/* ── Tokens ── */
:root{
  color-scheme:dark;
  --bg:#05070b;
  --panel:rgba(9,14,22,.7);
  --line:rgba(255,255,255,.12);
  --accent:#7aa2ff;
  --accent2:#9ae6ff;
  --good:#8affa8;
  --warn:#ffb454;
  --danger:#ff4060;
  --text:rgba(232,238,244,.96);
  --muted:rgba(232,238,244,.68);
}

/* ── Reset ── */
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;overflow:hidden}

/* ── Layout ── */
.shell{min-height:100vh;display:flex;flex-direction:column}
.bar{display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:.75rem 1rem;background:var(--panel);border-bottom:1px solid var(--line);backdrop-filter:blur(10px)}
.title{font-weight:800;letter-spacing:.14em;text-transform:uppercase;font-size:.82rem}
.actions{display:flex;gap:.5rem;flex-wrap:wrap}
.stage{position:relative;flex:1;min-height:0;display:grid;place-items:center;overflow:hidden}
#scene{width:100%;height:100%;display:block}
.footer{display:flex;justify-content:space-between;gap:1rem;padding:.6rem 1rem;background:rgba(8,12,18,.6);border-top:1px solid var(--line);font-size:.72rem;color:var(--muted)}
.footer .muted{color:rgba(232,238,244,.45)}

/* ── Button ── */
.btn{padding:.45rem .75rem;border-radius:999px;border:1px solid rgba(255,255,255,.18);background:rgba(255,255,255,.06);color:inherit;text-decoration:none;font-size:.72rem;font-weight:800;letter-spacing:.1em;text-transform:uppercase;cursor:pointer;transition:background 150ms ease,border-color 150ms ease}
.btn:hover{background:rgba(255,255,255,.12)}
.btn.primary{background:linear-gradient(135deg,rgba(122,162,255,.28),rgba(154,230,255,.14));border-color:rgba(122,162,255,.4)}
.btn.muted{opacity:.6}
#btnSound{min-width:5rem}

/* ═══════════════════════════════════════
   HUD — only what matters
   ═══════════════════════════════════════ */
.hud{
  position:absolute;left:16px;top:16px;
  padding:.65rem .8rem;border-radius:14px;
  background:rgba(8,12,18,.72);border:1px solid var(--line);
  backdrop-filter:blur(10px);
  display:flex;flex-direction:column;gap:.45rem;
  min-width:220px;max-width:260px;
  box-shadow:0 12px 32px rgba(0,0,0,.35);
  z-index:3;
}
.hud-row{display:flex;align-items:center;justify-content:space-between}
.hud-top-row{gap:.5rem}

/* Level indicator */
.hud-level-row{gap:.4rem;padding-bottom:.3rem;border-bottom:1px solid rgba(255,255,255,.08);margin-bottom:.15rem}
.level-name{font-weight:900;font-size:.82rem;letter-spacing:.1em;text-transform:uppercase;color:var(--accent2)}
.level-electrons{font-size:.62rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:700}

/* Hearts */
.hud-hearts{display:flex;gap:.3rem;font-size:1.15rem;line-height:1}
.heart{transition:color 300ms ease,opacity 300ms ease,transform 300ms ease}
.heart.full{color:var(--danger)}
.heart.lost{color:rgba(255,64,96,.18);transform:scale(.82)}
.heart.breaking{animation:heartBreak 500ms ease-out forwards}
@keyframes heartBreak{0%{color:var(--danger);transform:scale(1.35)}40%{color:var(--danger);transform:scale(1)}100%{color:rgba(255,64,96,.18);transform:scale(.82)}}

/* Stability badge */
.hud-stability-wrap{display:flex;flex-direction:column;align-items:flex-end;gap:.05rem}
.stability-label{font-size:.55rem;letter-spacing:.12em;text-transform:uppercase;color:rgba(154,230,255,.65);font-weight:700}
.stability-value{font-size:.95rem;font-weight:900;color:var(--good);transition:color 200ms ease}
.stability-value.danger{color:var(--danger)}
.stability-value.warning{color:var(--warn)}

/* Step hint */
.hud-step{font-size:.82rem;color:var(--muted);line-height:1.3}

/* Hold-time bar */
.hud-hold{display:flex;flex-direction:column;gap:.25rem}
.hold-bar{height:6px;border-radius:3px;background:rgba(255,255,255,.1);overflow:hidden}
.hold-fill{height:100%;border-radius:3px;background:linear-gradient(90deg,var(--accent2),var(--good));transition:width 120ms ease;min-width:0}
.hold-labels{display:flex;justify-content:space-between;font-size:.65rem;color:var(--muted)}
.hold-time{font-weight:700;color:var(--text)}
.hold-grace{color:var(--warn);font-weight:700}
.hold-grace:empty{display:none}

/* Orbit error gauge */
.hud-error{display:flex;align-items:center;gap:.5rem;padding:.35rem .5rem;border-radius:10px;border:1px solid rgba(255,255,255,.08);background:rgba(10,14,24,.55)}
.error-label{font-size:.6rem;letter-spacing:.1em;text-transform:uppercase;color:rgba(154,230,255,.7);font-weight:700}
.error-value{font-size:.82rem;font-weight:800;color:var(--text);flex:1}
.error-zone{font-size:.6rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;padding:.15rem .4rem;border-radius:6px}
.error-zone[data-state="in"]{background:rgba(138,255,168,.15);color:var(--good)}
.error-zone[data-state="warn"]{background:rgba(255,180,84,.15);color:var(--warn)}
.error-zone[data-state="danger"]{background:rgba(255,64,96,.15);color:var(--danger)}

.hud-thermo{display:flex;flex-direction:column;gap:.35rem;padding:.42rem .5rem;border-radius:10px;border:1px solid rgba(154,230,255,.18);background:rgba(8,14,22,.52)}
.thermo-header{display:flex;justify-content:space-between;align-items:center;gap:.35rem}
.thermo-title{font-size:.62rem;letter-spacing:.1em;text-transform:uppercase;color:var(--accent2);font-weight:800}
.thermo-target{font-size:.6rem;letter-spacing:.08em;text-transform:uppercase;color:var(--good);font-weight:800}
.thermo-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.28rem}
.thermo-pill{font-size:.58rem;letter-spacing:.04em;color:var(--text);padding:.17rem .34rem;border-radius:999px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1);white-space:nowrap}

/* ═══════════════════════════════════════
   Tutorial overlay
   ═══════════════════════════════════════ */
.tutorial-overlay{
  position:absolute;inset:0;z-index:10;
  display:grid;place-items:center;
  background:rgba(4,6,10,.75);
  backdrop-filter:blur(4px);
}
.tutorial-overlay[hidden]{display:none}
.tutorial-card{
  max-width:380px;width:calc(100% - 32px);
  padding:1.4rem 1.5rem;border-radius:18px;
  background:rgba(10,16,26,.92);border:1px solid rgba(154,230,255,.2);
  box-shadow:0 24px 64px rgba(0,0,0,.5);
  text-align:center;
}
.tutorial-dots{display:flex;justify-content:center;gap:.4rem;margin-bottom:.9rem}
.tutorial-dot{width:8px;height:8px;border-radius:50%;background:rgba(255,255,255,.2);transition:background 200ms ease}
.tutorial-dot.active{background:var(--accent2)}
.tutorial-dot.done{background:var(--good)}
.tutorial-title{margin:0 0 .5rem;font-size:1.15rem;font-weight:800;color:var(--accent2)}
.tutorial-body{margin:0 0 1rem;color:var(--muted);font-size:.92rem;line-height:1.55}
.tutorial-body strong{color:var(--text)}
.tutorial-body .key{display:inline-block;padding:.1rem .4rem;border-radius:4px;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);font-size:.78rem;font-weight:700;color:var(--text);font-family:inherit}
.tutorial-actions{display:flex;gap:.6rem;justify-content:center}

/* ═══════════════════════════════════════
   Orbit hint (center of screen)
   ═══════════════════════════════════════ */
.orbit-hint{position:absolute;left:50%;top:52%;transform:translate(-50%,-50%) scale(.985);z-index:2;pointer-events:none;opacity:0;transition:opacity 180ms ease,transform 180ms ease;padding:.65rem .9rem;border-radius:14px;border:1px solid rgba(255,255,255,.14);background:rgba(6,10,16,.6);backdrop-filter:blur(8px);text-align:center;min-width:min(300px,calc(100vw - 48px));box-shadow:0 20px 60px rgba(0,0,0,.4)}
.orbit-hint.show{opacity:1;transform:translate(-50%,-50%) scale(1)}
.orbit-hint[data-mode="hold"]{border-color:rgba(138,255,168,.28)}
.orbit-hint[data-mode="pull"]{border-color:rgba(154,230,255,.3)}
.orbit-hint[data-mode="push"]{border-color:rgba(255,180,84,.3)}
.orbit-hint-title{font-weight:950;letter-spacing:.12em;text-transform:uppercase;font-size:1rem}
.orbit-hint[data-mode="hold"] .orbit-hint-title{color:var(--good)}
.orbit-hint[data-mode="pull"] .orbit-hint-title{color:var(--accent2)}
.orbit-hint[data-mode="push"] .orbit-hint-title{color:var(--warn)}
.orbit-hint-sub{margin-top:.15rem;color:rgba(232,238,244,.7);font-size:.82rem;line-height:1.3}

/* ═══════════════════════════════════════
   Prompt panel (intro/fail/success)
   ═══════════════════════════════════════ */
.prompt{position:absolute;right:20px;bottom:20px;max-width:310px;padding:1rem;border-radius:16px;background:rgba(8,14,22,.85);border:1px solid var(--line);box-shadow:0 16px 48px rgba(0,0,0,.45);z-index:4}
.prompt-title{font-weight:800;font-size:1rem;margin-bottom:.3rem;color:var(--accent)}
.prompt-body{color:var(--muted);font-size:.88rem;line-height:1.5;white-space:pre-line}
.prompt-stats{display:grid;grid-template-columns:repeat(2,1fr);gap:.45rem;margin-top:.65rem;padding:.55rem;border-radius:10px;background:rgba(10,14,24,.6);border:1px solid rgba(255,255,255,.08)}
.prompt-stats[hidden]{display:none}
.prompt-stat{display:flex;flex-direction:column;gap:.12rem}
.prompt-stat-label{font-size:.6rem;letter-spacing:.1em;text-transform:uppercase;color:rgba(154,230,255,.7);font-weight:700}
.prompt-stat-value{font-size:.85rem;font-weight:800;color:var(--text)}
.prompt-stat-value.improved{color:var(--good);animation:pulseGlow 600ms ease-out}
.prompt-progress{position:relative;padding-left:2rem}
.prompt-progress::before{content:"";position:absolute;left:0;top:50%;transform:translateY(-50%);width:1.6rem;height:4px;border-radius:2px;background:rgba(255,255,255,.15)}
.prompt-progress::after{content:"";position:absolute;left:0;top:50%;transform:translateY(-50%);width:calc(var(--progress,0%) * 1.6rem / 100);height:4px;border-radius:2px;background:var(--good);transition:width 300ms ease}
.prompt-encourage{margin-top:.55rem;padding:.4rem .6rem;border-radius:8px;background:rgba(138,255,168,.1);border:1px solid rgba(138,255,168,.2);color:var(--good);font-size:.82rem;font-weight:700;text-align:center}
.prompt-test{margin-top:.5rem;padding:.48rem .6rem;border-radius:8px;background:rgba(154,230,255,.08);border:1px solid rgba(154,230,255,.18);color:rgba(232,238,244,.85);font-size:.75rem;line-height:1.45;white-space:pre-line}
.prompt-actions{display:flex;gap:.5rem;margin-top:.75rem;flex-wrap:wrap}
@keyframes pulseGlow{0%{text-shadow:0 0 8px rgba(138,255,168,.6)}100%{text-shadow:none}}

/* ═══════════════════════════════════════
   Control pad (touch buttons)
   ═══════════════════════════════════════ */
.control-pad{position:absolute;right:20px;bottom:100px;display:flex;gap:.5rem;z-index:4;flex-wrap:wrap;justify-content:flex-end;max-width:min(640px,calc(100vw - 40px))}
.control-pad[hidden]{display:none}
.control-pad .btn.control{padding:.55rem .85rem;font-size:.68rem;letter-spacing:.1em}
.control-pad .btn.pull{border-color:rgba(154,230,255,.45);background:rgba(154,230,255,.14)}
.control-pad .btn.thermo{padding:.45rem .62rem;font-size:.62rem;border-color:rgba(138,255,168,.34);background:rgba(138,255,168,.09)}
.molecule-options{display:flex;gap:.35rem;align-items:center;justify-content:flex-end;flex-basis:100%}
.molecule-options[hidden]{display:none}
.molecule-label{font-size:.58rem;letter-spacing:.1em;text-transform:uppercase;color:rgba(154,230,255,.78);font-weight:800;padding:.12rem .32rem;border-radius:999px;background:rgba(154,230,255,.1);border:1px solid rgba(154,230,255,.24)}
.control-pad .btn.molecule{padding:.42rem .6rem;font-size:.58rem;border-color:rgba(154,230,255,.28);background:rgba(154,230,255,.08)}
.control-pad .btn.molecule.is-active{border-color:rgba(138,255,168,.45);background:rgba(138,255,168,.16);color:var(--good)}
.control-pad .btn.suggest{animation:suggestPulse 900ms ease-in-out infinite;box-shadow:0 0 0 1px rgba(255,255,255,.12),0 0 24px rgba(154,230,255,.28)}
@keyframes suggestPulse{0%,100%{transform:translateY(0);filter:saturate(1)}50%{transform:translateY(-1px);filter:saturate(1.25)}}

/* Toast */
.toast{position:absolute;left:50%;bottom:18px;transform:translateX(-50%);padding:.45rem .8rem;border-radius:999px;background:rgba(0,0,0,.55);border:1px solid rgba(255,255,255,.12);font-size:.78rem;opacity:0;transition:opacity 200ms ease;z-index:5}
.toast.show{opacity:1}

/* Pause overlay */
.pause-overlay{
  position:absolute;inset:0;z-index:11;
  display:grid;place-items:center;
  background:rgba(4,6,10,.78);
  backdrop-filter:blur(6px);
}
.pause-overlay[hidden]{display:none}
.pause-card{
  max-width:360px;width:calc(100% - 32px);
  padding:1.3rem 1.35rem;border-radius:16px;
  background:rgba(10,16,26,.92);border:1px solid rgba(154,230,255,.2);
  box-shadow:0 22px 60px rgba(0,0,0,.5);
  text-align:center;
}
.pause-title{margin:0 0 .4rem;font-size:1.1rem;font-weight:900;color:var(--accent2);letter-spacing:.08em;text-transform:uppercase}
.pause-body{margin:0;color:var(--muted);font-size:.88rem;line-height:1.45}
.pause-actions{display:flex;gap:.6rem;justify-content:center;flex-wrap:wrap;margin-top:.9rem}

/* ═══════════════════════════════════════
   Level Select overlay
   ═══════════════════════════════════════ */
.level-select-overlay{
  position:absolute;inset:0;z-index:12;
  display:grid;place-items:center;
  background:rgba(4,6,10,.82);
  backdrop-filter:blur(6px);
}
.level-select-overlay[hidden]{display:none}
.level-select-card{
  max-width:440px;width:calc(100% - 32px);
  padding:1.6rem 1.8rem;border-radius:20px;
  background:rgba(10,16,26,.94);border:1px solid rgba(154,230,255,.18);
  box-shadow:0 24px 64px rgba(0,0,0,.5);
  text-align:center;
}
.level-select-title{margin:0 0 .3rem;font-size:1.2rem;font-weight:900;color:var(--accent2);letter-spacing:.1em;text-transform:uppercase}
.level-select-sub{margin:0 0 1.2rem;color:var(--muted);font-size:.85rem}
.level-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:.75rem;margin-bottom:1rem}
.level-card{
  position:relative;
  padding:1rem .8rem;border-radius:14px;
  background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.1);
  cursor:pointer;transition:background 150ms ease,border-color 150ms ease,transform 150ms ease;
  text-align:center;
}
.level-card:hover:not(.locked){background:rgba(122,162,255,.12);border-color:rgba(122,162,255,.35);transform:translateY(-2px)}
.level-card.locked{opacity:.45;cursor:not-allowed;filter:grayscale(.5)}
.level-card.completed{border-color:rgba(138,255,168,.3)}
.level-card .level-symbol{font-size:1.8rem;font-weight:900;color:var(--accent2);line-height:1.2}
.level-card.completed .level-symbol{color:var(--good)}
.level-card.locked .level-symbol{color:var(--muted)}
.level-card .level-label{font-size:.78rem;font-weight:700;color:var(--text);margin-top:.2rem;letter-spacing:.06em;text-transform:uppercase}
.level-card .level-info{font-size:.65rem;color:var(--muted);margin-top:.25rem;line-height:1.4}
.level-card .level-best{font-size:.6rem;color:rgba(232,238,244,.58);margin-top:.3rem;line-height:1.35;letter-spacing:.03em}
.level-card .level-badge{
  position:absolute;top:-.35rem;right:-.35rem;
  padding:.15rem .4rem;border-radius:6px;
  font-size:.55rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;
}
.level-badge.done{background:rgba(138,255,168,.18);color:var(--good);border:1px solid rgba(138,255,168,.3)}
.level-badge.new{background:rgba(154,230,255,.15);color:var(--accent2);border:1px solid rgba(154,230,255,.25)}
.level-badge.lock{background:rgba(255,255,255,.06);color:var(--muted);border:1px solid rgba(255,255,255,.1)}
.level-select-actions{display:flex;justify-content:center;gap:.5rem}

/* ═══════════════════════════════════════
   Reduced motion
   ═══════════════════════════════════════ */
@media(prefers-reduced-motion:reduce){
  .control-pad .btn.suggest{animation:none}
  .orbit-hint{transition:none}
  .heart.breaking{animation:none;color:rgba(255,64,96,.18);transform:scale(.82)}
  .hold-fill{transition:none}
  .tutorial-dot{transition:none}
}

/* ═══════════════════════════════════════
   Responsive
   ═══════════════════════════════════════ */
@media(max-width:720px){
  .hud{left:10px;top:10px;min-width:180px;max-width:210px;padding:.5rem .65rem;font-size:.92em}
  .control-pad{right:10px;bottom:80px}
  .prompt{right:10px;bottom:10px;max-width:260px}
  .level-select-card{padding:1rem 1.2rem}
  .level-grid{grid-template-columns:1fr}
}

@media(hover:hover)and(pointer:fine){
  .control-pad{opacity:.2;transition:opacity 160ms ease}
  .control-pad:hover{opacity:1}
}