:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --grid-bg: #1e293b;
  --cell: #334155;
  --cell-border: #1e293b;
  --wall: #0f172a;
  --start: #22c55e;
  --goal: #ef4444;
  --visited: #38bdf8;
  --current: #7dd3fc;
  --path: #facc15;
  --path-glow: rgba(250, 204, 21, 0.9);
  --text: #e2e8f0;
  --muted: #94a3b8;
}

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

body {
  background: radial-gradient(circle at 20% 10%, #1e293b, #0f172a 70%);
  min-height: 100vh;
  font-family: 'Segoe UI', system-ui, sans-serif;
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 20px;
}

.container {
  max-width: 920px;
  width: 100%;
}

header { text-align: center; margin-bottom: 16px; }

h1 {
  font-size: 2.2rem;
  background: linear-gradient(135deg, #22d3ee, #a78bfa);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 0.5px;
}

.subtitle {
  color: var(--muted);
  margin-top: 4px;
  font-size: 0.95rem;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  justify-content: center;
  background: var(--panel);
  border: 1px solid #334155;
  border-radius: 12px;
  padding: 12px;
  margin-bottom: 12px;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.2s ease, opacity 0.2s;
  color: #fff;
}

.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(135deg, #0ea5e9, #6366f1);
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}
.btn-primary:hover:not(:disabled) {
  box-shadow: 0 6px 22px rgba(99, 102, 241, 0.6);
  transform: translateY(-1px);
}

.btn-secondary {
  background: #475569;
}
.btn-secondary:hover:not(:disabled) {
  background: #64748b;
}

.speed-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  color: var(--muted);
  font-size: 0.85rem;
}

.speed-wrap input[type="range"] {
  accent-color: #22d3ee;
  cursor: pointer;
}

#speed-value {
  min-width: 20px;
  text-align: center;
  font-weight: 700;
  color: var(--text);
}

.stats {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
  font-size: 0.85rem;
  color: var(--muted);
}

.stat {
  display: flex;
  align-items: center;
  gap: 6px;
}

.dot { width: 12px; height: 12px; border-radius: 3px; display: inline-block; }
.dot-start { background: var(--start); }
.dot-goal { background: var(--goal); }

.grid-wrap {
  background: var(--panel);
  border: 1px solid #334155;
  border-radius: 12px;
  padding: 12px;
  overflow-x: auto;
}

.grid {
  display: grid;
  grid-template-columns: repeat(25, 1fr);
  gap: 1px;
  background: var(--cell-border);
  margin: 0 auto;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none;
  max-width: 640px;
}

.cell {
  aspect-ratio: 1 / 1;
  background: var(--cell);
  position: relative;
  cursor: crosshair;
  border-radius: 2px;
  transition: background 0.05s ease, box-shadow 0.15s ease;
  min-width: 8px;
}

.cell:hover { filter: brightness(1.2); }

.cell.wall {
  background: var(--wall);
  box-shadow: inset 0 0 0 1px #0f172a;
}
.cell.wall::after {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 3px,
    rgba(15, 23, 42, 0.85) 3px,
    rgba(15, 23, 42, 0.85) 5px
  );
}

.cell.start {
  background: var(--start);
  cursor: grab;
  box-shadow: 0 0 12px rgba(34, 197, 94, 0.5);
}
.cell.start::after {
  content: '🟢';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(10px, 2.2vw, 18px);
}
.cell.start.dragging { cursor: grabbing; filter: brightness(1.3); }

.cell.goal {
  background: var(--goal);
  cursor: grab;
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.5);
}
.cell.goal::after {
  content: '🎯';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(10px, 2.2vw, 18px);
}
.cell.goal.dragging { cursor: grabbing; filter: brightness(1.3); }

.cell.visited {
  background: var(--visited);
  animation: popIn 0.2s ease;
}

.cell.current {
  background: var(--current);
  box-shadow: 0 0 8px rgba(125, 211, 252, 0.8);
  animation: pulseCurrent 0.4s ease-in-out infinite alternate;
}

.cell.path {
  background: var(--path);
  animation: pathGlow 1s ease-in-out infinite alternate;
  z-index: 2;
}
.cell.path::before {
  content: '✦';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(8px, 1.8vw, 14px);
  color: #7a5b00;
}

@keyframes popIn {
  0% { transform: scale(0.8); opacity: 0.5; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes pulseCurrent {
  0% { filter: brightness(1); }
  100% { filter: brightness(1.4); }
}

@keyframes pathGlow {
  0% { box-shadow: 0 0 6px var(--path-glow); }
  100% { box-shadow: 0 0 18px var(--path-glow), 0 0 30px var(--path-glow); }
}

/* ─── Responsive ─── */
@media (max-width: 700px) {
  .grid-wrap { padding: 6px; }
  .cell { border-radius: 1px; }
  h1 { font-size: 1.6rem; }
  .controls { gap: 6px; }
  .btn { padding: 8px 10px; font-size: 0.8rem; }
  .legend { font-size: 0.7rem; flex-wrap: wrap; }
}

/* ─── Toast (Yol Bulunamadı — kırmızı neon) ─── */
.toast {
  position: fixed;
  top: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(-120%);
  background: rgba(127, 29, 29, 0.95);
  border: 2px solid #ff4d4d;
  border-radius: 14px;
  padding: 18px 28px;
  color: #fff;
  text-align: center;
  font-weight: 700;
  font-size: 1.2rem;
  z-index: 999;
  box-shadow: 0 0 20px rgba(255, 77, 77, 0.8), 0 0 60px rgba(255, 0, 0, 0.4);
  animation: neonToast 1.2s ease-in-out infinite alternate;
  transition: transform 0.4s cubic-bezier(0.18, 0.89, 0.32, 1.28), opacity 0.3s ease;
  pointer-events: none;
  max-width: 90vw;
  opacity: 0;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.toast-icon { font-size: 1.8rem; display: block; margin-bottom: 4px; }

.toast-sub {
  font-weight: 400;
  font-size: 0.85rem;
  color: #ffd6d6;
  margin-top: 8px;
}

@keyframes neonToast {
  0% {
    box-shadow: 0 0 15px rgba(255, 77, 77, 0.7), 0 0 40px rgba(255, 0, 0, 0.3);
    border-color: #ff4d4d;
  }
  100% {
    box-shadow: 0 0 30px rgba(255, 77, 77, 1), 0 0 80px rgba(255, 0, 0, 0.7);
    border-color: #ffdddd;
  }
}

/* ─── Legend ─── */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  margin-top: 14px;
  font-size: 0.8rem;
  color: var(--muted);
  user-select: none;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.legend-swatch {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  display: inline-block;
}
.wall-swatch { background: #0f172a; border: 1px solid #334155; }
.start-swatch { background: var(--start); }
.goal-swatch { background: var(--goal); }
.visited-swatch { background: var(--visited); }
.current-swatch { background: var(--current); }
.path-swatch { background: var(--path); }