/* ==========================================================================
   labuladong 算法笔记 - 1:1 官方原版视觉与排版系统 (Java 专享版)
   ========================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-hover: #f1f5f9;
  --bg-card: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  
  --accent-color: #2563eb;
  --accent-light: #eff6ff;
  --accent-hover: #1d4ed8;
  
  --code-bg: #f8fafc;
  --code-border: #e2e8f0;
  --code-header: #f1f5f9;
}

[data-theme="dark"] {
  --bg-primary: #090d16;
  --bg-secondary: #0f172a;
  --bg-hover: #1e293b;
  --bg-card: #131d31;
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-color: #1e293b;
  
  --accent-color: #3b82f6;
  --accent-light: rgba(59, 130, 246, 0.15);
  --accent-hover: #60a5fa;
  
  --code-bg: #0f172a;
  --code-border: #1e293b;
  --code-header: #1e293b;
}

html, body {
  margin: 0;
  padding: 0;
  height: auto !important;
  min-height: 100vh !important;
  overflow-x: hidden !important;
  overflow-y: auto !important;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

/* App Header (1:1 with online site) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  backdrop-filter: blur(12px);
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-primary);
  text-decoration: none;
}

.site-logo {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #a855f7, #6366f1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-link {
  padding: 0.45rem 0.85rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all 0.15s ease;
}

.nav-link:hover {
  background-color: var(--bg-hover);
  color: var(--text-primary);
}

.nav-link.active {
  background-color: var(--accent-light);
  color: var(--accent-color);
  font-weight: 700;
}

/* Dropdown */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--bg-card);
  min-width: 160px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  padding: 0.5rem 0;
  z-index: 100;
}

.dropdown:hover .dropdown-content {
  display: block;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: background 0.15s;
}

.dropdown-item:hover {
  background-color: var(--bg-hover);
  color: var(--accent-color);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-toggle-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.75rem;
  border-radius: 0.5rem;
  font-size: 0.85rem;
  cursor: pointer;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.theme-toggle-btn:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

/* App Main Container */
.app-container {
  display: flex !important;
  min-height: calc(100vh - 60px) !important;
  position: static !important;
}

/* Left Sidebar with Foldable Groups */
.sidebar {
  width: 310px !important;
  background-color: var(--bg-primary) !important;
  border-right: 1px solid var(--border-color) !important;
  position: sticky !important;
  top: 60px !important;
  height: calc(100vh - 60px) !important;
  overflow-y: auto !important;
  padding: 1.25rem 0.85rem !important;
  box-sizing: border-box !important;
  flex-shrink: 0 !important;
}

.search-box {
  width: 100%;
  padding: 0.55rem 0.85rem;
  border-radius: 0.5rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  box-sizing: border-box;
  margin-bottom: 1.25rem;
  font-size: 0.875rem;
  outline: none;
}

.search-box:focus {
  border-color: var(--accent-color);
  background-color: var(--bg-primary);
}

/* Foldable Category Group */
.category-group {
  margin-bottom: 0.4rem;
}

.category-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.75rem;
  border-radius: 0.375rem;
  cursor: pointer;
  user-select: none;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.15s ease;
}

.category-header:hover {
  background-color: var(--bg-hover);
  color: var(--text-primary);
}

.category-header .category-arrow {
  font-size: 0.75rem;
  transition: transform 0.2s ease;
  color: var(--text-muted);
}

.category-group.open .category-arrow {
  transform: rotate(90deg);
}

.category-links {
  list-style: none;
  padding: 0;
  margin: 0;
  padding-left: 0.75rem;
  display: none;
}

.category-group.open .category-links {
  display: block;
}

.nav-item {
  margin: 0.15rem 0;
}

.nav-item a {
  display: block;
  padding: 0.4rem 0.65rem;
  border-radius: 0.375rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  transition: all 0.15s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-item a:hover {
  background-color: var(--bg-hover);
  color: var(--text-primary);
}

.nav-item a.active {
  background-color: var(--accent-light);
  color: var(--accent-color);
  font-weight: 700;
}

/* Main Layout */
.main-wrapper {
  flex: 1 !important;
  min-width: 0 !important;
  display: flex !important;
  flex-direction: column !important;
}

.breadcrumbs {
  font-size: 0.875rem;
  color: var(--text-muted);
  padding: 1.25rem 2.5rem 0;
}

.breadcrumbs a {
  color: var(--text-secondary);
  text-decoration: none;
}

.breadcrumbs a:hover {
  color: var(--accent-color);
}

.breadcrumbs .current {
  color: var(--text-primary);
  font-weight: 600;
}

.content-layout {
  display: flex !important;
  padding: 1.5rem 2.5rem 3rem !important;
  max-width: 1400px !important;
  margin: 0 auto !important;
  width: 100% !important;
  box-sizing: border-box !important;
  gap: 3.5rem !important;
}

.article-container {
  flex: 1 !important;
  min-width: 0 !important;
  max-width: 880px !important;
}

.article-title {
  font-size: 2.25rem;
  font-weight: 850;
  margin-top: 0.5rem;
  margin-bottom: 1.75rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.article-body {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

.article-body p {
  margin: 1.25rem 0;
  line-height: 1.8;
}

.article-body strong {
  color: var(--text-primary);
  font-weight: 700;
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 800;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 750;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: 0.75rem;
  margin: 2rem auto;
  display: block;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

/* Callout Boxes */
.hint-container, details.hint-container {
  border-radius: 0.75rem;
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  border: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
}

.hint-container.note {
  background-color: rgba(22, 101, 52, 0.06);
  border-color: rgba(34, 197, 94, 0.3);
  color: var(--text-primary);
}

.hint-container.info {
  background-color: rgba(37, 99, 235, 0.06);
  border-color: rgba(59, 130, 246, 0.3);
  color: var(--text-primary);
}

.hint-container.warning {
  background-color: rgba(217, 119, 6, 0.06);
  border-color: rgba(245, 158, 11, 0.3);
  color: var(--text-primary);
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.75rem 0;
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
}

table th, table td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

table th {
  background-color: var(--bg-secondary);
  font-weight: 700;
}

/* Pure Java Code Block */
.language-java, .line-numbers-mode, .code-block-wrapper {
  position: relative;
  background-color: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 0.75rem;
  margin: 1.75rem 0;
  overflow: hidden;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--code-header);
  padding: 0.45rem 1rem;
  border-bottom: 1px solid var(--code-border);
}

.code-lang-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-color);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.code-copy-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: 0.375rem;
  padding: 0.2rem 0.6rem;
  font-size: 0.75rem;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.15s ease;
}

.code-copy-btn:hover {
  background: var(--bg-primary);
  border-color: var(--accent-color);
  color: var(--accent-color);
}

pre {
  margin: 0 !important;
  padding: 1.25rem !important;
  font-family: var(--font-mono) !important;
  font-size: 0.9rem !important;
  line-height: 1.65 !important;
  overflow-x: auto !important;
}

/* Visualization Panel */
.viz-container, .resizable, details.details {
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  overflow: hidden;
  margin: 2rem 0;
  background-color: var(--bg-card);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.viz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1.25rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  font-weight: 700;
  font-size: 0.95rem;
}

.viz-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-primary);
}

.viz-actions a {
  font-size: 0.8rem;
  color: var(--accent-color);
  text-decoration: none;
  padding: 0.25rem 0.5rem;
  border-radius: 0.25rem;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
}

.viz-frame-wrap {
  width: 100%;
  height: 550px;
}

.viz-frame-wrap iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* Bottom Prev/Next Cards (1:1 with online screenshot) */
.page-nav-cards {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.nav-card {
  flex: 1;
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  padding: 1rem 1.25rem;
  text-decoration: none;
  background-color: var(--bg-primary);
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.nav-card:hover {
  border-color: var(--accent-color);
  background-color: var(--accent-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.08);
}

.nav-card-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.nav-card.next {
  text-align: right;
}

.nav-card.next .nav-card-label {
  justify-content: flex-end;
}

/* TOC */
.toc-sidebar {
  width: 230px !important;
  position: sticky !important;
  top: 80px !important;
  height: calc(100vh - 100px) !important;
  overflow-y: auto !important;
  flex-shrink: 0 !important;
  font-size: 0.875rem !important;
}

.toc-title {
  font-weight: 800;
  margin-bottom: 0.85rem;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.toc-links {
  list-style: none;
  padding-left: 0;
  margin: 0;
  border-left: 2px solid var(--border-color);
}

.toc-links li a {
  display: block;
  padding: 0.3rem 0 0.3rem 0.85rem;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.85rem;
}

.toc-links li a:hover {
  color: var(--accent-color);
}

.katex-mathml {
  display: none !important;
}

@media (max-width: 1100px) {
  .toc-sidebar {
    display: none !important;
  }
}

@media (max-width: 768px) {
  .site-nav {
    display: none;
  }
  .sidebar {
    display: none !important;
  }
  .content-layout {
    padding: 1.25rem !important;
  }
}


/* Reset all inline SVGs and React Buttons */
.article-body svg,
.prose svg {
  max-width: 1.25rem !important;
  max-height: 1.25rem !important;
  display: inline-block !important;
  vertical-align: -0.15em !important;
  margin: 0 0.2rem !important;
}

.article-body button,
.prose button {
  background: transparent;
  border: none;
  padding: 0;
  margin: 0;
  display: inline;
  font: inherit;
  color: inherit;
  cursor: default;
}

.article-body button.playground-link,
.article-body .playground-link {
  color: var(--accent-color) !important;
  font-weight: 600 !important;
  cursor: pointer !important;
}

/* Ensure images maintain proper max bounds */
.article-body img {
  max-width: 100% !important;
  height: auto !important;
  max-height: 550px !important;
  object-fit: contain !important;
  margin: 1.5rem auto !important;
}

/* Category item ellipsis */
.category-links .nav-item a {
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
  font-size: 0.85rem !important;
  padding: 0.4rem 0.65rem !important;
}