:root {
  --ink: #1d1d1f; --muted: #6e6e73; --line: #e5e2dc; --bg: #faf8f5;
  --accent: #c2562f; --accent-soft: #f6e6de; --wall: #e9e2d6;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC", "Noto Sans TC", sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.6; -webkit-font-smoothing: antialiased;
}
button { font: inherit; cursor: pointer; }

.top {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 20px; padding-top: max(14px, env(safe-area-inset-top));
}
.brand { font-weight: 700; display: flex; align-items: center; gap: 8px; letter-spacing: .3px; }
.logo { width: 18px; height: 22px; border-radius: 3px; background: var(--accent); box-shadow: inset 0 0 0 4px var(--accent), inset 0 0 0 20px var(--accent-soft); }
.badge { font-size: 11px; font-weight: 600; color: var(--accent); background: var(--accent-soft); padding: 1px 8px; border-radius: 99px; }
.lang { display: flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: #fff; }
.lang button { border: 0; background: none; padding: 5px 11px; font-size: 13px; color: var(--muted); }
.lang button.on { background: var(--ink); color: #fff; }

main { max-width: 1040px; margin: 0 auto; display: grid; gap: 8px; }
@media (min-width: 860px) { main { grid-template-columns: 1.05fr 1fr; gap: 48px; padding: 24px 24px 0; align-items: start; } }

.wall {
  background: radial-gradient(ellipse at 30% 10%, #f4efe6, var(--wall) 70%);
  display: grid; place-items: center; padding: 36px 20px 40px;
}
@media (min-width: 860px) { .wall { border-radius: 16px; position: sticky; top: 24px; padding: 56px 40px; } }
.frame { margin: 0; width: min(62vw, 300px); box-shadow: 0 2px 3px rgba(40, 25, 10, .25), 10px 18px 30px rgba(40, 25, 10, .28); }
.frame img { display: block; width: 100%; height: auto; }

.info { padding: 4px 20px 24px; }
h1 { font-size: 30px; margin: 0; line-height: 1.2; }
.artist { margin: 4px 0 14px; color: var(--muted); }
.facts { margin: 0 0 14px; display: grid; gap: 2px; }
.facts div { display: flex; gap: 10px; font-size: 15px; }
.facts dt { color: var(--muted); min-width: 52px; }
.facts dd { margin: 0; font-weight: 600; }
.blurb { color: #3d3a36; margin: 0 0 18px; }

.btn { width: 100%; display: flex; align-items: center; justify-content: center; gap: 8px; border-radius: 12px; padding: 14px; font-size: 16px; font-weight: 600; }
.btn svg { width: 20px; height: 20px; fill: currentColor; }
.primary { background: var(--accent); color: #fff; border: 0; box-shadow: 0 6px 16px rgba(194, 86, 47, .3); }
.primary:active { transform: translateY(1px); }
.ghost { background: #fff; color: var(--ink); border: 1px solid #d6d1ca; margin-top: 10px; }
.tip { font-size: 13.5px; color: var(--muted); margin: 10px 2px 0; }
.notice { background: var(--accent-soft); color: #7a3417; padding: 10px 12px; border-radius: 10px; font-size: 14px; margin: 12px 0 0; }

.preview { margin-top: 12px; height: 380px; border-radius: 14px; overflow: hidden; background: radial-gradient(ellipse, #fff, #ece7df); border: 1px solid var(--line); }
.preview model-viewer { width: 100%; height: 100%; --poster-color: transparent; }

.qr-card { display: none; gap: 16px; align-items: center; margin-top: 22px; padding: 16px; background: #fff; border: 1px solid var(--line); border-radius: 14px; }
.desktop .qr-card { display: flex; }
.qr-card img { flex: none; border-radius: 6px; }
.qr-card h2 { font-size: 16px; margin: 0 0 4px; }
.qr-card p { margin: 0 0 6px; font-size: 14px; color: var(--muted); }
.qr-card code { font-size: 13px; background: #f3efe9; padding: 2px 6px; border-radius: 5px; }

.how { margin-top: 26px; }
.how h2 { font-size: 16px; margin: 0 0 6px; }
.how ol { margin: 0; padding-left: 20px; color: #3d3a36; font-size: 14.5px; }
.how li { margin: 4px 0; }

.foot { max-width: 1040px; margin: 0 auto; padding: 18px 20px 32px; padding-bottom: max(32px, env(safe-area-inset-bottom)); color: var(--muted); font-size: 12.5px; }

/* ---------- WebXR DOM overlay ---------- */
#ar-overlay { position: fixed; inset: 0; z-index: 100; color: #fff; font-size: 14px; }
#ar-overlay[hidden] { display: none; }
.ar-touch { position: absolute; inset: 0; touch-action: none; }
.ar-top { position: absolute; top: 0; left: 0; right: 0; display: flex; justify-content: space-between; align-items: center; padding: 14px; padding-top: max(14px, env(safe-area-inset-top)); pointer-events: none; }
.ar-top > * { pointer-events: auto; }
.ar-icon { width: 38px; height: 38px; border-radius: 50%; border: 0; background: rgba(0, 0, 0, .5); color: #fff; font-size: 16px; }
.ar-chip { background: rgba(0, 0, 0, .55); padding: 5px 12px; border-radius: 99px; font-size: 13px; }
.ar-spacer { width: 38px; }
.ar-bottom { position: absolute; left: 0; right: 0; bottom: 0; padding: 16px; padding-bottom: max(20px, env(safe-area-inset-bottom)); display: grid; gap: 12px; pointer-events: none; }
.ar-hint { background: rgba(0, 0, 0, .6); border-radius: 12px; padding: 10px 14px; text-align: center; }
.ar-sub { opacity: .75; font-size: 12.5px; margin-top: 2px; }
.ar-actions { display: flex; justify-content: center; gap: 10px; }
.ar-btn { pointer-events: auto; border: 0; background: rgba(255, 255, 255, .94); color: var(--ink); font-weight: 600; padding: 10px 18px; border-radius: 99px; font-size: 14px; }
.ar-btn[hidden] { display: none; }