/* ===== Sliding Puzzle - Mobile responsive ===== */
:root {
  --tile-gap: 4px;
  --tile-radius: 6px;
  --board-bg: #1a1a2e;
  --tile-bg: #16213e;
  --tile-border: #0f3460;
  --tile-text: #e8e8e8;
  --accent: #e94560;
  --empty-bg: rgba(15, 52, 96, 0.5);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Outfit", sans-serif;
  background: linear-gradient(135deg, #0f0c29 0%, #302b63 50%, #24243e 100%);
  min-height: 100vh;
  color: #f5f5f5;
  -webkit-tap-highlight-color: transparent;
}

.wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 12px;
}

/* ===== Level screen ===== */
.level-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
  text-align: center;
}

.level-screen h1 {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  margin: 0 0 8px;
  font-weight: 700;
}

.level-screen > p {
  margin: 0 0 24px;
  opacity: 0.9;
  font-size: 1rem;
}

.level-buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 320px;
}

.level-btn {
  padding: 16px 20px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.08);
  color: inherit;
  font-family: inherit;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s, transform 0.1s;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.level-btn:hover,
.level-btn:focus-visible {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.5);
}

.level-btn:active {
  transform: scale(0.98);
}

.level-name {
  font-weight: 700;
  font-size: 1.1rem;
}

.level-desc {
  font-size: 0.85rem;
  opacity: 0.85;
  margin-top: 4px;
}

.level-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 8px;
}

.level-header h1 {
  margin: 0;
}

/* ===== Help button ===== */
.help-btn {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.1);
  color: inherit;
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, border-color 0.2s;
  flex-shrink: 0;
}

.help-btn:hover,
.help-btn:focus-visible {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.6);
}

/* ===== Help modal ===== */
.help-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 300;
  padding: 20px;
}

.help-overlay.hidden {
  display: none;
}

.help-modal {
  background: linear-gradient(145deg, #1a1a2e 0%, #16213e 100%);
  border: 2px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  max-width: 420px;
  width: 100%;
  max-height: 90vh;
  overflow: auto;
}

.help-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 20px 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.help-header h2 {
  margin: 0;
  font-size: 1.35rem;
}

.help-close {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: inherit;
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.help-close:hover {
  background: rgba(255, 255, 255, 0.2);
}

.help-body {
  padding: 20px;
}

.help-body p {
  margin: 0 0 12px;
}

.help-body ul {
  margin: 0;
  padding-left: 20px;
}

.help-body li {
  margin-bottom: 10px;
  line-height: 1.45;
}

.help-body li:last-child {
  margin-bottom: 0;
}

/* ===== Game screen ===== */
.game-screen {
  width: 100%;
  max-width: 100%;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.game-screen.hidden,
.level-screen.hidden {
  display: none;
}

/* ===== Header ===== */
.header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  width: 100%;
  max-width: 720px;
}

.header h1 {
  font-size: clamp(1.25rem, 4vw, 1.5rem);
  margin: 0;
  font-weight: 700;
}

.level-badge {
  padding: 4px 10px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.2);
  font-size: 0.8rem;
  font-weight: 600;
}

.moves {
  font-size: 0.95rem;
  font-weight: 600;
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}

.btn {
  padding: 8px 14px;
  border: none;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.25);
  color: inherit;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:hover,
.btn:focus-visible {
  background: rgba(255, 255, 255, 0.35);
}

.btn:active {
  transform: scale(0.97);
}

.btn-ghost {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.1);
}

.btn-large {
  padding: 12px 24px;
  font-size: 1rem;
}

/* ===== Board ===== */
.game-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 200px;
  padding: 8px 0;
}

.board {
  display: grid;
  gap: var(--tile-gap);
  padding: 10px;
  background: var(--board-bg);
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  width: min(92vw, 720px);
  height: min(82vh, 720px);
  max-width: 100%;
  max-height: min(82vh, 720px);
  aspect-ratio: 1;
}

/* Board size is set inline via grid-template-columns/rows and --size */
.board.size-3 {
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
}

.board.size-4 {
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(4, 1fr);
}

.board.size-5 {
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
}

.tile {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--tile-bg);
  background-repeat: no-repeat;
  border: 2px solid var(--tile-border);
  border-radius: var(--tile-radius);
  color: var(--tile-text);
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.1s, background 0.15s;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}

.tile:hover {
  background-color: #1f3460;
  transform: scale(1.02);
}

.tile.tile-image:hover {
  background-color: transparent;
}

.tile:active {
  transform: scale(0.98);
}

.tile.empty {
  background: var(--empty-bg);
  border-color: transparent;
  cursor: default;
  box-shadow: none;
}

.tile.empty:hover {
  background: var(--empty-bg);
  transform: none;
}

/* Image tiles: no number, image slice only */
.tile.tile-image .tile-num {
  display: none;
}

/* ===== Win overlay ===== */
.win-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 20px;
}

.win-overlay.hidden {
  display: none;
}

.win-box {
  background: linear-gradient(145deg, #1a1a2e 0%, #16213e 100%);
  border: 2px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 32px;
  text-align: center;
  max-width: 360px;
}

.win-box h2 {
  margin: 0 0 8px;
  font-size: 1.75rem;
  color: var(--accent);
}

.win-box p {
  margin: 0 0 24px;
  opacity: 0.9;
}

.win-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* ===== Mobile: keep board large, use most of viewport ===== */
@media (max-width: 600px) {
  .header {
    max-width: 100%;
  }

  .header-actions {
    width: 100%;
    margin-left: 0;
    justify-content: flex-end;
  }

  .board {
    width: min(96vw, 420px);
    height: min(78vh, 96vw, 420px);
    max-height: min(78vh, 96vw, 420px);
    padding: 6px;
  }

  .tile.tile-image .tile-num {
    display: none;
  }
}