/* ==========================================================================
   MD Devlion - Markdown Live Editor & Viewer Stylesheet
   ========================================================================== */

:root {
  /* Color Palette - Dark Slate (Default) */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-hover: #475569;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-primary: #38bdf8;
  --accent-hover: #0284c7;
  --accent-light: rgba(56, 189, 248, 0.12);
  
  --success: #34d399;
  --danger: #f87171;
  
  --border-color: #334155;
  --border-light: #1e293b;
  
  --code-bg: #182232;
  --editor-bg: #0b1329;
  --preview-bg: #0f172a;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', Consolas, Monaco, 'Courier New', monospace;

  --header-height: 54px;
  --toolbar-height: 44px;
  --footer-height: 28px;
}

/* Light Theme Overrides */
html.light {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #e2e8f0;
  --bg-hover: #cbd5e1;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  --accent-primary: #0284c7;
  --accent-hover: #0369a1;
  --accent-light: rgba(2, 132, 199, 0.1);
  
  --border-color: #cbd5e1;
  --border-light: #f1f5f9;
  
  --code-bg: #f1f5f9;
  --editor-bg: #ffffff;
  --preview-bg: #f8fafc;
}

/* Reset & Box Sizing */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

/* Layout App Container */
.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

/* Header Styles */
.app-header {
  height: var(--header-height);
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  z-index: 20;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo {
  color: var(--accent-primary);
  display: flex;
  align-items: center;
}

.title-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.title-group h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.3px;
  color: var(--text-primary);
}

.badge {
  font-size: 11px;
  font-weight: 600;
  background-color: var(--accent-light);
  color: var(--accent-primary);
  padding: 2px 8px;
  border-radius: 12px;
  border: 1px solid rgba(56, 189, 248, 0.2);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Buttons & Selects */
.btn-select {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 13px;
  font-family: inherit;
  outline: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-select:hover {
  border-color: var(--accent-primary);
}

.btn-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  background: none;
}

.btn-secondary {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--text-muted);
}

.btn-sm {
  padding: 3px 8px;
  font-size: 11px;
  border-radius: 4px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  cursor: pointer;
}

.btn-sm.active, .btn-sm:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.btn-icon {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-icon:hover, .btn-icon.active {
  background-color: var(--accent-light);
  color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.icon-sun { display: none; }
.icon-moon { display: block; }

html.light .icon-sun { display: block; }
html.light .icon-moon { display: none; }

.divider-v {
  width: 1px;
  height: 20px;
  background-color: var(--border-color);
  margin: 0 4px;
}

/* Dropdown */
.dropdown {
  position: relative;
}

.dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 4px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
  min-width: 180px;
  z-index: 100;
  padding: 4px;
}

.dropdown-menu.show {
  display: block;
}

.dropdown-item {
  width: 100%;
  text-align: left;
  padding: 8px 12px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 13px;
  border-radius: 4px;
  cursor: pointer;
}

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

/* View Mode Group */
.view-mode-group {
  display: flex;
  gap: 4px;
}

/* Toolbar */
.toolbar {
  height: var(--toolbar-height);
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  overflow-x: auto;
  z-index: 15;
}

.toolbar-section {
  display: flex;
  align-items: center;
  gap: 4px;
}

.tb-btn {
  padding: 4px 8px;
  height: 28px;
  border-radius: 4px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.tb-btn:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.tb-btn.danger:hover {
  background-color: rgba(248, 113, 113, 0.15);
  color: var(--danger);
  border-color: var(--danger);
}

.tb-divider {
  width: 1px;
  height: 16px;
  background-color: var(--border-color);
  margin: 0 4px;
}

/* Workspace Layout */
.workspace {
  flex: 1;
  display: flex;
  position: relative;
  overflow: hidden;
  width: 100%;
}

/* TOC Sidebar */
.toc-sidebar {
  width: 260px;
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transition: margin-left 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 10;
  flex-shrink: 0;
}

.toc-sidebar.collapsed {
  margin-left: -260px;
}

.sidebar-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.sidebar-header h3 {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
}

.btn-icon-sm {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 18px;
  cursor: pointer;
}

.btn-icon-sm:hover { color: var(--text-primary); }

.toc-content {
  flex: 1;
  overflow-y: auto;
  padding: 12px;
}

.toc-empty {
  font-size: 12px;
  color: var(--text-muted);
  text-align: center;
  margin-top: 20px;
}

.toc-list {
  list-style: none;
}

.toc-item {
  margin-bottom: 4px;
}

.toc-link {
  display: block;
  padding: 4px 8px;
  border-radius: 4px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 12px;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.toc-link:hover {
  background-color: var(--bg-tertiary);
  color: var(--accent-primary);
}

.toc-h1 { padding-left: 4px; font-weight: 600; }
.toc-h2 { padding-left: 14px; }
.toc-h3 { padding-left: 24px; color: var(--text-muted); }
.toc-h4, .toc-h5, .toc-h6 { padding-left: 34px; color: var(--text-muted); font-size: 11px; }

/* Pane Common */
.pane {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.pane-header {
  height: 32px;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.pane-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.pane-tools {
  display: flex;
  align-items: center;
  gap: 8px;
}

.stat-tag {
  font-size: 11px;
  color: var(--text-muted);
}

/* Editor Pane */
.editor-pane {
  flex: 1;
  background-color: var(--editor-bg);
}

.editor-wrapper {
  flex: 1;
  display: flex;
  position: relative;
  overflow: hidden;
}

.line-numbers {
  width: 44px;
  padding: 16px 0;
  background-color: var(--editor-bg);
  border-right: 1px solid var(--border-light);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  text-align: right;
  padding-right: 10px;
  user-select: none;
  overflow: hidden;
}

#editor {
  flex: 1;
  height: 100%;
  background: transparent;
  border: none;
  outline: none;
  resize: none;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-primary);
  tab-size: 2;
  overflow-y: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
}

/* Resizer Divider Bar */
.resizer {
  width: 6px;
  background-color: var(--bg-secondary);
  border-left: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
  cursor: col-resize;
  transition: background-color 0.2s ease;
  z-index: 5;
  flex-shrink: 0;
}

.resizer:hover, .resizer.dragging {
  background-color: var(--accent-primary);
}

/* Preview Pane */
.preview-pane {
  flex: 1;
  background-color: var(--preview-bg);
}

.preview-wrapper {
  flex: 1;
  overflow-y: auto;
  padding: 24px 32px;
}

/* Markdown Rendered Typography */
.markdown-body {
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
  max-width: 900px;
  margin: 0 auto;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
  margin-top: 1.6em;
  margin-bottom: 0.6em;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
  scroll-margin-top: 20px;
}

.markdown-body h1:first-child { margin-top: 0; }

.markdown-body h1 {
  font-size: 2em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--border-color);
}

.markdown-body h2 {
  font-size: 1.5em;
  padding-bottom: 0.2em;
  border-bottom: 1px solid var(--border-light);
}

.markdown-body h3 { font-size: 1.25em; }
.markdown-body h4 { font-size: 1.1em; }
.markdown-body h5 { font-size: 1em; }
.markdown-body h6 { font-size: 0.9em; color: var(--text-secondary); }

.markdown-body p {
  margin-bottom: 1.1em;
}

.markdown-body a {
  color: var(--accent-primary);
  text-decoration: none;
  border-bottom: 1px dashed var(--accent-primary);
}

.markdown-body a:hover {
  text-decoration: none;
  border-bottom-style: solid;
}

.markdown-body strong {
  font-weight: 600;
  color: var(--text-primary);
}

.markdown-body em {
  font-style: italic;
}

.markdown-body del {
  color: var(--text-muted);
}

.markdown-body blockquote {
  margin: 1.2em 0;
  padding: 10px 18px;
  border-left: 4px solid var(--accent-primary);
  background-color: var(--accent-light);
  border-radius: 0 6px 6px 0;
  color: var(--text-secondary);
}

.markdown-body blockquote p:last-child {
  margin-bottom: 0;
}

.markdown-body ul,
.markdown-body ol {
  margin-bottom: 1.1em;
  padding-left: 1.8em;
}

.markdown-body li {
  margin-bottom: 0.3em;
}

.markdown-body li input[type="checkbox"] {
  margin-right: 8px;
  accent-color: var(--accent-primary);
  transform: scale(1.1);
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.4em;
  font-size: 14px;
  overflow-x: auto;
  display: block;
}

.markdown-body th,
.markdown-body td {
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  text-align: left;
}

.markdown-body th {
  background-color: var(--bg-secondary);
  font-weight: 600;
  color: var(--text-primary);
}

.markdown-body tr:nth-child(even) {
  background-color: rgba(255, 255, 255, 0.02);
}

html.light .markdown-body tr:nth-child(even) {
  background-color: rgba(0, 0, 0, 0.02);
}

.markdown-body hr {
  height: 1px;
  border: none;
  background-color: var(--border-color);
  margin: 2em 0;
}

.markdown-body img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: 1em 0;
  border: 1px solid var(--border-color);
}

/* Code Blocks & Inline Code */
.markdown-body code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  padding: 2px 6px;
  background-color: var(--code-bg);
  border-radius: 4px;
  color: var(--accent-primary);
}

.markdown-body pre {
  position: relative;
  margin: 1.2em 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border-color);
  background-color: var(--code-bg) !important;
}

.markdown-body pre code {
  display: block;
  padding: 16px;
  overflow-x: auto;
  background: transparent !important;
  color: inherit;
  font-size: 13px;
  line-height: 1.5;
}

.code-copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 8px;
  font-size: 11px;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s ease, background 0.15s ease;
}

.markdown-body pre:hover .code-copy-btn {
  opacity: 1;
}

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

/* Math (KaTeX) */
.katex-display {
  margin: 1.2em 0 !important;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 8px 0;
}

/* Mermaid Diagrams */
.mermaid-block {
  text-align: center;
  margin: 1.5em 0;
  padding: 16px;
  background-color: var(--bg-secondary);
  border-radius: 8px;
  border: 1px solid var(--border-color);
  overflow-x: auto;
}

/* Footer */
.app-footer {
  height: var(--footer-height);
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-muted);
  z-index: 20;
}

.footer-info {
  display: flex;
  align-items: center;
  gap: 6px;
}

.status-indicator {
  color: var(--success);
  font-size: 8px;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 36px;
  right: 20px;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--accent-primary);
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 13px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 1000;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

/* Print/PDF Media Styling */
@media print {
  .app-header, .toolbar, .editor-pane, .resizer, .toc-sidebar, .app-footer {
    display: none !important;
  }

  body, .app-container, .workspace, .preview-pane, .preview-wrapper {
    height: auto !important;
    overflow: visible !important;
    background: #fff !important;
    color: #000 !important;
  }

  .preview-wrapper {
    padding: 0 !important;
  }

  .markdown-body {
    max-width: 100% !important;
    color: #000 !important;
  }

  .markdown-body h1, .markdown-body h2 {
    border-bottom: 1px solid #ccc !important;
  }

  .markdown-body pre, .markdown-body table {
    border: 1px solid #ccc !important;
    page-break-inside: avoid;
  }

  .code-copy-btn { display: none !important; }
}

/* Responsive Breakpoints */
@media (max-width: 768px) {
  .title-group h1 { font-size: 14px; }
  .badge { display: none; }
  .btn-group span { display: none; }
  .toolbar { gap: 2px; }
  .preview-wrapper { padding: 16px; }
}