/* ============================================================================
   Demo shell — /demo catalogue home + specimen anatomy + stub page.
   ============================================================================

   Design rationale
   ----------------
   Four working specimens presented like a printed catalogue (Vitsœ 606,
   Swiss editorial), not a card grid. Each specimen is a numbered, labelled
   artefact with an intent paragraph, a technical metadata block, and a
   single clear affordance ("Open specimen").

   Rejects: tabs, hover-reveals, thumbnail grids, decorative hero images.
   Adopts:  hairlines, vertical rhythm, numbered sequence, monospace
            metadata, restrained accent-per-specimen colour bar.
============================================================================ */


/* --------------------------------------------------------------------------
   Page envelope
-------------------------------------------------------------------------- */
.demo-page {
    padding: var(--space-4xl) 0;
}

/* --------------------------------------------------------------------------
   Chapter opener — sits above the catalogue like a book chapter title
-------------------------------------------------------------------------- */
.demo-opener {
    max-width: 780px;
    margin-bottom: var(--space-3xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--surface-border);
}

.demo-opener__eyebrow {
    display: inline-block;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 12px;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--color-primary);
    margin-bottom: var(--space-lg);
    font-variant-numeric: tabular-nums;
}

.demo-opener h1 {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 48px;
    line-height: 1.04;
    letter-spacing: -0.02em;
    margin: 0 0 var(--space-lg);
    color: var(--text);
    max-width: 16ch;
}

.demo-opener__lede {
    font-size: 17px;
    line-height: 1.6;
    color: var(--text-muted);
    max-width: 62ch;
    margin: 0;
}


/* --------------------------------------------------------------------------
   Layout — main catalogue + sticky index in outer margin
-------------------------------------------------------------------------- */
.demo-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}
@media (min-width: 960px) {
    .demo-layout {
        grid-template-columns: minmax(0, 1fr) 200px;
        gap: var(--space-3xl);
        align-items: start;
    }
}


/* --------------------------------------------------------------------------
   Sticky index — reads like a table of contents in a printed catalogue.
   Mobile: appears above content as a horizontal strip.
   Desktop: pinned to the outer margin.
-------------------------------------------------------------------------- */
.demo-index {
    order: -1;
    padding: var(--space-md) 0;
    border-top: 1px solid var(--surface-border);
    border-bottom: 1px solid var(--surface-border);
    margin-bottom: var(--space-lg);
}
@media (min-width: 960px) {
    .demo-index {
        order: 0;
        position: sticky;
        top: 88px;         /* clear the sticky nav */
        align-self: start;
        padding: 0;
        border: 0;
        margin: 0;
    }
}

.demo-index__title {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 11px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin: 0 0 var(--space-md);
}
.demo-index ol {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-2xs);
}
.demo-index a {
    display: grid;
    grid-template-columns: 28px minmax(0, 1fr);
    gap: var(--space-xs);
    align-items: baseline;
    padding: 6px 0;
    color: var(--text-muted);
    font-family: var(--font-body);
    font-size: 14px;
    line-height: 1.35;
    text-decoration: none;
    transition: color var(--transition);
}
.demo-index a:hover,
.demo-index a:focus-visible {
    color: var(--text);
    outline: none;
}
.demo-index__num {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 11px;
    font-variant-numeric: tabular-nums;
    color: var(--color-secondary);
    letter-spacing: 0.02em;
}


/* --------------------------------------------------------------------------
   Specimen anatomy
   Two-column grid on tablet+: number rail on the left, body on the right.
   Single column on mobile.
-------------------------------------------------------------------------- */
.demo-specimens { display: block; }

.demo-specimen {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-sm);
    padding: var(--space-3xl) 0;
    border-top: 1px solid var(--surface-border);
    scroll-margin-top: 100px;
}
.demo-specimen:first-child {
    border-top: 0;
    padding-top: 0;
}
.demo-specimen:last-child { padding-bottom: 0; }

@media (min-width: 700px) {
    .demo-specimen {
        grid-template-columns: 88px minmax(0, 1fr);
        gap: var(--space-lg);
    }
}

/* Number rail — sits like a specimen label on a museum wall */
.demo-specimen__num {
    display: flex;
    flex-direction: row;
    align-items: baseline;
    gap: var(--space-sm);
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 12px;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    font-variant-numeric: tabular-nums;
    padding-top: 10px;   /* baseline-align with the title */
}
@media (min-width: 700px) {
    .demo-specimen__num {
        flex-direction: column;
        align-items: flex-start;
    }
}
.demo-specimen__rule {
    display: block;
    width: 32px;
    height: 2px;
    background: var(--specimen-accent, var(--color-secondary));
    margin-top: var(--space-2xs);
}

/* Palette rotation. Each specimen owns one accent from the site palette. */
.demo-specimen:nth-child(4n+1) { --specimen-accent: var(--palette-1); }
.demo-specimen:nth-child(4n+2) { --specimen-accent: var(--palette-2); }
.demo-specimen:nth-child(4n+3) { --specimen-accent: var(--palette-3); }
.demo-specimen:nth-child(4n+4) { --specimen-accent: var(--color-accent); }
/* Light theme: swap the pale-blue accent for the deeper blue (contrast). */
:root[data-theme="light"] .demo-specimen:nth-child(4n+3) {
    --specimen-accent: var(--color-secondary);
}

.demo-specimen__body {
    max-width: 62ch;
    min-width: 0;
}

.demo-specimen__title {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 30px;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin: 0 0 var(--space-md);
    color: var(--text);
}

.demo-specimen__intent {
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-muted);
    margin: 0 0 var(--space-xl);
}

/* Metadata block — monospace specimen tags, like a museum specification card */
.demo-specimen__meta {
    display: grid;
    grid-template-columns: max-content minmax(0, 1fr);
    row-gap: 6px;
    column-gap: var(--space-md);
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 12px;
    line-height: 1.5;
    padding: var(--space-md) 0 var(--space-md) var(--space-md);
    border-left: 2px solid var(--specimen-accent, var(--surface-border));
    margin: 0 0 var(--space-xl);
    max-width: 640px;
}
.demo-specimen__meta dt {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin: 0;
}
.demo-specimen__meta dd {
    color: var(--text);
    margin: 0;
    word-break: break-word;
}


/* --------------------------------------------------------------------------
   Specimen CTA — the single affordance
-------------------------------------------------------------------------- */
.demo-cta {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 12px 20px;
    background: transparent;
    color: var(--text);
    border: 1px solid var(--specimen-accent, var(--color-secondary));
    border-radius: var(--r-card);
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 0.01em;
    text-decoration: none;
    min-height: 44px;   /* A11Y-004 touch target */
    transition:
        background var(--transition),
        color      var(--transition),
        transform  var(--transition);
}
.demo-cta:hover,
.demo-cta:focus-visible {
    background: var(--specimen-accent, var(--color-secondary));
    color: #FFFFFF;
    transform: translateY(-1px);
    outline: none;
}
.demo-cta__arrow {
    display: inline-block;
    transition: transform var(--transition);
}
.demo-cta:hover .demo-cta__arrow,
.demo-cta:focus-visible .demo-cta__arrow {
    transform: translateX(4px);
}


/* --------------------------------------------------------------------------
   Stub page — used by /demo/{slug}/ until the real demo ships
-------------------------------------------------------------------------- */
.demo-stub {
    padding: var(--space-4xl) 0;
}
.demo-stub .wrap { max-width: 720px; }

.demo-stub__eyebrow {
    display: inline-block;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 12px;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
    font-variant-numeric: tabular-nums;
}
.demo-stub h1 {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 40px;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin: 0 0 var(--space-lg);
    color: var(--text);
}
.demo-stub p {
    font-size: 17px;
    line-height: 1.6;
    color: var(--text-muted);
    margin: 0 0 var(--space-md);
    max-width: 60ch;
}
.demo-stub__status {
    display: inline-block;
    margin: var(--space-md) 0 var(--space-lg);
    padding: 6px 12px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 11px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-primary);
    border: 1px solid var(--surface-border);
    border-left: 2px solid var(--color-primary);
    border-radius: var(--r-card);
    background: var(--surface);
}
.demo-stub__back {
    display: inline-block;
    margin-top: var(--space-lg);
    color: var(--color-accent);
    text-decoration: underline;
    text-underline-offset: 3px;
}


/* --------------------------------------------------------------------------
   Motion (A11Y-007)
-------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    .demo-cta,
    .demo-cta__arrow,
    .demo-index a { transition: none; }
    .demo-cta:hover,
    .demo-cta:focus-visible { transform: none; }
    .demo-cta:hover .demo-cta__arrow,
    .demo-cta:focus-visible .demo-cta__arrow { transform: none; }
}