:root {
  --snake-green: #4fe340;
  --snake-head: #8aff80;
  --snake-food: #ff4f4f;
  --snake-bg: #0b1026;
  --snake-grid: #ffffff08;
}

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

html, body { height: 100%; overflow: hidden; background: var(--snake-bg); color: #fff; font-family: system-ui, sans-serif; }

.snake-body { display: flex; flex-direction: column; height: 100%; }

.snake-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  background: #ffffff08;
  border-bottom: 1px solid #ffffff14;
  flex-shrink: 0;
}

.snake-back {
  color: #fff;
  text-decoration: none;
  font-size: 1.25rem;
  line-height: 1;
  padding: 0.25rem 0.5rem;
  border-radius: 6px;
  transition: background 0.15s;
}
.snake-back:hover { background: #ffffff18; }

.snake-score-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-left: auto;
}
.snake-score-display + .snake-score-display { margin-left: 1.5rem; }

.snake-score-label { font-size: 0.65rem; text-transform: uppercase; letter-spacing: 0.08em; opacity: 0.5; }
.snake-score-value { font-size: 1.4rem; font-weight: 700; font-variant-numeric: tabular-nums; }

.snake-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: 0.5rem;
}

#canvas {
  display: block;
  border-radius: 8px;
  image-rendering: pixelated;
  border: 1px solid #ffffff20;
}

/* Overlay */
.snake-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0b1026cc;
  backdrop-filter: blur(4px);
  border-radius: 8px;
}
.snake-overlay.hidden { display: none; }

.snake-overlay__box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 2rem;
  background: #ffffff0d;
  border: 1px solid #ffffff18;
  border-radius: 16px;
  text-align: center;
  max-width: 280px;
}

.snake-overlay__title { font-size: 2rem; font-weight: 800; color: var(--snake-green); }
.snake-overlay__sub { font-size: 0.85rem; opacity: 0.7; line-height: 1.5; }

.snake-btn {
  margin-top: 0.5rem;
  padding: 0.65rem 2rem;
  background: var(--snake-green);
  color: #0b1026;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s;
}
.snake-btn:hover { opacity: 0.85; }

/* D-pad */
.snake-dpad {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: grid;
  grid-template-areas:
    ". up ."
    "left . right"
    ". down .";
  grid-template-columns: 48px 48px 48px;
  grid-template-rows: 48px 48px 48px;
  gap: 4px;
}

.snake-dpad__btn {
  background: #ffffff14;
  border: 1px solid #ffffff22;
  color: #fff;
  font-size: 1rem;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.1s;
}
.snake-dpad__btn:active { background: #ffffff30; }
.snake-dpad__btn--up    { grid-area: up; }
.snake-dpad__btn--left  { grid-area: left; }
.snake-dpad__btn--right { grid-area: right; }
.snake-dpad__btn--down  { grid-area: down; }

/* Hide d-pad on non-touch if keyboard is likely */
@media (hover: hover) and (pointer: fine) {
  .snake-dpad { display: none; }
}