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

:root {
  --bg: #0d1712;
  --text: #f0e7cb;
  --text-muted: #9ca88c;
  --text-dim: #56624f;
  --panel-bg: rgba(18, 36, 24, 0.54);
  --panel-border: rgba(166, 145, 94, 0.24);
  --input-bg: rgba(13, 28, 18, 0.86);
  --input-border: rgba(104, 93, 58, 0.55);
  --input-focus: #dfbf67;
  --accent: #dfbf67;
  --accent2: #78a778;
  --success: #d6b558;
  --danger: #d25b43;
  --title-gradient: linear-gradient(135deg, #f6e7aa, #cda251, #7fb182);
  --btn-primary: linear-gradient(135deg, #d7bc6f, #6e9c73);
  --btn-secondary: linear-gradient(135deg, #c7603f, #a88139);
  --overlay-bg: rgba(8, 18, 11, 0.88);
  --lesson-bg: rgba(223, 191, 103, 0.1);
  --lesson-border: rgba(223, 191, 103, 0.2);
  --locked-opacity: 0.3;
  --display-font: 'Cinzel', serif;
}

body {
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  background:
    radial-gradient(circle at top, rgba(100, 147, 104, 0.18), transparent 34%),
    linear-gradient(180deg, #15251b 0%, #09110c 100%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
  transition: background 0.4s;
}

/* Header */
.header {
  width: 100%;
  max-width: 1100px;
  padding: 16px 20px 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.title {
  font-family: var(--display-font);
  font-size: 25px;
  font-weight: 800;
  background: var(--title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 2px;
  text-shadow: 0 0 24px rgba(223, 191, 103, 0.18);
}

.stats {
  display: flex;
  gap: 16px;
  font-size: 14px;
}

.stats span {
  color: var(--text-muted);
}

.stats .value {
  color: var(--text);
  font-weight: 600;
}

.lives .value {
  color: var(--danger);
  font-size: 16px;
}

.menu-btn {
  padding: 6px 14px;
  font-size: 13px;
  font-family: var(--display-font);
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--text-muted);
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 4px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}

.menu-btn:hover {
  color: var(--text);
  border-color: var(--accent);
  background: rgba(223, 191, 103, 0.1);
}

.menu-btn.hidden {
  display: none;
}

/* Theme selector */
.theme-selector {
  width: 100%;
  max-width: 1100px;
  padding: 4px 20px 4px;
  display: flex;
  justify-content: flex-end;
  gap: 6px;
}

.theme-btn {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  color: var(--text-muted);
  font-family: monospace;
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
}

.theme-btn:hover {
  color: var(--text);
  border-color: var(--accent);
}

.theme-btn.active {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
  font-weight: 700;
}

/* Info bar */
.info-bar {
  width: 100%;
  max-width: 1100px;
  padding: 4px 20px 8px;
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}

.hint-text {
  color: var(--accent2);
  font-style: italic;
}

/* Lesson banner */
.lesson-banner {
  width: 100%;
  max-width: 1100px;
  padding: 10px 20px;
  background: var(--lesson-bg);
  border: 1px solid var(--lesson-border);
  border-radius: 6px;
  margin: 0 0 8px;
  transition: background 0.4s, border-color 0.4s;
}

.lesson-banner.hidden {
  display: none;
}

.lesson-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
}

.lesson-label {
  font-size: 10px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
}

.lesson-method {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
}

.lesson-desc {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.lesson-example {
  font-size: 12px;
  color: var(--text-muted);
}

.lesson-example code {
  color: var(--success);
}

.lesson-progress {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

.progress-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--input-border);
  border: 1px solid var(--text-dim);
  transition: background 0.3s, border-color 0.3s;
}

.progress-dot.done {
  background: var(--success);
  border-color: var(--success);
}

/* Game row - method bank + canvas */
.game-row {
  display: flex;
  gap: 16px;
  width: 100%;
  max-width: 1100px;
  align-items: flex-start;
}

/* Method bank */
.method-bank {
  width: 170px;
  flex-shrink: 0;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 12px;
  backdrop-filter: blur(6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.22);
  transition: background 0.4s, border-color 0.4s;
}

.method-bank.hidden {
  display: none;
}

.bank-title {
  font-family: var(--display-font);
  font-size: 10px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 2px;
  margin-bottom: 10px;
  text-align: center;
}

.method-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 6px;
  border-radius: 4px;
  margin-bottom: 4px;
  transition: background 0.3s, opacity 0.3s;
}

.method-item.locked {
  opacity: var(--locked-opacity);
}

.method-item.locked .method-icon::after {
  content: '';
  display: block;
  width: 14px;
  height: 14px;
  border: 2px solid var(--text-dim);
  border-radius: 3px;
  background: transparent;
}

.method-item.unlocked {
  opacity: 1;
}

.method-item.unlocked .method-icon::after {
  content: '';
  display: block;
  width: 14px;
  height: 14px;
  border: 2px solid var(--success);
  border-radius: 3px;
  background: var(--success);
}

.method-item.just-unlocked {
  background: rgba(46, 204, 113, 0.2);
  animation: unlockPulse 1.5s ease-out;
}

@keyframes unlockPulse {
  0% { background: rgba(46, 204, 113, 0.5); transform: scale(1.05); }
  100% { background: rgba(46, 204, 113, 0); transform: scale(1); }
}

.method-info {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.method-info code {
  font-size: 12px;
  color: var(--accent);
}

.method-item.locked .method-info code {
  color: var(--text-dim);
}

.method-desc {
  font-size: 10px;
  color: var(--text-muted);
}

/* Game area */
#gameArea {
  width: 100%;
  position: relative;
  flex: 1;
}

canvas {
  display: block;
  width: 100%;
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.35);
  transition: border-color 0.4s;
}

/* Input area */
.input-area {
  width: 100%;
  max-width: 1100px;
  padding: 12px 20px;
}

.shape-display {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
  font-family: monospace;
}

.cmd-wrapper {
  display: flex;
  align-items: center;
  background: var(--input-bg);
  border: 2px solid var(--input-border);
  border-radius: 12px;
  padding: 4px 12px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03);
  transition: border-color 0.2s, background 0.4s;
}

.cmd-wrapper:focus-within {
  border-color: var(--input-focus);
}

.cmd-prefix {
  color: var(--text-muted);
  font-size: 14px;
  margin-right: 4px;
  user-select: none;
}

#cmdInput {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text);
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 15px;
  padding: 8px 0;
  caret-color: var(--input-focus);
}

#cmdInput::placeholder {
  color: var(--text-dim);
}

#cmdInput:disabled {
  opacity: 0.4;
}

.submit-hint {
  color: var(--text-dim);
  font-size: 11px;
  padding: 2px 6px;
  border: 1px solid var(--input-border);
  border-radius: 3px;
}

.drop-btn {
  background: var(--btn-secondary);
  border: none;
  color: #fff;
  font-family: monospace;
  font-size: 12px;
  font-weight: 700;
  padding: 6px 14px;
  margin-left: 8px;
  border-radius: 4px;
  cursor: pointer;
  letter-spacing: 1px;
  transition: transform 0.1s, box-shadow 0.1s;
}

.drop-btn:hover:not(:disabled) {
  transform: scale(1.05);
  box-shadow: 0 2px 10px rgba(231, 76, 60, 0.4);
}

.drop-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

.hint-btn {
  background: transparent;
  border: 1px solid var(--input-border);
  color: var(--text-muted);
  font-family: monospace;
  font-size: 12px;
  padding: 4px 12px;
  margin-left: 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
}

.hint-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.hint-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

#errorMsg {
  font-size: 13px;
  color: var(--danger);
  margin-top: 6px;
  min-height: 20px;
  opacity: 0;
  transition: opacity 0.2s;
}

#errorMsg.visible {
  opacity: 1;
}

/* Overlay screens */
.overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--overlay-bg);
  z-index: 10;
  border-radius: 18px;
  transition: background 0.4s;
}

.overlay.hidden {
  display: none;
}

.overlay h2 {
  font-family: var(--display-font);
  letter-spacing: 2px;
  font-size: 30px;
  margin-bottom: 12px;
  color: var(--text);
}

.overlay p {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 20px;
  max-width: 300px;
  text-align: center;
  line-height: 1.6;
}

.start-buttons {
  display: flex;
  gap: 12px;
}

.overlay button, .start-buttons button {
  border: none;
  color: #fff;
  font-family: monospace;
  font-size: 16px;
  font-weight: 700;
  padding: 12px 32px;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}

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

.btn-tutorial:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 20px rgba(52, 152, 219, 0.4);
}

.difficulty-section {
  margin-top: 16px;
  text-align: center;
}

.diff-label {
  font-size: 10px;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.diff-buttons {
  display: flex;
  gap: 8px;
}

.diff-btn {
  padding: 8px 16px !important;
  font-size: 13px !important;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}

.diff-play {
  background: linear-gradient(135deg, #ffd700, #b8860b) !important;
  color: #1a1208 !important;
}

.diff-easy {
  background: linear-gradient(135deg, #2ecc71, #27ae60) !important;
}

.diff-medium {
  background: linear-gradient(135deg, #f39c12, #e67e22) !important;
}

.diff-hard {
  background: linear-gradient(135deg, #e74c3c, #c0392b) !important;
}

.diff-expert {
  background: linear-gradient(135deg, #9b59b6, #8e44ad) !important;
}

.diff-btn:hover {
  transform: scale(1.08) !important;
  box-shadow: 0 3px 15px rgba(0, 0, 0, 0.3);
}

.overlay button:hover {
  transform: scale(1.05);
}

.game-over-title {
  color: var(--danger) !important;
}

.victory-title {
  background: linear-gradient(135deg, #ffd700, #f5a623);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tutorial-complete-title {
  background: var(--btn-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.final-score {
  font-size: 48px;
  font-weight: 800;
  color: var(--accent2);
  margin: 8px 0 16px;
}

/* Lesson select screen */
.lesson-select-title {
  background: var(--title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  font-size: 22px;
}

.lesson-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 100%;
  max-width: 380px;
  max-height: 400px;
  overflow-y: auto;
  padding: 0 16px;
}

.lesson-select-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s;
  text-align: left;
  font-family: monospace;
  color: var(--text);
}

.lesson-select-item:hover {
  border-color: var(--accent);
  background: var(--lesson-bg);
  transform: translateX(4px);
}

.lesson-select-item.completed {
  border-color: var(--success);
}

.lesson-select-item.completed .lesson-check {
  background: var(--success);
  color: var(--bg);
  border-color: var(--success);
}

.lesson-check {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 2px solid var(--text-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  color: var(--text-dim);
  flex-shrink: 0;
}

.lesson-select-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.lesson-select-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
}

.lesson-select-desc {
  font-size: 11px;
  color: var(--text-muted);
}

.btn-back {
  margin-top: 16px;
  background: transparent !important;
  border: 1px solid var(--input-border) !important;
  color: var(--text-muted) !important;
  font-size: 13px !important;
  padding: 8px 20px !important;
}

.btn-back:hover {
  border-color: var(--accent) !important;
  color: var(--text) !important;
}

/* Responsive */
@media (max-width: 600px) {
  .game-row {
    flex-direction: column;
  }

  .method-bank {
    width: 100%;
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    padding: 8px;
  }

  .bank-title {
    width: 100%;
  }

  .method-item {
    flex: 0 0 auto;
    margin-bottom: 0;
    padding: 4px 8px;
  }

  .method-desc {
    display: none;
  }

  .header {
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
  }

  .title {
    font-size: 18px;
  }

  #cmdInput {
    font-size: 14px;
  }

  .theme-selector {
    justify-content: flex-start;
  }
}