:root {
  --bg: #f8f9fa;
  --card: #fff;
  --border: #e2e8f0;
  --text: #1e293b;
  --muted: #64748b;
  --accent: #2563eb;
  --success: #16a34a;
  --error: #dc2626;
  --user-bg: #eff6ff;
}

* { box-sizing: border-box; }

body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  max-width: min(1280px, 96vw);
  margin: 0 auto;
  padding: 2rem 2rem 1rem;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

h1 { font-size: 1.5rem; font-weight: 600; margin-bottom: 0.25rem; }
.subtitle { color: var(--muted); font-size: 0.9rem; margin-bottom: 1.5rem; }

/* Conversation */
#conversation {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1rem;
}

.turn {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
  overflow: hidden;
}

.turn-question {
  padding: 0.75rem 1rem;
  background: var(--user-bg);
  border-bottom: 1px solid var(--border);
  font-weight: 500;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  user-select: none;
}
.turn-question:hover { background: #e0ecfa; }
.turn.collapsed .turn-question { border-bottom: none; }

.turn-chevron {
  font-size: 0.65rem;
  color: var(--muted);
  transition: transform 0.2s;
  flex-shrink: 0;
}
.turn.collapsed .turn-chevron { transform: rotate(-90deg); }

.turn-question-text { flex: 1; }

.turn-status {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--muted);
  white-space: nowrap;
  animation: pulse 1.5s ease-in-out infinite;
}

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

.turn-body { display: none; }
.turn-body.open { display: block; }

.turn-steps { padding: 0.75rem 1rem 0; }
.turn-answer { padding: 0.75rem 1rem; }

.turn-meta {
  padding: 0.4rem 1rem 0.75rem;
  font-size: 0.78rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}
.turn-meta:empty { display: none; }
.turn-answer table { border-collapse: collapse; width: 100%; font-size: 0.85rem; margin: 0.5rem 0; }
.turn-answer th, .turn-answer td { border: 1px solid var(--border); padding: 0.5rem 0.75rem; }
.turn-answer th { background: #f8fafc; text-align: left; }

/* Steps */
.step {
  margin-bottom: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.step-header {
  padding: 0.5rem 0.75rem;
  background: #f1f5f9;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
}
.step-header:hover { background: #e2e8f0; }
.step-header .icon { color: var(--accent); }
.step-header .tool { font-weight: 500; }
.step-header .step-status { color: var(--muted); margin-left: auto; font-size: 0.8rem; }

.step-body {
  padding: 0.75rem;
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  max-height: 300px;
  overflow-y: auto;
  display: none;
}
.step-body.open { display: block; }

.step-body pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: 'Consolas', 'Monaco', monospace;
  font-size: 0.85rem;
  background: #f8fafc;
  padding: 0.5rem;
  border-radius: 4px;
}

.step-body table { border-collapse: collapse; width: 100%; font-size: 0.8rem; }
.step-body th, .step-body td { border: 1px solid var(--border); padding: 0.4rem 0.6rem; }
.step-body th { background: #f8fafc; text-align: left; }

.sql-preview { color: var(--accent); margin-bottom: 0.5rem; }

.error-step .step-header { background: #fef2f2; }

/* Input area */
.input-area {
  position: sticky;
  bottom: 0;
  background: var(--bg);
  padding: 0.75rem 0;
}

textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  resize: vertical;
  background: var(--card);
  color: var(--text);
  font-family: inherit;
}
textarea::placeholder { color: var(--muted); }
textarea:focus { outline: none; border-color: var(--accent); }

.input-controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.compare-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text);
  cursor: pointer;
  user-select: none;
}
.compare-toggle input { cursor: pointer; }

/* Side-by-side model comparison */
.compare-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 0.75rem;
  padding: 0.75rem 1rem 1rem;
}

.compare-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fafbfc;
  display: flex;
  flex-direction: column;
  min-height: 120px;
  overflow: hidden;
}

.compare-card-header {
  padding: 0.5rem 0.65rem;
  font-weight: 600;
  font-size: 0.82rem;
  background: #eef2f7;
  border-bottom: 1px solid var(--border);
}

.compare-card-meta {
  padding: 0.35rem 0.65rem;
  font-size: 0.72rem;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
}

.compare-card-answer {
  padding: 0.65rem;
  font-size: 0.85rem;
  flex: 1;
}

.compare-card-answer table { border-collapse: collapse; width: 100%; font-size: 0.8rem; margin: 0.4rem 0; }
.compare-card-answer th, .compare-card-answer td { border: 1px solid var(--border); padding: 0.35rem 0.5rem; }
.compare-card-answer th { background: #f8fafc; text-align: left; }

.compare-card-steps {
  padding: 0 0.5rem 0.5rem;
  max-height: 220px;
  overflow-y: auto;
}

.compare-card-steps .step { margin-bottom: 0.5rem; }

.compare-card-error {
  padding: 0.65rem;
  font-size: 0.82rem;
  color: var(--error);
  background: #fef2f2;
  flex: 1;
  white-space: pre-wrap;
  word-break: break-word;
}

.compare-card-pending {
  opacity: 0.55;
}

.compare-card-placeholder {
  padding: 1.2rem 0.65rem;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

button {
  padding: 0.5rem 1.25rem;
  font-size: 0.9rem;
  cursor: pointer;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-weight: 500;
}
button:hover:not(:disabled) { opacity: 0.9; }
button:disabled { opacity: 0.5; cursor: not-allowed; }

select {
  padding: 0.45rem 0.75rem;
  font-size: 0.85rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--card);
  color: var(--text);
  font-family: inherit;
  cursor: pointer;
}
select:focus { outline: none; border-color: var(--accent); }

.btn-secondary {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  font-weight: 400;
}
.btn-secondary:hover:not(:disabled) { background: #f1f5f9; opacity: 1; }