/* ==========================================================================
   Shatter — Styles
   Uses design tokens from design-tokens.css via var(--token-name)
   ========================================================================== */

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  height: 100dvh;
  overflow: hidden;
  background: var(--color-background);
  touch-action: none;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: var(--font-family);
}

/* Game Container */
#game-container {
  position: relative;
  width: 100vw;
  height: calc(100vw * 3 / 4);
  max-height: 100vh;
  max-height: 100dvh;
  max-width: calc(100vh * 4 / 3);
  max-width: calc(100dvh * 4 / 3);
  touch-action: none;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
}

/* Canvas */
#game-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* HUD Bar */
#hud {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 var(--spacing-4);
  background: var(--color-hud-bg);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  z-index: var(--z-hud);
}

#hud-score.pulse {
  animation: scorePulse 200ms ease-out;
}

@keyframes scorePulse {
  50% {
    transform: scale(1.2);
    color: var(--color-warning);
  }
}

/* Individual heart icons for animated life gain/loss */
.heart {
  display: inline-block;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
  color: var(--color-error);
}

.heart.removing {
  transform: scale(0);
  opacity: 0;
}

.heart.adding {
  animation: heartBounceIn 300ms ease-out;
}

@keyframes heartBounceIn {
  0% { transform: scale(0); }
  60% { transform: scale(1.3); }
  100% { transform: scale(1); }
}

/* Power-Up HUD Notification */
#hud-powerup {
  position: absolute;
  top: 44px;
  left: 50%;
  transform: translateX(-50%);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  z-index: var(--z-hud);
  opacity: 0;
  transition: opacity var(--transition-fast);
  pointer-events: none;
}

#hud-powerup.show {
  opacity: 1;
}

/* Overlay Base */
.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: var(--z-overlay);
  background: var(--color-overlay-backdrop);
  opacity: 1;
  visibility: visible;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.overlay[hidden] {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.overlay h2 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: var(--letter-spacing-wide);
  color: var(--color-text);
  margin-bottom: var(--spacing-4);
  text-shadow: var(--shadow-medium);
}

.overlay p {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-normal);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-6);
}

/* Buttons */
.btn {
  font-size: 18px;
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  padding: var(--spacing-3) var(--spacing-8);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-md);
  background: var(--color-background);
  color: var(--color-primary);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
  box-shadow: var(--shadow-subtle);
}

.btn:hover,
.btn:focus-visible {
  background: var(--color-primary-dark);
  color: var(--color-text);
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn + .btn {
  margin-top: var(--spacing-3);
}

.btn.disabled {
  pointer-events: none;
  opacity: 0.5;
}

/* Difficulty Selector */
.difficulty-select {
  display: flex;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-4);
}

.btn-diff {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  padding: var(--spacing-2) var(--spacing-4);
  border: 1px solid var(--color-neutral-700);
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 36px;
}

.btn-diff:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-diff.selected {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: var(--color-neutral-900);
}

/* Sound Toggle Button */
#btn-mute {
  position: absolute;
  top: 44px;
  left: var(--spacing-1);
  z-index: 15;
  width: 36px;
  height: 36px;
  font-size: 18px;
  background: rgba(10, 14, 39, 0.7);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  cursor: pointer;
  line-height: 1;
  padding: 0;
  transition: background var(--transition-fast);
}

#btn-mute:hover,
#btn-mute:focus-visible {
  background: var(--color-primary-dark);
}

/* Mobile Pause Button */
#btn-mobile-pause {
  position: absolute;
  top: var(--spacing-1);
  right: var(--spacing-1);
  z-index: 15;
  width: 44px;
  height: 44px;
  font-size: 24px;
  background: rgba(10, 14, 39, 0.7);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  cursor: pointer;
  display: none;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

#btn-mobile-pause:hover,
#btn-mobile-pause:focus-visible {
  background: var(--color-primary-dark);
  color: var(--color-text);
  border-color: var(--color-primary);
}

/* Touch Zone */
#touch-zone {
  position: absolute;
  inset: 0;
  z-index: 5;
  touch-action: none;
  display: none;
  -webkit-touch-callout: none;
}

/* Control Hints */
.control-hints {
  font-size: var(--font-size-xs);
  color: var(--color-neutral-100);
  margin-top: 20px;
}

/* How to Play Section */
.how-to-play {
  margin-top: var(--spacing-4);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  text-align: center;
}

.how-to-play summary {
  cursor: pointer;
  color: var(--color-primary);
  font-weight: var(--font-weight-semibold);
}

.how-to-play p {
  font-size: var(--font-size-xs);
  margin-bottom: var(--spacing-2);
}

/* Level Transition */
#level-overlay .level-title {
  animation: scaleIn 400ms ease-out;
}

@keyframes scaleIn {
  from {
    transform: scale(0.5);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

/* Game Over Slide-Up */
#gameover-overlay {
  transform: translateY(0);
  transition: opacity 400ms ease-out, transform 400ms ease-out, visibility 400ms;
}

#gameover-overlay[hidden] {
  transform: translateY(100%);
}

/* Score "New!" Badge */
.new-badge {
  display: inline-block;
  background: var(--color-error);
  color: var(--color-text);
  padding: 2px var(--spacing-2);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  margin-left: var(--spacing-2);
}

/* Upgrade Selection Cards */
.upgrade-cards {
  display: flex;
  gap: var(--spacing-4);
  justify-content: center;
  flex-wrap: wrap;
  padding: 0 var(--spacing-4);
}

.upgrade-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-2);
  width: 180px;
  padding: var(--spacing-6) var(--spacing-4);
  background: var(--color-neutral-800);
  border: 2px solid var(--color-neutral-700);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  cursor: pointer;
  transition: border-color var(--transition-fast),
              transform var(--transition-fast),
              box-shadow var(--transition-fast);
  text-align: center;
  font-family: var(--font-family);
  animation: cardReveal 400ms ease-out backwards;
}

.upgrade-card:nth-child(1) { animation-delay: 0ms; }
.upgrade-card:nth-child(2) { animation-delay: 100ms; }
.upgrade-card:nth-child(3) { animation-delay: 200ms; }

@keyframes cardReveal {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.upgrade-card:hover,
.upgrade-card:focus-visible {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-medium);
}

.upgrade-card:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.upgrade-icon {
  font-size: 2.5rem;
  line-height: 1;
  text-shadow: 0 0 12px currentColor;
}

.upgrade-name {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.05em;
}

.upgrade-desc {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  line-height: var(--line-height-normal);
}

.upgrade-stack {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  padding: var(--spacing-1) var(--spacing-2);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
}

/* Responsive Breakpoints */
@media (min-width: 768px) {
  #game-container {
    width: 90vw;
    max-width: 800px;
    margin: 0 auto;
  }
}

@media (min-width: 1024px) {
  #game-container {
    width: 800px;
  }
}

@media (max-width: 767px) {
  #hud {
    font-size: var(--font-size-xs);
    height: 36px;
  }
  .overlay h2 {
    font-size: 28px;
  }
  .overlay p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-3);
  }
  .btn {
    font-size: var(--font-size-sm);
    padding: 10px var(--spacing-6);
    min-height: 44px;
    min-width: 44px;
  }
  .control-hints {
    font-size: 11px;
    padding: 0 var(--spacing-2);
  }
  .btn-diff {
    padding: var(--spacing-1) var(--spacing-3);
    font-size: 11px;
    min-height: 32px;
  }
  .upgrade-cards {
    flex-direction: column;
    align-items: center;
  }
  .upgrade-card {
    width: 85%;
    padding: var(--spacing-3) var(--spacing-4);
    flex-direction: row;
    gap: var(--spacing-3);
  }
  .upgrade-icon { font-size: 1.8rem; }
  .upgrade-name { font-size: var(--font-size-sm); }
}

@media (max-width: 400px) {
  .overlay h2 {
    font-size: 24px;
  }
  .overlay p {
    font-size: var(--font-size-xs);
  }
  .btn {
    font-size: var(--font-size-xs);
    padding: 8px var(--spacing-4);
  }
}

/* Focus Visible (Accessibility) */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}