:root {
  --bg-deep: #0a0a12;
  --bg-panel: rgba(255, 255, 255, 0.04);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --text-primary: #f0f0f5;
  --text-muted: #8888a0;
  --accent-cyan: #00e5ff;
  --font: 'Outfit', system-ui, sans-serif;
}

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

body {
  font-family: var(--font);
  background: var(--bg-deep);
  color: var(--text-primary);
  min-height: 100vh;
  overflow: hidden;
}

.game-layout {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* ---- Header ---- */
.game-header {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.back-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

.back-link:hover {
  color: var(--accent-cyan);
}

.game-header h1 {
  font-size: 1.5rem;
  font-weight: 600;
  background: linear-gradient(135deg, var(--text-primary), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.size-picker {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.size-picker__label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.size-range {
  -webkit-appearance: none;
  appearance: none;
  width: 130px;
  height: 6px;
  border-radius: 100px;
  background: rgba(255, 255, 255, 0.12);
  cursor: pointer;
}

.size-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.5);
  cursor: pointer;
}

.size-range::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border: none;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.5);
  cursor: pointer;
}

.size-picker__value {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
  min-width: 4.5rem;
}

.hints-toggle {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
}

.hints-toggle input {
  accent-color: var(--accent-cyan);
  cursor: pointer;
}

.tool-btn {
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.5rem 1.1rem;
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  background: var(--bg-panel);
  color: var(--text-primary);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, opacity 0.2s;
}

.tool-btn:hover:not(:disabled) {
  border-color: rgba(0, 229, 255, 0.4);
  color: var(--accent-cyan);
}

.tool-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.tool-btn--primary {
  margin-left: auto;
}

/* ---- Container ---- */
.game-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 1rem;
  min-height: 0;
}

.stat-bar {
  display: flex;
  gap: 2rem;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.15rem;
}

.stat__label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.stat__value {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

/* ---- Board ---- */
.board-wrap {
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
}

.board {
  height: 100%;
  max-height: min(70vh, 620px);
  aspect-ratio: 1;
  max-width: 100%;
  background:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: calc(100% / var(--cells, 6)) calc(100% / var(--cells, 6));
  border: 1px solid var(--border-subtle);
  border-radius: 14px;
  overflow: hidden;
}

.arrow {
  cursor: pointer;
  transition: transform 0.42s cubic-bezier(0.5, 0, 0.75, 0.2), opacity 0.42s ease;
}

.arrow__body,
.arrow__head {
  transition: filter 0.15s ease;
}

.arrow:hover .arrow__body,
.arrow:hover .arrow__head {
  filter: brightness(1.18);
}

.arrow--safe .arrow__body { filter: drop-shadow(0 0 6px #22c55e) brightness(1.15); }
.arrow--safe .arrow__head { filter: drop-shadow(0 0 6px #22c55e) brightness(1.15); }
.arrow--danger .arrow__body { filter: drop-shadow(0 0 6px #ef4444) brightness(1.1); }
.arrow--danger .arrow__head { filter: drop-shadow(0 0 6px #ef4444) brightness(1.1); }

.arrow--crash .arrow__body,
.arrow--crash .arrow__head {
  fill: #ef4444 !important;
  stroke: #ef4444 !important;
  animation: shake 0.5s ease;
}

.arrow--hit .arrow__body,
.arrow--hit .arrow__head {
  filter: drop-shadow(0 0 10px #ef4444) brightness(1.2);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

.hint-text {
  color: var(--text-muted);
  font-size: 0.85rem;
  text-align: center;
  max-width: 42rem;
  line-height: 1.5;
}

/* ---- End overlay ---- */
.overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(10, 10, 18, 0.75);
  backdrop-filter: blur(8px);
  z-index: 10;
}

.overlay--hidden {
  display: none;
}

.overlay-content {
  text-align: center;
  padding: 2.5rem;
  background: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  backdrop-filter: blur(12px);
  max-width: 90vw;
  width: 30rem;
}

.overlay-content h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.end-title--win {
  background: linear-gradient(135deg, #22c55e, var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.overlay-content p {
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1.5rem;
}

.end-stats {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 1.75rem;
}

.end-stat__value {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.end-stat__label {
  display: block;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.overlay-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-start {
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  padding: 0.75rem 2rem;
  border: none;
  border-radius: 100px;
  background: linear-gradient(135deg, #00e5ff, #0099cc);
  color: #0a0a12;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-start:hover {
  transform: scale(1.05);
  box-shadow: 0 0 30px rgba(0, 229, 255, 0.4);
}

@media (max-width: 620px) {
  .game-header {
    padding: 0.8rem 1rem;
    gap: 0.8rem;
  }
  .game-header h1 { font-size: 1.2rem; }
  .tool-btn--primary { margin-left: 0; }
  .hint-text { font-size: 0.78rem; }
}