.reading-progress {
    --reading-progress: 0;
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: rgba(0, 102, 204, 0.12);
    opacity: 0;
    pointer-events: none;
    z-index: 1100;
    transition: opacity 0.2s ease;
}

.reading-progress.is-visible {
    opacity: 1;
}

.reading-progress-bar {
    width: 100%;
    height: 100%;
    background-color: #0066cc;
    transform: scaleX(var(--reading-progress));
    transform-origin: left center;
    will-change: transform;
}

body.dark-mode .reading-progress {
    background-color: rgba(74, 158, 255, 0.18);
}

body.dark-mode .reading-progress-bar {
    background-color: #4a9eff;
}

@media (prefers-reduced-motion: reduce) {
    .reading-progress {
        transition: none;
    }
}