* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-tile: #efefe6;
  --color-tile-selected: #5a594e;
  --color-tile-text: #1a1a1a;
  --color-tile-selected-text: #ffffff;
  --color-level-0: #f9df6d;
  --color-level-1: #a0c35a;
  --color-level-2: #b0c4ef;
  --color-level-3: #ba81c5;
  --color-btn-primary: #1a1a1a;
  --color-btn-primary-text: #ffffff;
  --color-btn-secondary: #ffffff;
  --color-btn-secondary-text: #1a1a1a;
  --color-mistake: #5a594e;
  --grid-gap: 8px;
  --radius: 8px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  display: flex;
  justify-content: center;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
}

#app {
  width: 100%;
  max-width: 500px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  height: 100dvh;
  position: relative;
}

header {
  text-align: center;
  padding: 8px 0 12px;
}

header h1 {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.subtitle {
  font-size: 14px;
  color: #6b6b6b;
  margin-top: 2px;
}

/* Solved area */
#solved-area {
  display: flex;
  flex-direction: column;
  gap: var(--grid-gap);
}

.solved-group {
  border-radius: var(--radius);
  padding: 16px 12px;
  text-align: center;
  animation: solveReveal 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.solved-group .solved-category {
  font-weight: 800;
  font-size: 16px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.solved-group .solved-words {
  font-size: 14px;
  margin-top: 4px;
  font-weight: 500;
}

.solved-group.level-0 { background: var(--color-level-0); }
.solved-group.level-1 { background: var(--color-level-1); }
.solved-group.level-2 { background: var(--color-level-2); }
.solved-group.level-3 { background: var(--color-level-3); }

@keyframes solveReveal {
  from {
    transform: scaleY(0);
    opacity: 0;
  }
  to {
    transform: scaleY(1);
    opacity: 1;
  }
}

/* Grid */
#grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--grid-gap);
  margin-top: var(--grid-gap);
  flex: 1;
  align-content: start;
}

.tile {
  background: var(--color-tile);
  border: none;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  color: var(--color-tile-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 8px 4px;
  min-height: 60px;
  user-select: none;
  transition: transform 0.1s, background 0.15s, color 0.15s;
  word-break: break-word;
  line-height: 1.15;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.tile:active {
  transform: scale(0.95);
}

.tile.selected {
  background: var(--color-tile-selected);
  color: var(--color-tile-selected-text);
}

.tile.shake {
  animation: shake 0.5s ease-in-out;
}

.tile.bounce {
  animation: bounce 0.5s ease-in-out;
}

.tile.pop-out {
  animation: popOut 0.3s ease-in forwards;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-6px); }
  80% { transform: translateX(6px); }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  30% { transform: translateY(-12px); }
  50% { transform: translateY(0); }
  70% { transform: translateY(-6px); }
}

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

/* Mistakes */
#mistakes {
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  padding: 12px 0 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.dot {
  width: 14px;
  height: 14px;
  background: var(--color-mistake);
  border-radius: 50%;
  display: inline-block;
  margin: 0 2px;
  transition: opacity 0.3s, transform 0.3s;
}

.dot.used {
  opacity: 0;
  transform: scale(0);
}

/* Action buttons */
#actions {
  display: flex;
  gap: 8px;
  padding: 10px 0;
  justify-content: center;
}

.btn {
  border: none;
  border-radius: 24px;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
}

.btn:active {
  transform: scale(0.96);
}

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

.btn:disabled:active {
  transform: none;
}

.btn-primary {
  background: var(--color-btn-primary);
  color: var(--color-btn-primary-text);
}

.btn-secondary {
  background: var(--color-btn-secondary);
  color: var(--color-btn-secondary-text);
  border: 1.5px solid #1a1a1a;
}

/* Puzzle nav */
#puzzle-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 4px 0 8px;
  font-size: 14px;
  font-weight: 600;
  color: #6b6b6b;
}

.btn-nav {
  background: none;
  border: 1.5px solid #ccc;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
  transition: background 0.15s;
}

.btn-nav:active {
  background: #f0f0f0;
}

/* Overlay */
#overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 24px;
  animation: fadeIn 0.3s ease;
}

#overlay.hidden {
  display: none;
}

#overlay-content {
  background: white;
  border-radius: 16px;
  padding: 32px 24px;
  max-width: 380px;
  width: 100%;
  text-align: center;
  animation: slideUp 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

#overlay-title {
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 20px;
}

#overlay-results {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 16px;
}

.result-row {
  display: flex;
  gap: 4px;
  justify-content: center;
}

.result-dot {
  width: 36px;
  height: 36px;
  border-radius: 6px;
}

.result-dot.level-0 { background: var(--color-level-0); }
.result-dot.level-1 { background: var(--color-level-1); }
.result-dot.level-2 { background: var(--color-level-2); }
.result-dot.level-3 { background: var(--color-level-3); }

#overlay-answers {
  text-align: left;
  margin-bottom: 20px;
}

.answer-group {
  margin-bottom: 8px;
}

.answer-category {
  font-weight: 800;
  font-size: 14px;
  text-transform: uppercase;
}

.answer-words {
  font-size: 13px;
  color: #555;
}

#overlay-content .btn {
  width: 100%;
  margin-top: 8px;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(40px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* Toast */
#toast {
  position: fixed;
  top: 60px;
  left: 50%;
  transform: translateX(-50%);
  background: #1a1a1a;
  color: white;
  padding: 12px 24px;
  border-radius: 24px;
  font-size: 15px;
  font-weight: 700;
  z-index: 200;
  animation: toastIn 0.3s ease;
  white-space: nowrap;
}

#toast.hidden {
  display: none;
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(-50%) translateY(-10px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* Small phones */
@media (max-height: 667px) {
  header { padding: 4px 0 8px; }
  header h1 { font-size: 24px; }
  .tile { min-height: 52px; font-size: 13px; }
  .btn { padding: 10px 18px; font-size: 14px; }
  #mistakes { padding: 8px 0 2px; }
}