.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 100%;
    transform-origin: left center;
    transform: scaleX(0);
    background: linear-gradient(90deg, #9f71ff, #66c0f4);
    z-index: 999;
    pointer-events: none;
}

.reveal-init {
    opacity: 0;
    transform: translateY(18px) scale(0.98);
    transition:
            opacity 0.45s ease-out,
            transform 0.45s cubic-bezier(0.19, 1, 0.22, 1),
            box-shadow 0.35s ease-out;
}

.reveal-in {
    opacity: 1;
    transform: translateY(0) scale(1);
}

section.is-active .channel-block,
section.is-active .about-block,
section.is-active .contact-block {
    box-shadow: 0 0 0 1px rgba(159, 113, 255, 0.5),
    0 0 30px rgba(159, 113, 255, 0.25);
}

.btn-ripple {
    position: absolute;
    top: 50%;
    width: 260px;
    height: 260px;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.35);
    pointer-events: none;
    animation: btn-ripple 0.45s ease-out;
}

@keyframes btn-ripple {
    from {
        transform: translate(-50%, -50%) scale(0.05);
        opacity: 0.55;
    }
    to {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0;
    }
}

.back-to-top {
    position: fixed;
    right: 16px;
    bottom: 16px;
    width: 40px;
    height: 40px;
    border-radius: 999px;
    border: none;
    background: radial-gradient(circle at 30% 30%, #ffffff, #9f71ff);
    color: #0f0f1c;
    font-weight: 700;
    font-size: 1.3rem;
    cursor: pointer;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.75);
    opacity: 0;
    transform: translateY(14px) scale(0.9);
    pointer-events: none;
    transition:
            opacity 0.25s ease-out,
            transform 0.25s ease-out,
            box-shadow 0.25s ease-out;
    z-index: 998;
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
}

.back-to-top:hover {
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.9);
}