:root {
  --bg: #FFF6E9;
  --surface: #FFFFFF;
  --stage: #F6E9D4;
  --ink: #1E2238;
  --ink-2: rgba(30, 34, 56, 0.74);
  --ink-3: rgba(30, 34, 56, 0.6);
  --line: rgba(30, 34, 56, 0.12);
  --sun: #FFC531;
  --bad: #C8102E;
  --good: #0A7D45;
  --w: #F4F4EE; --y: #FFD21F; --g: #00A15C; --b: #1F5FD6; --r: #D7263D; --o: #FF7A1A; --empty: #D9D4E3;
  --radius: 16px;
  --f-s: 14px; --f-m: 18px; --f-l: 24px; --f-xl: 36px;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Fredoka', system-ui, sans-serif;
  font-size: var(--f-m);
  font-weight: 400;
  line-height: 1.4;
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
}
button { font: inherit; color: inherit; cursor: pointer; }
[hidden] { display: none !important; }

/* ---------- header ---------- */
.top {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 16px 32px; flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 12px; font-size: var(--f-l); font-weight: 600; }
.logo { display: grid; grid-template-columns: 12px 12px; gap: 3px; }
.logo i { width: 12px; height: 12px; border-radius: 3px; }
.logo i:nth-child(1) { background: var(--r); }
.logo i:nth-child(2) { background: var(--y); }
.logo i:nth-child(3) { background: var(--b); }
.logo i:nth-child(4) { background: var(--g); }
.steps { display: flex; gap: 8px; list-style: none; margin: 0; padding: 0; font-size: var(--f-s); }
.steps li {
  display: flex; align-items: center; gap: 8px; padding: 8px 12px; border-radius: 999px;
  color: var(--ink-3); background: transparent;
}
.steps li b {
  display: grid; place-items: center; width: 24px; height: 24px; border-radius: 50%;
  background: var(--line); font-weight: 600;
}
.steps li.on { color: var(--ink); background: var(--surface); box-shadow: 0 1px 0 var(--line); }
.steps li.on b { background: var(--sun); }
.steps li.done b { background: var(--ink); color: var(--bg); }

/* ---------- layout ---------- */
.layout {
  display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 32px;
  max-width: 1200px; margin: 0 auto; padding: 8px 32px 64px;
}
.stage {
  position: sticky; top: 16px; align-self: start;
  background: var(--stage); border-radius: 24px; padding: 16px;
}
.cube3d { width: 100%; aspect-ratio: 1 / 1; max-height: 72vh; touch-action: none; cursor: grab; }
.cube3d:active { cursor: grabbing; }
.cube3d { overflow: hidden; }
.cube3d canvas { display: block; width: 100% !important; height: 100% !important; }
.stage { min-width: 0; }
.stage-hint { margin: 8px 0 0; text-align: center; font-size: var(--f-s); color: var(--ink-2); }

.panel { display: flex; flex-direction: column; gap: 24px; min-width: 0; }

/* ---------- paint ---------- */
.faces { display: flex; flex-wrap: wrap; gap: 8px; }
.face-tab {
  display: flex; align-items: center; gap: 8px; padding: 8px 12px; border-radius: 999px;
  border: 2px solid var(--line); background: var(--surface); font-size: var(--f-s);
  transition: transform 120ms ease-out, border-color 120ms ease-out;
}
.face-tab:hover { border-color: rgba(30, 34, 56, 0.3); }
.face-tab:active { transform: scale(0.96); }
.face-tab:focus-visible, .btn:focus-visible, .link:focus-visible, .sq:focus-visible, .dot:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; }
.face-tab .chip { width: 16px; height: 16px; border-radius: 4px; box-shadow: inset 0 0 0 1px rgba(0,0,0,.15); }
.face-tab.on { border-color: var(--ink); font-weight: 600; }
.face-tab .tick { color: var(--good); font-weight: 600; }
.face-tab.bad { border-color: var(--bad); }

.hold { display: flex; gap: 16px; align-items: center; background: var(--surface); border-radius: var(--radius); padding: 16px; }
.hold svg { flex: none; width: 72px; height: 72px; }
.hold p { margin: 0; color: var(--ink); }

.grid3 {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px;
  width: min(100%, 312px); padding: 12px; border-radius: 20px; background: #1C1B29; align-self: center;
}
.sq {
  aspect-ratio: 1 / 1; border: 0; border-radius: 12px; background: var(--empty);
  transition: transform 120ms ease-out;
  position: relative;
}
.sq:hover { transform: scale(0.97); }
.sq:active { transform: scale(0.92); }
.sq.center { cursor: default; }
.sq.center::after {
  content: 'middle'; position: absolute; inset: auto 0 8px; font-size: var(--f-s); color: rgba(0,0,0,.45);
}
.sq.center.dark::after { color: rgba(255,255,255,.8); }
.sq.bad { animation: pulse 900ms ease-in-out infinite; }
@keyframes pulse { 50% { box-shadow: 0 0 0 4px var(--bad); transform: scale(0.94); } }

.palette { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.dot {
  width: 56px; height: 56px; border-radius: 50%; border: 0;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,.15);
  transition: transform 120ms ease-out, box-shadow 120ms ease-out;
}
.dot:hover { transform: translateY(-2px); }
.dot[aria-checked="true"] { box-shadow: 0 0 0 4px var(--bg), 0 0 0 7px var(--ink); transform: scale(1.06); }

.msg { border-radius: var(--radius); padding: 16px; background: #FDE7EA; color: #7A0A1C; }
.msg.ok { background: #E3F5EA; color: #064D2B; }

.actions { display: flex; flex-direction: column; gap: 12px; align-items: stretch; }
.minor { display: flex; gap: 24px; justify-content: center; flex-wrap: wrap; }

.btn {
  border: 2px solid var(--ink); background: var(--surface); border-radius: 999px;
  padding: 12px 24px; font-weight: 600; font-size: var(--f-m);
  transition: transform 120ms ease-out, background-color 120ms ease-out;
}
.btn:hover { background: #F4EFE6; }
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }
.btn.primary { background: var(--ink); color: var(--bg); }
.btn.primary:hover { background: #2E3352; }
.btn.big { font-size: var(--f-l); padding: 16px 32px; }
.link {
  border: 0; background: none; padding: 8px 0; font-size: var(--f-s); color: var(--ink-2);
  text-decoration: underline; text-underline-offset: 4px; text-decoration-color: var(--line);
}
.link:hover { color: var(--ink); text-decoration-color: currentColor; }

.overview { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.label { margin: 0; font-size: var(--f-s); color: var(--ink-3); }
.net { display: grid; grid-template-columns: repeat(12, 14px); grid-template-rows: repeat(9, 14px); gap: 2px; }
.net button { border: 0; padding: 0; border-radius: 3px; background: var(--empty); }
.net button.bad { animation: pulse 900ms ease-in-out infinite; }
.net button.cur { outline: 2px solid var(--ink); outline-offset: 0; }

/* ---------- learn ---------- */
.levels { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; }
.levels button {
  width: 100%; border: 0; background: none; padding: 4px 0; display: flex; flex-direction: column; align-items: center; gap: 4px;
  font-size: 12px; color: var(--ink-3); line-height: 1.15; text-align: center;
}
.levels b {
  display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%;
  background: var(--surface); border: 2px solid var(--line); font-weight: 600; font-size: var(--f-s); color: var(--ink-2);
  transition: transform 160ms ease-out;
}
.levels .done b { background: var(--ink); border-color: var(--ink); color: var(--bg); }
.levels .on b { background: var(--sun); border-color: var(--ink); color: var(--ink); transform: scale(1.12); }
.levels .on { color: var(--ink); font-weight: 600; }

.card {
  background: var(--surface); border-radius: 24px; padding: 32px; min-height: 240px;
  display: flex; flex-direction: column; gap: 12px; box-shadow: 0 1px 0 var(--line);
}
.card p { margin: 0; }
.card-level { font-size: var(--f-s); color: var(--ink-3); font-weight: 600; letter-spacing: .02em; }
.card-chunk { color: var(--ink-2); }
.card-move { font-size: var(--f-xl); font-weight: 600; line-height: 1.15; display: flex; gap: 16px; align-items: center; }
.card-move .arrow { font-size: 48px; line-height: 1; }
.card-move .arrow:empty { display: none; }
.card.intro .card-move { font-size: var(--f-l); }
.card-code { font-size: var(--f-s); color: var(--ink-3); }
.card-code b {
  display: inline-block; min-width: 32px; text-align: center; padding: 2px 8px; border-radius: 8px;
  background: var(--bg); color: var(--ink); font-family: ui-monospace, Menlo, monospace;
}
.card.enter { animation: cardIn 220ms ease-out; }
@keyframes cardIn { from { opacity: 0; transform: translateY(8px); } }

.progress { height: 8px; border-radius: 999px; background: var(--line); overflow: hidden; }
.progress i { display: block; height: 100%; width: 100%; background: var(--sun); transform-origin: left; transform: scaleX(0); transition: transform 240ms ease-out; }
.counter { margin: -16px 0 0; font-size: var(--f-s); color: var(--ink-3); text-align: center; }
.controls { display: grid; grid-template-columns: 1fr 2fr; gap: 12px; }

/* ---------- confetti ---------- */
.confetti { position: fixed; inset: 0; pointer-events: none; overflow: hidden; z-index: 10; }
.confetti i {
  position: absolute; top: -20px; width: 10px; height: 14px; border-radius: 3px;
  animation: fall var(--d) ease-out forwards;
}
@keyframes fall {
  to { transform: translate(var(--x), 110vh) rotate(var(--r)); opacity: 0.9; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 1ms !important; transition-duration: 1ms !important; }
  .confetti { display: none; }
}

/* ---------- phone ---------- */
@media (max-width: 860px) {
  .top { padding: 12px 16px; }
  .steps li { padding: 4px 8px; }
  .layout { grid-template-columns: 1fr; gap: 16px; padding: 0 16px 48px; }
  .stage { position: relative; top: 0; padding: 8px; border-radius: 20px; }
  .cube3d { aspect-ratio: 4 / 3; max-height: 44vh; }
  .card { padding: 24px; min-height: 200px; }
  .card-move { font-size: 30px; }
  .levels button span { display: none; }
}
@media (max-width: 420px) {
  .brand { font-size: var(--f-m); }
  .steps { font-size: 12px; }
  .dot { width: 48px; height: 48px; }
}