/* ===== Type families ===== */
:root {
  --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  /* Reading font is user-selectable via [data-font]; defaults to Lora (serif). */
  --font-read: 'Lora', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
:root[data-font="lora"] { --font-read: 'Lora', Georgia, 'Times New Roman', serif; }
:root[data-font="inter"] { --font-read: var(--font-ui); }

/* ===== Theme tokens ===== */
/* Light: warm paper, gently reduced contrast (off-white bg, soft near-black ink). */
:root {
  --bg: #faf8f3;
  --bg-soft: #f1ece2;
  --bg-sidebar: #f3eee5;
  --fg: #353029;
  --fg-soft: #756c5e;
  --border: #e5ddcf;
  --accent: #3c6797;
  --accent-soft: #ece2d2;
  --danger: #b5402f;
  --code-bg: #f2ece0;
  --sel: #e3d9c4;
  --sidebar-w: 286px;
  --reading-max: 720px;
  font-family: var(--font-ui);
}
/* Dark: warm off-black (lifted from pure black), soft off-white ink — lower contrast. */
:root[data-theme="dark"] {
  --bg: #1b1a17;
  --bg-soft: #242219;
  --bg-sidebar: #211f1a;
  --fg: #d9d3c6;
  --fg-soft: #9a9183;
  --border: #34322b;
  --accent: #8fb1d6;
  --accent-soft: #2c2920;
  --danger: #e0796a;
  --code-bg: #232119;
  --sel: #3a3525;
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-ui);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--sel); }
kbd {
  font-family: var(--font-mono);
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 5px; padding: 1px 5px; font-size: 0.8em;
}

/* ===== Login ===== */
.login-body { display: grid; place-items: center; height: 100vh; }
.login-card {
  display: flex; flex-direction: column; gap: 13px;
  width: 300px; padding: 32px; border: 1px solid var(--border);
  border-radius: 14px; background: var(--bg-soft);
  box-shadow: 0 10px 40px rgba(0,0,0,0.06);
}
.login-logo {
  margin: 0; text-align: center;
  font-family: var(--font-read); font-style: italic; font-weight: 500;
  font-size: 2.6rem; letter-spacing: -0.5px;
}
.login-sub { margin: 0 0 4px; text-align: center; color: var(--fg-soft); font-size: 0.9rem; }
.login-card input, .login-card button {
  padding: 11px 13px; border-radius: 9px; border: 1px solid var(--border);
  font-size: 1rem; font-family: var(--font-ui); background: var(--bg); color: var(--fg);
}
.login-card input:focus { outline: none; border-color: var(--accent); }
.login-card button {
  background: var(--accent); color: #fff; border: none; cursor: pointer; font-weight: 600;
}
.login-error { margin: 0; color: var(--danger); text-align: center; font-size: 0.85rem; }

/* ===== Layout ===== */
#app { display: flex; height: 100vh; overflow: hidden; }

#sidebar {
  width: var(--sidebar-w); flex: 0 0 var(--sidebar-w);
  background: var(--bg-sidebar); border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  transition: margin-left 0.2s ease;
}
#app.sidebar-collapsed #sidebar { margin-left: calc(-1 * var(--sidebar-w)); }

.sidebar-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 18px; border-bottom: 1px solid var(--border);
}
.logo {
  font-family: var(--font-read); font-style: italic; font-weight: 500;
  font-size: 1.7rem; letter-spacing: -0.3px; line-height: 1;
}
.search-wrap { padding: 12px; }
#search {
  width: 100%; padding: 9px 11px; border-radius: 9px;
  border: 1px solid var(--border); background: var(--bg); color: var(--fg);
  font-size: 0.92rem; font-family: var(--font-ui);
}
#search:focus { outline: none; border-color: var(--accent); }

.doc-list { list-style: none; margin: 0; padding: 4px 9px; overflow-y: auto; flex: 1; }
.doc-item {
  display: flex; align-items: center; gap: 6px;
  padding: 9px 11px; border-radius: 9px; cursor: pointer;
  color: var(--fg); font-size: 0.92rem; line-height: 1.35;
}
.doc-item:hover { background: var(--bg-soft); }
.doc-item.active { background: var(--accent-soft); font-weight: 500; }
.doc-item.dragging { opacity: 0.4; }
.doc-item.drag-over { box-shadow: inset 0 2px 0 var(--accent); }
.doc-title { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.doc-title-input {
  flex: 1; font: inherit; border: 1px solid var(--accent);
  border-radius: 5px; padding: 2px 5px; background: var(--bg); color: var(--fg);
}
.doc-actions { display: none; gap: 2px; }
.doc-item:hover .doc-actions { display: flex; }
.doc-actions button {
  background: none; border: none; cursor: pointer; color: var(--fg-soft);
  padding: 2px 4px; border-radius: 5px; font-size: 0.85rem;
}
.doc-actions button:hover { color: var(--fg); background: var(--bg); }

.sidebar-foot {
  display: flex; align-items: center; gap: 8px; padding: 11px 13px; border-top: 1px solid var(--border);
}
.font-picker {
  display: inline-flex; align-items: center; gap: 5px;
  color: var(--fg-soft); font-size: 0.85rem; cursor: pointer;
}
.font-picker > span {
  font-family: var(--font-read); font-weight: 600; font-size: 1rem; line-height: 1;
}
.font-picker select {
  appearance: none; -webkit-appearance: none;
  background: none; border: 1px solid var(--border); color: var(--fg);
  font-family: var(--font-ui); font-size: 0.82rem;
  padding: 4px 7px; border-radius: 7px; cursor: pointer;
}
.font-picker select:hover { background: var(--bg-soft); }
.font-picker select:focus { outline: none; border-color: var(--accent); }
.text-btn {
  background: none; border: none; color: var(--fg-soft); cursor: pointer;
  font-size: 0.85rem; font-family: var(--font-ui); padding: 5px 7px; border-radius: 7px;
}
.text-btn:hover { color: var(--fg); background: var(--bg-soft); }
.icon-btn {
  background: none; border: 1px solid transparent; cursor: pointer;
  color: var(--fg); font-size: 1.15rem; line-height: 1;
  padding: 4px 9px; border-radius: 9px;
}
.icon-btn:hover { background: var(--bg-soft); }

#sidebar-toggle {
  position: fixed; top: 12px; left: 12px; z-index: 20;
  background: var(--bg-soft); border: 1px solid var(--border);
  display: none;
}
#app.sidebar-collapsed #sidebar-toggle { display: block; }

#main { flex: 1; overflow-y: auto; padding: 64px 40px 110px; }

.empty-state {
  max-width: 520px; margin: 16vh auto 0; text-align: center; color: var(--fg-soft);
}
.empty-state h2 {
  color: var(--fg); font-family: var(--font-read); font-weight: 500;
  font-size: 1.9rem; letter-spacing: -0.2px;
}
.empty-state p { font-size: 1.02rem; line-height: 1.6; }

/* ===== Markdown reading typography ===== */
.markdown-body {
  max-width: var(--reading-max); margin: 0 auto;
  font-family: var(--font-read);
  font-size: 1.235rem;        /* ~20px — larger, comfortable reading size */
  line-height: 1.78;
  word-wrap: break-word;
  font-feature-settings: "kern", "liga", "clig", "onum", "pnum";
  font-variant-numeric: oldstyle-nums proportional-nums;
}
.markdown-body > :first-child { margin-top: 0; }

.markdown-body h1, .markdown-body h2, .markdown-body h3,
.markdown-body h4, .markdown-body h5, .markdown-body h6 {
  font-family: var(--font-read);
  line-height: 1.2; letter-spacing: -0.012em;
  margin: 1.9em 0 0.55em; font-weight: 600;
}
.markdown-body h1 {
  font-size: 2.45rem; font-weight: 700; letter-spacing: -0.022em;
  margin-top: 0.2em; padding-bottom: 0.28em; border-bottom: 1px solid var(--border);
}
.markdown-body h2 {
  font-size: 1.78rem; font-weight: 600; letter-spacing: -0.016em;
  padding-bottom: 0.25em; border-bottom: 1px solid var(--border);
}
.markdown-body h3 { font-size: 1.42rem; }
.markdown-body h4 { font-size: 1.18rem; }
.markdown-body h5, .markdown-body h6 {
  font-size: 0.95rem; font-family: var(--font-ui); font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.06em; color: var(--fg-soft);
}

.markdown-body p, .markdown-body ul, .markdown-body ol, .markdown-body blockquote { margin: 0 0 1.05em; }
.markdown-body li { margin: 0.25em 0; }
.markdown-body li > ul, .markdown-body li > ol { margin: 0.25em 0; }
.markdown-body em { font-style: italic; }
.markdown-body strong { font-weight: 700; }

.markdown-body a {
  color: var(--accent); text-decoration: underline;
  text-decoration-thickness: 1px; text-underline-offset: 2px;
  text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent);
}
.markdown-body a:hover { text-decoration-color: var(--accent); }

.markdown-body img { max-width: 100%; border-radius: 10px; }

.markdown-body blockquote {
  margin-left: 0; padding: 0.1em 1.15em; color: var(--fg-soft);
  border-left: 3px solid var(--accent); font-style: italic;
}
.markdown-body blockquote p { margin-bottom: 0.5em; }

/* Code uses mono + tabular figures; opt out of body's oldstyle numerals. */
.markdown-body code, .markdown-body pre {
  font-family: var(--font-mono);
  font-variant-numeric: normal; font-feature-settings: normal;
}
.markdown-body code {
  background: var(--code-bg); padding: 0.15em 0.4em; border-radius: 6px;
  font-size: 0.82em;
}
.markdown-body pre {
  background: var(--code-bg); padding: 18px 20px; border-radius: 12px;
  overflow-x: auto; border: 1px solid var(--border);
  line-height: 1.6; margin: 0 0 1.2em;
}
.markdown-body pre code { background: none; padding: 0; font-size: 0.86rem; }

.markdown-body table {
  border-collapse: collapse; width: auto; max-width: 100%; margin: 0 0 1.2em;
  display: block; overflow-x: auto;
  font-family: var(--font-ui); font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}
.markdown-body th, .markdown-body td { border: 1px solid var(--border); padding: 8px 14px; }
.markdown-body th { background: var(--bg-soft); font-weight: 600; }
.markdown-body tr:nth-child(2n) td { background: color-mix(in srgb, var(--bg-soft) 55%, transparent); }

.markdown-body hr {
  border: none; height: 1px; background: var(--border);
  margin: 2.4em auto; width: 60%;
}
.markdown-body .task-list-item { list-style: none; }
.markdown-body .task-list-item input { margin: 0 0.55em 0 -1.5em; transform: translateY(1px); }
.markdown-body ul.contains-task-list { padding-left: 1.5em; }

.mermaid-rendered { display: flex; justify-content: center; margin: 1.6em 0; }
.mermaid-rendered svg { max-width: 100%; height: auto; }
.mermaid-error { color: var(--danger); border-color: var(--danger); }

/* KaTeX: nudge size to harmonize with larger serif body. */
.markdown-body .katex { font-size: 1.04em; }

/* ===== Toast ===== */
.toast {
  position: fixed; bottom: 26px; left: 50%; transform: translateX(-50%);
  background: var(--fg); color: var(--bg); padding: 10px 20px; border-radius: 999px;
  font-size: 0.9rem; font-family: var(--font-ui); z-index: 50;
  box-shadow: 0 6px 22px rgba(0,0,0,0.22);
}

/* ===== Mobile ===== */
@media (max-width: 720px) {
  #sidebar { position: fixed; z-index: 30; height: 100%; box-shadow: 2px 0 16px rgba(0,0,0,0.2); }
  #main { padding: 60px 22px 90px; }
  .markdown-body { font-size: 1.16rem; }
  .markdown-body h1 { font-size: 2.05rem; }
  .markdown-body h2 { font-size: 1.55rem; }
}