/* ===== RESET & BASE ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* Terminal (default) */
  --bg: #0a0a0a;
  --bg-elevated: #111111;
  --bg-input: #1a1a1a;
  --text: #33ff33;
  --text-dim: #1a8f1a;
  --accent: #33ff33;
  --accent-hover: #66ff66;
  --border: #1a8f1a;
  --danger: #ff3333;
  --success: #33ff33;
  --font-mono: "SF Mono", "Fira Code", "Consolas", "Courier New", monospace;
  --radius: 6px;
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

/* Neon theme */
[data-theme="neon"] {
  --bg: #0d0221;
  --bg-elevated: #1a0a2e;
  --bg-input: #16082b;
  --text: #00f5d4;
  --text-dim: #7b2cbf;
  --accent: #ff00aa;
  --accent-hover: #ff33bb;
  --border: #7b2cbf;
  --danger: #ff2a6d;
  --success: #00f5d4;
}

/* Midnight theme */
[data-theme="midnight"] {
  --bg: #0f172a;
  --bg-elevated: #1e293b;
  --bg-input: #1e293b;
  --text: #e2e8f0;
  --text-dim: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #7dd3fc;
  --border: #334155;
  --danger: #f87171;
  --success: #4ade80;
}

/* Amber theme */
[data-theme="amber"] {
  --bg: #1a120b;
  --bg-elevated: #2a1f14;
  --bg-input: #2a1f14;
  --text: #ffb000;
  --text-dim: #b37800;
  --accent: #ffb000;
  --accent-hover: #ffc933;
  --border: #b37800;
  --danger: #ff5e5e;
  --success: #ffb000;
}

html, body {
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

#app {
  height: 100%;
  max-width: 480px;
  margin: 0 auto;
  position: relative;
  display: flex;
  flex-direction: column;
}

/* ===== SCREENS ===== */
.screen {
  display: none;
  flex-direction: column;
  height: 100%;
  padding: 1.25rem;
  padding-bottom: calc(1.25rem + var(--safe-bottom));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.screen.active {
  display: flex;
}

/* ===== TITLE ===== */
#screen-title {
  justify-content: center;
  align-items: center;
  text-align: center;
  gap: 1.5rem;
}

.title-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  width: 100%;
}

.logo {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-shadow: 0 0 20px var(--accent);
  animation: pulse 2.5s ease-in-out infinite;
}

.logo.small {
  font-size: 1.4rem;
  animation: none;
}

.tagline {
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.version {
  position: absolute;
  bottom: 1.5rem;
  font-size: 0.75rem;
  color: var(--text-dim);
  opacity: 0.6;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.1s;
  width: 100%;
  max-width: 280px;
  touch-action: manipulation;
}

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

.btn.primary {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

.btn.primary:hover,
.btn.primary:focus {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

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

.btn.secondary:hover,
.btn.secondary:focus {
  background: var(--bg-elevated);
  border-color: var(--accent);
}

.btn.full {
  max-width: none;
  width: 100%;
}

.btn-back, .btn-icon {
  width: 44px;
  height: 44px;
  min-height: 44px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.btn-icon {
  font-weight: 700;
}

/* ===== THEMES ===== */
.screen-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.screen-header h1 {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.theme-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.theme-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  padding: 1rem;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: inherit;
  font-size: 0.85rem;
  cursor: pointer;
  transition: border-color 0.15s;
}

.theme-card:hover,
.theme-card.active {
  border-color: var(--accent);
}

.theme-preview {
  width: 100%;
  height: 56px;
  border-radius: 4px;
  border: 1px solid rgba(255,255,255,0.1);
}

.terminal-preview { background: linear-gradient(135deg, #0a0a0a, #1a8f1a); }
.neon-preview { background: linear-gradient(135deg, #0d0221, #ff00aa, #00f5d4); }
.midnight-preview { background: linear-gradient(135deg, #0f172a, #38bdf8); }
.amber-preview { background: linear-gradient(135deg, #1a120b, #ffb000); }

/* ===== STORY ===== */
#screen-story {
  justify-content: center;
  align-items: center;
}

.story-box {
  width: 100%;
  max-width: 360px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.story-label {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  color: var(--text-dim);
  text-transform: uppercase;
}

#story-text {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  min-height: 4.5em;
}

/* ===== LEVEL ===== */
.level-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
  gap: 0.75rem;
}

.level-info {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

#level-number {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  text-transform: uppercase;
}

#level-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.level-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  overflow-y: auto;
  min-height: 0;
}

.brief {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.55;
  padding: 0.75rem;
  background: var(--bg-elevated);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  white-space: pre-line;
}

.content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.feedback {
  min-height: 1.5em;
  font-size: 0.9rem;
  text-align: center;
}

.feedback.error {
  color: var(--danger);
}

.feedback.success {
  color: var(--success);
}

.level-footer {
  padding-top: 1rem;
  flex-shrink: 0;
}

/* ===== COMMON LEVEL UI ===== */
.cipher-text {
  font-size: 1.15rem;
  letter-spacing: 0.08em;
  word-break: break-all;
  padding: 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  line-height: 1.7;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.input-group label {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

input[type="text"],
input[type="number"] {
  width: 100%;
  min-height: 48px;
  padding: 0.75rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: inherit;
  font-size: 1.1rem;
  letter-spacing: 0.05em;
  outline: none;
  -webkit-appearance: none;
}

input[type="text"]:focus,
input[type="number"]:focus {
  border-color: var(--accent);
}

input::placeholder {
  color: var(--text-dim);
  opacity: 0.6;
}

/* Caesar tool */
.tool-box {
  padding: 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.tool-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.slider-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.slider-row input[type="range"] {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 3px;
  outline: none;
}

.slider-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
}

.shift-value {
  min-width: 2.2rem;
  text-align: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.preview-output {
  font-size: 1rem;
  letter-spacing: 0.06em;
  word-break: break-all;
  min-height: 1.5em;
  color: var(--accent);
}

/* Mastermind */
.mm-board {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.mm-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  justify-content: center;
}

.mm-peg {
  width: 40px;
  height: 40px;
  min-width: 40px;
  min-height: 40px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--bg-input);
  color: var(--text-dim);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  padding: 0;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.mm-peg.filled {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg);
}

.mm-feedback {
  display: flex;
  gap: 3px;
  margin-left: 0.5rem;
  min-width: 48px;
}

.mm-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
}

.mm-dot.black {
  background: var(--text);
}

.mm-dot.white {
  background: transparent;
  border: 1.5px solid var(--text);
}

.mm-palette {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.5rem;
}

.mm-color {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bg);
  transition: transform 0.1s, border-color 0.15s;
}

.mm-color:active {
  transform: scale(0.92);
}

.mm-color.selected {
  border-color: var(--text);
  box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--accent);
}

.mm-attempts {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
}

/* Word / letter tiles */
.letter-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  justify-content: center;
  padding: 0.5rem 0;
  touch-action: manipulation;
}

.letter-tile {
  width: 48px;
  height: 52px;
  min-width: 48px;
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 6px;
  font-size: 1.25rem;
  font-weight: 700;
  font-family: inherit;
  color: var(--text);
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition: background 0.1s, border-color 0.1s, opacity 0.1s, transform 0.05s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  padding: 0;
  margin: 0;
  flex-shrink: 0;
}

.letter-tile:active {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
  transform: scale(0.94);
}

.letter-tile.used {
  opacity: 0.28;
  pointer-events: none;
  transform: none;
}

.letter-tile.selected {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg);
}

.letter-tile.display-only {
  cursor: default;
  pointer-events: none;
  opacity: 1;
}

.answer-slots {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  justify-content: center;
  min-height: 48px;
}

.slot {
  width: 36px;
  height: 44px;
  border-bottom: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
}

.slot.filled {
  border-color: var(--accent);
  color: var(--accent);
}

/* Teaching box */
.teach-box {
  padding: 0.85rem;
  background: var(--bg-elevated);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.5;
}

.teach-box strong {
  color: var(--text);
}

/* ===== COMPLETE / VICTORY ===== */
#screen-complete,
#screen-victory {
  justify-content: center;
  align-items: center;
  text-align: center;
}

.complete-box,
.victory-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  width: 100%;
  max-width: 320px;
}

.complete-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  border: 2px solid var(--success);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--success);
  margin-bottom: 0.5rem;
}

/* ===== MODAL ===== */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.75);
  z-index: 100;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal.open {
  display: flex;
}

.modal-content {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-width: 340px;
  width: 100%;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.modal-content h3 {
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
}

.modal-content p {
  font-size: 0.95rem;
  line-height: 1.5;
}

/* ===== UTILS ===== */
.hidden {
  display: none !important;
}

/* Mobile safety */
@media (max-width: 360px) {
  .logo { font-size: 1.8rem; }
  .mm-peg { width: 32px; height: 32px; }
  /* Keep letter tiles large enough for reliable taps */
  .letter-tile { width: 44px; height: 48px; min-width: 44px; min-height: 48px; font-size: 1.15rem; }
}