/* §2.4 shared PWA shell block (verbatim) */
html{touch-action:manipulation;-webkit-text-size-adjust:100%}
html,body{position:fixed;inset:0;margin:0;overflow:hidden;overscroll-behavior:none;background:var(--of-paper)}
.game-shell{display:grid;grid-template-rows:auto 1fr auto;height:100%;height:100dvh;
  --T:env(safe-area-inset-top,0px);--R:env(safe-area-inset-right,0px);--B:env(safe-area-inset-bottom,0px);--L:env(safe-area-inset-left,0px);--G:12px}
.hud{min-height:calc(44px + var(--T));padding:var(--T) calc(var(--R) + var(--G)) 0 calc(var(--L) + var(--G));background:#05070b;color:#f3f6ff}
.stage{position:relative;min-height:0;padding:8px calc(var(--R) + var(--G)) 8px calc(var(--L) + var(--G))}
#board{touch-action:none;display:block;margin:0 auto}
.deck{padding:0 calc(var(--R) + var(--G)) calc(var(--B) + 8px) calc(var(--L) + var(--G))}
.hud,.deck,.stage,canvas,button{-webkit-user-select:none;user-select:none;-webkit-touch-callout:none}
button{touch-action:manipulation;-webkit-tap-highlight-color:transparent;min-width:44px;min-height:44px;font-size:16px}
button:active{background:var(--pressed);transition:background var(--motion-press,80ms) var(--ease-out,ease-out)}
.card-body{overflow:auto;overscroll-behavior:contain;min-height:0;touch-action:pan-y pinch-zoom}
input,select,textarea{font-size:max(16px,1rem);-webkit-user-select:text;user-select:text}

/* Game chrome. The stage is night artwork in both themes; HUD, cards and lobby follow the shell theme. */
:root{--accent:#2e9fe0;--accent-fill:color-mix(in srgb,var(--accent) 75%,#111a2d);--of-paper:#0c1a2d;--of-ink:#eaf3ff;--of-muted:#a9bdd2;
  --of-line:color-mix(in srgb,var(--of-ink) 14%,transparent);--of-chip:color-mix(in srgb,var(--of-ink) 8%,transparent);--pressed:color-mix(in srgb,var(--accent) 30%,transparent);
  --star:#ffc94d;--motion-press:80ms;--motion-fast:140ms;--motion-base:200ms;--motion-sheet:280ms;--ease-out:cubic-bezier(.2,.8,.2,1);
  color:var(--of-ink);font:16px/1.4 system-ui,-apple-system,"Segoe UI",sans-serif;color-scheme:dark}
html[data-theme=light]{--of-paper:#f3f6fa;--of-ink:#0e1c2c;--of-muted:#4c6075;--accent-fill:color-mix(in srgb,var(--accent) 75%,#111a2d);color-scheme:light}
*{box-sizing:border-box}
button{font:inherit;font-weight:700;color:inherit;border:1px solid var(--of-line);border-radius:10px;background:var(--of-chip);cursor:pointer;padding:0 12px}
button:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
button:disabled{opacity:.45;cursor:default}
svg{flex:none}

/* HUD: one line, never wraps */
.hud{display:flex;align-items:center;gap:6px;white-space:nowrap;border-bottom:1px solid #1b2c44;position:relative;z-index:4}
html[data-theme=light] .hud{background:#e9eff6;color:#0e1c2c;border-bottom-color:#c9d5e3}
.hud button{width:44px;height:44px;padding:0;display:grid;place-items:center;background:transparent;border-color:transparent;border-radius:12px}
.hud button:hover{background:var(--of-chip)}
.hud .readout{font-variant-numeric:tabular-nums;min-width:0;overflow:hidden;text-overflow:ellipsis}
#score-readout{font-size:20px;font-weight:800;letter-spacing:-.01em;margin-right:auto;padding-left:2px}
.hud .pill{display:inline-flex;align-items:center;gap:6px;height:28px;padding:0 10px;border-radius:14px;background:rgba(127,214,255,.12);border:1px solid rgba(127,214,255,.35);font-size:13px;font-weight:800}
html[data-theme=light] .hud .pill{background:rgba(46,159,224,.12);border-color:rgba(46,159,224,.45)}
.hud .pill small{font-size:10px;font-weight:800;letter-spacing:.08em;opacity:.8}
#level-readout,#best-readout{display:none;font-size:14px;font-weight:700;color:var(--of-muted)}
@media (min-width:600px){#level-readout,#best-readout{display:block}}
.game-shell.in-lobby .hud .play-only{visibility:hidden}

/* Stage: the canvas fills the stage box; the world letterboxes inside it */
.stage{padding:0;background:#0b2242;overflow:hidden}
#board{position:absolute;inset:0;width:100%;height:100%;cursor:crosshair}

/* Deck: sand band under the ground line */
.deck{display:flex;align-items:center;justify-content:center;gap:8px;min-height:calc(52px + var(--B));padding-top:4px;background:#3f3322;color:#f3e6cc;position:relative;z-index:1}
.deck .hint{margin:0;font-size:13px;font-weight:600;opacity:.85;text-align:center;line-height:1.3}
.game-shell{grid-template-columns:minmax(0,1fr)}
.deck button{flex:1 1 0;max-width:72px;height:48px;min-width:48px;padding:0 4px;white-space:nowrap;border-radius:12px;background:rgba(255,240,210,.1);border-color:rgba(255,240,210,.28);color:#fff4df;font-size:15px}
.deck .launch{flex:1.6 1 0;max-width:120px;min-width:96px;background:var(--accent-fill);border-color:transparent;color:#fff}
.deck .ability{flex:0 0 64px;max-width:none;min-width:64px;height:64px;margin-left:auto;background:#c2512f;border-color:transparent;color:#fff;letter-spacing:.04em}

/* Card layers */
/* card layers sit under the HUD, so the HUD's sound and help stay reachable and nothing overlaps it */
.card-layer{position:fixed;inset:calc(44px + var(--T)) 0 0 0;z-index:5;display:grid;place-items:center;padding:12px calc(var(--R) + 12px) calc(var(--B) + 12px) calc(var(--L) + 12px);background:rgba(3,8,18,.35)}
.card{width:100%;max-width:28rem;max-height:calc(100dvh - var(--T) - var(--B) - 24px);display:flex;flex-direction:column;border-radius:12px;color:var(--of-ink);
  background:color-mix(in srgb,var(--of-paper) 72%,transparent);-webkit-backdrop-filter:blur(16px) saturate(140%);backdrop-filter:blur(16px) saturate(140%);
  border:1px solid color-mix(in srgb,var(--of-ink) 14%,transparent);box-shadow:0 8px 24px rgba(0,0,0,.35)}
@supports not (backdrop-filter:blur(1px)){.card{background:color-mix(in srgb,var(--of-paper) 94%,transparent)}}
.card-layer .card{max-height:calc(100dvh - 44px - var(--T) - var(--B) - 24px)}
.card-body{padding:20px;display:flex;flex-direction:column;gap:12px}
.card h1,.card h2{margin:0;font-weight:800;letter-spacing:-.01em;line-height:1.15}
.card h1{font-size:28px}
.card h2{font-size:20px}
.card p{margin:0}
.eyebrow{font-size:12px;font-weight:800;letter-spacing:.14em;color:var(--accent)}
html[data-theme=light] .eyebrow{color:#1668a3}
.lede{font-size:16px;color:var(--of-muted)}
.primary{width:100%;min-height:52px;border-radius:12px;background:var(--accent-fill);border-color:transparent;color:#fff;font-size:18px;font-weight:800}
.primary:active{background:color-mix(in srgb,var(--accent) 60%,#111a2d)}
.stack{display:flex;flex-direction:column;gap:8px}
.stack button{min-height:48px}
.row{display:flex;gap:8px}
.row>button{flex:1 1 0;min-height:44px;min-width:0;white-space:nowrap;padding:0 8px;font-size:15px}
#lobby-row{flex-wrap:wrap}
.best{font-size:15px;color:var(--of-muted);text-align:center}
.best strong{color:var(--of-ink);font-variant-numeric:tabular-nums}
.note{font-size:13px;color:var(--of-muted)}
.linkish{align-self:center;background:transparent;border-color:transparent;color:var(--of-muted);font-weight:600;font-size:14px;text-decoration:underline;text-underline-offset:3px}

/* Mode segmented control */
.segmented{display:grid;grid-template-columns:1fr 1fr;padding:3px;gap:3px;border-radius:12px;background:var(--of-chip);border:1px solid var(--of-line)}
.segmented button{min-height:44px;border:0;border-radius:9px;background:transparent;font-size:15px}
.segmented button[aria-pressed=true]{background:var(--accent-fill);color:#fff}

/* Level grid: 4 x 3 tiles of 64 px with stars */
.levels{display:grid;grid-template-columns:repeat(4,64px);gap:8px;justify-content:center}
.levels button{width:64px;height:64px;padding:4px 0 0;border-radius:12px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;font-size:20px;font-weight:800;font-variant-numeric:tabular-nums}
.levels button.next{border-color:var(--accent);box-shadow:inset 0 0 0 1px var(--accent)}
.levels .stars{display:flex;gap:1px;height:12px}
.stars svg{width:12px;height:12px}
.stars .on,.big-stars .on{fill:var(--star)}.stars .off,.big-stars .off{fill:none;stroke:currentColor;stroke-width:2;opacity:.4}
.big-stars .on{filter:drop-shadow(0 2px 4px rgba(255,190,60,.35))}
.levels .lock{width:14px;height:14px;opacity:.7}
.levels button:disabled{opacity:.4}
.big-stars{display:flex;justify-content:center;gap:10px}
.big-stars svg{width:44px;height:44px}

/* Explainer (§2.7 / PWA §7b) */
.scrim{position:fixed;inset:0;z-index:6;display:grid;place-items:center;padding:calc(var(--T) + 12px) calc(var(--R) + 12px) calc(var(--B) + 12px) calc(var(--L) + 12px);background:rgba(0,0,0,.35);cursor:pointer}
.scrim .card{position:relative;animation:pop var(--motion-fast) var(--ease-out)}
#app:has(#explainer:not([hidden])) .card-layer .card{visibility:hidden} /* one translucent layer per stack (PWA §9) */
.close{position:absolute;top:6px;right:6px;width:44px;height:44px;padding:0;display:grid;place-items:center;background:transparent;border-color:transparent;border-radius:10px}
.close svg{width:16px;height:16px}
.close:focus-visible{outline-offset:-4px}
#explainer-title{padding-right:44px}
.explain{display:grid;grid-template-columns:48px 1fr;gap:10px 12px;align-items:center;margin:0}
.explain svg{width:48px;height:48px;border-radius:10px;background:#0b2242}
.explain p{font-size:15px}
.keys{font-size:14px;color:var(--of-muted)}
kbd{font:700 12px/1 ui-monospace,monospace;padding:3px 5px;border-radius:5px;border:1px solid var(--of-line);background:var(--of-chip);color:var(--of-ink)}
.birdlist{display:grid;grid-template-columns:1fr 1fr;gap:4px 12px;margin:0;padding:0;list-style:none;font-size:13px;color:var(--of-muted)}
.birdlist b{color:var(--of-ink);font-family:ui-monospace,monospace}
.joke{padding:10px 12px;border-radius:10px;border-left:3px solid var(--accent);background:var(--of-chip)}
.joke h3,.tip h3{margin:0 0 2px;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--of-muted)}
.foot{font-size:13px;color:var(--of-muted);text-align:center}
.scores{margin:0;padding:0;list-style:none;display:grid;gap:2px;font-variant-numeric:tabular-nums;font-size:14px}
.scores li{display:flex;justify-content:space-between;padding:4px 8px;border-radius:6px}
.scores li.me{background:var(--pressed);font-weight:800}
.tally{display:grid;grid-template-columns:1fr auto;gap:2px 0;font-size:14px;color:var(--of-muted);font-variant-numeric:tabular-nums}
.tally b{color:var(--of-ink);text-align:right;padding-left:12px}
.tally .total{color:var(--of-ink);font-weight:800;font-size:16px;padding-top:4px;border-top:1px solid var(--of-line)}

.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}
[hidden]{display:none!important}
@keyframes pop{from{opacity:0;transform:scale(.98)}to{opacity:1;transform:none}}
@keyframes fade{from{opacity:0}to{opacity:1}}
html[data-reduced-motion=on] .scrim .card{animation:fade 120ms linear}
@media (prefers-reduced-motion:reduce){.scrim .card{animation:fade 120ms linear}*,*::before,*::after{transition-duration:0ms!important}}
@media (orientation:landscape) and (max-height:480px){
  .card-body{padding:14px;gap:8px}
  .lobby-card{max-width:46rem}
  .lobby-card .card-body{display:grid;grid-template-columns:1fr auto;grid-auto-flow:dense;column-gap:20px;align-content:start}
  .lobby-card .card-body>*{grid-column:1}
  .lobby-card .lobby-side{grid-column:2;grid-row:1 / span 6;align-self:start}
  .pause-card .eyebrow{display:none}.pause-card .stack{display:grid;grid-template-columns:repeat(3,1fr)}.pause-card .stack .primary{grid-column:1 / -1}
  .lobby-head{display:flex;flex-direction:column;gap:4px}.lobby-card h1{font-size:24px}.lobby-card .lede{font-size:14px}
  .levels{grid-template-columns:repeat(4,56px);gap:6px}.levels button{width:56px;height:56px;font-size:17px}
  .over-card{max-width:46rem}.over-card .card-body{display:grid;grid-template-columns:1fr 1fr;column-gap:20px;align-content:start}
  .over-main,.over-side{display:flex;flex-direction:column;gap:8px}.over-card .lede{display:none}.big-stars{justify-content:flex-start}.big-stars svg{width:32px;height:32px}}
.over-main,.over-side,.lobby-side{display:flex;flex-direction:column;gap:12px}