/* Base layout */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif; color: #1f2937; background: #fafafa; }

.container { max-width: 1120px; margin: 0 auto; padding: 24px; }
.header { background: #111827; color: #fff; }
.header .nav { display: flex; align-items: center; gap: 16px; padding: 12px 24px; }
.header a { color: #e5e7eb; text-decoration: none; font-weight: 500; }
.header a:hover { color: #fff; }
.header .spacer { flex: 1; }

.search { position: relative; }
.search input { padding: 8px 12px; width: 280px; border: 1px solid #d1d5db; border-radius: 6px; }
.search .hint { position: absolute; right: 8px; top: 50%; transform: translateY(-50%); color: #9ca3af; font-size: 12px; }

h1 { font-size: 28px; margin: 16px 0; }
h2 { font-size: 20px; margin: 16px 0 8px; }
.section { margin: 16px 0 24px; }

/* Cards (still used by other pages) */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.card { background: #fff; border: 1px solid #e5e7eb; border-radius: 10px; padding: 16px; box-shadow: 0 1px 2px rgba(0,0,0,0.03); }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: #4b5563; }
.badge { display: inline-block; background: #eef2ff; color: #3730a3; padding: 2px 8px; border-radius: 999px; font-size: 12px; margin-right: 6px; }

.table { width: 100%; border-collapse: collapse; background: #fff; border: 1px solid #e5e7eb; border-radius: 10px; overflow: hidden; table-layout: fixed; }
.table th, .table td { border-bottom: 1px solid #f3f4f6; padding: 12px; text-align: left; vertical-align: top; line-height: 1.65; }
/* ensure the first (模型)列更宽且不换行 */
.table th:first-child, .table td:first-child { width: 100px !important; min-width: 100px !important; white-space: nowrap; }
.table td:first-child a { white-space: nowrap; }
.table th { background: #f9fafb; font-weight: 600; color: #374151; }
.table tr:nth-child(odd) td { background: #fcfcff; }
.table tr:nth-child(even) td { background: #ffffff; }
.compare-table { width: max-content; min-width: 100%; }
.compare-table th:first-child, .compare-table td:first-child { width: 120px; font-weight: 700; color: #111827; background: #f8fafc; }
.compare-table td { word-break: normal; overflow-wrap: break-word; }
.compare-table thead th { position: sticky; top: 0; z-index: 1; }

/* Compact markdown inside compare cells */
.compare-table td .markdown-body { padding: 0; font-size: 15px; line-height: 1.6; }
.compare-table td .markdown-body p,
.compare-table td .markdown-body ul,
.compare-table td .markdown-body ol,
.compare-table td .markdown-body blockquote,
.compare-table td .markdown-body pre,
.compare-table td .markdown-body table,
.compare-table td .markdown-body figure { padding-left: 0; padding-right: 0; margin: 6px 0; }
.compare-table td .markdown-body ul { padding-left: 18px; margin: 4px 0; }
.compare-table td .markdown-body ol { padding-left: 20px; margin: 4px 0; }
.compare-table td .markdown-body ul ul { padding-left: 10px; }
.compare-table td .markdown-body ol ol { padding-left: 12px; }
.compare-table td .markdown-body ul ul ul, .compare-table td .markdown-body ol ol ol { padding-left: 8px; }
.compare-table td .markdown-body li { margin: 3px 0; }
.compare-table td .markdown-body h1,
.compare-table td .markdown-body h2,
.compare-table td .markdown-body h3,
.compare-table td .markdown-body h4,
.compare-table td .markdown-body h5,
.compare-table td .markdown-body h6 { margin: 6px 0; padding: 0; font-size: 15px; font-weight: 600; }
.compare-table td .markdown-body pre { font-size: 13px; padding: 10px; margin: 8px 0; }
.compare-table td .markdown-body blockquote { margin: 6px 0; padding: 6px 10px; }

/* horizontal scroll when content columns need more width */
.compare-wrap { overflow-x: auto; }

.toolbar { display: flex; align-items: center; gap: 12px; margin: 8px 0 16px; width: 100%; }
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 12px; border-radius: 8px; border: 1px solid #d1d5db; background: #fff; color: #111827; text-decoration: none; cursor: pointer; font-size: 16px; line-height: 1.2; font-weight: 600; }
.btn.primary { background: #2563eb; border-color: #2563eb; color: #fff; }
.btn:hover { filter: brightness(0.98); }

.footer { color: #6b7280; padding: 24px; text-align: center; }

.highlight { background: #fff7cc; }
.hidden { display: none !important; }

/* Hierarchical list */
.list-section { margin-bottom: 24px; }
.section-header { display: flex; align-items: center; gap: 8px; cursor: pointer; user-select: none; }
.section-header h2 { margin: 0; }
.twisty { display: inline-block; width: 16px; color: #6b7280; }
.collapsible .fold { display: none; }
.collapsible:not(.collapsed) .fold { display: block; }

.list { list-style: none; padding-left: 0; margin: 8px 0; background: #fff; border: 1px solid #e5e7eb; border-radius: 10px; }
.list-item { padding: 8px 16px; border-top: 1px solid #f3f4f6; }
.list-item:first-child { border-top: none; }
.item-header { display: flex; align-items: center; gap: 10px; cursor: pointer; user-select: none; }
.item-header a { color: #111827; text-decoration: none; font-weight: 600; }
.item-header a:hover { text-decoration: underline; }
.item-meta {
  color: #4b5563;
  margin: 6px 0;
  white-space: normal;
  word-break: break-word;
  overflow-wrap: anywhere;
  line-height: 1.6;
}

/* visual max ~150 chars per line naturally wraps by container width; ensure comfortable width */
.list { max-width: 100%; }
.item-actions { display: flex; gap: 12px; margin: 6px 0 4px; }
.link-action { color: #2563eb; text-decoration: none; font-size: 14px; }
.link-action.disabled { color: #9ca3af; pointer-events: none; }

/* when collapsed, keep overview visible and hide only children */
.list-item.collapsible.collapsed > .item-body { display: block; }
.list-item.collapsible.collapsed > .item-body > .sublist { display: none; }

.sublist { list-style: disc; padding-left: 24px; margin: 6px 0 4px; }
.sublist li a { color: #2563eb; text-decoration: none; }
.sublist li a:hover { text-decoration: underline; }

.list-item .item-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  cursor: pointer;
  border-bottom: 1px solid #e5e7eb;
}

.list-item .item-left {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
}

.list-item .item-right {
  display: flex;
  gap: 12px;
  align-items: center;
}

.list-item .sub-item-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
  margin-bottom: 4px;
}

.list-item .sub-item-header .item-left {
  display: flex;
  align-items: center;
  flex: 1;
}

.list-item .sub-item-header .item-right {
  display: flex;
  gap: 12px;
  align-items: center;
}

.list-item .item-header a,
.list-item .sub-item-header a {
  color: #2563eb;
  text-decoration: none;
  font-weight: 500;
}

.list-item .item-header a:hover,
.list-item .sub-item-header a:hover {
  text-decoration: underline;
}

.list-item .disabled-link {
  color: #6b7280 !important;
  cursor: not-allowed;
}

.list-item .disabled-link:hover {
  text-decoration: none !important;
}

.list-item .link-action {
  color: #2563eb;
  text-decoration: none;
  font-size: 14px;
  padding: 4px 8px;
  border-radius: 4px;
  transition: background-color 0.2s;
}

.list-item .link-action:hover {
  background-color: #eff6ff;
  text-decoration: none;
}

.list-item .link-action.disabled {
  color: #9ca3af;
  cursor: not-allowed;
}

.list-item .link-action.disabled:hover {
  background-color: transparent;
}

/* Page content width */
#app { max-width: 980px; margin: 0 auto; padding: 16px 20px; }

/* Markdown body general styles */
.markdown-body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  font-size: 16px;
  line-height: 1.5;
  word-wrap: break-word;
  color: #333;
  padding: 0; /* Remove overall padding from the body */
}

/* Apply horizontal padding to content elements within markdown-body */
.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body pre,
.markdown-body table,
.markdown-body figure { /* Add figure for code panels */
  padding-left: 20px;
  padding-right: 20px;
}

/* Headings should not be indented, but still have horizontal padding for alignment */
.markdown-body h2, .markdown-body h3, .markdown-body h4, .markdown-body h5, .markdown-body h6 {
  margin: 20px 0 12px 0;
  padding: 0 20px; /* Apply horizontal padding to headings */
  text-align: left;
  font-weight: 600;
  color: #111827;
}

/* Code blocks - white background with black text, merged together */
.markdown-body pre {
  background: #ffffff;
  color: #000000;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 16px;
  margin: 12px 0;
  overflow-x: auto;
  font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
  font-size: 14px;
  line-height: 1.5;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.markdown-body pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  border: none;
  border-radius: 0;
  font-size: inherit;
  line-height: inherit;
}

/* Code panel (Step-4) - ensure it also uses white background */
.code-panel {
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  margin: 14px 0;
  overflow: hidden;
  background: #ffffff; /* Ensure white background for the panel itself */
}
.code-panel .code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #f8fafc;
  padding: 8px 12px;
  border-bottom: 1px solid #e5e7eb;
}
.code-panel .code-lang {
  color: #374151;
  font-weight: 600;
  font-size: 13px;
}
.code-panel .code-actions {
  display: flex;
  gap: 8px;
}
.code-panel .btn-mini {
  background: #e5e7eb;
  border: none;
  color: #111827;
  padding: 4px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
}
.code-panel .btn-mini:hover {
  background: #d1d5db;
}
.code-panel pre {
  margin: 0;
  border: none;
  border-radius: 0;
  background: #ffffff; /* Ensure pre inside panel is also white */
  color: #000000;
  box-shadow: none; /* Remove shadow from inner pre */
}

/* Nested lists with proper hierarchy */
.markdown-body ul, .markdown-body ol { margin: 8px 0; padding-left: 20px; }
.markdown-body ul ul, .markdown-body ol ol, .markdown-body ul ol, .markdown-body ol ul { margin: 4px 0; }
.markdown-body li { margin: 4px 0; line-height: 1.6; }
.markdown-body li > ul, .markdown-body li > ol { margin: 4px 0; }

/* First level list items (main sections) */
.markdown-body > ul > li, .markdown-body > ol > li { 
  font-weight: 600; 
  margin: 12px 0; 
  font-size: 15px; 
}

/* Second level list items (sub-sections) */
.markdown-body > ul > li > ul > li, .markdown-body > ol > li > ol > li,
.markdown-body > ul > li > ol > li, .markdown-body > ol > li > ul > li {
  font-weight: 500;
  margin: 6px 0;
  font-size: 14px;
}

/* Third level and deeper list items */
.markdown-body > ul > li > ul > li > ul > li, .markdown-body > ol > li > ol > li > ol > li,
.markdown-body > ul > li > ol > li > ul > li, .markdown-body > ol > li > ul > li > ol > li,
.markdown-body > ul > li > ul > li > ol > li, .markdown-body > ol > li > ol > li > ul > li,
.markdown-body > ul > li > ol > li > ol > li, .markdown-body > ol > li > ul > li > ul > li {
  font-weight: normal;
  margin: 4px 0;
  font-size: 13px;
}

/* List item bullet styles */
.markdown-body ul { list-style-type: disc; } /* Default solid circle */
.markdown-body ul ul { list-style-type: circle; } /* Second level hollow circle */
.markdown-body ul ul ul { list-style-type: square; } /* Third level square */
.markdown-body ul ul ul ul { list-style-type: disc; } /* Fourth level back to solid circle */

/* Blockquotes */
.markdown-body blockquote {
  border-left: 4px solid #e5e7eb;
  color: #6b7280;
  padding: 8px 12px;
  margin: 12px 0;
  background-color: #f9fafb;
  border-radius: 4px;
}

/* Inline code */
.markdown-body code:not(pre code) {
  background-color: #f3f4f6;
  border-radius: 4px;
  padding: 2px 4px;
  font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
  font-size: 0.9em;
  color: #374151;
}

/* Table styles */
.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}
.markdown-body th, .markdown-body td {
  border: 1px solid #e5e7eb;
  padding: 8px 12px;
  text-align: left;
}
.markdown-body th {
  background-color: #f9fafb;
  font-weight: 600;
  color: #374151;
}
.markdown-body tr:nth-child(even) {
  background-color: #fcfcfc;
}

/* Images */
.markdown-body img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 16px auto;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Horizontal rule */
.markdown-body hr {
  border: 0;
  border-top: 1px solid #e5e7eb;
  margin: 24px 0;
}

/* Anchor links for headings */
.markdown-body .anchor-link {
  margin-left: 8px;
  font-size: 0.8em;
  color: #9ca3af;
  text-decoration: none;
  visibility: hidden;
}
.markdown-body h2:hover .anchor-link,
.markdown-body h3:hover .anchor-link {
  visibility: visible;
}
.markdown-body .anchor-link:hover {
  color: #4b5563;
}

/* Copy button for code blocks (default) */
.markdown-body pre .copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: #e5e7eb;
  border: none;
  color: #111827;
  padding: 4px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.2s ease-in-out;
}
.markdown-body pre:hover .copy-btn {
  opacity: 1;
}
.markdown-body pre {
  position: relative; /* For copy button positioning */
}

/* Typography scale for markdown content */
.markdown-body { font-size: 16px; line-height: 1.65; }
.markdown-body h1 { font-size: 22px; font-weight: 700; margin: 22px 0 14px; padding: 0 20px; color: #0b1220; }
.markdown-body h2 { font-size: 18px; font-weight: 700; margin: 20px 0 12px; padding: 0 20px; color: #0b1220; }
.markdown-body h3 { font-size: 16px; font-weight: 600; margin: 18px 0 10px; padding: 0 20px; color: #111827; }
.markdown-body h4 { font-size: 15px; font-weight: 600; margin: 16px 0 8px; padding: 0 20px; color: #111827; }
/* Metric detail: enlarge layer heading size and ensure clean look */
.metric-detail .section.metric-layer h2 { font-size: 20px; }

/* Paragraphs */
.markdown-body p { margin: 12px 0; padding: 0 20px; }

/* Emphasis for top-level labels within the extracted section */
.markdown-body h2.md-top, .markdown-body h3.md-top { font-size: 20px; font-weight: 800; }
.markdown-body h2.md-step, .markdown-body h3.md-step { font-size: 19px; font-weight: 700; }

/* Strong emphasis for top/step headings (override) */
.markdown-body .md-top { font-size: 22px !important; font-weight: 800 !important; margin-top: 14px !important; }
.markdown-body .md-step { font-size: 20px !important; font-weight: 700 !important; margin-top: 12px !important; }

/* Sub-section headings like 问题类型定义/学习方法 keep smaller default sizes (H3/H4) */
.compare-picker { display: flex; flex-direction: column; gap: 8px; max-height: 220px; overflow: hidden; border: 1px solid #e5e7eb; border-radius: 8px; padding: 10px; background: #fff; width: 100%; flex: 1 1 auto; align-self: stretch; }
/* Force the picker to extend to desired width within the toolbar */
.toolbar > .compare-picker { width: 920px !important; max-width: 100%; flex: 0 0 920px; }
.compare-picker input[type="search"] { width: 100%; padding: 6px 8px; border: 1px solid #e5e7eb; border-radius: 6px; }
.compare-list { display: grid; grid-template-columns: repeat(3, minmax(220px, 1fr)); gap: 4px 16px; overflow: auto; max-height: 170px; padding-right: 6px; width: 100%; }
.compare-cat { grid-column: 1 / -1; margin-top: 4px; }
.compare-cat-title { font-weight: 700; color: #374151; font-size: 13px; margin: 4px 0; }
.compare-item { display: flex; align-items: center; gap: 8px; padding: 1px 0; font-size: 14px; color: #111827; }
.compare-item input { width: 14px; height: 14px; }

/* === UI Refresh v0.2.72 =============================================== */
/* Theme tokens */
:root {
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --border-soft: #f3f4f6;
  --brand: #2563eb;
  --brand-ink: #1e3a8a;
  --brand-soft: #eff6ff;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 6px 14px rgba(17,24,39,0.06);
  --radius-sm: 6px;
  --radius-md: 10px;
}

/* Header: sticky gradient + subtle hover */
.header { position: sticky; top: 0; z-index: 10; background: linear-gradient(180deg, #0f172a 0%, #111827 100%); box-shadow: 0 2px 8px rgba(0,0,0,0.05); border-bottom: 1px solid rgba(255,255,255,0.06); }
.header .nav { gap: 8px; }
.header a { padding: 8px 10px; border-radius: var(--radius-sm); font-weight: 600; }
.header a:hover { background: rgba(255,255,255,0.08); }

/* Search: focus ring */
.search input { border-radius: 8px; background: rgba(255,255,255,0.95); transition: box-shadow .15s ease, border-color .15s ease; }
.search input:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px rgba(37,99,235,0.15); }

/* Cards: lift on hover */
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 18px; box-shadow: var(--shadow-sm); transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease; }
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: #dbe0ea; }

/* Badges: clearer brand tone */
.badge { background: var(--brand-soft); color: var(--brand-ink); border: 1px solid rgba(37,99,235,0.25); }

/* Table: soft shadow and radius */
.table { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }

/* Toolbar buttons: elevation + active feedback */
.btn { border-radius: 10px; border: 1px solid var(--border); color: var(--text); box-shadow: var(--shadow-sm); transition: transform .06s ease, box-shadow .15s ease, border-color .15s ease; }
.btn:hover { border-color: #cbd5e1; box-shadow: var(--shadow-md); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; box-shadow: 0 6px 14px rgba(37,99,235,0.22); }

/* Hierarchical list container */
.list { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.list-item { border-top: 1px solid var(--border-soft); }
.list-item .item-header { border-bottom: 1px solid var(--border); }
.list-item .item-header:hover { background: #f9fafb; }

/* Link actions */
.list-item .link-action { color: var(--brand); border-radius: 6px; transition: background-color 0.2s, color .15s ease; }
.list-item .link-action:hover { background-color: var(--brand-soft); text-decoration: none; }