.vd-app .concepts-page { padding-top: 44px; padding-bottom: 64px; }
.concepts-heading { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-bottom: 36px; }
.concepts-eyebrow { margin: 0 0 12px; color: var(--vd-action); font-size: 12px; font-weight: 750; letter-spacing: .15em; text-transform: uppercase; }
.concepts-heading h1, .concepts-detail h1 { margin: 0; font-size: clamp(2.25rem, 4.5vw, 3.75rem); font-weight: 750; letter-spacing: -.05em; line-height: 1.08; }
.concepts-heading h1 + p, .concepts-tagline { color: var(--vd-muted); font-size: 18px; line-height: 1.5; margin: 16px 0 0; }
.concepts-status { flex-shrink: 0; padding: 10px 16px; background: #f6dfd4; color: #853922; border-radius: 999px; font-size: 13px; font-weight: 650; }
.vd-app .concepts-grid { row-gap: 40px; }
.concepts-tile { min-width: 0; }
.concepts-tile-link { display: block; border-radius: 26px; color: inherit; text-decoration: none; }
.concepts-tile img, .concepts-cover { display: block; width: 100%; height: auto; aspect-ratio: 3 / 2; object-fit: cover; border-radius: 26px; box-shadow: var(--lc-shadow); }
.concepts-tile h2 { margin: 18px 0 6px; font-size: 24px; line-height: 1.15; font-weight: 750; letter-spacing: -.035em; }
.concepts-tile p { margin: 0 0 10px; color: var(--vd-muted); font-size: 16px; line-height: 1.45; }
.concepts-meta { display: block; color: var(--vd-muted); font-size: 13px; line-height: 1.7; }
.concepts-read, .concepts-back { display: inline-block; padding: 12px 0; color: var(--vd-action); font-size: 14px; font-weight: 650; }
.concepts-tile-link:hover .concepts-read, .concepts-back:hover { text-decoration: underline; text-underline-offset: 4px; }
.concepts-research { margin-top: 48px; border-top: 1px solid var(--vd-line); padding-top: 20px; }
.concepts-research summary { cursor: pointer; padding: 12px 0; font-weight: 650; }
.concepts-detail-heading { display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 48px; margin: 20px 0 48px; }
.concepts-detail-heading .concepts-meta { margin-top: 20px; }
.concepts-prose { max-width: 740px; font-size: 17px; line-height: 1.75; overflow-wrap: anywhere; }
.concepts-prose h2 { margin: 36px 0 12px; font-size: 26px; line-height: 1.25; letter-spacing: -.03em; font-weight: 750; }
.concepts-prose h3 { margin: 26px 0 10px; font-size: 20px; font-weight: 700; }
.concepts-prose p { margin: 0 0 16px; }
.concepts-prose ul, .concepts-prose ol { margin: 0 0 20px; padding-left: 24px; }
.concepts-prose ul { list-style: disc; }
.concepts-prose ol { list-style: decimal; }
.concepts-prose li { padding-left: 4px; margin-bottom: 8px; }
.concepts-prose li p { margin: 0; }
.concepts-prose a { color: var(--vd-action); text-decoration: underline; text-underline-offset: 3px; }
.concepts-prose h2 a, .concepts-prose h3 a { color: inherit; text-decoration: none; }
.concepts-prose .rdoc-link, .concepts-prose .heading-link { display: none; }
@media (max-width: 900px) {
  .concepts-heading { align-items: flex-start; flex-direction: column; }
  .concepts-detail-heading { gap: 28px; }
}
@media (max-width: 600px) {
  .vd-app .concepts-page { padding-top: 28px; }
  .concepts-heading { margin-bottom: 28px; }
  .concepts-detail-heading { grid-template-columns: 1fr; margin-bottom: 28px; }
  .concepts-prose { font-size: 16px; }
  .concepts-tile h2 { font-size: 23px; }
}

/* Art library */
.vd-app .art-page { padding-top: 44px; padding-bottom: 64px; }
.art-jump { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 40px; }
.art-jump a { padding: 8px 14px; border-radius: 999px; background: var(--vd-panel); box-shadow: var(--lc-shadow); color: inherit; font-size: 13px; font-weight: 650; text-decoration: none; }
.art-jump a:hover { color: var(--vd-action); }
.art-game { margin-bottom: 56px; scroll-margin-top: 80px; }
.art-game > header { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; }
.art-game h2 { margin: 0; font-size: 28px; font-weight: 750; letter-spacing: -.04em; }
.art-badge { padding: 5px 12px; border-radius: 999px; font-size: 12px; font-weight: 700; background: #e8e3d6; color: #5d584a; }
.art-badge.is-in_app { background: #dcf1e6; color: #1f7a4c; } .art-badge.is-concept { background: #f6dfd4; color: #853922; }
.art-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 22px; }
.art-card { margin: 0; min-width: 0; }
.art-card button { display: block; width: 100%; padding: 0; border: 0; background: none; border-radius: 22px; cursor: zoom-in; }
.art-card img { display: block; width: 100%; height: auto; aspect-ratio: 3 / 2; object-fit: cover; border-radius: 22px; box-shadow: var(--lc-shadow); transition: transform .2s ease; }
.art-card button:hover img { transform: translateY(-3px); }
.art-card figcaption { display: grid; gap: 2px; padding: 10px 4px 0; font-size: 14px; } .art-card figcaption span { color: var(--vd-muted); font-size: 12px; }
.art-lightbox { margin: auto; width: min(1100px, 94vw); max-height: 94vh; padding: 14px; border: 0; border-radius: 26px; background: var(--vd-panel, #fffefa); overflow: auto; }
.art-lightbox::backdrop { background: #0b0f18d9; }
.art-lightbox img { display: block; width: 100%; height: auto; border-radius: 18px; }
.art-close { position: absolute; top: 20px; right: 20px; width: 40px; height: 40px; border: 0; border-radius: 50%; background: #fffefacc; font-size: 26px; line-height: 1; cursor: pointer; }
.art-caption { display: grid; gap: 8px; padding: 14px 6px 4px; } .art-caption a { color: var(--vd-action); font-weight: 650; }
.art-caption details p { margin: 8px 0 0; white-space: pre-wrap; color: var(--vd-muted); font-size: 14px; line-height: 1.6; }