/* ─── Google Fonts ──────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Rajdhani:wght@400;600;700&display=swap');

/* ─── Design Tokens ─────────────────────────────────────────── */
:root {
  --bg:            #080c0a;
  --bg-mid:        #0d1410;
  --surface:       #111a14;
  --surface-hi:    #172018;
  --border:        rgba(74, 222, 128, 0.12);
  --border-bright: rgba(74, 222, 128, 0.35);

  --green:         #4ade80;
  --green-dim:     #22c55e;
  --green-glow:    rgba(74, 222, 128, 0.25);
  --green-head:    #a3f4b4;
  --red:           #f87171;
  --red-glow:      rgba(248, 113, 113, 0.4);
  --amber:         #fbbf24;

  --text:          #e2ffe9;
  --text-muted:    #6b8f74;
  --text-dim:      #3d5e46;

  --cell-bg:       #0e1a11;
  --cell-line:     rgba(74, 222, 128, 0.045);

  --board-size:    min(480px, calc(100vw - 40px));
  --radius:        10px;
  --radius-sm:     6px;

  --font-display:  'Rajdhani', sans-serif;
  --font-mono:     'Share Tech Mono', monospace;
}

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

html { scroll-behavior: smooth; }

body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-display);
  font-size: 16px;
  line-height: 1.5;
  /* Subtle scanline texture */
  background-image:
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(0,0,0,0.15) 2px,
      rgba(0,0,0,0.15) 4px
    );
}

/* ─── Shell ──────────────────────────────────────────────────── */
.game-shell {
  width: min(680px, 100% - 32px);
  margin: 0 auto;
  padding: 40px 0 32px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* ─── Header ─────────────────────────────────────────────────── */
.game-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 20px;
}

.header-left { flex: 1; }

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--green-dim);
  margin-bottom: 6px;
}

.game-header h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 3.6rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1;
  color: var(--green);
  text-shadow:
    0 0 20px var(--green-glow),
    0 0 60px rgba(74,222,128,0.1);
}

.header-tagline {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

/* Speed indicator in header */
.speed-indicator {
  text-align: right;
  font-family: var(--font-mono);
}

.speed-label {
  display: block;
  font-size: 0.62rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 4px;
}

.speed-bar {
  display: flex;
  gap: 3px;
  justify-content: flex-end;
}

.speed-pip {
  width: 8px;
  height: 16px;
  border-radius: 2px;
  background: var(--surface-hi);
  border: 1px solid var(--border);
  transition: background 0.3s, box-shadow 0.3s;
}

.speed-pip.active {
  background: var(--green);
  border-color: var(--green-dim);
  box-shadow: 0 0 6px var(--green-glow);
}

.speed-pip.active.hot {
  background: var(--red);
  border-color: #ef4444;
  box-shadow: 0 0 6px var(--red-glow);
}

/* ─── Score Panel ────────────────────────────────────────────── */
.score-panel {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 10px;
}

.score-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s;
}

.score-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(74,222,128,0.04) 0%, transparent 60%);
  pointer-events: none;
}

.score-card:first-child {
  border-color: var(--border-bright);
  box-shadow: 0 0 20px rgba(74, 222, 128, 0.06);
}

.score-card-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.score-card-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.9rem;
  font-weight: 400;
  color: var(--green);
  line-height: 1;
  text-shadow: 0 0 12px var(--green-glow);
}

.score-card-value.score-main {
  font-size: 2.2rem;
}

/* Status badge */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 4px;
  margin-top: 8px;
  border: 1px solid var(--border);
  color: var(--text-muted);
  background: var(--bg-mid);
}

.status-badge::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--text-dim);
}

.status-badge[data-status="running"] { color: var(--green); border-color: var(--border-bright); }
.status-badge[data-status="running"]::before { background: var(--green); box-shadow: 0 0 6px var(--green); animation: blink 1s ease infinite; }
.status-badge[data-status="paused"]  { color: var(--amber); border-color: rgba(251,191,36,0.3); }
.status-badge[data-status="paused"]::before  { background: var(--amber); }
.status-badge[data-status="game-over"] { color: var(--red); border-color: rgba(248,113,113,0.3); }
.status-badge[data-status="game-over"]::before { background: var(--red); }

@keyframes blink {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.3; }
}

/* ─── Game Area ──────────────────────────────────────────────── */
.game-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

/* ─── Board Wrap ─────────────────────────────────────────────── */
.board-wrap {
  position: relative;
  width: var(--board-size);
}

/* Outer glow frame */
.board-frame {
  position: relative;
  padding: 3px;
  border-radius: calc(var(--radius) + 3px);
  background: linear-gradient(135deg, var(--green-dim), rgba(74,222,128,0.1) 50%, rgba(74,222,128,0.4));
  box-shadow:
    0 0 0 1px rgba(74,222,128,0.08),
    0 0 30px rgba(74,222,128,0.1),
    0 0 80px rgba(74,222,128,0.04),
    inset 0 1px 0 rgba(255,255,255,0.04);
}

/* ─── Game Board ─────────────────────────────────────────────── */
.game-board {
  display: grid;
  grid-template-columns: repeat(var(--grid-size, 20), 1fr);
  width: 100%;
  aspect-ratio: 1;
  background: var(--bg);
  border-radius: var(--radius);
  overflow: hidden;
  outline: none;
  /* Subtle grid lines */
  gap: 0;
}

.game-board:focus-visible .board-frame {
  box-shadow:
    0 0 0 2px var(--green),
    0 0 30px rgba(74,222,128,0.2);
}

/* ─── Cells ──────────────────────────────────────────────────── */
.cell {
  background: var(--cell-bg);
  border: 0.5px solid var(--cell-line);
  transition: background 0.05s;
  position: relative;
}

/* Snake body */
.cell.snake {
  background: var(--green-dim);
  border-color: rgba(34,197,94,0.3);
  box-shadow: inset 0 0 4px rgba(74,222,128,0.3);
}

/* Snake head — bright, glowing */
.cell.head {
  background: var(--green-head);
  border-color: var(--green);
  box-shadow:
    0 0 8px var(--green-glow),
    inset 0 0 6px rgba(255,255,255,0.2);
  z-index: 2;
}

/* Snake tail — subtly dimmer */
.cell.tail {
  background: #1a5c35;
  border-color: rgba(34,197,94,0.15);
}

/* Food — pulsing red dot */
.cell.food {
  background: var(--red);
  border-color: #ef4444;
  box-shadow:
    0 0 10px var(--red-glow),
    0 0 20px rgba(248,113,113,0.2);
  animation: food-pulse 0.9s ease-in-out infinite;
  z-index: 2;
}

@keyframes food-pulse {
  0%, 100% { box-shadow: 0 0 10px var(--red-glow), 0 0 20px rgba(248,113,113,0.2); }
  50%       { box-shadow: 0 0 18px rgba(248,113,113,0.7), 0 0 36px rgba(248,113,113,0.35); }
}

/* ─── Food Burst Particle ────────────────────────────────────── */
#foodBurst {
  position: absolute;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--red);
  pointer-events: none;
  transform: translate(-50%, -50%) scale(0);
  opacity: 0;
  z-index: 10;
}

#foodBurst.burst-active {
  animation: burst 0.4s ease-out forwards;
}

@keyframes burst {
  0%   { transform: translate(-50%,-50%) scale(0);  opacity: 1; box-shadow: 0 0 0 0 rgba(248,113,113,0.8); }
  60%  { transform: translate(-50%,-50%) scale(1);  opacity: 0.8; box-shadow: 0 0 0 12px rgba(248,113,113,0); }
  100% { transform: translate(-50%,-50%) scale(1.4); opacity: 0; box-shadow: 0 0 0 18px rgba(248,113,113,0); }
}

/* ─── Overlay ────────────────────────────────────────────────── */
.overlay {
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  text-align: center;
  background: rgba(8, 12, 10, 0.88);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
  z-index: 20;
}

.overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

.overlay-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 8vw, 3rem);
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--green);
  text-shadow: 0 0 30px var(--green-glow), 0 0 60px rgba(74,222,128,0.15);
  margin-bottom: 14px;
}

.overlay-body {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.9;
  margin-bottom: 22px;
  max-width: 300px;
}

/* Keyboard hint pill */
.kbd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 1px 7px;
  border-radius: 4px;
  background: var(--surface-hi);
  border: 1px solid var(--border-bright);
  color: var(--green);
  letter-spacing: 0.04em;
}

/* Game Over score display */
.go-scores {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin-top: 8px;
}

.go-score-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.go-score-item span {
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.go-score-item strong {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 400;
  color: var(--green);
  text-shadow: 0 0 16px var(--green-glow);
  line-height: 1;
}

/* ─── Overlay Button ─────────────────────────────────────────── */
.overlay-btn {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 12px 32px;
  min-height: 48px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--green);
  color: var(--bg);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
  box-shadow: 0 0 20px var(--green-glow), 0 4px 12px rgba(0,0,0,0.4);
}

.overlay-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.15), transparent);
  pointer-events: none;
}

.overlay-btn:hover {
  background: #6ee7a0;
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(74,222,128,0.5), 0 6px 18px rgba(0,0,0,0.5);
}

.overlay-btn:active {
  transform: translateY(0);
  box-shadow: 0 0 12px var(--green-glow), 0 2px 6px rgba(0,0,0,0.4);
}

/* ─── Controls Bar ───────────────────────────────────────────── */
.controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  width: 100%;
  max-width: var(--board-size);
}

/* Control buttons */
.ctrl-btn {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0 20px;
  min-height: 42px;
  flex: 1 1 110px;
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--green);
  cursor: pointer;
  transition: background 0.15s, box-shadow 0.15s, transform 0.1s, border-color 0.15s;
  position: relative;
  overflow: hidden;
}

.ctrl-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(74,222,128,0.07), transparent);
  pointer-events: none;
}

.ctrl-btn:hover:not(:disabled) {
  background: var(--surface-hi);
  border-color: var(--green);
  box-shadow: 0 0 12px rgba(74,222,128,0.15);
  transform: translateY(-1px);
}

.ctrl-btn:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: none;
}

.ctrl-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.ctrl-btn.primary {
  background: var(--green);
  color: var(--bg);
  border-color: var(--green);
  box-shadow: 0 0 16px var(--green-glow);
}

.ctrl-btn.primary:hover:not(:disabled) {
  background: #6ee7a0;
  box-shadow: 0 0 24px rgba(74,222,128,0.4);
}

/* ─── Mobile D-Pad ───────────────────────────────────────────── */
.mobile-controls {
  display: none;
  grid-template-columns: repeat(3, 52px);
  grid-template-rows: repeat(3, 52px);
  grid-template-areas:
    ". up ."
    "left . right"
    ". down .";
  gap: 6px;
}

.dpad-btn {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--green);
  font-size: 1.1rem;
  cursor: pointer;
  transition: background 0.12s, box-shadow 0.12s, transform 0.1s;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.dpad-btn:active {
  background: var(--surface-hi);
  box-shadow: 0 0 10px var(--green-glow);
  transform: scale(0.93);
}

.move-up    { grid-area: up; }
.move-left  { grid-area: left; }
.move-right { grid-area: right; }
.move-down  { grid-area: down; }

/* ─── Help Text ──────────────────────────────────────────────── */
.help {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  letter-spacing: 0.06em;
  text-align: center;
}

/* ─── Footer ─────────────────────────────────────────────────── */
footer {
  padding: 20px;
  text-align: center;
  border-top: 1px solid var(--border);
}

footer p {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}

/* ─── Responsive ─────────────────────────────────────────────── */
@media (max-width: 600px) {
  .game-shell { padding: 20px 0 24px; gap: 16px; }

  .game-header { flex-direction: column; align-items: flex-start; gap: 12px; }

  .score-panel { grid-template-columns: 1fr 1fr; }
  .score-panel .score-card:last-child { grid-column: 1 / -1; }

  .mobile-controls { display: grid; }

  .help { display: none; }
}

@media (max-width: 400px) {
  .score-panel { grid-template-columns: 1fr; }
  .score-panel .score-card:last-child { grid-column: auto; }
}

/* ─── Reduced motion ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .cell.food { animation: none; }
  #foodBurst.burst-active { animation: none; }
  .status-badge[data-status="running"]::before { animation: none; }
}