/* ===== SCROLL TO TOP BUTTON ===== */
.scroll-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 9999;
    width: 46px;
    height: 46px;
    border: none;
    border-radius: 50%;
    background: #e8192c;
    color: #fff;
    font-size: 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: opacity 0.35s ease, visibility 0.35s ease, transform 0.35s ease, background 0.25s ease, box-shadow 0.25s ease;
    box-shadow: 0 4px 14px rgba(232, 25, 44, 0.35);
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top-btn:hover {
    background: #c91425;
    box-shadow: 0 6px 20px rgba(232, 25, 44, 0.5);
    transform: translateY(-3px);
}

.scroll-top-btn:active {
    transform: translateY(0);
}

/* Dark mode */
[data-theme="dark"] .scroll-top-btn,
body.dark-mode .scroll-top-btn {
    background: #ff3b4e;
    box-shadow: 0 4px 14px rgba(255, 59, 78, 0.4);
}

[data-theme="dark"] .scroll-top-btn:hover,
body.dark-mode .scroll-top-btn:hover {
    background: #e8192c;
    box-shadow: 0 6px 20px rgba(255, 59, 78, 0.55);
}

/* Responsive */
@media (max-width: 768px) {
    .scroll-top-btn {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
        font-size: 16px;
    }
}