: none;
}

.scroll-top.is-visible {
    opacity: 1;
    transform: translate(0, -50%);
}

.scroll-top:hover {
    background-color: #1A56DB;
}

.scroll-top:focus-visible {
    outline: 2px solid #fff;
    outline-offset: -4px;
    background-color: #1A56DB;
}

.scroll-top-label {
    writing-mode: vertical-rl;
    transform: rotate(180deg); /* reads bottom to top */
    white-space: nowrap;
    line-height: 1;
}

.scroll-top-arrow {
    transition: transform 0.2s ease;
}

.scroll-top:hover .scroll-top-arrow {
    transform: translateY(-3px);
}

@media (prefers-reduced-motion: reduce) {
    .scroll-top,
    .scroll-top-arrow {
        transition: none;
    }
}