:root {
  --bg: #0d1117;
  --bg-panel: #161b22;
  --bg-input: #0d1117;
  --border: #30363d;
  --text: #e6edf3;
  --text-dim: #8b949e;
  --accent: #58a6ff;
  --accent-dim: #1f6feb;
  --ok: #3fb950;
  --error: #f85149;
  --prompt: #d2a8ff;
  --output: #79c0ff;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
}

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

body {
  font-family: var(--font-mono);
  font-size: 14px;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  overflow: hidden;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 16px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
}

header h1 {
  font-size: 16px;
  font-weight: 600;
  color: var(--accent);
}

header .subtitle {
  font-size: 11px;
  color: var(--text-dim);
  font-weight: 400;
  margin-left: 8px;
}

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

.header-actions button, .init-actions button, #btn-toggle-words {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 4px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  transition: all 0.15s;
}

.header-actions button:hover, .init-actions button:hover, #btn-toggle-words:hover {
  color: var(--text);
  border-color: var(--accent-dim);
  background: var(--bg-panel);
}

/* Main layout */
.main-layout {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Word panel */
#word-panel {
  width: 260px;
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: width 0.2s;
  overflow: hidden;
}

#word-panel.collapsed {
  width: 42px;
}

#word-panel.collapsed .word-content {
  display: none;
}

#btn-toggle-words {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  padding: 12px 6px;
  border: none;
  border-radius: 0;
  background: transparent;
  width: 100%;
}

#word-panel:not(.collapsed) #btn-toggle-words {
  writing-mode: horizontal-tb;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.word-content {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

#word-filter {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 8px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  margin-bottom: 8px;
}

.word-category h4 {
  color: var(--accent);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin: 12px 0 4px;
  cursor: pointer;
  user-select: none;
}

.word-category h4::before {
  content: '\25BE ';
  font-size: 10px;
}

.word-category.collapsed h4::before {
  content: '\25B8 ';
}

.word-category.collapsed .word-list {
  display: none;
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
}

.word-chip {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 11px;
  cursor: pointer;
  transition: all 0.1s;
}

.word-chip:hover {
  color: var(--text);
  border-color: var(--accent-dim);
  background: rgba(88, 166, 255, 0.1);
}

.word-chip.user-word {
  border-color: var(--ok);
  color: var(--ok);
}

/* Terminal */
#terminal-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#output {
  flex: 1;
  overflow-y: auto;
  padding: 12px 16px;
  white-space: pre-wrap;
  word-break: break-all;
  line-height: 1.6;
  font-size: 14px;
}

.line { margin: 0; }
.line-input { color: var(--text); }
.line-output { color: var(--output); }
.line-ok { color: var(--ok); }
.line-error { color: var(--error); }

#input-line {
  display: flex;
  align-items: center;
  padding: 8px 16px;
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
}

#prompt {
  color: var(--prompt);
  font-weight: 600;
  margin-right: 4px;
  user-select: none;
}

#input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 14px;
  outline: none;
  caret-color: var(--accent);
}

#stack-bar {
  padding: 4px 16px;
  font-size: 11px;
  color: var(--text-dim);
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
  min-height: 24px;
}

/* Init panel */
#init-panel {
  border-top: 1px solid var(--border);
  background: var(--bg-panel);
}

.init-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 16px;
  cursor: pointer;
  font-size: 12px;
  color: var(--text-dim);
}

.init-body {
  overflow: hidden;
  transition: max-height 0.2s;
  max-height: 200px;
}

.init-body.collapsed {
  max-height: 0;
}

#init-code {
  width: 100%;
  height: 120px;
  background: var(--bg);
  border: none;
  border-top: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 8px 16px;
  resize: vertical;
  outline: none;
}

/* Help overlay */
#help-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

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

.help-content {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  max-width: 640px;
  max-height: 80vh;
  overflow-y: auto;
  position: relative;
}

.help-content h2 {
  color: var(--accent);
  font-size: 18px;
  margin-bottom: 16px;
}

.help-content h3 {
  color: var(--text-dim);
  font-size: 12px;
  text-transform: uppercase;
  margin: 12px 0 4px;
}

.help-content code {
  display: block;
  color: var(--text);
  font-size: 12px;
  line-height: 1.8;
  word-spacing: 8px;
}

.help-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.help-footer {
  margin-top: 16px;
  font-size: 12px;
  color: var(--text-dim);
}

.close-help {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 24px;
  cursor: pointer;
}

.close-help:hover { color: var(--text); }

/* Loading state */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-dim);
  font-size: 16px;
}

@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

.loading span {
  animation: pulse 1.5s ease-in-out infinite;
}

/* Responsive */
@media (max-width: 768px) {
  #word-panel { display: none; }
  .help-columns { grid-template-columns: 1fr; }
}