/* Shape Explorer – mobile first */
:root {
  --bg1: #f3f9ff;
  --bg2: #e9f6f1;
  --ink: #17232f;
  --dim: #5d6f7e;
  --line: #dbe5ee;
  --card: #ffffff;
  --teal: #0f8f7d;
  --teal-soft: #dff5f0;
  --purple: #6a5acd;
  --blue: #4f86e0;
  --orange: #ff7a00;
  --pink: #e0246f;
  --gold: #f2b01e;
  --radius: 20px;
  --shadow: 0 1px 2px rgba(23, 35, 47, .06), 0 8px 24px rgba(23, 35, 47, .06);
  --head: 'Fredoka', 'Nunito', system-ui, sans-serif;
  --body: 'Nunito', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --gutter: clamp(14px, 4vw, 32px);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100dvh;
  font: 500 1rem/1.5 var(--body);
  color: var(--ink);
  background: linear-gradient(180deg, var(--bg1), var(--bg2)) fixed;
}
button, select, input { font: inherit; color: inherit; }
button { cursor: pointer; }
[hidden] { display: none !important; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 8px; background: #fff; padding: 8px 14px; border-radius: 10px; z-index: 99; }
.skip:focus { left: 8px; }
:focus-visible { outline: 3px solid var(--purple); outline-offset: 2px; }

/* ---------- header ---------- */
.top {
  position: sticky; top: 0; z-index: 20;
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 6px 16px;
  padding: 10px var(--gutter);
  padding-top: max(10px, env(safe-area-inset-top));
  background: rgba(255, 255, 255, .86);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font: 700 1.3rem var(--head); }
.tabs { display: flex; gap: 6px; padding: 4px; background: #eaf0f5; border-radius: 999px; }
.tabs button {
  border: 0; background: transparent; padding: 8px 14px; border-radius: 999px;
  font: 600 .95rem var(--head); color: var(--dim); white-space: nowrap; min-height: 40px;
  transition: background .2s, color .2s, box-shadow .2s;
}
.tabs button[aria-selected="true"] { background: #fff; color: var(--teal); box-shadow: 0 1px 4px rgba(23, 35, 47, .15); }
@media (max-width: 520px) {
  .top { flex-wrap: nowrap; gap: 10px; padding-block: 8px; }
  .brand { font-size: 1.05rem; gap: 6px; }
  .brand svg { width: 28px; height: 28px; }
  .tabs .lg { display: none; }
  .tabs .sm { display: inline; }
  .tabs button { gap: 4px; }
  .tabs { flex: 1; }
  .tabs button { flex: 1; padding-inline: 4px; font-size: .85rem; min-height: 38px; }
}

/* ---------- layout ---------- */
main { width: 100%; padding: 18px var(--gutter) 28px; }
h1 { font: 600 clamp(1.6rem, 5vw, 2.3rem)/1.15 var(--head); margin: 8px 0 14px; letter-spacing: -.01em; }
h2 { font: 600 1.2rem var(--head); margin: 0 0 8px; }
.panel { animation: fade .3s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.note { display: flex; gap: 12px; align-items: flex-start; margin: 0 0 16px; color: #2b3a47; max-width: 70ch; }
.ico {
  flex: none; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  background: var(--teal-soft); color: var(--teal); font: 700 1rem var(--head);
}

/* ---------- shape picker ---------- */
.picker { display: flex; gap: 10px; overflow-x: auto; padding: 4px 2px 12px; scroll-snap-type: x proximity; scrollbar-width: thin; }
.picker button {
  flex: none; scroll-snap-align: start;
  display: grid; justify-items: center; gap: 2px; min-width: 88px; padding: 10px 12px;
  background: var(--card); border: 2px solid transparent; border-radius: 18px; box-shadow: var(--shadow);
  font: 600 .88rem var(--head); color: var(--ink);
  transition: transform .15s, border-color .2s, background .2s;
}
.picker button .em { font-size: 1.8rem; line-height: 1.1; }
.picker button:hover { transform: translateY(-2px); }
.picker button[aria-selected="true"] { border-color: var(--teal); background: var(--teal-soft); }
.picker.pills button { min-width: 0; grid-auto-flow: column; align-items: center; gap: 8px; padding: 8px 16px; border-radius: 999px; }
.picker.pills button .em { font-size: 1.2rem; }
@media (min-width: 900px) { .picker { flex-wrap: wrap; overflow: visible; } }

/* ---------- stage ---------- */
.stage {
  position: relative; display: flex; flex-direction: column;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden;
}
.gl-host {
  position: relative; flex: 1 1 auto; min-height: 0;
  height: clamp(320px, 62dvh, 580px);
  background: radial-gradient(120% 90% at 50% 20%, #ffffff 0%, #f1f7fc 55%, #e4eef7 100%);
  touch-action: none; user-select: none; -webkit-user-select: none;
}
canvas.gl { position: absolute; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; cursor: grab; outline: none; }
canvas.gl:active { cursor: grabbing; }
.labels { position: absolute; inset: 0; pointer-events: none; overflow: hidden; z-index: 2; }
.nogl { position: absolute; inset: 0; margin: 0; display: grid; place-items: center; padding: 24px; text-align: center; color: var(--dim); }

.vlabel {
  position: absolute; left: 0; top: 0; min-width: 26px; height: 26px; padding: 0 8px; border-radius: 13px;
  display: grid; place-items: center; font: 600 .95rem/1 var(--head); color: #fff;
  background: var(--blue); border: 2px solid #fff; box-shadow: 0 2px 6px rgba(0, 0, 0, .28);
  will-change: transform; transition: opacity .2s;
}
.vlabel[data-kind="edges"] { background: var(--orange); }
.vlabel[data-kind="vertices"] { background: var(--pink); }
.vlabel[data-kind="curved"] { background: var(--teal); }
.vlabel.behind { opacity: .38; }
.vlabel.pop { animation: pop .45s cubic-bezier(.25, 1, .5, 1); }
@keyframes pop { from { scale: .3; } to { scale: 1; } }

/* HUD chips */
.hud { position: absolute; z-index: 3; top: 12px; left: 12px; right: 64px; display: flex; flex-wrap: wrap; gap: 8px; pointer-events: none; }
.chip {
  pointer-events: auto; display: flex; align-items: baseline; gap: 6px; padding: 6px 12px 6px 10px;
  background: rgba(255, 255, 255, .92); border: 2px solid var(--c, var(--blue)); border-radius: 999px;
  box-shadow: 0 2px 8px rgba(23, 35, 47, .1); font: 600 .85rem var(--head); color: var(--ink); min-height: 40px;
  transition: background .2s, color .2s, transform .15s;
}
.chip b { font: 700 1.3rem/1 var(--head); color: var(--c, var(--blue)); min-width: 1ch; text-align: center; transition: color .2s; }
.chip:hover { transform: translateY(-1px); }
.chip[data-kind="faces"], .chip[data-kind="sides"] { --c: var(--blue); }
.chip[data-kind="edges"] { --c: var(--orange); }
.chip[data-kind="vertices"], .chip[data-kind="corners"] { --c: var(--pink); }
.chip[data-kind="curved"], .chip[data-kind="right"] { --c: var(--teal); }
.chip[data-kind="sym"] { --c: var(--purple); }
.chip.on { background: var(--c); color: #fff; }
.chip.on b { color: #fff; }
.chip.zero { opacity: .7; }

.tools { position: absolute; z-index: 3; top: 12px; right: 12px; display: flex; flex-direction: column; gap: 8px; }
.tool {
  width: 42px; height: 42px; padding: 0; display: grid; place-items: center; border-radius: 12px;
  background: rgba(255, 255, 255, .95); border: 1px solid var(--line); color: var(--ink);
  box-shadow: 0 2px 8px rgba(23, 35, 47, .12);
}
.tool svg { width: 22px; height: 22px; }
.tool:hover { background: #fff; color: var(--teal); }
.i-exit { display: none; }
.is-fs .i-enter, .stage:fullscreen .i-enter { display: none; }
.is-fs .i-exit, .stage:fullscreen .i-exit { display: block; }

.toast {
  position: absolute; z-index: 4; left: 50%; bottom: 14px; transform: translate(-50%, 12px); opacity: 0;
  max-width: calc(100% - 32px); padding: 9px 16px; border-radius: 999px; background: #17232f; color: #fff;
  font: 600 .95rem var(--head); text-align: center; pointer-events: none; transition: opacity .25s, transform .25s;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* control bar */
.bar {
  display: grid; grid-template-columns: 1fr auto; gap: 12px 16px; align-items: end;
  padding: 12px 16px calc(14px + env(safe-area-inset-bottom)); background: #fff; border-top: 1px solid var(--line);
}
.field.pick { grid-column: 1; }
.play { grid-column: 2; grid-row: 1; }
.field.fold { grid-column: 1 / -1; grid-row: 2; }
.field.sides { grid-column: 1 / -1; grid-row: 3; }
@media (min-width: 760px) {
  .bar { grid-template-columns: auto minmax(220px, 1fr) auto minmax(150px, 220px); gap: 8px 28px; align-items: center; padding-inline: 22px; }
  .field.pick { grid-column: 1; grid-row: 1; }
  .field.fold { grid-column: 2; grid-row: 1; }
  .play { grid-column: 3; grid-row: 1; }
  .field.sides { grid-column: 4; grid-row: 1; }
}
select {
  appearance: none; -webkit-appearance: none; width: 100%; min-height: 46px; padding: 8px 40px 8px 14px; border-radius: 10px;
  border: 2px solid var(--purple); background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='9'%3E%3Cpath d='M1 1l6 6 6-6' fill='none' stroke='%23555' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat right 14px center;
  font: 600 1rem var(--head); cursor: pointer;
}
.ends { display: flex; justify-content: space-between; font: 700 .95rem var(--head); color: var(--teal); margin-bottom: 2px; }
.field.sides { display: grid; grid-template-columns: auto 1fr; align-items: center; column-gap: 12px; }
.field.sides output { grid-row: 1; grid-column: 1; font: 700 1.2rem var(--head); color: var(--purple); min-width: 1.5ch; text-align: center; }
.field.sides input { grid-row: 1; grid-column: 2; }
.field.sides .cap { grid-column: 1 / -1; text-align: center; font: 600 .9rem var(--head); color: var(--ink); }
.play {
  min-height: 46px; padding: 8px 20px; border: 0; border-radius: 999px; background: var(--teal); color: #fff;
  font: 700 1.05rem var(--head); box-shadow: 0 3px 0 #0a6b5d; transition: transform .1s, box-shadow .1s, background .2s; white-space: nowrap;
}
.play:active { transform: translateY(2px); box-shadow: 0 1px 0 #0a6b5d; }
.play:disabled, input:disabled { opacity: .45; cursor: not-allowed; }

/* range sliders */
input[type="range"] {
  --p: 100%; --col: var(--teal);
  -webkit-appearance: none; appearance: none; width: 100%; height: 30px; margin: 0; background: transparent; touch-action: pan-y;
}
input[type="range"]::-webkit-slider-runnable-track { height: 6px; border-radius: 6px; background: linear-gradient(to right, var(--col) var(--p), #d5e1ea var(--p)); }
input[type="range"]::-moz-range-track { height: 6px; border-radius: 6px; background: linear-gradient(to right, var(--col) var(--p), #d5e1ea var(--p)); }
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 26px; height: 26px; margin-top: -10px; border-radius: 50%;
  background: var(--col); border: 4px solid #fff; box-shadow: 0 0 0 3px color-mix(in srgb, var(--col) 45%, white), 0 2px 6px rgba(0,0,0,.3);
}
input[type="range"]::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%; background: var(--col); border: 4px solid #fff;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--col) 45%, white), 0 2px 6px rgba(0,0,0,.3);
}
#sides { --col: var(--purple); }

/* full screen */
.stage:fullscreen { border-radius: 0; border: 0; width: 100vw; height: 100dvh; background: #fff; }
.stage.is-fs { position: fixed; inset: 0; z-index: 100; border-radius: 0; border: 0; height: 100dvh; }
.stage:fullscreen .gl-host, .stage.is-fs .gl-host { height: auto; flex: 1 1 0; }
.stage:fullscreen .hud, .stage.is-fs .hud { top: max(12px, env(safe-area-inset-top)); }
body.noscroll { overflow: hidden; }

/* ---------- cards ---------- */
.cards { display: grid; gap: 16px; margin-top: 18px; grid-template-columns: 1fr; }
@media (min-width: 700px) { .cards { grid-template-columns: repeat(2, 1fr); } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.card p { margin: 0 0 8px; }
.net { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; color: var(--dim); }
.pill { display: inline-block; padding: 2px 10px; border-radius: 999px; background: var(--teal-soft); color: var(--teal); font: 600 .8rem var(--head); }
.defs, .goto { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.defs li { display: grid; grid-template-columns: 14px 1fr; gap: 0 10px; align-items: baseline; }
.defs li b { grid-column: 2; display: inline; }
.defs .dim { color: var(--dim); }
.dot { width: 12px; height: 12px; border-radius: 50%; display: inline-block; background: var(--blue); }
.dot.e { background: var(--orange); } .dot.v { background: var(--pink); } .dot.s { background: var(--purple); }
.defs li { display: block; padding-left: 24px; position: relative; }
.defs li .dot { position: absolute; left: 0; top: .45em; }
.euler { margin-top: 12px !important; padding: 8px 12px; border-radius: 12px; background: #fff6e6; font-weight: 700; }
.examples { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 10px; }
.examples li { display: grid; justify-items: center; gap: 2px; padding: 10px 6px; border-radius: 14px; background: #f4f8fb; text-align: center; font-weight: 700; font-size: .92rem; line-height: 1.25; }
.examples .em { font-size: 2rem; line-height: 1.1; }
.fun p { font-size: 1.05rem; }
.goto button {
  width: 100%; text-align: left; padding: 10px 14px; border: 2px solid var(--line); border-radius: 14px; background: #f8fbfd;
  font-weight: 700; display: flex; gap: 10px; align-items: center; justify-content: space-between;
}
.goto button:hover { border-color: var(--teal); background: var(--teal-soft); }

/* ---------- 2D ---------- */
.svg-host { height: clamp(320px, 56dvh, 520px); }
#svg2d { position: absolute; inset: 0; width: 100%; height: 100%; }
#svg2d .shape { fill: #cfe3ff; stroke: #1b2733; stroke-width: 5; stroke-linejoin: round; transition: fill .3s; }
#svg2d .side { stroke: transparent; stroke-width: 12; stroke-linecap: round; fill: none; transition: stroke .2s; }
#svg2d .side.hot { stroke: var(--orange); }
#svg2d .corner { fill: var(--pink); stroke: #fff; stroke-width: 3; transform-box: fill-box; transform-origin: center; }
#svg2d .rmark { fill: rgba(15, 143, 125, .25); stroke: var(--teal); stroke-width: 3; }
#svg2d .sym { stroke: var(--purple); stroke-width: 3; stroke-dasharray: 9 7; stroke-linecap: round; }
#svg2d .n { font: 700 18px var(--head); fill: #fff; text-anchor: middle; dominant-baseline: central; paint-order: stroke; }
#svg2d .badge { stroke: #fff; stroke-width: 3; }
#svg2d g.pop { animation: svgpop .4s cubic-bezier(.25, 1, .5, 1); transform-box: fill-box; transform-origin: center; }
@keyframes svgpop { from { scale: .2; opacity: 0; } to { scale: 1; opacity: 1; } }
.svg-host .hud { right: 12px; }

/* ---------- quiz ---------- */
.quiz { max-width: 720px; margin-inline: auto; padding: 22px; }
.q-top { display: flex; justify-content: space-between; align-items: center; font: 600 .95rem var(--head); color: var(--dim); margin-bottom: 8px; }
.q-bar { height: 10px; background: #e5edf3; border-radius: 10px; overflow: hidden; margin-bottom: 18px; }
.q-bar i { display: block; height: 100%; width: 100%; background: linear-gradient(90deg, var(--teal), var(--blue)); border-radius: 10px; transform: scaleX(0); transform-origin: left; transition: transform .4s cubic-bezier(.25, 1, .5, 1); }
.q-text { font: 600 clamp(1.25rem, 4.5vw, 1.6rem)/1.3 var(--head); margin: 0 0 6px; }
.q-emoji { font-size: 3rem; line-height: 1.2; margin-bottom: 4px; }
.q-opts { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.q-opts button {
  min-height: 64px; padding: 10px; border: 3px solid var(--line); border-radius: 16px; background: #fff;
  font: 600 1.15rem var(--head); transition: transform .12s, border-color .2s, background .2s;
}
.q-opts button:hover:not(:disabled) { transform: translateY(-2px); border-color: var(--purple); }
.q-opts button.right { border-color: #1faa59; background: #e3f8ec; }
.q-opts button.wrong { border-color: #e04b4b; background: #fde8e8; }
.q-opts button:disabled { cursor: default; }
.q-fb { min-height: 3em; font-weight: 700; }
.q-next, .q-again {
  min-height: 48px; padding: 10px 26px; border: 0; border-radius: 999px; background: var(--teal); color: #fff;
  font: 700 1.1rem var(--head); box-shadow: 0 3px 0 #0a6b5d;
}
.q-result { text-align: center; padding: 10px 0; }
.q-result .stars { font-size: 2.6rem; letter-spacing: 6px; }
.q-result .score { font: 700 3rem var(--head); color: var(--teal); }

/* ---------- vlabels / misc ---------- */
footer { text-align: center; color: var(--dim); font-size: .9rem; padding: 0 var(--gutter) 28px; }

@media (max-width: 520px) {
  .hud { right: 60px; gap: 6px; }
  .chip { padding: 4px 10px 4px 8px; min-height: 36px; font-size: .78rem; }
  .chip b { font-size: 1.15rem; }
  .q-opts { grid-template-columns: 1fr; }
}
@media (max-height: 480px) and (orientation: landscape) {
  .gl-host { height: 70dvh; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

.note .short { display: none; }
@media (max-width: 520px) {
  main { padding-top: 10px; }
  h1 { margin: 4px 0 8px; }
  .note { margin-bottom: 10px; font-size: .92rem; line-height: 1.4; }
  .note .long { display: none; }
  .note .short { display: inline; }
  .ico { width: 24px; height: 24px; font-size: .85rem; }
  .picker { gap: 8px; padding-bottom: 10px; scrollbar-width: none; }
  .picker::-webkit-scrollbar { display: none; }
  .picker button { min-width: 68px; padding: 6px 8px; font-size: .8rem; border-radius: 14px; }
  .picker button .em { font-size: 1.5rem; }
  .picker.pills button { padding: 6px 12px; }
  .gl-host { height: clamp(280px, 46dvh, 480px); }
  .bar { padding: 10px 14px calc(12px + env(safe-area-inset-bottom)); gap: 8px 12px; }
}

/* ---------- v2: tabs, brand, hidden counts, dashboard layout, games ---------- */
.tabs button { display: inline-flex; align-items: center; gap: 6px; }
.tabs .sm { display: none; }
.brand span { white-space: nowrap; }
footer a { color: var(--teal); font-weight: 700; text-underline-offset: 3px; }
footer { padding-top: 6px; }

.chip b.hid { display: grid; place-items: center; min-width: 22px; }
.chip b.hid .eye { width: 22px; height: 22px; color: var(--c); opacity: .85; }
.chip.on b.hid .eye { color: #fff; }

.dash { display: block; }
.dash .cards { margin-top: 18px; }
@media (min-width: 1100px) {
  .dash { display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, 400px); gap: 20px; align-items: start; }
  .dash .cards { margin-top: 0; grid-template-columns: 1fr; }
  .gl-host { height: clamp(400px, calc(100dvh - 300px), 900px); }
  .svg-host { height: clamp(400px, calc(100dvh - 300px), 900px); }
}
.stage:fullscreen .gl-host, .stage.is-fs .gl-host { height: auto; }

.games { padding: 16px; }
.game-tabs { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; margin-bottom: 18px; }
.game-tabs button {
  padding: 9px 18px; border-radius: 999px; border: 2px solid var(--line); background: #fff;
  font: 600 1rem var(--head); min-height: 44px;
}
.game-tabs button[aria-selected="true"] { border-color: var(--teal); background: var(--teal-soft); color: var(--teal); }
.game-body { max-width: 780px; margin-inline: auto; }
.q-top { flex-wrap: wrap; gap: 4px 12px; }
.q-again { margin-top: 6px; }

.mem { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin: 8px 0 12px; }
.mem-card { padding: 0; border: 0; background: none; aspect-ratio: 1 / 1.08; perspective: 700px; }
.mem-card .inner { position: relative; display: block; width: 100%; height: 100%; transform-style: preserve-3d; transition: transform .45s cubic-bezier(.25, 1, .5, 1); }
.mem-card.flip .inner { transform: rotateY(180deg); }
.mem-card .back, .mem-card .front {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px;
  border-radius: 14px; backface-visibility: hidden; -webkit-backface-visibility: hidden; padding: 4px; text-align: center; line-height: 1.15;
}
.mem-card .back { background: linear-gradient(135deg, var(--teal), var(--blue)); color: #fff; font: 700 clamp(1.4rem, 5vw, 2.2rem) var(--head); box-shadow: 0 3px 0 rgba(0, 0, 0, .15); }
.mem-card .front { transform: rotateY(180deg); background: #fff; border: 3px solid var(--line); font: 600 clamp(.72rem, 2.6vw, 1rem) var(--head); }
.mem-card .front .em { font-size: clamp(1.6rem, 6vw, 2.6rem); line-height: 1.1; }
.mem-card .front small { font: 600 clamp(.62rem, 2.2vw, .85rem) var(--body); color: var(--dim); }
.mem-card.done .front { border-color: #1faa59; background: #e3f8ec; }
.mem-card:focus-visible .back, .mem-card:focus-visible .front { outline: 3px solid var(--purple); outline-offset: 2px; }

.match { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 8px 0 12px; }
.match .col { display: grid; gap: 10px; align-content: start; }
.m-item {
  display: flex; align-items: center; gap: 8px; min-height: 58px; padding: 8px 12px; border-radius: 14px;
  border: 3px solid var(--line); background: #fff; font: 600 clamp(.85rem, 3.2vw, 1.05rem)/1.2 var(--head); text-align: left;
  transition: border-color .2s, background .2s, transform .12s;
}
.m-item .em { font-size: 1.7rem; line-height: 1; }
.m-item.clue { font-family: var(--body); font-weight: 700; }
.m-item:hover:not(:disabled) { border-color: var(--purple); }
.m-item.sel { border-color: var(--purple); background: #efeaff; transform: scale(1.02); }
.m-item.done { border-color: #1faa59; background: #e3f8ec; opacity: .85; }
.m-item.shake { animation: shake .4s; border-color: #e04b4b; background: #fde8e8; }
@keyframes shake { 20%, 60% { translate: -6px 0; } 40%, 80% { translate: 6px 0; } }

/* never let anything push the page sideways on phones */
html, body { max-width: 100%; overflow-x: clip; }
@media (max-width: 520px) {
  .games { padding: 12px; }
  .game-tabs { gap: 6px; flex-wrap: nowrap; }
  .game-tabs button { flex: 1; padding-inline: 6px; font-size: .88rem; white-space: nowrap; }
  .mem { gap: 7px; }
  .match { gap: 8px; }
  .m-item { padding: 6px 8px; min-height: 54px; }
  .m-item .em { font-size: 1.4rem; }
}

@media (max-width: 520px) {
  .tabs .lg { display: none; }
  .tabs .sm { display: inline; }
}

.chip { align-items: center; }
.chip b { display: inline-grid; place-items: center; }
@media (max-width: 520px) {
  .hud { right: 58px; gap: 5px; }
  .chip { padding: 3px 9px 3px 7px; gap: 4px; min-height: 34px; }
  .chip b.hid { min-width: 18px; }
  .chip b.hid .eye { width: 18px; height: 18px; }
}

/* ---------- v3: picker lives in the header, one-screen desktop layout ---------- */
.top { flex-wrap: nowrap; gap: 14px; }
.hdr-pick { flex: 1 1 auto; min-width: 0; display: flex; justify-content: center; }
.hdr-pick .picker {
  display: flex; flex-wrap: nowrap; gap: 6px; padding: 4px; overflow-x: auto; scrollbar-width: none;
  max-width: 100%; background: #eaf0f5; border-radius: 999px; scroll-snap-type: none;
}
.hdr-pick .picker::-webkit-scrollbar { display: none; }
.hdr-pick .picker button {
  display: block; flex: none; min-width: 0; padding: 9px 18px; border: 2px solid transparent; border-radius: 999px;
  background: transparent; box-shadow: none; color: var(--dim);
  font: 700 1.05rem var(--head); text-transform: uppercase; letter-spacing: .06em; white-space: nowrap;
  transition: background .2s, color .2s;
}
.hdr-pick .picker button:hover { transform: none; color: var(--ink); background: #fff8; }
.hdr-pick .picker button[aria-selected="true"] { background: #fff; color: var(--teal); border-color: var(--teal); box-shadow: 0 1px 4px rgba(23, 35, 47, .15); }
.hdr-pick .picker.pills button { padding: 9px 18px; }
.cards .examples { grid-template-columns: repeat(auto-fill, minmax(92px, 1fr)); }

@media (max-width: 1099px) {
  .top { position: static; flex-wrap: wrap; row-gap: 8px; }
  .hdr-pick { order: 3; flex: 1 1 100%; justify-content: flex-start; }
  .hdr-pick .picker { border-radius: 16px; width: 100%; }
  .hdr-pick .picker button { padding: 8px 14px; font-size: .9rem; letter-spacing: .04em; }
}
@media (max-width: 520px) {
  .top { flex-wrap: wrap; }
  .brand { flex: 0 0 auto; }
  .tabs { flex: 1 1 0; min-width: 0; }
}

@media (min-width: 1100px) and (min-height: 620px) {
  html, body { height: 100dvh; overflow: hidden; }
  body { display: flex; flex-direction: column; }
  .top { position: static; flex: none; padding-block: 8px; }
  main { flex: 1 1 auto; min-height: 0; padding-block: 12px 0; }
  .panel { height: 100%; display: grid; grid-template-columns: minmax(0, 1fr) clamp(340px, 27vw, 420px); grid-template-rows: auto auto minmax(0, 1fr); column-gap: 20px; }
  .panel h1 { grid-column: 1; grid-row: 1; margin: 0 0 4px; font-size: 1.7rem; }
  .panel .note { grid-column: 1; grid-row: 2; margin: 0 0 10px; font-size: .95rem; line-height: 1.4; }
  .dash { display: contents; }
  .stage { grid-column: 1; grid-row: 3; min-height: 0; }
  .gl-host, .svg-host { height: auto; flex: 1 1 0; min-height: 0; }
  .dash .cards { grid-column: 2; grid-row: 1 / 4; margin: 0; gap: 12px; overflow-y: auto; align-content: start; min-height: 0; padding-bottom: 6px; scrollbar-width: thin; }
  .dash .cards .card { padding: 14px 16px; }
  .cards h2 { font-size: 1.08rem; margin-bottom: 6px; }
  .cards .defs { gap: 6px; font-size: .95rem; }
  .cards .examples li { padding: 6px 4px; font-size: .82rem; }
  .cards .examples .em { font-size: 1.6rem; }
  #tab-quiz { grid-template-columns: minmax(0, 1fr); }
  #tab-quiz .games { grid-column: 1; grid-row: 3; overflow-y: auto; min-height: 0; }
  footer { flex: none; padding: 4px 0 8px; font-size: .85rem; }
}

/* ---------- v3: games (levels, bigger memory cards) ---------- */
.game-bar { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px 16px; margin-bottom: 14px; }
.game-bar .game-tabs { margin: 0; justify-content: flex-start; }
.levels { display: flex; gap: 6px; padding: 4px; background: #eaf0f5; border-radius: 999px; }
.levels button { border: 0; background: transparent; padding: 8px 14px; border-radius: 999px; font: 700 .95rem var(--head); color: var(--dim); min-height: 40px; white-space: nowrap; }
.levels button[aria-pressed="true"] { background: #fff; color: var(--purple); box-shadow: 0 1px 4px rgba(23, 35, 47, .18); }
.game-body { max-width: none; }
.q-top { font-size: 1.05rem; }
.q-main { display: flex; align-items: center; gap: 16px; margin-bottom: 4px; }
.q-main .q-emoji { margin: 0; }
.q-opts.n2 { grid-template-columns: 1fr 1fr; }
.q-opts.n3 { grid-template-columns: repeat(3, 1fr); }
.q-opts.n4 { grid-template-columns: repeat(2, 1fr); }
@media (min-width: 900px) { .q-opts.n4 { grid-template-columns: repeat(4, 1fr); } .q-opts button { font-size: 1.3rem; min-height: 84px; } .q-text { font-size: 1.8rem; } }
@media (max-width: 520px) { .q-opts.n3 { grid-template-columns: 1fr; } .q-opts.n2 { grid-template-columns: 1fr 1fr; } .levels { width: 100%; } .levels button { flex: 1; padding-inline: 4px; font-size: .85rem; } .q-main { gap: 10px; } }

.mem-card .front { font: 700 clamp(1rem, 3.8vw, 1.7rem)/1.15 var(--head); }
.mem-card .front strong { font-weight: 700; }
.mem-card .front .em { font-size: clamp(2rem, 8vw, 3.6rem); }
.mem-card .front small { font: 700 clamp(.8rem, 2.9vw, 1.1rem) var(--head); color: var(--dim); }
.mem-card .front .clue { font: 700 clamp(.8rem, 3vw, 1.15rem)/1.2 var(--body); }
.mem-card .back { font-size: clamp(1.8rem, 6vw, 3rem); }
.mem.hard .mem-card .front { gap: 4px; }
@media (min-width: 900px) {
  .mem { grid-template-columns: repeat(var(--cols-d, 8), minmax(0, 1fr)); gap: 12px; }
  .mem-card { aspect-ratio: 1 / 1.15; max-height: 34dvh; width: 100%; }
  .mem-card .front { font-size: clamp(1.1rem, 1.7vw, 1.9rem); }
  .mem-card .front .em { font-size: clamp(2.2rem, 3.6vw, 4rem); }
  .mem-card .front small { font-size: clamp(.85rem, 1.1vw, 1.2rem); }
  .mem-card .front .clue { font-size: clamp(.85rem, 1.05vw, 1.2rem); }
  .mem.hard .mem-card .front .em { font-size: clamp(1.8rem, 2.6vw, 3rem); }
}
@media (min-width: 900px) { .match .col { gap: 10px; } .m-item { font-size: 1.15rem; min-height: 54px; } }

/* ---------- v4: stage toolbar on top, title + intro on one row ---------- */
.head { display: block; }
#stage {
  display: grid; grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas: "hud tools" "canvas canvas" "bar bar"; grid-template-rows: auto minmax(0, 1fr) auto;
}
#stage > .hud { grid-area: hud; position: static; padding: 10px 0 10px 12px; align-self: center; pointer-events: auto; }
#stage > .tools { grid-area: tools; position: static; flex-direction: row; padding: 10px 12px 10px 0; align-self: center; }
#stage > .gl-host { grid-area: canvas; border-top: 1px solid var(--line); }
#stage > .bar { grid-area: bar; }
.tool { width: 40px; height: 40px; }

@media (max-width: 520px) {
  #stage > .hud { padding: 8px 0 8px 10px; }
  #stage > .tools { padding: 8px 10px 8px 0; gap: 6px; }
  .tool { width: 36px; height: 36px; border-radius: 10px; }
  .tool svg { width: 20px; height: 20px; }
  #stage > .gl-host { height: clamp(250px, 40dvh, 440px); }
}

@media (min-width: 1100px) {
  .head { display: flex; align-items: center; flex-wrap: wrap; gap: 4px 22px; }
  .head h1 { margin: 0; white-space: nowrap; }
  .head .note { margin: 0; max-width: none; flex: 1 1 420px; }
  #stage { grid-template-columns: auto minmax(0, 1fr) auto; grid-template-areas: "hud bar tools" "canvas canvas canvas"; grid-template-rows: auto minmax(0, 1fr); }
  #stage > .bar { border: 0; background: transparent; padding: 8px 14px; align-self: center; gap: 4px 22px; grid-template-columns: auto minmax(180px, 1fr) auto minmax(140px, 200px); }
  #stage > .bar .field.pick select { min-height: 42px; padding-block: 5px; min-width: 130px; }
  #stage > .bar .play { min-height: 42px; padding-block: 5px; }
}
@media (min-width: 1100px) and (min-height: 620px) {
  .panel { grid-template-rows: auto minmax(0, 1fr); }
  .panel .head { grid-column: 1; grid-row: 1; margin: 0 0 10px; }
  .stage { grid-row: 2; }
  .dash .cards { grid-row: 1 / 3; }
  #tab-quiz .games { grid-row: 2; }
}

@media (min-width: 1100px) {
  #stage > .bar { display: flex; align-items: center; gap: 12px 22px; }
  #stage > .bar .field { grid-column: auto; grid-row: auto; }
  #stage > .bar .field.fold { flex: 1 1 200px; min-width: 0; }
  #stage > .bar .field.sides { flex: 0 0 180px; }
  #stage > .bar .play { flex: none; }
  #stage > .bar .field.pick { flex: 0 0 150px; }
  /* the header already has the shape picker; keep the dropdown for full screen only */
  #stage:not(:fullscreen):not(.is-fs) > .bar .field.pick { display: none; }
}

@media (min-width: 1100px) {
  .hdr-pick .picker button { padding: 9px clamp(10px, .95vw, 18px); font-size: clamp(.86rem, .98vw, 1.05rem); letter-spacing: .05em; }
  .hdr-pick .picker.pills button { padding: 9px clamp(10px, .95vw, 18px); }
}