/* ============================================
   Flappy Bird — Neon Night Sky Theme
   ============================================ */

:root {
  --sky:      #0a0e1a;
  --sky2:     #0f1628;
  --pipe:     #00e676;
  --pipe-dk:  #00b359;
  --bird:     #ffd740;
  --accent:   #ff6b6b;
  --text:     #ffffff;
  --muted:    #4a6080;
  --glow:     rgba(0,230,118,.3);
  --font-px:  'Press Start 2P', monospace;
  --font-ui:  'Nunito', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--sky);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  overflow: hidden;
  font-family: var(--font-ui);
  position: relative;
}

/* Stars */
.stars {
  position: fixed; inset: 0;
  pointer-events: none; z-index: 0;
}

.star {
  position: absolute;
  background: white;
  border-radius: 50%;
  animation: twinkle var(--dur, 3s) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
  opacity: .6;
}

@keyframes twinkle {
  0%, 100% { opacity: .2; transform: scale(1); }
  50%       { opacity: .9; transform: scale(1.3); }
}

/* Game wrapper */
.game-wrapper {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

/* HUD */
.hud {
  display: flex;
  gap: 32px;
  background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,255,255,.08);
  padding: 10px 28px;
  border-radius: 40px;
  backdrop-filter: blur(8px);
}

.hud-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.hud-label {
  font-family: var(--font-px);
  font-size: .4rem;
  color: var(--muted);
  letter-spacing: .1em;
}

.hud-value {
  font-family: var(--font-px);
  font-size: .85rem;
  color: var(--text);
}

/* Canvas */
#gameCanvas {
  display: block;
  border-radius: 12px;
  border: 2px solid rgba(255,255,255,.08);
  box-shadow:
    0 0 40px rgba(0,230,118,.08),
    0 20px 60px rgba(0,0,0,.6);
}

/* Screens */
.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  border-radius: 12px;
  background: rgba(10,14,26,.85);
  backdrop-filter: blur(6px);
  animation: fadeIn .3s ease;
  padding: 20px;
  text-align: center;
}

.screen.hidden { display: none; }

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Start screen */
.bird-emoji {
  font-size: 3.5rem;
  animation: float 1.5s ease-in-out infinite;
  filter: drop-shadow(0 0 12px var(--bird));
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-10px); }
}

.game-title {
  font-family: var(--font-px);
  font-size: clamp(1rem, 4vw, 1.5rem);
  line-height: 1.6;
  color: var(--text);
  text-shadow: 0 0 20px rgba(255,255,255,.3);
}

.title-accent {
  color: var(--pipe);
  text-shadow: 0 0 20px var(--glow);
}

.instruction {
  font-family: var(--font-px);
  font-size: .5rem;
  color: var(--muted);
  letter-spacing: .1em;
  animation: blink 1.2s step-end infinite;
}

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

kbd {
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.2);
  padding: 2px 6px;
  border-radius: 3px;
  font-family: var(--font-px);
  font-size: .45rem;
}

.tip {
  font-size: .75rem;
  color: var(--muted);
  max-width: 240px;
}

/* Game over screen */
.over-title {
  font-family: var(--font-px);
  font-size: clamp(.9rem, 3vw, 1.3rem);
  color: var(--accent);
  text-shadow: 0 0 20px rgba(255,107,107,.5);
  animation: shake .4s ease;
}

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

.result-box {
  background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,255,255,.1);
  border-radius: 8px;
  padding: 16px 40px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 200px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
  font-family: var(--font-px);
  font-size: .55rem;
  color: var(--muted);
}

.result-row span:last-child {
  color: var(--text);
  font-size: .8rem;
}

.result-divider {
  height: 1px;
  background: rgba(255,255,255,.08);
}

.play-btn {
  font-family: var(--font-px);
  font-size: .55rem;
  background: var(--pipe);
  color: #000;
  border: none;
  padding: 14px 28px;
  border-radius: 6px;
  cursor: pointer;
  letter-spacing: .1em;
  box-shadow: 0 0 20px var(--glow);
  transition: transform .1s, box-shadow .1s;
}

.play-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 30px var(--glow);
}

.play-btn:active { transform: scale(.97); }

.instruction-small {
  font-family: var(--font-px);
  font-size: .38rem;
  color: var(--muted);
  letter-spacing: .1em;
}

/* Responsive canvas sizing handled in JS */
@media (max-height: 700px) {
  .hud { padding: 8px 20px; }
  .game-wrapper { gap: 8px; }
}