:root {
  --bg: #0a0a0f;
  --bg-card: #12121a;
  --bg-hover: #1a1a2e;
  --border: #2a2a3e;
  --text: #e0e0e8;
  --text-dim: #888898;
  --accent: #6c5ce7;
  --accent-glow: rgba(108, 92, 231, 0.3);
  --green: #00b894;
  --red: #e17055;
  --yellow: #fdcb6e;
  --blue: #74b9ff;
  --radius: 12px;
  --transition: 0.2s ease;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- Layout --- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* --- Header --- */
header {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  position: sticky;
  top: 0;
  background: rgba(10, 10, 15, 0.9);
  backdrop-filter: blur(20px);
  z-index: 100;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo span { color: var(--accent); }

nav { display: flex; gap: 8px; }

nav button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.875rem;
  transition: var(--transition);
}

nav button:hover, nav button.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

/* --- Hero --- */
.hero {
  text-align: center;
  padding: 80px 0 40px;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #6c5ce7, #74b9ff, #00b894);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-dim);
  max-width: 700px;
  margin: 0 auto 32px;
}

.hero .stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}

.stat {
  text-align: center;
}

.stat .number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent);
}

.stat .label {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* --- Sections --- */
.section { display: none; padding: 40px 0; }
.section.active { display: block; }

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 24px;
}

/* --- Game Grid --- */
.game-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

.game-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.game-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.game-card .emoji {
  font-size: 2.5rem;
  margin-bottom: 12px;
}

.game-card h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.game-card p {
  color: var(--text-dim);
  font-size: 0.875rem;
  margin-bottom: 16px;
}

.game-card .benchmark {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  color: var(--text-dim);
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.game-card .benchmark .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
}

/* --- Play Area --- */
#play-area {
  padding: 40px 0;
}

.play-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.play-header h2 { font-size: 1.5rem; }

.back-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.875rem;
  transition: var(--transition);
}

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

.play-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

@media (max-width: 768px) {
  .play-layout { grid-template-columns: 1fr; }
  .hero h1 { font-size: 2rem; }
}

.panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.panel h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* --- Forms --- */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  color: var(--text);
  font-size: 0.875rem;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-group textarea {
  resize: vertical;
  min-height: 80px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
}

.form-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23888898' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  font-family: inherit;
}

.btn-primary {
  background: var(--accent);
  color: white;
  width: 100%;
}

.btn-primary:hover {
  background: #5a4bd1;
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
}

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

.btn-sm {
  padding: 6px 12px;
  font-size: 0.75rem;
}

/* --- Scenario Box --- */
.scenario-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 16px;
  font-size: 0.875rem;
  line-height: 1.8;
  white-space: pre-line;
  color: var(--text-dim);
}

/* --- Result Display --- */
.result-card {
  background: var(--bg);
  border-radius: 8px;
  padding: 20px;
  margin-top: 16px;
  border-left: 3px solid var(--accent);
  animation: slideIn 0.3s ease;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.result-card .choice {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.result-card .reasoning {
  color: var(--text-dim);
  font-size: 0.875rem;
  font-style: italic;
  margin-bottom: 12px;
}

.result-card .payoffs {
  display: flex;
  gap: 16px;
  font-size: 0.875rem;
}

.result-card .payoff-item {
  background: var(--bg-card);
  padding: 8px 14px;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.result-card .payoff-item .label { color: var(--text-dim); font-size: 0.75rem; }
.result-card .payoff-item .value { font-weight: 700; color: var(--green); }

/* --- Loading Spinner --- */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* --- Dashboard --- */
.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.dash-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.dash-card h4 {
  font-size: 0.875rem;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.dash-card .big-number {
  font-size: 2rem;
  font-weight: 800;
}

.chart-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.chart-container h3 {
  font-size: 1rem;
  margin-bottom: 16px;
}

.chart-container canvas {
  width: 100% !important;
  max-height: 400px;
}

/* --- Results Table --- */
.results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.results-table th {
  text-align: left;
  padding: 10px 12px;
  background: var(--bg);
  color: var(--text-dim);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.7rem;
  border-bottom: 1px solid var(--border);
}

.results-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
}

.results-table tr:hover td {
  background: var(--bg-hover);
}

/* --- Research Section --- */
.finding-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}

.finding-card h3 {
  font-size: 1rem;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.finding-card p {
  color: var(--text-dim);
  font-size: 0.875rem;
}

.finding-card .highlight {
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 12px 16px;
  margin-top: 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
}

/* --- Prompt Browser --- */
.prompt-browser {
  max-height: 400px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.prompt-item {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  font-size: 0.8rem;
  font-family: 'JetBrains Mono', monospace;
  transition: var(--transition);
  white-space: pre-line;
}

.prompt-item:hover {
  background: var(--bg-hover);
}

.prompt-item.selected {
  background: var(--accent-glow);
  border-left: 3px solid var(--accent);
}

/* --- Toast notifications --- */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 20px;
  font-size: 0.875rem;
  z-index: 1000;
  animation: slideUp 0.3s ease;
}

.toast.error { border-color: var(--red); }
.toast.success { border-color: var(--green); }

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- History in play area --- */
.history-list {
  max-height: 400px;
  overflow-y: auto;
}

.history-item {
  padding: 12px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
}

.history-item:last-child { border-bottom: none; }

.history-item .choice-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  font-size: 0.7rem;
  text-transform: uppercase;
}

.badge-cooperate { background: rgba(0, 184, 148, 0.2); color: var(--green); }
.badge-defect { background: rgba(225, 112, 85, 0.2); color: var(--red); }
.badge-neutral { background: rgba(116, 185, 255, 0.2); color: var(--blue); }

/* --- Simulation progress --- */
.sim-progress {
  margin-top: 16px;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 8px;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--blue));
  border-radius: 4px;
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-dim); }