/* Class 2 Maths – shared smartboard styles (sized for 75" panels, 1080p and 4K) */
@import url('https://fonts.googleapis.com/css2?family=Baloo+2:wght@500;700;800&family=Andika:wght@400;700&display=swap');

:root {
  --bg: #fff8ec;
  --ink: #2b2140;
  --muted: #6b6280;
  --card: #ffffff;
  --line: #eadfcd;
  --red: #e63946;
  --blue: #2f7de1;
  --green: #2bb673;
  --yellow: #ffc93c;
  --orange: #ff8a3d;
  --purple: #8a5cf6;
  --pink: #ff6fa8;
  --teal: #13b5b1;
  --shadow: 0 0.35rem 0 rgba(43, 33, 64, 0.12);
  --radius: 1.4rem;
  --head: 'Baloo 2', 'Comic Sans MS', 'Chalkboard SE', system-ui, sans-serif;
  --read: 'Andika', 'Comic Sans MS', system-ui, sans-serif;
}

/* Font scales with the panel: ~22px on 1080p, ~44px on 4K */
html { font-size: clamp(14px, 1.05vw + 0.25vh, 46px); }
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--head);
  user-select: none;
  -webkit-user-select: none;
  overflow-x: hidden;
}
button { font-family: inherit; color: inherit; cursor: pointer; touch-action: manipulation; }
img, svg { max-width: 100%; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 0.8rem;
  padding: 0.6rem 1.2rem;
  background: #fff;
  border-bottom: 0.25rem solid var(--line);
}
.topbar h1 { margin: 0; font-size: 1.7rem; line-height: 1.1; flex: 1; }
.topbar h1 small { display: block; font-size: 0.85rem; color: var(--muted); font-weight: 500; }
.tb-btn {
  border: 0; border-radius: 1rem;
  background: #f1ebff; color: var(--purple);
  font-size: 1.1rem; font-weight: 800;
  padding: 0.55rem 1rem; min-height: 3rem;
  display: inline-flex; align-items: center; gap: 0.4rem;
  box-shadow: var(--shadow);
}
.tb-btn:active { transform: translateY(0.2rem); box-shadow: none; }
.stars {
  font-size: 1.4rem; font-weight: 800;
  background: #fff4cc; color: #9a6b00;
  border-radius: 1rem; padding: 0.4rem 1rem; min-height: 3rem;
  display: inline-flex; align-items: center; gap: 0.3rem;
}

/* ---------- layout helpers ---------- */
.stage { padding: 1.2rem 1.6rem 2rem; max-width: 120rem; margin: 0 auto; }
.center { display: flex; flex-direction: column; align-items: center; text-align: center; }
.row { display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; align-items: center; }
.card {
  background: var(--card); border-radius: var(--radius);
  border: 0.2rem solid var(--line); box-shadow: var(--shadow);
  padding: 1.2rem;
}
.prompt { font-size: 2rem; font-weight: 800; margin: 0.4rem 0 1rem; }
.hint { font-size: 1.15rem; color: var(--muted); margin: 0 0 1rem; }

/* ---------- buttons ---------- */
.big-btn {
  border: 0; border-radius: 1.2rem;
  font-size: 1.6rem; font-weight: 800;
  padding: 0.8rem 1.6rem; min-height: 4rem; min-width: 8rem;
  background: var(--blue); color: #fff;
  box-shadow: 0 0.4rem 0 rgba(0, 0, 0, 0.18);
  transition: transform 0.08s;
}
.big-btn:active { transform: translateY(0.3rem); box-shadow: none; }
.big-btn.green { background: var(--green); }
.big-btn.red { background: var(--red); }
.big-btn.orange { background: var(--orange); }
.big-btn.purple { background: var(--purple); }
.big-btn.ghost { background: #fff; color: var(--ink); border: 0.2rem solid var(--line); }
.big-btn[disabled] { opacity: 0.45; pointer-events: none; }

.choice {
  border: 0.25rem solid var(--line); border-radius: 1.4rem;
  background: #fff; font-size: 2.2rem; font-weight: 800;
  padding: 0.8rem 1.8rem; min-height: 5rem; min-width: 9rem;
  box-shadow: var(--shadow);
  transition: transform 0.1s, background 0.2s, border-color 0.2s;
}
.choice:active { transform: scale(0.96); }
.choice.right { background: #d9f7e8; border-color: var(--green); animation: pop 0.35s; }
.choice.wrong { background: #ffe1e3; border-color: var(--red); animation: shake 0.4s; }

/* ---------- feedback ---------- */
.feedback {
  min-height: 3rem; font-size: 1.8rem; font-weight: 800; margin: 0.8rem 0;
}
.feedback.good { color: var(--green); }
.feedback.bad { color: var(--red); }

.progress { display: flex; gap: 0.4rem; justify-content: center; margin: 0.4rem 0 1rem; flex-wrap: wrap; }
.progress span { width: 1.2rem; height: 1.2rem; border-radius: 50%; background: var(--line); }
.progress span.done { background: var(--green); }
.progress span.now { background: var(--yellow); transform: scale(1.3); }

/* ---------- end screen ---------- */
.overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(43, 33, 64, 0.55);
  display: none; align-items: center; justify-content: center;
}
.overlay.show { display: flex; }
.overlay .card { text-align: center; padding: 2rem 3rem; max-width: 90vw; animation: pop 0.4s; }
.overlay h2 { font-size: 3rem; margin: 0; }
.overlay .big-stars { font-size: 4rem; margin: 0.6rem 0; }

/* ---------- speaker chip ---------- */
.say {
  border: 0; background: #e7f1ff; color: var(--blue);
  border-radius: 50%; width: 3.4rem; height: 3.4rem; font-size: 1.7rem;
  display: inline-flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow); flex: none;
}
.say:active { transform: scale(0.92); }

/* ---------- confetti ---------- */
.confetti { position: fixed; top: -2rem; z-index: 200; pointer-events: none; font-size: 2rem; animation: fall linear forwards; }

@keyframes fall { to { transform: translateY(110vh) rotate(540deg); } }
@keyframes pop { 0% { transform: scale(0.7); } 70% { transform: scale(1.08); } 100% { transform: scale(1); } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-0.6rem); } 75% { transform: translateX(0.6rem); } }
@keyframes bob { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-0.5rem); } }

/* drag ghost */
.dragging { position: fixed !important; z-index: 300; pointer-events: none; transform: scale(1.08); opacity: 0.92; }
.picked { outline: 0.3rem dashed var(--orange); outline-offset: 0.2rem; }

/* ---------- maths helpers (math.js) ---------- */
.m-blocks { display: inline-flex; align-items: flex-end; gap: 0.35rem; flex-wrap: wrap; justify-content: center; }
.m-strip { display: inline-flex; flex-direction: column; gap: 0.08rem; padding: 0.1rem; background: #2b2140; border-radius: 0.3rem; }
.m-strip i { display: block; width: var(--s); height: calc(var(--s) * 0.92); background: var(--c); border-radius: 0.15rem; }
.m-units { display: inline-grid; grid-template-columns: repeat(3, auto); gap: 0.2rem; margin-left: 0.4rem; }
.m-unit { display: block; width: var(--s); height: var(--s); background: var(--c); border: 0.12rem solid #2b2140; border-radius: 0.2rem; }
.m-pad { display: grid; grid-template-columns: repeat(3, 5rem); gap: 0.5rem; justify-content: center; }
.m-pad button { min-height: 3.9rem; border: 0.25rem solid var(--line); border-radius: 1.2rem; background: #fff; font-size: 2.2rem; font-weight: 800; box-shadow: var(--shadow); }
.m-pad.one-row { grid-template-columns: repeat(12, 4.6rem); }
.m-pad button:active { transform: scale(0.95); }
.m-pad button.ok { background: var(--green); border-color: var(--green); color: #fff; }
.m-pad button.del { background: #ffe1e3; border-color: #ffc2c7; color: var(--red); }
.m-box { display: inline-flex; align-items: center; justify-content: center; min-width: 5rem; height: 4.4rem; padding: 0 0.6rem; border: 0.3rem dashed var(--purple); border-radius: 1rem; background: #f6f1ff; font-size: 3rem; font-weight: 800; color: var(--purple); vertical-align: middle; }
.m-box.on { border-style: solid; background: #fff4cc; border-color: var(--orange); color: var(--ink); }
.m-box.good { border-style: solid; background: #d9f7e8; border-color: var(--green); color: #117a4a; }
.to-table { display: inline-grid; grid-template-columns: repeat(2, 6rem); border: 0.25rem solid var(--ink); border-radius: 0.8rem; overflow: hidden; }
.to-table b { background: #e7f1ff; font-size: 1.5rem; padding: 0.2rem; border-bottom: 0.2rem solid var(--ink); }
.to-table b + b, .to-table span + span { border-left: 0.2rem solid var(--ink); }
.to-table span { font-size: 3.4rem; font-weight: 800; padding: 0.2rem; text-align: center; }

.m-coin { display: inline-flex; flex-direction: column; align-items: center; justify-content: center; width: var(--s); height: var(--s); border-radius: 50%; border: 0.2rem solid #8a7a50; font-weight: 800; font-size: calc(var(--s) * 0.3); line-height: 1; box-shadow: inset 0 -0.2rem 0 rgba(0, 0, 0, 0.15); color: #3b3020; }
.m-coin small { font-size: 0.45em; }
.m-note { display: inline-flex; align-items: center; justify-content: space-between; width: calc(var(--s) * 8.6rem); height: calc(var(--s) * 4.2rem); border-radius: 0.5rem; border: 0.18rem solid rgba(0, 0, 0, 0.35); padding: 0 0.5rem; font-weight: 800; color: #2b2140; box-shadow: var(--shadow); position: relative; }
.m-note b { font-size: calc(var(--s) * 1.6rem); }
.m-note i { font-style: normal; font-size: calc(var(--s) * 1.1rem); width: calc(var(--s) * 2.6rem); height: calc(var(--s) * 2.6rem); border-radius: 50%; background: rgba(255, 255, 255, 0.45); display: flex; align-items: center; justify-content: center; }