:root {
  --text-main: #222222;
  --text-muted: #555555;
  --vial-glass-border: #222222;
  --vial-glass-bg: rgba(130, 222, 230, 0.12);
  --vial-glass-inner: rgba(255, 255, 255, 0.7);
  --ball-size: 52px;
  --vial-width: 68px;
  --vial-padding: 8px;
}

#game-app {
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
  font-family: "Comic Relief", system-ui, sans-serif;
  color: var(--text-main);
}

/* Header & Controls */
.game-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 8px 12px;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 12px;
}

.title-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.title-group h1 {
  font-size: 1.8rem;
  margin: 0;
  font-weight: 700;
  color: #000;
}

.level-badge {
  font-size: 0.95rem;
  padding: 4px 14px;
  cursor: default;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.icon-btn:active {
  transform: scale(0.92);
}

.game-instructions {
  margin-bottom: 20px;
  font-size: 1rem;
  color: var(--text-muted);
  text-align: center;
  max-width: 620px;
}

/* Main Playing Container */
.game-container {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  min-height: 380px;
  padding: 30px 10px 20px;
  position: relative;
}

.vials-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-content: center;
  gap: 36px 18px;
  max-width: 820px;
  width: 100%;
}

/* Test Tube / Vial */
.vial {
  position: relative;
  width: var(--vial-width);
  height: 250px;
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  padding: var(--vial-padding);
  background: var(--vial-glass-bg);
  border: 2px solid var(--vial-glass-border);
  border-top: none;
  border-radius: 0 0 34px 34px;
  box-shadow: 
    inset 0 0 12px rgba(255, 255, 255, 0.8),
    0 6px 14px rgba(0, 0, 0, 0.08);
  cursor: pointer;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s ease, border-color 0.2s ease;
}

/* Glass rim at top */
.vial::before {
  content: '';
  position: absolute;
  top: -7px;
  left: -7px;
  right: -7px;
  height: 10px;
  border: 2px solid var(--vial-glass-border);
  border-radius: 6px;
  background: #e6f9fa;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Glass reflection shine down the side */
.vial::after {
  content: '';
  position: absolute;
  top: 10px;
  left: 6px;
  width: 4px;
  bottom: 25px;
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0.85), rgba(255, 255, 255, 0.1));
  border-radius: 3px;
  pointer-events: none;
}


.vial.selected {
  border-color: #3a7ede;
  box-shadow: 0 12px 24px rgba(58, 126, 222, 0.25);
  transform: translateY(-8px);
}

.vial.selected::before {
  border-color: #3a7ede;
  background: #cce5ff;
}

.vial.completed {
  border-color: #589a56;
  box-shadow: 0 8px 20px rgba(88, 154, 86, 0.2);
}

.vial.completed::before {
  border-color: #589a56;
  background: #d4edda;
}

.vial.invalid-shake {
  animation: shake 0.35s ease;
}

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

/* Balls */
.ball {
  width: var(--ball-size);
  height: var(--ball-size);
  border-radius: 50%;
  margin-top: 4px;
  flex-shrink: 0;
  position: relative;
  border: 1.5px solid rgba(0, 0, 0, 0.25);
  box-shadow: 
    inset -5px -6px 10px rgba(0, 0, 0, 0.4),
    inset 6px 7px 10px rgba(255, 255, 255, 0.65),
    0 4px 8px rgba(0, 0, 0, 0.18);
  transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1);
  will-change: transform;
}

/* Top pop-out when tube is selected */
.ball.popped-up {
  transform: translateY(-42px) scale(1.08);
  box-shadow: 
    inset -5px -6px 10px rgba(0, 0, 0, 0.4),
    inset 6px 7px 10px rgba(255, 255, 255, 0.7),
    0 12px 22px rgba(0, 0, 0, 0.28);
}

/* Ball Color Palettes (Vibrant, accessible, Giraffian matching) */
.ball-color-1 { background: radial-gradient(circle at 35% 35%, #ff8f70, #d93829); } /* Coral Red */
.ball-color-2 { background: radial-gradient(circle at 35% 35%, #66b5ff, #1d6ed8); } /* Royal Blue */
.ball-color-3 { background: radial-gradient(circle at 35% 35%, #86e08c, #3f993f); } /* Spring Green */
.ball-color-4 { background: radial-gradient(circle at 35% 35%, #ffd45e, #e08b1b); } /* Sunny Yellow/Amber */
.ball-color-5 { background: radial-gradient(circle at 35% 35%, #e1b4f7, #9b51cc); } /* Giraffian Purple */
.ball-color-6 { background: radial-gradient(circle at 35% 35%, #76e7f2, #1caab8); } /* Giraffian Aqua */
.ball-color-7 { background: radial-gradient(circle at 35% 35%, #ff9ebb, #e63973); } /* Candy Pink */
.ball-color-8 { background: radial-gradient(circle at 35% 35%, #ffa566, #d45911); } /* Tangerine */
.ball-color-9 { background: radial-gradient(circle at 35% 35%, #88f0d0, #259e7a); } /* Mint */
.ball-color-10 { background: radial-gradient(circle at 35% 35%, #d1c0ff, #6f42c1); } /* Lavender */

/* Flying ball animation element */
.flying-ball {
  position: fixed !important;
  pointer-events: none;
  z-index: 9999;
  border-radius: 50%;
  border: 1.5px solid rgba(0, 0, 0, 0.25);
  box-shadow: 
    inset -5px -6px 10px rgba(0, 0, 0, 0.4),
    inset 6px 7px 10px rgba(255, 255, 255, 0.7),
    0 14px 28px rgba(0, 0, 0, 0.35);
  will-change: transform;
}

/* Bottom Toolbar */
.toolbar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 16px 8px 8px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.toolbar button.button {
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.toolbar button.button:active {
  transform: scale(0.95);
}

.toolbar button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

/* Modals */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 10000;
  padding: 20px;
  transition: opacity 0.2s ease;
}

.modal-backdrop.hidden {
  opacity: 0;
  pointer-events: none;
}

.modal-card {
  background: #ffffff;
  border: 2px solid #000;
  border-radius: 24px;
  padding: 32px 28px;
  max-width: 420px;
  width: 100%;
  text-align: center;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.3);
  position: relative;
  animation: modal-pop 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modal-pop {
  from { transform: scale(0.85); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.celebration-icon {
  font-size: 3rem;
  margin-bottom: 8px;
  animation: bounce 0.6s infinite alternate ease-in-out;
}

@keyframes bounce {
  from { transform: translateY(0); }
  to { transform: translateY(-8px); }
}

.modal-card h2 {
  font-size: 1.8rem;
  margin-bottom: 8px;
  color: #000;
}

.modal-subtext {
  color: #666;
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.modal-stats {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 24px;
  padding: 12px 18px;
  background: #f4f8fa;
  border: 2px solid #ddd;
  border-radius: 16px;
}

.modal-stats div {
  font-size: 0.95rem;
  color: #555;
  display: flex;
  flex-direction: column;
}

.modal-stats strong {
  font-size: 1.5rem;
  color: #000;
}

.modal-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 24px;
}

/* Settings Card */
.settings-card {
  text-align: left;
}

.settings-card h2 {
  text-align: center;
  margin-bottom: 18px;
}

.setting-row {
  margin-bottom: 16px;
}

.setting-row label {
  display: block;
  font-weight: bold;
  margin-bottom: 6px;
  font-size: 0.95rem;
  color: #333;
}

.setting-row select {
  width: 100%;
  padding: 10px 14px;
  font-size: 1rem;
  font-family: "Comic Relief", system-ui, sans-serif;
  border: 2px solid #000;
  border-radius: 16px;
  background: #ffffff;
  color: #000;
  outline: none;
}

.setting-row select:focus {
  border-color: #3a7ede;
  box-shadow: 0 0 6px rgba(58, 126, 222, 0.35);
}

.hidden {
  display: none !important;
}

@media (max-width: 600px) {
  :root {
    --ball-size: 44px;
    --vial-width: 58px;
    --vial-padding: 6px;
  }
  .vials-grid {
    gap: 28px 12px;
  }
  .toolbar button.button {
    padding: 8px 16px;
    font-size: 0.9rem;
  }
}

/* Site page pattern: centred title, with the level badge and buttons as a nav row beneath it */
.game-header {
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 12px;
}

.title-group {
  display: contents;
}

.title-group h1 {
  flex-basis: 100%;
  margin: 0 0 4px;
  font-size: 2em;
  text-align: center;
}