:root {
  --bg: #f8f9fa;
  --surface: #ffffff;
  --border: #dee2e6;
  --text: #212529;
  --text-secondary: #6c757d;
  --accent: #1a5276;
  --accent-light: #2980b9;
  --accent-bg: #eaf2f8;
  --success: #27ae60;
  --code-bg: #f4f6f8;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.10);
}

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

body {
  font-family: 'Georgia', 'Times New Roman', serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

/* ── Top bar ── */
.topbar {
  background: var(--accent);
  color: white;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-lg);
}
.topbar h1 {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
.topbar nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex: 1;
  justify-content: center;
}
.nav-main {
  display: flex;
  gap: 0.5rem;
}
.nav-primary {
  background: rgba(255,255,255,0.12);
  border: 2px solid rgba(255,255,255,0.5);
  color: white;
  padding: 0.55rem 1.4rem;
  border-radius: 5px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  transition: all 0.15s;
  letter-spacing: 0.01em;
}
.nav-primary:hover,
.nav-primary.active {
  background: rgba(255,255,255,0.25);
  border-color: white;
}
.nav-secondary {
  background: transparent;
  border: 1px solid rgba(255,255,255,0.25);
  color: rgba(255,255,255,0.8);
  padding: 0.4rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.8rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  transition: all 0.15s;
  margin-left: auto;
}
.nav-secondary:hover,
.nav-secondary.active {
  background: rgba(255,255,255,0.1);
  color: white;
  border-color: rgba(255,255,255,0.5);
}

/* ── Views ── */
.view { display: none; }
.view.active { display: block; }

/* ── Intro ── */
.intro-container {
  max-width: 860px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}
.intro-content {
  background: var(--surface);
  border-radius: 6px;
  padding: 2.5rem 3rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.intro-content h1 {
  font-size: 1.6rem;
  color: var(--accent);
  margin-bottom: 0.3rem;
  border-bottom: 2px solid var(--accent);
  padding-bottom: 0.6rem;
}
.intro-content h2 {
  font-size: 1.25rem;
  color: var(--accent);
  margin-top: 2rem;
  margin-bottom: 0.8rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}
.intro-content h3 {
  font-size: 1.05rem;
  color: var(--text);
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}
.intro-content p {
  margin-bottom: 0.9rem;
}
.intro-content strong {
  color: var(--accent);
}
.intro-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.9rem;
}
.intro-content th {
  background: var(--accent-bg);
  color: var(--accent);
  text-align: left;
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--border);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-weight: 600;
}
.intro-content td {
  padding: 0.5rem 0.8rem;
  border: 1px solid var(--border);
  vertical-align: top;
}
.intro-content tr:nth-child(even) { background: #fafbfc; }
.intro-content code {
  background: var(--code-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  font-size: 0.88em;
  font-family: 'SF Mono', 'Fira Code', monospace;
}
.intro-content pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1rem;
  overflow-x: auto;
  font-size: 0.85rem;
  margin: 1rem 0;
}
.intro-content pre code {
  background: none;
  padding: 0;
}
.intro-content ul, .intro-content ol {
  margin: 0.5rem 0 1rem 1.5rem;
}
.intro-content li { margin-bottom: 0.3rem; }
.intro-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}
.intro-content em {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ── Search & Ask panels ── */
.panel-container {
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}

.search-box {
  background: var(--surface);
  border-radius: 6px;
  padding: 1.5rem 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  margin-bottom: 1.5rem;
}
.search-box h2 {
  font-size: 1.1rem;
  color: var(--accent);
  margin-bottom: 0.8rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
.input-row {
  display: flex;
  gap: 0.5rem;
}
.input-row input,
.input-row textarea {
  flex: 1;
  padding: 0.7rem 1rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.95rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  transition: border-color 0.15s;
}
.input-row input:focus,
.input-row textarea:focus {
  outline: none;
  border-color: var(--accent-light);
  box-shadow: 0 0 0 2px rgba(41,128,185,0.15);
}
.input-row textarea {
  min-height: 3.5rem;
  resize: vertical;
}
.btn {
  padding: 0.7rem 1.5rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.9rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-weight: 500;
  transition: background 0.15s;
  white-space: nowrap;
}
.btn:hover { background: var(--accent-light); }
.btn:disabled {
  background: var(--text-secondary);
  cursor: not-allowed;
}

/* ── Results ── */
.results-area { margin-top: 1rem; }

.result-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1.2rem 1.5rem;
  margin-bottom: 0.75rem;
  box-shadow: var(--shadow);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.result-card.clickable {
  cursor: pointer;
}
.result-card.clickable:hover {
  border-color: var(--accent-light);
  box-shadow: var(--shadow-lg);
}
.result-card.expanded {
  border-color: var(--accent);
  border-left: 4px solid var(--accent);
}
.result-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.5rem;
  gap: 1rem;
}
.result-path {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
}
.result-score {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--accent-bg);
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  flex-shrink: 0;
  font-weight: 500;
}
.result-file {
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  font-family: 'SF Mono', 'Fira Code', monospace;
}
.result-file a {
  color: var(--accent-light);
  text-decoration: none;
}
.result-file a:hover {
  text-decoration: underline;
}
.sources-list a {
  color: var(--accent-light);
  text-decoration: none;
}
.sources-list a:hover {
  text-decoration: underline;
}
.doc-view a {
  color: var(--accent-light);
  text-decoration: underline;
}
.doc-view a:hover {
  color: var(--accent);
}
.result-preview {
  font-size: 0.88rem;
  line-height: 1.5;
  color: #555;
}
.result-full {
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--text);
}
.result-full h2, .result-full h3, .result-full h4 { color: var(--accent); margin-top: 1rem; }
.result-full h2 { font-size: 1.05rem; }
.result-full h3 { font-size: 0.95rem; }
.result-full a { color: var(--accent-light); text-decoration: underline; }
.result-full a:hover { color: var(--accent); }
.result-full li { margin-bottom: 0.2rem; }
.result-full p { margin-bottom: 0.6rem; }

/* ── Usage hints ── */
.usage-hint {
  margin-top: 0.8rem;
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
.usage-hint summary {
  cursor: pointer;
  color: var(--accent-light);
  font-weight: 500;
  padding: 0.3rem 0;
}
.usage-hint summary:hover { color: var(--accent); }
.usage-hint ul {
  margin: 0.5rem 0 0 1.2rem;
  line-height: 1.8;
}
.usage-hint li { margin-bottom: 0.1rem; }
.search-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.8rem;
}

/* ── Answer actions ── */
.answer-actions {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.btn-secondary {
  background: var(--surface);
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 0.45rem 1rem;
  font-size: 0.82rem;
}
.btn-secondary:hover {
  background: var(--accent-bg);
}
.source-score {
  font-size: 0.72rem;
  color: var(--accent);
  background: var(--accent-bg);
  padding: 0.1rem 0.4rem;
  border-radius: 2px;
  margin-left: 0.3rem;
}

/* ── Answer panel ── */
.answer-card {
  background: var(--surface);
  border: 1px solid var(--accent);
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  padding: 1.5rem 2rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-lg);
}
.answer-card h1, .answer-card h2, .answer-card h3 {
  color: var(--accent);
}
.answer-card h2 { font-size: 1.1rem; margin-top: 1.2rem; }
.answer-card h3 { font-size: 1rem; margin-top: 1rem; }
.answer-card p { margin-bottom: 0.7rem; font-size: 0.93rem; }
.answer-card ul, .answer-card ol { margin: 0.5rem 0 0.8rem 1.5rem; font-size: 0.93rem; }
.answer-card table { width: 100%; border-collapse: collapse; margin: 0.8rem 0; font-size: 0.85rem; }
.answer-card th { background: var(--accent-bg); padding: 0.5rem; border: 1px solid var(--border); text-align: left; }
.answer-card td { padding: 0.5rem; border: 1px solid var(--border); }
.answer-card code {
  background: var(--code-bg);
  padding: 0.1rem 0.3rem;
  border-radius: 2px;
  font-size: 0.85em;
}
.answer-card strong { color: var(--accent); }
.answer-card a { color: var(--accent-light); text-decoration: underline; }
.answer-card a:hover { color: var(--accent); }

.sources-list {
  background: var(--accent-bg);
  border-radius: 4px;
  padding: 1rem 1.2rem;
  margin-top: 0.8rem;
}
.sources-list h4 {
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 0.5rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
.sources-list ol {
  margin: 0;
  padding-left: 1.2rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
.sources-list li { margin-bottom: 0.2rem; }

/* ── Loading ── */
.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  vertical-align: middle;
  margin-right: 0.4rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

.loading-text {
  color: var(--text-secondary);
  font-style: italic;
  padding: 1rem 0;
}

/* ── Disclaimer footer ── */
.disclaimer {
  background: #2c3e50;
  color: rgba(255,255,255,0.75);
  padding: 1.5rem 2rem;
  margin-top: 3rem;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 0.78rem;
  line-height: 1.6;
}
.disclaimer-inner {
  max-width: 860px;
  margin: 0 auto;
}
.disclaimer strong {
  color: rgba(255,255,255,0.95);
  font-size: 0.82rem;
}
.disclaimer p { margin-bottom: 0.5rem; }
.disclaimer-meta {
  color: rgba(255,255,255,0.45);
  font-size: 0.72rem;
  margin-top: 0.8rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 0.6rem;
}

/* ── Responsive ── */
@media (max-width: 700px) {
  .intro-content { padding: 1.5rem; }
  .topbar { padding: 0.8rem 1rem; flex-wrap: wrap; }
  .topbar h1 { font-size: 0.95rem; width: 100%; }
  .topbar nav { width: 100%; justify-content: center; }
  .nav-secondary { margin-left: 0; }
}