:root {
  --bg: #fef6e4;
  --ink: #2b2830;
  --muted: #8a8494;
  --good: #4caf50;
  --bad: #ef5350;
  --panel: #ffffff;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: "Comic Sans MS", "Segoe UI Rounded", "Baloo 2", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  overflow: hidden;
  -webkit-user-select: none;
  user-select: none;
}

.app {
  height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 16px;
  gap: 16px;
}

/* --- top bar --- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.stars {
  display: flex;
  gap: 4px;
  font-size: clamp(18px, 3vw, 28px);
  min-width: 120px;
}

.stars .star {
  opacity: 0.25;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.stars .star.filled {
  opacity: 1;
  transform: scale(1.1);
}

.topbar-actions {
  display: flex;
  gap: 8px;
}

.icon-btn {
  border: none;
  background: var(--panel);
  border-radius: 50%;
  width: clamp(36px, 6vw, 48px);
  height: clamp(36px, 6vw, 48px);
  font-size: clamp(16px, 2.5vw, 20px);
  box-shadow: 0 2px 0 rgba(0,0,0,0.08);
  cursor: pointer;
}

.icon-btn:active {
  transform: translateY(2px);
  box-shadow: none;
}

/* --- board --- */

.board {
  flex: 1;
  display: grid;
  gap: 16px;
  place-items: stretch;
}

.letter-btn {
  border: none;
  border-radius: 28px;
  font-size: clamp(60px, 18vw, 200px);
  font-weight: 700;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 6px 0 rgba(0,0,0,0.15);
  transition: transform 0.08s ease;
  line-height: 1;
  padding: 0;
}

.letter-btn:active {
  transform: translateY(4px);
  box-shadow: 0 2px 0 rgba(0,0,0,0.15);
}

.letter-btn.correct {
  animation: pop 0.5s ease;
}

.letter-btn.wrong {
  animation: shake 0.4s ease;
}

.letter-btn.combo {
  font-size: clamp(36px, 10vw, 110px);
}

@keyframes pop {
  0% { transform: scale(1); }
  40% { transform: scale(1.12); }
  100% { transform: scale(1); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-10px); }
  40% { transform: translateX(10px); }
  60% { transform: translateX(-8px); }
  80% { transform: translateX(8px); }
}

/* --- confetti --- */

.confetti-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.confetti-piece {
  position: absolute;
  top: -20px;
  font-size: 28px;
  animation: fall linear forwards;
}

@keyframes fall {
  to {
    transform: translateY(110vh) rotate(360deg);
    opacity: 0.9;
  }
}

/* --- responsive grid layouts --- */

@media (min-width: 640px) {
  .board[data-count="2"] { grid-template-columns: 1fr 1fr; }
  .board[data-count="3"] { grid-template-columns: 1fr 1fr 1fr; }
  .board[data-count="4"] { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
}

@media (max-width: 639px) {
  .board { grid-template-columns: 1fr; }
}

/* --- settings --- */

.settings-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 30;
}

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

.celebration-video-wrap {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 15;
}

.celebration-video-wrap.hidden {
  display: none;
}

.celebration-video {
  max-width: 92vw;
  max-height: 92vh;
  border-radius: 20px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
}

.word-popup {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  z-index: 20;
}

.word-popup.hidden {
  display: none;
}

.word-popup-content {
  background: var(--panel);
  border-radius: 28px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 90vw;
  max-height: 90vh;
}

.word-popup-image {
  max-width: 60vw;
  max-height: 45vh;
  object-fit: contain;
  border-radius: 16px;
}

.word-popup-text {
  font-size: clamp(32px, 8vw, 90px);
  font-weight: 700;
  color: var(--ink);
  text-align: center;
  line-height: 1;
}

.word-target-letter {
  color: var(--bad);
  font-size: 1.3em;
}

.settings-panel {
  background: var(--panel);
  border-radius: 20px;
  padding: 20px;
  max-width: 480px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 10px 30px rgba(0,0,0,0.25);
}

.settings-panel h2 {
  margin: 0 0 4px;
}

.settings-sub {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 14px;
}

.settings-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.preset-btn {
  border: none;
  background: #eee;
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 14px;
  cursor: pointer;
}

.preset-btn:active {
  transform: translateY(1px);
}

.settings-group-title {
  margin: 18px 0 8px;
  font-size: 15px;
  color: var(--muted);
}

.settings-group-title:first-of-type {
  margin-top: 4px;
}

.letters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(44px, 1fr));
  gap: 8px;
}

.letter-chip {
  border: 2px solid #ddd;
  background: white;
  border-radius: 10px;
  padding: 8px 0;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  color: var(--ink);
}

.letter-chip.combo {
  font-size: 14px;
}

.letter-chip.selected {
  border-color: var(--good);
  background: #e8f7e9;
}

.settings-warning {
  color: var(--bad);
  font-size: 14px;
  margin: 12px 0 0;
}

.settings-warning.hidden {
  display: none;
}

.validate-btn {
  margin-top: 16px;
  width: 100%;
  border: none;
  background: var(--good);
  color: white;
  font-size: 16px;
  font-weight: 700;
  padding: 12px;
  border-radius: 12px;
  cursor: pointer;
}

.validate-btn:disabled {
  background: #bbb;
  cursor: not-allowed;
}