/*
 * Music Album Sidebar Navigation
 *
 * Desktop (>=1400px): fixed sidebar on far-left viewport edge —
 *   no layout footprint, no background, text floats in the gutter
 *   like marginalia. Content centers naturally as if sidebar isn't there.
 * Mobile (<1400px): floating button + slide-in panel from left.
 *
 * Uses design tokens exclusively.
 * Group labels with aria-labelledby replace the report-TOC's ::before divider pattern.
 */

.music-toc {
    display: none;
}

@media (min-width: 1400px) {
    .music-toc {
        display: block;
        position: fixed;
        left: 0;
        top: 5rem;
        width: 170px;
        max-height: calc(100vh - 6rem);
        overflow-y: auto;
        padding: var(--space-lg) 0 var(--space-lg) var(--space-lg);
        scrollbar-width: thin;
        scrollbar-color: color-mix(in srgb, var(--accent-gold) 10%, transparent) transparent;
        z-index: 10;
    }
}

.music-toc__heading {
    font-family: 'Cinzel', serif;
    font-size: 0.65rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: color-mix(in srgb, var(--accent-gold) 50%, transparent);
    margin: 0 0 var(--space-md) 0;
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid color-mix(in srgb, var(--accent-gold) 6%, transparent);
}

.music-toc__group {
    margin: 0;
}

.music-toc > .music-toc__list + .music-toc__group {
    margin-top: var(--space-sm);
    padding-top: var(--space-sm);
    border-top: 1px solid color-mix(in srgb, var(--accent-gold) 8%, transparent);
}

.music-toc__group + .music-toc__group {
    margin-top: var(--space-sm);
}

.music-toc__group-label {
    font-family: 'Cinzel', serif;
    font-size: 0.58rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: color-mix(in srgb, var(--accent-gold) 40%, transparent);
    margin: 0;
    padding: 0.2rem 0.6rem 0.35rem;
}

.music-toc__group-label a {
    color: inherit;
    text-decoration: none;
}

.music-toc__list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.music-toc__item {
    margin-bottom: 0.15rem;
}

.music-toc__link {
    display: block;
    padding: 0.35rem 0.6rem;
    font-size: 0.78rem;
    line-height: 1.35;
    color: color-mix(in srgb, var(--vision-text) 45%, transparent);
    text-decoration: none;
    border-left: 2px solid transparent;
    border-radius: 0 4px 4px 0;
    transition: color var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}

.music-toc__link:hover {
    color: color-mix(in srgb, var(--vision-text) 75%, transparent);
    background: color-mix(in srgb, var(--accent-gold) 3%, transparent);
}

.music-toc__link--active {
    color: var(--accent-gold-soft);
    border-left-color: var(--accent-gold-soft);
    background: color-mix(in srgb, var(--accent-gold) 4%, transparent);
}

.music-toc-toggle {
    display: none;
    position: fixed;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 20;
    background: color-mix(in srgb, var(--reading-bg) 85%, transparent);
    border: 1px solid color-mix(in srgb, var(--accent-gold) 15%, transparent);
    border-left: none;
    border-radius: 0 6px 6px 0;
    padding: 0.6rem 0.45rem;
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.music-toc-toggle:hover {
    background: color-mix(in srgb, var(--reading-bg) 95%, transparent);
    border-color: color-mix(in srgb, var(--accent-gold) 30%, transparent);
}

.music-toc-toggle__text {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-family: 'Cinzel', serif;
    font-size: 0.6rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: color-mix(in srgb, var(--accent-gold) 60%, transparent);
}

.music-toc-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 25;
    background: color-mix(in srgb, var(--bg-dark) 50%, transparent);
}

.music-toc-backdrop--visible {
    display: block;
}

@media (max-width: 1399px) {
    .music-toc {
        display: block;
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        z-index: 30;
        width: 260px;
        max-height: 100vh;
        padding: 5rem var(--space-lg) var(--space-lg) var(--space-lg);
        background: color-mix(in srgb, var(--reading-bg) 95%, transparent);
        border-right: 1px solid color-mix(in srgb, var(--accent-gold) 8%, transparent);
        backdrop-filter: blur(var(--panel-blur));
        -webkit-backdrop-filter: blur(var(--panel-blur));
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
    }

    .music-toc--open {
        transform: translateX(0);
    }

    .music-toc-toggle {
        display: block;
    }

    .music-toc--open ~ .music-toc-toggle {
        display: none;
    }
}

@media print {
    .music-toc,
    .music-toc-toggle,
    .music-toc-backdrop {
        display: none !important;
    }
}