:root {
  color-scheme: light dark;
  --bg: #FBFBFA;
  --side: #EDEFF2;
  --ink: #1B2027;
  --muted: #626E7B;
  --line: #D6DBE1;
  --hover: #E0E4E9;
  --accent: #0E7C7B;
  --accent-ink: #FFFFFF;
  --accent-soft: #D3EDEB;
  --danger: #B3261E;
  --code-bg: #EFF1F4;
  --ui: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Charter, Georgia, serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14181D;
    --side: #1A1F26;
    --ink: #E4E8EC;
    --muted: #8D99A7;
    --line: #2B323B;
    --hover: #252C35;
    --accent: #4FC9BE;
    --accent-ink: #0B1B1A;
    --accent-soft: #173A3A;
    --danger: #F2B8B5;
    --code-bg: #1E242C;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 14px/1.45 var(--ui); }
button, input, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
[hidden] { display: none !important; }

button {
  background: transparent; border: 1px solid var(--line); border-radius: 6px;
  padding: 5px 11px; cursor: pointer;
}
button:hover { background: var(--hover); }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 600; }
button.primary:hover { filter: brightness(1.08); }
button.danger { background: var(--danger); border-color: var(--danger); color: var(--bg); }
button.link { border: 0; padding: 4px 0; color: var(--muted); }
button.link:hover { background: none; color: var(--ink); text-decoration: underline; }
input[type=text], input[type=password], input[type=search] {
  width: 100%; padding: 7px 9px; border: 1px solid var(--line); border-radius: 6px; background: var(--bg);
}

/* Layout */
.app { display: grid; grid-template-columns: 288px 1fr; height: 100vh; height: 100dvh; }
.sidebar { background: var(--side); border-right: 1px solid var(--line); display: flex; flex-direction: column; min-height: 0; }
.side-head { padding: 14px 12px 8px; display: grid; gap: 10px; }
.brand { margin: 0; font: 700 18px/1 var(--serif); letter-spacing: 0.01em; }
.side-actions { display: flex; gap: 6px; }
.tree { flex: 1; overflow: auto; padding: 4px 6px 12px; min-height: 0; }
.side-foot { border-top: 1px solid var(--line); padding: 8px 14px; }
.main { display: flex; flex-direction: column; min-width: 0; min-height: 0; }

/* Tree */
.tree-list { list-style: none; margin: 0; padding: 0; }
.tree-empty, .search-empty { color: var(--muted); padding: 10px 8px; margin: 0; }
.row { display: flex; align-items: center; padding-left: calc(2px + var(--depth, 0) * 14px); border-radius: 6px; }
.row:hover { background: var(--hover); }
.item {
  flex: 1; min-width: 0; text-align: left; border: 0; background: none; padding: 5px 6px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.item:hover { background: none; }
.item::before { content: ""; display: inline-block; width: 1.15em; color: var(--muted); }
.item.dir { font-weight: 600; }
.item.dir::before { content: "\25B8"; }
.item.dir[aria-expanded="true"]::before { content: "\25BE"; }
.row.active { background: var(--accent-soft); }
.row.active .item { font-weight: 600; }
.more { border: 0; padding: 2px 8px; color: var(--muted); opacity: 0; line-height: 1; }
.row:hover .more, .row:focus-within .more, .more:focus-visible { opacity: 1; }
@media (hover: none) { .more { opacity: 1; } }

.hit { display: block; width: 100%; text-align: left; border: 0; border-radius: 6px; padding: 6px 8px; }
.hit .hit-path { display: block; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.hit .hit-snip { display: block; color: var(--muted); font-size: 12.5px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* Top bar */
.topbar { display: flex; align-items: center; gap: 12px; padding: 8px 14px; border-bottom: 1px solid var(--line); min-height: 48px; }
.note-title { margin: 0; flex: 1; min-width: 0; font: 600 14px/1.2 var(--ui); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.note-title .dir { color: var(--muted); font-weight: 400; }
.save-status { color: var(--muted); font-size: 12.5px; white-space: nowrap; }
.save-status.error { color: var(--danger); }
.segmented { display: inline-flex; }
.segmented button { border-radius: 0; margin-left: -1px; }
.segmented button:first-child { border-radius: 6px 0 0 6px; margin-left: 0; }
.segmented button:last-child { border-radius: 0 6px 6px 0; }
.segmented button[aria-pressed="true"] { background: var(--accent-soft); border-color: var(--accent); position: relative; z-index: 1; font-weight: 600; }
.only-narrow { display: none; }

/* Empty state */
.empty { flex: 1; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; padding: 0 12%; gap: 4px; }
.empty h2 { margin: 0; font: 700 26px/1.2 var(--serif); }
.empty p { margin: 0 0 14px; color: var(--muted); }

/* Workspace */
.workspace { flex: 1; display: grid; grid-template-columns: 1fr 1fr; min-height: 0; }
.workspace.mode-edit { grid-template-columns: 1fr; }
.workspace.mode-edit .preview { display: none; }
.workspace.mode-preview { grid-template-columns: 1fr; }
.workspace.mode-preview .editor { display: none; }
.editor {
  border: 0; outline: 0; resize: none; background: var(--bg); color: var(--ink);
  padding: 24px 28px 40vh; font: 14px/1.7 var(--mono); tab-size: 2; min-width: 0; min-height: 0;
}
.preview { overflow: auto; padding: 24px 40px 40vh; border-left: 1px solid var(--line); min-width: 0; }
.mode-preview .preview { border-left: 0; }
.mode-preview .markdown { margin-inline: auto; }

/* Rendered markdown */
.markdown { font: 17px/1.65 var(--serif); max-width: 68ch; overflow-wrap: break-word; }
.markdown > :first-child { margin-top: 0; }
.markdown h1, .markdown h2, .markdown h3, .markdown h4, .markdown h5, .markdown h6 { line-height: 1.25; margin: 1.6em 0 0.5em; }
.markdown h1 { font-size: 1.9em; }
.markdown h2 { font-size: 1.5em; padding-bottom: 0.2em; border-bottom: 1px solid var(--line); }
.markdown h3 { font-size: 1.22em; }
.markdown h4, .markdown h5, .markdown h6 { font-size: 1em; }
.markdown p, .markdown ul, .markdown ol, .markdown pre, .markdown blockquote, .markdown table { margin: 0 0 1em; }
.markdown a { color: var(--accent); }
.markdown code { font: 0.86em var(--mono); background: var(--code-bg); padding: 0.12em 0.35em; border-radius: 4px; }
.markdown pre { background: var(--code-bg); padding: 12px 14px; border-radius: 8px; overflow: auto; line-height: 1.5; }
.markdown pre code { background: none; padding: 0; font-size: 0.85em; }
.markdown blockquote { margin-left: 0; padding: 0 0 0 1em; border-left: 3px solid var(--accent); color: var(--muted); }
.markdown img { max-width: 100%; height: auto; }
.markdown hr { border: 0; border-top: 1px solid var(--line); margin: 2em 0; }
.markdown table { border-collapse: collapse; display: block; overflow-x: auto; }
.markdown th, .markdown td { border: 1px solid var(--line); padding: 5px 10px; }
.markdown th { background: var(--code-bg); }
.markdown li:has(> input[type=checkbox]) { list-style: none; margin-left: -1.3em; }
.markdown input[type=checkbox] { margin-right: 0.5em; }

/* Menu & dialog */
.menu {
  position: fixed; z-index: 20; list-style: none; margin: 0; padding: 4px; min-width: 170px;
  background: var(--bg); border: 1px solid var(--line); border-radius: 8px; box-shadow: 0 6px 24px rgba(0, 0, 0, 0.18);
}
.menu button { display: block; width: 100%; text-align: left; border: 0; border-radius: 5px; padding: 7px 10px; }
.menu button.danger { background: none; color: var(--danger); }
.menu button.danger:hover { background: var(--hover); }
dialog { border: 1px solid var(--line); border-radius: 10px; background: var(--bg); color: var(--ink); padding: 20px; width: min(420px, 92vw); }
dialog::backdrop { background: rgba(0, 0, 0, 0.4); }
dialog h2 { margin: 0 0 6px; font: 700 18px/1.3 var(--serif); }
dialog p { margin: 0 0 12px; color: var(--muted); }
dialog p:empty { display: none; }
.dlg-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 16px; }

/* Login */
.login-page { display: grid; place-items: center; }
.login { width: min(340px, 90vw); }
.login form { display: grid; gap: 8px; }
.login h1 { margin: 0 0 12px; font: 700 28px/1.1 var(--serif); }
.login label { font-weight: 600; }
.login .error { margin: 0; color: var(--danger); }
.login button { margin-top: 8px; padding: 8px 12px; }

/* Narrow screens: sidebar becomes a drawer, split view becomes edit */
@media (max-width: 760px) {
  .app { grid-template-columns: 1fr; }
  .sidebar { position: fixed; inset: 0 22% 0 0; z-index: 10; transform: translateX(-100%); transition: transform 0.15s; min-width: 260px; }
  .sidebar-open .sidebar { transform: none; box-shadow: 8px 0 30px rgba(0, 0, 0, 0.25); }
  .only-narrow { display: inline-block; }
  .split-btn { display: none; }
  .workspace.mode-split { grid-template-columns: 1fr; }
  .workspace.mode-split .preview { display: none; }
  .editor { padding: 16px 16px 40vh; }
  .preview { padding: 16px 16px 40vh; }
  .empty { padding: 0 24px; }
}
@media (prefers-reduced-motion: reduce) { .sidebar { transition: none; } }