/* =========================================================================
   BROMINE — style.css
   Design tokens:
     Background : #060814 → #0d1224 (deep space navy)
     Accent A   : #4fd8ff (ionized blue)   — logic / correctness
     Accent B   : #a855f7 (bromine violet) — depth / mystery
     Success    : #22e584   Danger: #ff4d6d   Gold: #ffd166
     Display font : 'Orbitron' (geometric, reactor-like)
     Body font    : 'Space Grotesk'
     Signature    : hexagonal "molecule" nodes for levels & logo atoms
   ========================================================================= */

:root {
  --bg-0: #060814;
  --bg-1: #0b0f20;
  --bg-2: #10152b;
  --glass: rgba(255, 255, 255, 0.055);
  --glass-strong: rgba(255, 255, 255, 0.09);
  --glass-border: rgba(255, 255, 255, 0.14);
  --blue: #4fd8ff;
  --blue-deep: #3b82f6;
  --violet: #a855f7;
  --violet-deep: #7c3aed;
  --text: #eef2ff;
  --muted: #93a0c4;
  --success: #22e584;
  --danger: #ff5d78;
  --gold: #ffd166;
  --font-display: 'Orbitron', 'Segoe UI', sans-serif;
  --font-body: 'Space Grotesk', 'Segoe UI', sans-serif;
  --radius-lg: 26px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --shadow-glow: 0 0 40px rgba(79, 216, 255, 0.15), 0 0 80px rgba(168, 85, 247, 0.08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  background: var(--bg-0);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3 { font-family: var(--font-display); margin: 0; }
p { line-height: 1.55; color: var(--muted); }

/* -------------------------------------------------------------------------
   Background ambience
   ------------------------------------------------------------------------- */
.bg-layer {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}

.bg-grid {
  background-image:
    linear-gradient(rgba(79, 216, 255, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79, 216, 255, 0.055) 1px, transparent 1px);
  background-size: 42px 42px;
  background-position: center;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, black 40%, transparent 90%);
}

.bg-glow {
  background:
    radial-gradient(circle at 15% 15%, rgba(168, 85, 247, 0.28), transparent 45%),
    radial-gradient(circle at 85% 20%, rgba(79, 216, 255, 0.22), transparent 45%),
    radial-gradient(circle at 50% 100%, rgba(124, 58, 237, 0.2), transparent 50%),
    var(--bg-0);
}

/* -------------------------------------------------------------------------
   Layout / Screens
   ------------------------------------------------------------------------- */
#app {
  flex: 1;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 32px 18px 60px;
  width: 100%;
}

.screen {
  display: none;
  width: 100%;
  max-width: 1080px;
  animation: screenIn 0.5s ease;
}

.screen.active { display: block; }

@keyframes screenIn {
  from { opacity: 0; transform: translateY(14px) scale(0.985); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

/* -------------------------------------------------------------------------
   Glass panel base
   ------------------------------------------------------------------------- */
.panel {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow-glow);
  max-width: 720px;
  margin: 40px auto;
}

.panel-wide { max-width: 980px; }

.panel-center { text-align: center; }

.panel-title {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  letter-spacing: 1px;
  margin-bottom: 22px;
  background: linear-gradient(90deg, var(--blue), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 22px;
}
.panel-header .panel-title { margin-bottom: 0; }

.section-subtitle {
  font-family: var(--font-display);
  font-size: 1.05rem;
  margin: 28px 0 14px;
  color: var(--blue);
}

.muted { color: var(--muted); font-size: 0.9rem; margin: 4px 0 0; }

/* -------------------------------------------------------------------------
   Buttons
   ------------------------------------------------------------------------- */
.btn {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.5px;
  color: var(--text);
  background: var(--glass-strong);
  border: 1px solid var(--glass-border);
  border-radius: 999px;
  padding: 14px 28px;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, border-color 0.18s ease;
  -webkit-tap-highlight-color: transparent;
}

.btn:hover { transform: translateY(-2px); border-color: rgba(255,255,255,0.3); }
.btn:active { transform: translateY(0) scale(0.98); }

.btn:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 3px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--blue-deep), var(--violet-deep));
  border: none;
  box-shadow: 0 8px 24px rgba(124, 58, 237, 0.35);
}
.btn-primary:hover { box-shadow: 0 10px 30px rgba(79, 216, 255, 0.45); }

.btn-lg { padding: 18px 40px; font-size: 1rem; width: 100%; max-width: 320px; }

.btn-ghost { background: transparent; }
.btn-ghost:hover { background: var(--glass-strong); }

.btn-sm { padding: 9px 16px; font-size: 0.72rem; }

.btn-danger {
  background: rgba(255, 93, 120, 0.15);
  border: 1px solid rgba(255, 93, 120, 0.5);
  color: #ffc7d1;
}
.btn-danger:hover { background: rgba(255, 93, 120, 0.28); }

.btn-hint {
  margin-top: 18px;
  width: 100%;
  background: rgba(255, 209, 102, 0.1);
  border: 1px solid rgba(255, 209, 102, 0.4);
  color: var(--gold);
  border-radius: var(--radius-md);
  padding: 14px;
  font-family: var(--font-body);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-hint:hover:not(:disabled) { background: rgba(255, 209, 102, 0.2); transform: translateY(-1px); }
.btn-hint:disabled { opacity: 0.4; cursor: not-allowed; }

button:disabled { cursor: not-allowed; }

/* =========================================================================
   HOME SCREEN
   ========================================================================= */
.home-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 34px;
  padding-top: 6vh;
}

.logo-block { display: flex; flex-direction: column; align-items: center; gap: 10px; }

/* Signature element: three orbiting hex "atoms" behind the wordmark,
   nodding to Bromine's diatomic molecule (Br2) + the game's hex level-map. */
.logo-hex {
  position: relative;
  width: 180px;
  height: 100px;
  margin-bottom: -30px;
}
.hex-atom {
  position: absolute;
  width: 46px;
  height: 40px;
  clip-path: polygon(25% 0%, 75% 0%, 100% 50%, 75% 100%, 25% 100%, 0% 50%);
  background: linear-gradient(135deg, var(--blue), var(--violet));
  opacity: 0.85;
  filter: blur(0.2px);
  animation: orbit 6s ease-in-out infinite;
}
.hex-a { top: 30px; left: 10px; animation-delay: 0s; box-shadow: 0 0 24px rgba(79,216,255,0.6); }
.hex-b { top: 0; left: 67px; animation-delay: 1.2s; box-shadow: 0 0 24px rgba(168,85,247,0.6); }
.hex-c { top: 30px; left: 124px; animation-delay: 2.4s; box-shadow: 0 0 24px rgba(79,216,255,0.6); }

@keyframes orbit {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-10px) rotate(8deg); }
}

.logo-title {
  font-size: clamp(2.6rem, 9vw, 4.6rem);
  font-weight: 900;
  letter-spacing: 6px;
  display: flex;
  gap: 2px;
}
.logo-letter {
  background: linear-gradient(180deg, #ffffff 0%, var(--blue) 55%, var(--violet) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: none;
  filter: drop-shadow(0 0 18px rgba(79, 216, 255, 0.35));
  animation: letterRise 0.6s ease backwards;
}
.logo-letter:nth-child(1){animation-delay:.02s}
.logo-letter:nth-child(2){animation-delay:.08s}
.logo-letter:nth-child(3){animation-delay:.14s}
.logo-letter:nth-child(4){animation-delay:.20s}
.logo-letter:nth-child(5){animation-delay:.26s}
.logo-letter:nth-child(6){animation-delay:.32s}
.logo-letter:nth-child(7){animation-delay:.38s}

@keyframes letterRise {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.logo-subtitle {
  font-family: var(--font-body);
  font-size: 1.05rem;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--blue);
  opacity: 0.9;
}

.home-buttons {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  width: 100%;
}

.home-stats { margin-top: 8px; }

.stat-pill {
  display: inline-block;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--muted);
}
.stat-pill span { color: var(--gold); font-weight: 700; }

/* =========================================================================
   HOW TO PLAY
   ========================================================================= */
.howto-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 26px;
}
.howto-card {
  background: var(--glass-strong);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: transform 0.2s ease;
}
.howto-card:hover { transform: translateY(-4px); }
.howto-icon { font-size: 1.8rem; margin-bottom: 8px; }
.howto-card h3 { font-family: var(--font-body); font-size: 1rem; margin-bottom: 6px; color: var(--text); }
.howto-card p { font-size: 0.86rem; margin: 0; }

/* =========================================================================
   SETTINGS
   ========================================================================= */
.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--glass-border);
}
.settings-label { font-weight: 600; }
.settings-danger { border-bottom: none; margin-top: 8px; flex-wrap: wrap; }

.switch { position: relative; display: inline-block; width: 52px; height: 30px; flex-shrink: 0; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
  position: absolute; cursor: pointer; inset: 0;
  background: rgba(255,255,255,0.15);
  border-radius: 999px;
  transition: 0.25s;
}
.slider::before {
  content: "";
  position: absolute;
  height: 22px; width: 22px;
  left: 4px; top: 4px;
  background: white;
  border-radius: 50%;
  transition: 0.25s;
}
.switch input:checked + .slider { background: linear-gradient(135deg, var(--blue-deep), var(--violet-deep)); }
.switch input:checked + .slider::before { transform: translateX(22px); }
.switch input:focus-visible + .slider { outline: 3px solid var(--blue); outline-offset: 2px; }

.achievements-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 10px; }
.achievement {
  display: flex; align-items: center; gap: 14px;
  background: var(--glass-strong);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
}
.achievement.locked { opacity: 0.45; }
.achievement-icon { font-size: 1.6rem; width: 34px; text-align: center; }
.achievement-name { font-weight: 700; font-size: 0.92rem; }
.achievement-desc { font-size: 0.78rem; color: var(--muted); }

/* =========================================================================
   LEVEL SELECT — honeycomb / molecule grid (signature element)
   ========================================================================= */
.level-grid { display: flex; flex-direction: column; gap: 30px; }

.stage-heading {
  font-size: 1rem;
  letter-spacing: 1px;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  color: var(--text);
}
.stage-range { color: var(--muted); font-size: 0.75rem; font-family: var(--font-body); margin-left: auto; }

.stage-dot { width: 12px; height: 12px; border-radius: 50%; display: inline-block; box-shadow: 0 0 10px currentColor; }
.stage-1 { background: #22e584; color: #22e584; }
.stage-2 { background: #4fd8ff; color: #4fd8ff; }
.stage-3 { background: #7c9bff; color: #7c9bff; }
.stage-4 { background: #a855f7; color: #a855f7; }
.stage-5 { background: #f97ac1; color: #f97ac1; }
.stage-6 { background: #ffd166; color: #ffd166; }

.level-grid-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 10px;
}

.level-node {
  position: relative;
  width: 86px;
  height: 96px;
  clip-path: polygon(25% 3%, 75% 3%, 100% 50%, 75% 97%, 25% 97%, 0% 50%);
  background: var(--glass);
  border: 1px solid var(--glass-border);
  color: var(--text);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  font-family: var(--font-display);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.level-node.locked {
  opacity: 0.4;
  cursor: not-allowed;
  filter: grayscale(0.6);
}

.level-node.unlocked {
  background: linear-gradient(160deg, rgba(79,216,255,0.14), rgba(168,85,247,0.14));
  box-shadow: 0 0 0 rgba(0,0,0,0);
}
.level-node.unlocked:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 0 10px 26px rgba(79, 216, 255, 0.35);
}
.level-node.unlocked:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 3px;
}

.level-node.completed {
  background: linear-gradient(160deg, rgba(34,229,132,0.18), rgba(79,216,255,0.14));
}

.level-num { font-size: 1.15rem; font-weight: 700; }
.level-lock { font-size: 0.95rem; opacity: 0.85; }
.level-stars { font-size: 0.68rem; letter-spacing: -1px; }

/* level unlocking pop animation, applied via JS-triggered class if desired */
@keyframes unlockPop {
  0% { transform: scale(0.7); opacity: 0; }
  60% { transform: scale(1.08); opacity: 1; }
  100% { transform: scale(1); }
}

/* =========================================================================
   QUESTION SCREEN
   ========================================================================= */
.question-wrap { max-width: 720px; margin: 0 auto; }

.hud {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  margin-bottom: 20px;
  backdrop-filter: blur(14px);
}
.hud-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.hud-row:last-child { margin-bottom: 0; }
.hud-item { font-size: 0.85rem; color: var(--muted); display: flex; align-items: center; gap: 6px; }
#hud-lives { font-size: 1rem; letter-spacing: 2px; }
#hud-score { color: var(--gold); font-weight: 700; display: inline-block; }
#hud-score.score-pop { animation: scorePop 0.5s ease; }
@keyframes scorePop {
  0% { transform: scale(1); color: var(--gold); }
  40% { transform: scale(1.35); color: #fff2c9; }
  100% { transform: scale(1); color: var(--gold); }
}
#hud-streak { color: #ff9d4d; font-weight: 700; }

.hud-difficulty {
  font-family: var(--font-display);
  font-size: 0.68rem;
  letter-spacing: 1px;
  padding: 5px 12px;
  border-radius: 999px;
  text-transform: uppercase;
}
.diff-beginner { background: rgba(34,229,132,0.18); color: #22e584; }
.diff-easy     { background: rgba(79,216,255,0.18); color: #4fd8ff; }
.diff-medium   { background: rgba(124,155,255,0.2); color: #a9baff; }
.diff-hard     { background: rgba(168,85,247,0.2); color: #cd9bff; }
.diff-expert   { background: rgba(249,122,193,0.2); color: #ff9fd6; }
.diff-master   { background: rgba(255,209,102,0.22); color: var(--gold); }

.timer-track {
  height: 8px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  overflow: hidden;
  margin-top: 4px;
}
.timer-fill {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--blue), var(--violet));
  transition: width 1s linear;
}
.timer-fill.timer-low { background: linear-gradient(90deg, #ff9d4d, var(--danger)); animation: pulseTimer 0.6s infinite; }

@keyframes pulseTimer {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.55; }
}

.hud-row-timer { margin-top: 8px; font-size: 0.8rem; }
.hud-hints { color: var(--gold); }

.question-card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: var(--shadow-glow);
  animation: cardFloat 0.4s ease;
}

@keyframes cardFloat {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.question-tag {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(79, 216, 255, 0.15);
  color: var(--blue);
  margin-bottom: 16px;
}

.question-text {
  font-family: var(--font-body);
  font-weight: 700;
  font-size: clamp(1.1rem, 2.6vw, 1.4rem);
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 24px;
}

.options-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }

.option-btn {
  width: 100%;
  text-align: left;
  font-family: var(--font-body);
  font-size: 0.98rem;
  font-weight: 500;
  color: var(--text);
  background: var(--glass-strong);
  border: 1.5px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: 15px 18px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}
.option-btn:hover:not(:disabled) { border-color: var(--blue); transform: translateX(3px); }
.option-btn:focus-visible { outline: 3px solid var(--blue); outline-offset: 2px; }
.option-btn:disabled { cursor: default; }

.option-btn.correct-choice {
  border-color: var(--success);
  background: rgba(34, 229, 132, 0.16);
  animation: correctPulse 0.5s ease;
}
.option-btn.correct-choice::after { content: " ✓"; color: var(--success); font-weight: 700; }

.option-btn.wrong-choice {
  border-color: var(--danger);
  background: rgba(255, 93, 120, 0.16);
  animation: shake 0.4s ease;
}
.option-btn.wrong-choice::after { content: " ✕"; color: var(--danger); font-weight: 700; }

@keyframes correctPulse {
  0% { transform: scale(1); }
  40% { transform: scale(1.02); }
  100% { transform: scale(1); }
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

.hint-box {
  margin-top: 18px;
  padding: 14px 16px;
  background: rgba(255, 209, 102, 0.1);
  border: 1px solid rgba(255, 209, 102, 0.35);
  border-radius: var(--radius-sm);
  color: var(--gold);
  font-size: 0.9rem;
  animation: cardFloat 0.3s ease;
}

/* =========================================================================
   RESULT SCREEN (correct / wrong)
   ========================================================================= */
#screen-result { display: none; }
#screen-result.active { display: flex; justify-content: center; }

.result-card {
  max-width: 560px;
  width: 100%;
  margin: 8vh auto 0;
  text-align: center;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 44px 32px;
  box-shadow: var(--shadow-glow);
  animation: resultPop 0.45s cubic-bezier(.2,1.4,.4,1);
}

@keyframes resultPop {
  0% { opacity: 0; transform: scale(0.85); }
  100% { opacity: 1; transform: scale(1); }
}

.result-icon { font-size: 3.2rem; margin-bottom: 10px; }

.result-correct .result-icon { animation: bounceIn 0.6s ease; }
.result-wrong .result-icon { animation: shake 0.5s ease; }

@keyframes bounceIn {
  0% { transform: scale(0); }
  60% { transform: scale(1.25); }
  100% { transform: scale(1); }
}

.result-title { font-size: 1.9rem; letter-spacing: 1px; margin-bottom: 10px; }
.result-correct .result-title { color: var(--success); }
.result-wrong .result-title { color: var(--danger); }

.result-points { font-size: 1.05rem; font-weight: 700; color: var(--gold); margin-bottom: 14px; }
.result-correct-answer { font-weight: 700; color: var(--text); margin-bottom: 6px; }
.result-explanation {
  background: rgba(255,255,255,0.05);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 0.92rem;
  margin: 12px 0 18px;
  text-align: left;
}
.result-lives { font-size: 1rem; margin-bottom: 18px; }

/* =========================================================================
   GAME OVER
   ========================================================================= */
.gameover-icon { font-size: 3.4rem; margin-bottom: 10px; animation: shake 0.6s ease; }
.gameover-title { color: var(--danger); margin-bottom: 8px; -webkit-text-fill-color: unset; background: none; }
.gameover-copy { margin-bottom: 18px; }
.gameover-score-label { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 2px; color: var(--muted); margin-bottom: 2px; }
.gameover-score { font-family: var(--font-display); font-size: 2.6rem; color: var(--gold); margin: 0 0 26px; }
.gameover-buttons { display: flex; flex-direction: column; align-items: center; gap: 12px; }

/* =========================================================================
   COMPLETION SCREEN
   ========================================================================= */
.completion-panel { position: relative; overflow: hidden; }
.completion-trophy { font-size: 4rem; animation: bounceIn 0.7s ease; margin-bottom: 8px; }
.completion-title {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  margin-bottom: 10px;
  background: linear-gradient(90deg, var(--gold), var(--violet), var(--blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: shimmer 3s linear infinite;
  background-size: 200% auto;
}
@keyframes shimmer {
  to { background-position: 200% center; }
}
.completion-copy { margin-bottom: 24px; }

.completion-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 14px;
  margin-bottom: 30px;
}
.completion-stat {
  background: var(--glass-strong);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 16px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.completion-stat-value { font-family: var(--font-display); font-size: 1.4rem; color: var(--blue); }
.completion-stat-label { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 1px; color: var(--muted); }

.completion-confetti {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 10% 20%, var(--gold) 0 4px, transparent 5px),
    radial-gradient(circle at 80% 10%, var(--blue) 0 4px, transparent 5px),
    radial-gradient(circle at 30% 80%, var(--violet) 0 4px, transparent 5px),
    radial-gradient(circle at 65% 60%, var(--success) 0 4px, transparent 5px),
    radial-gradient(circle at 90% 85%, var(--gold) 0 4px, transparent 5px),
    radial-gradient(circle at 45% 15%, var(--blue) 0 4px, transparent 5px);
  opacity: 0.7;
  animation: confettiFall 4s ease-in-out infinite;
}
@keyframes confettiFall {
  0% { transform: translateY(-10px); opacity: 0.9; }
  50% { transform: translateY(10px); opacity: 0.5; }
  100% { transform: translateY(-10px); opacity: 0.9; }
}

/* =========================================================================
   TOASTS
   ========================================================================= */
.toast-container {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
}
.toast {
  background: var(--glass-strong);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(12px);
  color: var(--text);
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: var(--shadow-glow);
  opacity: 0;
  transform: translateY(-12px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.toast.show { opacity: 1; transform: translateY(0); }

/* =========================================================================
   ACCESSIBILITY / FOCUS
   ========================================================================= */
a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* =========================================================================
   RESPONSIVE
   ========================================================================= */
@media (max-width: 720px) {
  .panel { padding: 26px 20px; }
  .home-buttons .btn-lg { max-width: 100%; }
  .level-node { width: 78px; height: 88px; }
  .result-card { padding: 32px 22px; margin-top: 4vh; }
}

@media (max-width: 480px) {
  #app { padding: 20px 12px 44px; }
  .logo-title { letter-spacing: 3px; }
  .hud-row { font-size: 0.78rem; }
  .question-card { padding: 22px 18px; }
  .level-node { width: 70px; height: 80px; }
  .btn-lg { padding: 16px 24px; }
  .completion-stats { grid-template-columns: repeat(2, 1fr); }
}