:root {
  --bg: #101820;
  --panel: #182532;
  --line: #2f4252;
  --text: #f8fafc;
  --muted: #b9c6d3;
  --accent: #f4c95d;
  --accent-2: #61d394;
  --tile: #f8fafc;
  --tile-text: #15202b;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color-scheme: dark;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100dvh;
  background:
    linear-gradient(135deg, rgba(97, 211, 148, .16), transparent 38%),
    linear-gradient(315deg, rgba(244, 201, 93, .14), transparent 34%),
    var(--bg);
  color: var(--text);
}
button, select { font: inherit; }
button { border: 0; color: inherit; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.app-shell { width: min(760px, 100%); min-height: 100dvh; margin: 0 auto; padding: 16px 14px 22px; }
.topbar, .status-strip, .toolbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.topbar { margin-bottom: 12px; }
.eyebrow, .status-label, .hint-label, .select-wrap span {
  margin: 0 0 4px;
  color: var(--accent);
  font-size: .74rem;
  font-weight: 900;
  letter-spacing: .06em;
  text-transform: uppercase;
}
h1 { margin: 0; font-size: clamp(2rem, 10vw, 3.6rem); line-height: .95; letter-spacing: 0; }
.icon-button, .secondary {
  min-height: 44px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: rgba(24, 37, 50, .94);
  font-weight: 900;
}
.icon-button { width: 48px; font-size: 1.35rem; }
.status-strip, .toolbar, .hint-box {
  padding: 12px;
  border: 1px solid rgba(244, 201, 93, .24);
  border-radius: 8px;
  background: rgba(24, 37, 50, .88);
}
.status-text, .hint-box p { margin: 0; color: var(--muted); line-height: 1.35; }
.stats { display: grid; gap: 4px; text-align: right; color: var(--accent-2); font-size: .86rem; font-weight: 900; white-space: nowrap; }
.toolbar { flex-wrap: wrap; margin-top: 10px; justify-content: flex-start; }
.select-wrap { display: grid; gap: 2px; }
.image-picker { min-width: min(260px, 100%); }
select {
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0 36px 0 12px;
  background: #0f1a23;
  color: var(--text);
  font-weight: 900;
}
.secondary { padding: 0 14px; }
.secondary:disabled, .tile:disabled { opacity: .48; cursor: not-allowed; }
.board-wrap { display: grid; place-items: center; padding: 14px 0; }
.board {
  --size: 3;
  display: grid;
  grid-template-columns: repeat(var(--size), 1fr);
  gap: clamp(4px, 1.4vw, 8px);
  width: min(94vw, 640px);
  aspect-ratio: 1;
  padding: clamp(6px, 1.8vw, 12px);
  border-radius: 8px;
  border: 1px solid var(--line);
  background: rgba(8, 13, 18, .7);
  touch-action: manipulation;
}
.tile {
  --tile-bg-x: 0%;
  --tile-bg-y: 0%;
  display: grid;
  place-items: center;
  width: 100%;
  min-width: 0;
  aspect-ratio: 1;
  border-radius: 7px;
  border: 1px solid rgba(255, 255, 255, .66);
  background-image:
    linear-gradient(145deg, rgba(255, 255, 255, .2), transparent 30%),
    var(--puzzle-image);
  background-size: calc(var(--size) * 100%) calc(var(--size) * 100%);
  background-position:
    0 0,
    var(--tile-bg-x) var(--tile-bg-y);
  color: #fff;
  font-size: clamp(.55rem, calc(10vw / var(--size)), 1.65rem);
  font-weight: 1000;
  line-height: 1;
  text-shadow: 0 2px 4px rgba(0, 0, 0, .9), 0 0 1px #000;
  box-shadow: 0 8px 16px rgba(0, 0, 0, .24), inset 0 0 0 1px rgba(0, 0, 0, .2);
}
.tile.blank {
  border-style: dashed;
  background: rgba(248, 250, 252, .07);
  box-shadow: inset 0 0 0 1px rgba(248, 250, 252, .08);
}
.hint-box { margin-top: 2px; }
@media (max-width: 520px) {
  .status-strip { align-items: flex-start; flex-direction: column; }
  .stats { text-align: left; }
  .toolbar { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .select-wrap, .image-picker { grid-column: 1 / -1; }
}