/* ============================================================
   Markread — "a quiet reading room"
   Warm, literary, paper-first. Three reading themes.
   ============================================================ */

/* ---------- Themes ---------- */
:root {
  /* 100% system fonts — nothing downloaded, instant, offline, native.
     ui-serif → New York on Apple, a refined reading serif; graceful
     fallbacks to Iowan/Charter/Palatino/Georgia elsewhere. */
  --serif: ui-serif, "New York", "Iowan Old Style", Charter, "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --display: var(--serif);
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --ui: ui-monospace, "SF Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;
  --mono: ui-monospace, "SF Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  --body: var(--serif);          /* reading typeface, toggled */
  --reading-scale: 1.12;         /* text size multiplier */
  --measure: 42rem;              /* reading line width */

  --radius: 10px;
  --ease: cubic-bezier(.22,.61,.36,1);
  --sidebar-w: 17rem;
  --toc-w: 14rem;
}

html[data-theme="day"] {
  --paper:    #faf6ee;
  --paper-2:  #f3ecdf;
  --surface:  #f5eee1;
  --ink:      #2c2620;
  --ink-soft: #5b5347;
  --ink-faint:#8c8474;
  --line:     #e2d8c5;
  --line-2:   #d8ccb4;
  --accent:   #b6502f;   /* ember */
  --accent-soft:#e7c9bb;
  --sel:      #f0d9cb;
  --shadow:   0 1px 2px rgba(60,45,25,.05), 0 8px 30px -12px rgba(80,55,25,.18);
  --grain: .035;
  /* code tokens */
  --c-bg:#f1e9da; --c-kw:#9a3b2e; --c-str:#5e6f3f; --c-num:#9a6b2e;
  --c-com:#a59a85; --c-fn:#7a5a2c; --c-var:#3a4b6b; --c-punc:#7d7361;
  color-scheme: light;
}
html[data-theme="sepia"] {
  --paper:    #f3e7d2;
  --paper-2:  #ecdcc1;
  --surface:  #ecdcc2;
  --ink:      #41372a;
  --ink-soft: #6a5b46;
  --ink-faint:#9a8868;
  --line:     #ddc9a7;
  --line-2:   #d2bb93;
  --accent:   #a8542a;
  --accent-soft:#e0c19f;
  --sel:      #ecd3a8;
  --shadow:   0 1px 2px rgba(80,55,20,.06), 0 8px 30px -12px rgba(90,60,20,.22);
  --grain: .04;
  --c-bg:#e9d7b6; --c-kw:#9a3b22; --c-str:#5f6a38; --c-num:#94591f;
  --c-com:#ab9871; --c-fn:#7a541f; --c-var:#43507a; --c-punc:#83734f;
  color-scheme: light;
}
html[data-theme="night"] {
  --paper:    #16140f;
  --paper-2:  #1d1a14;
  --surface:  #1b1812;
  --ink:      #e9e1d2;
  --ink-soft: #b3a890;
  --ink-faint:#7d735f;
  --line:     #2c281f;
  --line-2:   #3a3327;
  --accent:   #e0894b;   /* warm amber */
  --accent-soft:#4a3a28;
  --sel:      #3a2f1f;
  --shadow:   0 1px 2px rgba(0,0,0,.3), 0 14px 40px -16px rgba(0,0,0,.6);
  --grain: .05;
  --c-bg:#211d16; --c-kw:#e08a55; --c-str:#a8b87a; --c-num:#d8a35a;
  --c-com:#6b6453; --c-fn:#d8b97a; --c-var:#8fa6c8; --c-punc:#8a8068;
  color-scheme: dark;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
/* the [hidden] attribute must win over class rules that set `display`
   (e.g. .popover{display:flex}, .icon-btn{display:grid}) */
[hidden] { display: none !important; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-optical-sizing: auto;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background .4s var(--ease), color .4s var(--ease);
  overflow: hidden;
}
/* paper grain */
body::before {
  content: "";
  position: fixed; inset: 0;
  pointer-events: none; z-index: 9999;
  opacity: var(--grain);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: multiply;
}
html[data-theme="night"] body::before { mix-blend-mode: screen; }

::selection { background: var(--sel); }
button { font: inherit; color: inherit; cursor: pointer; background: none; border: none; }
input { font: inherit; }

/* nicer scrollbars */
* { scrollbar-width: thin; scrollbar-color: var(--line-2) transparent; }
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 10px; border: 3px solid transparent; background-clip: padding-box; }
*::-webkit-scrollbar-thumb:hover { background: var(--ink-faint); background-clip: padding-box; }

/* ---------- Progress bar ---------- */
.progress { position: fixed; top: 0; left: 0; right: 0; height: 2px; z-index: 60; pointer-events: none; }
.progress span { display: block; height: 100%; width: 0; background: var(--accent); transition: width .12s linear; }

/* ---------- App shell ---------- */
.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  height: 100dvh;
}
.app[data-sidebar="hidden"] { grid-template-columns: 0 1fr; }

/* ================= Sidebar ================= */
.sidebar {
  display: flex; flex-direction: column;
  min-height: 0;
  background: var(--surface);
  border-right: 1px solid var(--line);
  overflow: hidden;
  transition: opacity .25s var(--ease);
}
.app[data-sidebar="hidden"] .sidebar { opacity: 0; pointer-events: none; }

.brand {
  display: flex; align-items: center; gap: .55rem;
  padding: 1.05rem 1rem .7rem 1.1rem;
}
.brand__mark { color: var(--accent); display: grid; place-items: center; }
.brand__name {
  font-family: var(--display);
  font-weight: 560;
  font-size: 1.18rem;
  letter-spacing: -.01em;
  flex: 1;
}
.brand__collapse { color: var(--ink-faint); }

.sources { display: flex; gap: .4rem; padding: 0 1rem .7rem; }
.src-btn {
  flex: 1; min-width: 0; display: flex; align-items: center; justify-content: center; gap: .32rem;
  padding: .5rem .3rem; white-space: nowrap; overflow: hidden;
  font-family: var(--ui); font-size: .7rem; letter-spacing: .01em;
  color: var(--ink-soft);
  border: 1px solid var(--line-2); border-radius: 8px;
  background: var(--paper);
  transition: .18s var(--ease);
}
.src-btn:hover { color: var(--ink); border-color: var(--accent); transform: translateY(-1px); }
.src-btn svg { color: var(--accent); flex-shrink: 0; }
.src-btn--new { color: var(--accent); border-color: var(--accent-soft); }

.curfolder {
  display: flex; align-items: center; gap: .4rem;
  margin: 0 1rem .55rem; padding: .42rem .55rem;
  border: 1px solid var(--line-2); border-radius: 8px; background: var(--paper-2);
  font-family: var(--ui); font-size: .72rem; color: var(--ink-soft);
}
.curfolder > svg { color: var(--accent); flex: none; }
.curfolder__name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.curfolder__close { color: var(--ink-faint); display: grid; place-items: center; width: 1.35rem; height: 1.35rem; border-radius: 6px; flex: none; transition: .14s var(--ease); }
.curfolder__close:hover { color: var(--accent); background: var(--paper); }

.search {
  display: flex; align-items: center; gap: .5rem;
  margin: 0 1rem .6rem;
  padding: .42rem .6rem;
  border: 1px solid var(--line-2); border-radius: 8px;
  background: var(--paper);
  color: var(--ink-faint);
}
.search input {
  border: none; outline: none; background: none; width: 100%;
  font-family: var(--ui); font-size: .8rem; color: var(--ink);
}
.search input::placeholder { color: var(--ink-faint); }

.tree {
  flex: 1; min-height: 0; overflow-y: auto;
  padding: .2rem .55rem 1rem;
}
.tree details { margin: 0; }
.tree summary {
  list-style: none; cursor: pointer;
  display: flex; align-items: center; gap: .35rem;
  padding: .28rem .45rem; border-radius: 6px;
  font-family: var(--ui); font-size: .76rem; color: var(--ink-soft);
  user-select: none;
}
.tree summary::-webkit-details-marker { display: none; }
.tree summary:hover { background: var(--paper-2); }
.tree summary .caret { transition: transform .18s var(--ease); color: var(--ink-faint); display: inline-flex; }
.tree details[open] > summary .caret { transform: rotate(90deg); }
.tree .kids { padding-left: .7rem; border-left: 1px solid var(--line); margin-left: .65rem; }

.file {
  display: flex; align-items: baseline; gap: .45rem; width: 100%;
  padding: .3rem .5rem; border-radius: 6px;
  text-align: left; color: var(--ink-soft);
  font-size: .87rem; line-height: 1.3;
  transition: .14s var(--ease);
  animation: rise .4s var(--ease) both;
}
.file:hover { background: var(--paper-2); color: var(--ink); }
.file.is-active { background: var(--accent); color: #fff; }
html[data-theme="night"] .file.is-active { color: #1a1610; }
.file .dot { color: var(--accent); font-size: .7rem; opacity: 0; }
.file.is-active .dot { color: currentColor; }
.file.is-dirty .dot { opacity: 1; }
.file__name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.sidebar__foot {
  border-top: 1px solid var(--line);
  padding: .6rem .9rem;
  display: flex; flex-direction: column; gap: .55rem;
}
/* recent folders — sidebar */
.recents { display: flex; flex-direction: column; }
.recents__toggle {
  display: flex; align-items: center; gap: .45rem; width: 100%;
  padding: .45rem .55rem; border-radius: 8px;
  font-family: var(--ui); font-size: .72rem; letter-spacing: .01em; color: var(--ink-soft);
  transition: .16s var(--ease);
}
.recents__toggle:hover { background: var(--paper-2); color: var(--ink); }
.recents__toggle > span { flex: 1; text-align: left; }
.recents__toggle > svg:first-child { color: var(--accent); flex: none; }
.recents__chev { transition: transform .2s var(--ease); color: var(--ink-faint); flex: none; }
.recents.open .recents__chev { transform: rotate(180deg); }
.recents__list { display: none; flex-direction: column; gap: 1px; margin-top: .25rem; max-height: 11rem; overflow-y: auto; }
.recents.open .recents__list { display: flex; }

.recent-item {
  display: flex; align-items: center; gap: .5rem; width: 100%;
  padding: .4rem .55rem; border-radius: 7px; text-align: left;
  color: var(--ink-soft); transition: .14s var(--ease);
}
.recent-item:hover { background: var(--paper-2); color: var(--ink); }
.recent-item.is-active { color: var(--accent); }
.recent-item > svg { color: var(--ink-faint); flex: none; }
.recent-item.is-active > svg { color: var(--accent); }
.recent-item__name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: .82rem; }
.recent-item__time { font-family: var(--ui); font-size: .62rem; color: var(--ink-faint); flex: none; }
.recent-item__rm {
  flex: none; width: 1.15rem; height: 1.15rem; border-radius: 5px;
  display: grid; place-items: center; font-size: 1rem; line-height: 1;
  color: var(--ink-faint); opacity: 0; transition: .14s var(--ease);
}
.recent-item:hover .recent-item__rm, .recent-item:focus-within .recent-item__rm { opacity: .65; }
.recent-item__rm:hover { opacity: 1; color: var(--accent); background: var(--paper); }
/* when the remove button is present, hide the timestamp on hover so layout stays calm */
.recent-item:hover .recent-item__time { display: none; }

/* recent folders — welcome */
.welcome__recent { margin-top: 1.9rem; }
.welcome__recent-label { font-family: var(--ui); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-faint); margin-bottom: .75rem; }
.welcome__recent-list { display: flex; gap: .5rem; justify-content: center; flex-wrap: wrap; }
.recent-pill {
  display: inline-flex; align-items: center; gap: .45rem;
  padding: .5rem .9rem; border-radius: 999px;
  border: 1px solid var(--line-2); background: var(--paper);
  font-size: .85rem; color: var(--ink); transition: .16s var(--ease); max-width: 16rem;
}
.recent-pill:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.recent-pill > svg { color: var(--accent); flex: none; }
.recent-pill > span:not(.recent-pill__rm) { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.recent-pill__rm {
  flex: none; width: 1.2rem; height: 1.2rem; margin: -.2rem -.45rem -.2rem .1rem;
  border-radius: 50%; display: grid; place-items: center; font-size: 1.05rem; line-height: 1;
  color: var(--ink-faint); transition: .14s var(--ease);
}
.recent-pill__rm:hover { color: var(--accent); background: var(--paper-2); }

.theme-switch { display: flex; gap: .25rem; align-self: flex-start; }
.theme-switch button {
  width: 1.9rem; height: 1.9rem; border-radius: 7px;
  display: grid; place-items: center;
  color: var(--ink-faint); border: 1px solid transparent;
  font-size: .95rem; transition: .16s var(--ease);
}
.theme-switch button:hover { color: var(--ink); background: var(--paper-2); }
.theme-switch button.is-on { color: var(--accent); border-color: var(--line-2); background: var(--paper); }
.theme-switch--wide { gap: .3rem; }
.theme-switch--wide button { width: auto; padding: 0 .7rem; height: 1.8rem; font-family: var(--ui); font-size: .72rem; }

/* ================= Main / reading column ================= */
.main { position: relative; min-width: 0; display: flex; flex-direction: column; height: 100dvh; }

.topbar {
  display: flex; align-items: center; gap: .75rem;
  padding: .55rem .9rem .55rem 1.1rem;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: blur(8px);
  z-index: 30;
}
.topbar__expand { color: var(--ink-soft); }
.doc-meta { flex: 1; min-width: 0; display: flex; flex-direction: column; line-height: 1.15; }
.doc-meta__name {
  font-family: var(--display); font-weight: 520; font-size: 1.02rem;
  letter-spacing: -.01em; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.doc-meta__sub { font-family: var(--ui); font-size: .66rem; color: var(--ink-faint); letter-spacing: .03em; margin-top: .12rem; }

.topbar__actions { display: flex; align-items: center; gap: .35rem; }

.icon-btn {
  width: 2.05rem; height: 2.05rem; border-radius: 8px;
  display: grid; place-items: center; color: var(--ink-soft);
  transition: .16s var(--ease);
}
.icon-btn:hover { color: var(--ink); background: var(--paper-2); }
.icon-btn.is-on { color: var(--accent); background: var(--accent-soft); }

.seg { display: inline-flex; padding: 2px; border: 1px solid var(--line-2); border-radius: 8px; background: var(--paper-2); }
.seg button {
  padding: .28rem .6rem; border-radius: 6px;
  font-family: var(--ui); font-size: .7rem; letter-spacing: .02em; color: var(--ink-faint);
  transition: .16s var(--ease);
}
.seg button:hover { color: var(--ink); }
.seg button.is-on { background: var(--paper); color: var(--ink); box-shadow: var(--shadow); }
.seg--wide button { flex: 1; padding: .35rem .8rem; }

/* panes */
.panes { flex: 1; min-height: 0; display: grid; grid-template-columns: 1fr; }
.app[data-mode="split"] .panes { grid-template-columns: 1fr 1fr; }

.reading-scroll { overflow-y: auto; scroll-behavior: smooth; height: 100%; }
.app[data-mode="edit"] .reading-scroll { display: none; }
.app[data-mode="split"] .reading-scroll { border-left: 1px solid var(--line); order: 2; }

.editor-pane { display: none; height: 100%; min-height: 0; }
.app[data-mode="edit"] .editor-pane,
.app[data-mode="split"] .editor-pane { display: block; }

.editor {
  display: block; width: 100%; height: 100%; resize: none; border: none; outline: none;
  background: var(--paper); color: var(--ink);
  font-family: var(--mono); font-size: 1.01rem; line-height: 1.85;
  padding: clamp(2rem, 5vh, 3.5rem) clamp(1.25rem, 5vw, 2rem) 42vh;
  max-width: 50rem; margin: 0 auto; tab-size: 2;
  caret-color: var(--accent);
}
.app[data-mode="split"] .editor { font-size: .95rem; }
.editor::placeholder { color: var(--ink-faint); }

/* ---------- The reading surface ---------- */
.reading {
  max-width: var(--measure);
  margin: 0 auto;
  padding: clamp(2.2rem, 5vw, 4.5rem) clamp(1.25rem, 5vw, 2rem) 38vh;
  font-size: calc(1.2rem * var(--reading-scale));
  line-height: 1.78;                 /* roomy leading for long sessions */
  color: var(--ink);
  font-variant-numeric: oldstyle-nums proportional-nums;
  letter-spacing: .002em;
  animation: docin .5s var(--ease) both;
}
@keyframes docin { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.reading > * { animation: rise .5s var(--ease) both; }

.reading p { margin: 0 0 1.2em; hanging-punctuation: first allow-end; text-wrap: pretty; }
.reading h1, .reading h2, .reading h3, .reading h4 {
  font-family: var(--display); font-weight: 600; line-height: 1.18;
  letter-spacing: -.006em; color: var(--ink);
  margin: 1.9em 0 .55em; scroll-margin-top: 5rem; text-wrap: balance;
}
.reading h1 { font-size: 2.4em; line-height: 1.1; margin-top: .2em; letter-spacing: -.014em; }
.reading h2 { font-size: 1.66em; margin-top: 1.8em; padding-bottom: .25em; border-bottom: 1px solid var(--line); }
.reading h3 { font-size: 1.3em; }
.reading h4 { font-size: 1.08em; font-weight: 700; }
.reading h5, .reading h6 { font-family: var(--ui); font-size: .8em; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-soft); margin: 2em 0 .5em; }

/* anchor on heading hover */
.reading .anchor {
  opacity: 0; margin-left: .35em; color: var(--accent); text-decoration: none;
  font-weight: 400; transition: opacity .15s;
}
.reading h1:hover .anchor, .reading h2:hover .anchor, .reading h3:hover .anchor, .reading h4:hover .anchor { opacity: .55; }

/* drop cap */
html[data-dropcap="on"] .reading > p:first-of-type::first-letter {
  font-family: var(--display); font-weight: 540;
  float: left; font-size: 3.4em; line-height: .72;
  padding: .06em .12em 0 0; margin-top: .04em; color: var(--accent);
}

.reading a { color: var(--accent); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2.5px; text-decoration-color: var(--accent-soft); transition: text-decoration-color .15s; }
.reading a:hover { text-decoration-color: var(--accent); }

.reading strong { font-weight: 600; }
.reading em { font-style: italic; }
.reading del { color: var(--ink-faint); }
.reading mark { background: var(--sel); padding: 0 .15em; border-radius: 3px; }

.reading ul, .reading ol { margin: 0 0 1.15em; padding-left: 1.4em; }
.reading li { margin: .3em 0; padding-left: .2em; }
.reading li::marker { color: var(--ink-faint); }
.reading ul ul, .reading ol ol, .reading ul ol, .reading ol ul { margin: .3em 0; }

/* task lists */
.reading li:has(> input[type=checkbox]) { list-style: none; margin-left: -1.2em; }
.reading input[type=checkbox] {
  appearance: none; -webkit-appearance: none;
  width: 1.15em; height: 1.15em; flex: none;
  border: 1.5px solid var(--line-2); border-radius: 5px;
  margin-right: .5em; vertical-align: -.2em; background-color: var(--paper);
  background-repeat: no-repeat; background-position: center; background-size: 78%;
}
.reading input[type=checkbox]:checked {
  background-color: var(--accent); border-color: var(--accent);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='none' stroke='%23fff' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round' d='M3.5 8.5l3 3 6-7'/%3E%3C/svg%3E");
}

.reading blockquote {
  margin: 1.5em 0; padding: .2em 0 .2em 1.3em;
  border-left: 3px solid var(--accent-soft);
  color: var(--ink-soft); font-style: italic;
}
.reading blockquote p { margin-bottom: .6em; }

/* horizontal rule → asterism */
.reading hr { border: none; text-align: center; margin: 2.6em 0; }
.reading hr::before { content: "✶ ✶ ✶"; color: var(--ink-faint); letter-spacing: .6em; font-size: .8em; }

.reading img { max-width: 100%; height: auto; border-radius: var(--radius); box-shadow: var(--shadow); margin: .4em 0; }

/* inline code */
.reading :not(pre) > code {
  font-family: var(--mono); font-size: .85em;
  background: var(--c-bg); padding: .12em .4em; border-radius: 5px;
  color: var(--ink); border: 1px solid var(--line);
}
/* code blocks */
.reading pre {
  margin: 1.4em 0; padding: 1.05rem 1.2rem; overflow-x: auto;
  background: var(--c-bg); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
  font-size: .86em; line-height: 1.6;
}
.reading pre code { font-family: var(--mono); color: var(--ink); background: none; padding: 0; border: none; }

/* tables */
.reading table { width: 100%; border-collapse: collapse; margin: 1.5em 0; font-size: .92em; }
.reading th, .reading td { padding: .55em .75em; border-bottom: 1px solid var(--line); text-align: left; }
.reading thead th { font-family: var(--ui); font-size: .82em; letter-spacing: .03em; text-transform: uppercase; color: var(--ink-soft); border-bottom: 2px solid var(--line-2); }
.reading tbody tr:hover { background: var(--paper-2); }

/* footnotes / small */
.reading sup a { text-decoration: none; }

/* ---------- highlight.js (custom warm tokens) ---------- */
.hljs-comment, .hljs-quote { color: var(--c-com); font-style: italic; }
.hljs-keyword, .hljs-selector-tag, .hljs-literal, .hljs-section, .hljs-link { color: var(--c-kw); }
.hljs-string, .hljs-attr, .hljs-template-tag, .hljs-addition { color: var(--c-str); }
.hljs-number, .hljs-meta, .hljs-bullet, .hljs-symbol { color: var(--c-num); }
.hljs-title, .hljs-name, .hljs-title.function_, .hljs-built_in { color: var(--c-fn); }
.hljs-variable, .hljs-attribute, .hljs-tag, .hljs-template-variable, .hljs-type, .hljs-params { color: var(--c-var); }
.hljs-punctuation, .hljs-operator { color: var(--c-punc); }
.hljs-emphasis { font-style: italic; } .hljs-strong { font-weight: 700; }

/* ================= TOC rail ================= */
.toc {
  position: absolute; top: 3.4rem; right: 0; width: var(--toc-w);
  height: calc(100dvh - 3.4rem); overflow-y: auto;
  padding: 1.4rem 1.2rem 4rem .4rem;
  opacity: 0; transform: translateX(8px); pointer-events: none;
  transition: opacity .25s var(--ease), transform .25s var(--ease);
}
.app[data-toc="on"][data-mode="read"] .toc { opacity: 1; transform: none; pointer-events: auto; }
/* the floating TOC rail only makes sense over the single reading column */
.app:not([data-mode="read"]) .toc { display: none; }
@media (min-width: 1180px) {
  .app[data-toc="on"][data-mode="read"] .reading { margin-right: calc(var(--toc-w) - 2rem); }
}
.toc__head { font-family: var(--ui); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-faint); margin-bottom: .7rem; }
.toc__list { display: flex; flex-direction: column; gap: .1rem; border-left: 1px solid var(--line); }
.toc__list a {
  display: block; padding: .2rem .7rem; margin-left: -1px;
  border-left: 2px solid transparent;
  color: var(--ink-faint); text-decoration: none; font-size: .78rem; line-height: 1.35;
  transition: .15s var(--ease);
}
.toc__list a:hover { color: var(--ink); }
.toc__list a.lvl-3 { padding-left: 1.4rem; font-size: .74rem; }
.toc__list a.lvl-4 { padding-left: 2rem; font-size: .72rem; }
.toc__list a.is-active { color: var(--accent); border-left-color: var(--accent); }

/* ================= Welcome ================= */
.welcome { position: absolute; inset: 3.4rem 0 0; display: grid; place-items: center; padding: 2rem; overflow-y: auto; }
.app[data-has-doc="true"] .welcome { display: none; }
.app[data-has-doc="true"] .panes { display: grid; }
.app:not([data-has-doc="true"]) .panes { display: none; }
.welcome__inner { max-width: 53rem; text-align: center; margin: auto; padding: 1rem 0; animation: docin .6s var(--ease) both; }
.welcome__mark { color: var(--accent); display: inline-grid; place-items: center; margin-bottom: 1.2rem; }
.welcome__title { font-family: var(--display); font-weight: 460; font-size: clamp(2rem, 5vw, 2.9rem); line-height: 1.08; letter-spacing: -.025em; margin: 0 0 .9rem; }
.welcome__lede { color: var(--ink-soft); font-size: 1.06rem; line-height: 1.6; margin: 0 auto 1.8rem; max-width: 28rem; }
.welcome__actions { display: flex; gap: .6rem; justify-content: center; flex-wrap: wrap; }

.welcome__features {
  list-style: none; padding: 0; margin: 2.6rem auto 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem;
  max-width: 53rem; text-align: left;
}
.wf {
  background: var(--paper-2); border: 1px solid var(--line);
  border-radius: 13px; padding: 1.15rem 1.2rem;
  transition: .18s var(--ease);
}
.wf:hover { border-color: var(--line-2); transform: translateY(-2px); }
.wf__icon { color: var(--accent); display: inline-flex; margin-bottom: .55rem; }
.wf__t { font-family: var(--display); font-weight: 600; font-size: 1.05rem; letter-spacing: -.01em; margin: 0 0 .35rem; }
.wf__d { font-size: .88rem; line-height: 1.55; color: var(--ink-soft); margin: 0; }
.wf__d strong { color: var(--ink); font-weight: 600; }

.welcome__hint { margin-top: 1.6rem; font-family: var(--ui); font-size: .72rem; color: var(--ink-faint); letter-spacing: .02em; }

.btn {
  padding: .62rem 1.1rem; border-radius: 9px;
  border: 1px solid var(--line-2); background: var(--paper);
  font-family: var(--ui); font-size: .78rem; letter-spacing: .01em; color: var(--ink);
  transition: .16s var(--ease);
}
.btn:hover { transform: translateY(-1px); border-color: var(--accent); }
.btn--primary { background: var(--accent); border-color: var(--accent); color: var(--paper); }
html[data-theme="night"] .btn--primary { color: #1a1610; }
.btn--primary:hover { filter: brightness(1.06); }
.btn--ghost { border-color: transparent; color: var(--ink-soft); }
.btn--ghost:hover { color: var(--accent); }

/* ================= Dropzone ================= */
.dropzone {
  position: fixed; inset: 0; z-index: 200;
  display: none; place-items: center;
  background: color-mix(in srgb, var(--paper) 72%, transparent);
  backdrop-filter: blur(6px);
}
.dropzone.is-active { display: grid; }
.dropzone__card {
  display: grid; place-items: center; gap: .8rem;
  padding: 3.5rem 4.5rem; border-radius: 18px;
  border: 2px dashed var(--accent); color: var(--accent);
  background: var(--paper);
  font-family: var(--ui); font-size: .9rem; letter-spacing: .04em;
  animation: pop .25s var(--ease) both;
}
@keyframes pop { from { transform: scale(.96); opacity: 0; } to { transform: none; opacity: 1; } }

/* ================= Popover ================= */
.popover {
  position: fixed; z-index: 80;
  width: 19rem; padding: 1rem 1.1rem;
  background: var(--surface); border: 1px solid var(--line-2);
  border-radius: 14px; box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: .85rem;
  animation: pop .18s var(--ease) both;
}
.popover__row { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.popover__row--toggle { }
.popover__label { font-family: var(--ui); font-size: .72rem; color: var(--ink-soft); letter-spacing: .02em; white-space: nowrap; }
.popover input[type=range] {
  -webkit-appearance: none; appearance: none; height: 3px; border-radius: 3px;
  background: var(--line-2); flex: 1; max-width: 9.5rem;
}
.popover input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; width: 15px; height: 15px; border-radius: 50%; background: var(--accent); border: 2px solid var(--paper); box-shadow: 0 0 0 1px var(--line-2); cursor: pointer; }
.popover input[type=range]::-moz-range-thumb { width: 15px; height: 15px; border: 2px solid var(--paper); border-radius: 50%; background: var(--accent); cursor: pointer; }

.toggle { width: 2.5rem; height: 1.4rem; border-radius: 99px; background: var(--line-2); position: relative; transition: .18s var(--ease); }
.toggle span { position: absolute; top: 2px; left: 2px; width: 1.05rem; height: 1.05rem; border-radius: 50%; background: var(--paper); transition: .18s var(--ease); }
.toggle[aria-checked="true"] { background: var(--accent); }
.toggle[aria-checked="true"] span { transform: translateX(1.1rem); }

/* ================= Toast ================= */
.toast {
  position: fixed; bottom: 1.4rem; left: 50%; transform: translateX(-50%) translateY(10px);
  z-index: 300; padding: .6rem 1.05rem; border-radius: 10px;
  background: var(--ink); color: var(--paper);
  font-family: var(--ui); font-size: .76rem; letter-spacing: .01em;
  box-shadow: var(--shadow); opacity: 0; transition: .22s var(--ease);
}
.toast.is-show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ================= Focus mode ================= */
.app[data-focus="on"] { grid-template-columns: 0 1fr; }
.app[data-focus="on"] .sidebar { opacity: 0; pointer-events: none; }
.app[data-focus="on"] .topbar { opacity: 0; transform: translateY(-100%); pointer-events: none; transition: .3s var(--ease); }
.app[data-focus="on"] .panes { padding-top: 0; }
.app[data-focus="on"] .reading { padding-top: clamp(3rem, 9vh, 7rem); }
.app[data-focus="on"] .toc { display: none; }
/* reveal a thin exit hint */
.focus-exit {
  position: fixed; top: 1rem; right: 1rem; z-index: 50;
  font-family: var(--ui); font-size: .68rem; color: var(--ink-faint);
  opacity: 0; transition: opacity .2s; pointer-events: none;
}
.app[data-focus="on"] .focus-exit { opacity: .6; }

/* ---------- animations ---------- */
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}

/* ---------- Responsive ---------- */
/* tap-to-close scrim behind the mobile sidebar */
.scrim { position: fixed; inset: 0; z-index: 110; background: rgba(20,15,8,.4);
  opacity: 0; pointer-events: none; transition: opacity .25s var(--ease); }
.scrim.on { opacity: 1; pointer-events: auto; }

@media (max-width: 820px) {
  .app, .app[data-sidebar="hidden"] { grid-template-columns: 1fr; }
  /* sidebar becomes a slide-over panel */
  .sidebar {
    position: fixed; top: 0; bottom: 0; left: 0; z-index: 120;
    width: min(84vw, 19rem);
    transform: translateX(0); opacity: 1;
    transition: transform .25s var(--ease); box-shadow: var(--shadow);
  }
  .app[data-sidebar="hidden"] .sidebar { transform: translateX(-102%); opacity: 1; pointer-events: none; }

  /* split stacks vertically */
  .app[data-mode="split"] .panes { grid-template-columns: 1fr; grid-template-rows: 1fr 1fr; }
  .app[data-mode="split"] .reading-scroll { border-left: none; border-top: 1px solid var(--line); }

  /* trim the top bar so actions fit on a phone */
  .topbar { padding: .5rem .55rem; gap: .35rem; }
  .topbar__actions { gap: .15rem; }
  .icon-btn { width: 1.95rem; height: 1.95rem; }
  #tocBtn, #focusBtn { display: none; }
  .doc-meta__sub { display: none; }
  .seg button { padding: .3rem .55rem; }

  .toc { display: none !important; }
  .welcome { inset: 3.1rem 0 0; padding: 1.25rem; }
  .welcome__features { grid-template-columns: 1fr; max-width: 26rem; gap: .7rem; }
  .welcome__title { font-size: clamp(1.7rem, 8vw, 2.3rem); }
  .welcome__lede { font-size: .98rem; }
  .reading { padding-top: 1.8rem; }
}

@media (max-width: 420px) {
  .src-btn span { display: none; }   /* icon-only source buttons on tiny screens */
  .src-btn { padding: .5rem; }
  .seg button { font-size: .66rem; padding: .3rem .45rem; }
}