/* Fractbox Engine demo — minimal chrome, the render is the star. */
:root {
  color-scheme: dark;
  --fg: #e8eaf0;
  --dim: #9aa3b2;
  --accent: #6fd0e0;
}
* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: #0a0c12;
  color: var(--fg);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
#view {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none; /* let the engine handle orbit/pinch */
}

#title {
  position: fixed;
  top: max(18px, env(safe-area-inset-top));
  left: 20px;
  max-width: 30ch;
  pointer-events: none;
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.7);
}
#title h1 {
  margin: 0;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.5px;
}
#title h1 span {
  color: var(--accent);
  font-weight: 300;
}
#title p {
  margin: 6px 0 0;
  color: var(--dim);
  font-size: 13px;
}

#presets {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  bottom: max(16px, env(safe-area-inset-bottom));
  display: flex;
  gap: 8px;
  padding: 8px;
  max-width: calc(100vw - 24px);
  overflow-x: auto;
  scrollbar-width: thin;
  background: rgba(10, 12, 18, 0.55);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
}
.thumb {
  flex: 0 0 auto;
  width: 84px;
  padding: 0;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  background: #111722;
  color: var(--dim);
  cursor: pointer;
  overflow: hidden;
  transition:
    border-color 0.15s,
    transform 0.1s;
}
.thumb:hover {
  border-color: rgba(255, 255, 255, 0.35);
  transform: translateY(-2px);
}
.thumb[aria-current="true"] {
  border-color: var(--accent);
  color: var(--fg);
}
.thumb img {
  display: block;
  width: 100%;
  height: 56px;
  object-fit: cover;
  background: #0a0c12;
}
.thumb .lbl {
  padding: 4px 2px;
  font-size: 11px;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#meta {
  position: fixed;
  top: max(18px, env(safe-area-inset-top));
  right: 20px;
  text-align: right;
  font-size: 13px;
}
#meta a {
  color: var(--accent);
  text-decoration: none;
}
#meta a:hover {
  text-decoration: underline;
}
#fps {
  display: block;
  margin-top: 4px;
  color: var(--dim);
  font-variant-numeric: tabular-nums;
}

/* Guided-tour launch button (top-left, under the title) */
.tour-btn {
  position: fixed;
  top: 118px;
  left: 20px;
  z-index: 5;
  padding: 8px 14px;
  border-radius: 10px;
  border: 1px solid var(--accent);
  background: rgba(111, 208, 224, 0.12);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  backdrop-filter: blur(6px);
}
.tour-btn:hover {
  background: rgba(111, 208, 224, 0.22);
}

/* Guided-tour step card (bottom-left, clear of the preset strip) */
#tour {
  position: fixed;
  left: 20px;
  bottom: 150px;
  z-index: 6;
  width: min(380px, calc(100vw - 40px));
  padding: 16px 18px;
  background: rgba(10, 12, 18, 0.82);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.5);
}
#tour[hidden] {
  display: none;
}
.tour-dots {
  display: flex;
  gap: 6px;
  margin-bottom: 10px;
}
.tour-dot {
  width: 7px;
  height: 7px;
  padding: 0;
  border-radius: 50%;
  border: none;
  background: rgba(255, 255, 255, 0.25);
  cursor: pointer;
}
.tour-dot[aria-current="true"] {
  background: var(--accent);
}
.tour-title {
  margin: 0 0 6px;
  font-size: 16px;
  color: var(--fg);
}
.tour-body {
  margin: 0 0 14px;
  font-size: 13.5px;
  color: var(--dim);
  line-height: 1.55;
}
.tour-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}
.tour-spacer {
  flex: 1;
}
.tour-nav button {
  padding: 7px 13px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.05);
  color: var(--fg);
  font-size: 13px;
  cursor: pointer;
}
.tour-nav button:hover:not(:disabled) {
  border-color: rgba(255, 255, 255, 0.35);
}
.tour-skip {
  color: var(--dim) !important;
}
.tour-next {
  border-color: var(--accent) !important;
  color: var(--accent) !important;
  background: rgba(111, 208, 224, 0.12) !important;
}
.tour-nav button:disabled {
  opacity: 0.35;
  cursor: default;
}

#nogpu {
  position: fixed;
  inset: 0;
  display: grid;
  place-content: center;
  text-align: center;
  padding: 24px;
  max-width: 44ch;
  margin: auto;
}
/* The `hidden` attribute must win over the ID rule above (ID specificity would
   otherwise keep `display: grid`, leaving the overlay permanently visible on
   top of a perfectly good render). */
#nogpu[hidden] {
  display: none;
}
#nogpu h2 {
  color: var(--accent);
}
#nogpu p {
  color: var(--dim);
}
#nogpu .why {
  margin-top: 14px;
  padding: 10px 12px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.04);
  font-size: 13px;
  text-align: left;
}

@media (max-width: 560px) {
  #title {
    max-width: 22ch;
  }
  #title h1 {
    font-size: 21px;
  }
}

/* ── Text-mode demo (no GPU, or ?ascii=1) — core/cpu.js output ─────────────── */
#asciiview {
  position: fixed;
  inset: 0;
  margin: 0;
  display: grid;
  place-content: center;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  line-height: 1; /* square-ish cells; the demo passes the real char aspect */
  letter-spacing: 0;
  background: #06080f;
  color: #9ab;
  user-select: none;
  cursor: grab;
}
#asciiview[hidden] {
  display: none;
}
#asciiview:active {
  cursor: grabbing;
}
/* Preset chips — text stand-ins for the GPU thumbnail gallery. */
.ascii-chip {
  flex: none;
  font: 12px/1 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color: #cdd6e4;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  padding: 7px 10px;
  cursor: pointer;
}
.ascii-chip:hover {
  background: rgba(255, 255, 255, 0.12);
}
.ascii-chip[aria-current='true'] {
  background: #e08a3c;
  border-color: transparent;
  color: #14100a;
}
/* In text mode the diagnostic is a corner note, not a full-screen overlay —
   there's a live render underneath it now. */
body.ascii #nogpu {
  inset: auto 16px auto auto;
  top: 16px;
  place-content: start;
  text-align: left;
  max-width: 34ch;
  padding: 12px 14px;
  background: rgba(10, 12, 18, 0.82);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  backdrop-filter: blur(8px);
}
body.ascii #nogpu h2 {
  font-size: 14px;
  margin: 0 0 6px;
}
body.ascii #nogpu p {
  font-size: 12px;
  margin: 0 0 4px;
}