:root {
  color-scheme: dark;
  --editor-width: 50%;

  /* Shared "vx" tool-family palette (matches vxgraph/vxglobe/vxspan) */
  --bg: #14161c;
  --panel: #1e2129;
  --panel-2: #24272c;
  --border: #2c303a;
  --text: #f2f3f5;
  --muted: #9aa0ab;
  --accent: #5b8cff;
  --accent-ink: #0c1220;
  --error: #ff6b6b;

  /* The rendered document is a "paper" page floating in the dark chrome —
     stays light regardless of app theme, since it's what actually prints. */
  --paper: #ffffff;
  --paper-ink: #1c1f24;
  --paper-border: #e2e4e8;
  --paper-muted: #555b66;

  --toolbar-h: 56px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.toolbar {
  height: var(--toolbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.toolbar h1 {
  font-size: 16px;
  font-weight: 600;
  margin: 0;
  letter-spacing: 0.02em;
  color: var(--text);
}

.actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.btn {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--panel-2);
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text);
  user-select: none;
  transition: border-color 0.15s ease, filter 0.15s ease;
}

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

.btn.primary {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: var(--accent);
  font-weight: 600;
}

.btn.primary:hover {
  border-color: var(--accent);
  filter: brightness(1.1);
}

.workspace {
  display: grid;
  grid-template-columns: var(--editor-width) 6px 1fr;
  height: calc(100vh - var(--toolbar-h));
}

.pane {
  min-width: 0;
  overflow: auto;
}

.editor-pane {
  background: var(--panel);
}

.editor-pane #editor {
  width: 100%;
  height: 100%;
  border: none;
  resize: none;
  padding: 20px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 14px;
  line-height: 1.6;
  outline: none;
  background: transparent;
  color: var(--text);
  caret-color: var(--accent);
}

.editor-pane #editor::placeholder {
  color: var(--muted);
}

.divider {
  cursor: col-resize;
  background: var(--border);
  transition: background 0.15s ease;
}

.divider:hover {
  background: var(--accent);
}

.preview-pane {
  background: var(--bg);
  padding: 28px;
}

.markdown-body {
  background: var(--paper);
  color: var(--paper-ink);
  padding: 40px;
  max-width: 820px;
  margin: 0 auto;
  line-height: 1.65;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.45);
  user-select: text;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3 {
  border-bottom: 1px solid var(--paper-border);
  padding-bottom: 6px;
}

.markdown-body pre {
  background: #f2f3f5;
  padding: 12px 14px;
  border-radius: 6px;
  overflow: auto;
}

.markdown-body code {
  background: #f2f3f5;
  padding: 1px 5px;
  border-radius: 4px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.markdown-body pre code {
  background: none;
  padding: 0;
}

.markdown-body blockquote {
  margin: 0;
  padding: 2px 16px;
  border-left: 4px solid var(--paper-border);
  color: var(--paper-muted);
}

.markdown-body table {
  border-collapse: collapse;
  width: 100%;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--paper-border);
  padding: 6px 10px;
}

.markdown-body img,
.markdown-body .plantuml-diagram {
  max-width: 100%;
}

.markdown-body .mermaid {
  text-align: center;
}

/* Print / PDF export: show only the rendered document, on plain paper.
   Margins come from @page (repeats on every printed page, unlike element
   padding) so the exported PDF keeps roughly the same framing the on-screen
   "paper" card shows, instead of the browser's arbitrary default margin. */
@page {
  margin: 1.5cm;
}

@media print {
  .toolbar,
  .editor-pane,
  .divider {
    display: none !important;
  }

  .workspace {
    display: block;
    height: auto;
  }

  .preview-pane {
    background: none;
    overflow: visible;
    height: auto;
    padding: 0;
  }

  .markdown-body {
    max-width: none;
    padding: 0;
    margin: 0;
    border-radius: 0;
    box-shadow: none;
  }
}

@media (max-width: 760px) {
  .workspace {
    grid-template-columns: 1fr;
    grid-auto-rows: 1fr;
  }
  .divider { display: none; }
  .preview-pane { padding: 16px; }
}