:root {
  --bg: #f7f5f0;
  --page: #ffffff;
  --fg: #1c1d1f;
  --muted: #62656b;
  --line: #dedbd3;
  --chip: #eeebe4;
  --accent: #1f5c8a;
  --accent-fg: #ffffff;
  --shadow: 0 10px 40px rgba(0, 0, 0, .16);
  --bar-h: 52px;
  --foot-h: 52px;
  --safe-t: env(safe-area-inset-top, 0px);
  --safe-b: env(safe-area-inset-bottom, 0px);
  --safe-l: env(safe-area-inset-left, 0px);
  --safe-r: env(safe-area-inset-right, 0px);
  color-scheme: light;
}
:root[data-theme="sepia"] {
  --bg: #efe6d2;
  --page: #f6eedb;
  --fg: #3b2f22;
  --muted: #7a6a55;
  --line: #d9cbb0;
  --chip: #e8dcc2;
  --accent: #8a4b1f;
}
:root[data-theme="dark"] {
  --bg: #16181c;
  --page: #1d2025;
  --fg: #e3e4e6;
  --muted: #9a9ea6;
  --line: #30343b;
  --chip: #2a2e35;
  --accent: #7fb2e5;
  --accent-fg: #0f1418;
  --shadow: 0 10px 40px rgba(0, 0, 0, .5);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
  overflow: hidden;
}
button, input, output { font: inherit; color: inherit; }
button { cursor: pointer; }
svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; flex: none; }
[hidden] { display: none !important; }

#app {
  position: fixed;
  inset: 0;
  display: grid;
  grid-template-rows: calc(var(--bar-h) + var(--safe-t)) minmax(0, 1fr) calc(var(--foot-h) + var(--safe-b));
  grid-template-columns: minmax(0, 1fr);
}

.bar {
  display: flex;
  align-items: center;
  gap: 2px;
  padding-left: max(8px, var(--safe-l));
  padding-right: max(8px, var(--safe-r));
  background: var(--bg);
  z-index: 5;
}
.bar.top { padding-top: var(--safe-t); border-bottom: 1px solid var(--line); }
.bar.bottom { padding-bottom: var(--safe-b); border-top: 1px solid var(--line); gap: 8px; }

.icon {
  width: 44px; height: 44px;
  display: inline-flex; align-items: center; justify-content: center;
  border: 0; border-radius: 10px; background: transparent; color: var(--fg);
}
.icon:hover { background: var(--chip); }
.icon:focus-visible, .nav:focus-visible, .seg button:focus-visible, .primary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.title { flex: 1; min-width: 0; display: flex; flex-direction: column; align-items: center; text-align: center; padding: 0 6px; }
.title .book { font-size: 12px; color: var(--muted); letter-spacing: .02em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 100%; }
.title .chapter { font-size: 14px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 100%; min-height: 1.2em; }

.nav {
  display: inline-flex; align-items: center; gap: 4px;
  height: 40px; padding: 0 12px;
  border: 1px solid var(--line); border-radius: 999px;
  background: var(--page); color: var(--fg); white-space: nowrap;
}
.nav:hover { border-color: var(--muted); }
.nav:disabled { opacity: .4; cursor: default; }
.nav svg { width: 18px; height: 18px; }
.progress { flex: 1; min-width: 0; display: flex; flex-direction: column; align-items: center; gap: 5px; }
.progress span { font-size: 12px; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 100%; }
.track { width: 100%; max-width: 360px; height: 3px; border-radius: 3px; background: var(--line); overflow: hidden; }
.fill { height: 100%; width: 0; background: var(--accent); transition: width .2s; }

#stage { position: relative; min-height: 0; min-width: 0; overflow: hidden; background: var(--page); }
#viewer { position: absolute; inset: 0; }
#viewer .epub-container { margin: 0 auto; }
:root[data-flow="scrolled"] #viewer .epub-container { -webkit-overflow-scrolling: touch; overscroll-behavior: contain; }

.edge { position: absolute; top: 0; bottom: 0; width: 44px; border: 0; background: transparent; opacity: 0; z-index: 2; }
.edge.prev { left: 0; }
.edge.next { right: 0; }
:root[data-flow="scrolled"] .edge { display: none; }

.scrim { position: fixed; inset: 0; background: rgba(0, 0, 0, .35); z-index: 20; }

.drawer {
  position: fixed; top: 0; bottom: 0;
  width: min(400px, 92vw);
  display: flex; flex-direction: column;
  background: var(--page); color: var(--fg);
  box-shadow: var(--shadow);
  z-index: 30;
  padding-top: var(--safe-t);
  padding-bottom: var(--safe-b);
}
.drawer.left { left: 0; padding-left: var(--safe-l); }
.drawer.right { right: 0; padding-right: var(--safe-r); }
.drawer-head { display: flex; align-items: center; justify-content: space-between; padding: 6px 6px 6px 16px; }
.drawer-head h2 { font-size: 17px; margin: 0; }
.drawer-tools { display: flex; gap: 8px; padding: 4px 12px 10px; border-bottom: 1px solid var(--line); }
.drawer-tools input {
  flex: 1; min-width: 0; height: 42px; padding: 0 12px;
  border: 1px solid var(--line); border-radius: 10px; background: var(--bg);
  font-size: 16px;
}
.drawer-tools input:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.drawer-body { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; overscroll-behavior: contain; padding: 6px 0 24px; }

.primary {
  display: inline-flex; align-items: center; justify-content: center;
  height: 42px; padding: 0 16px; border: 0; border-radius: 10px;
  background: var(--accent); color: var(--accent-fg); font-weight: 600; text-decoration: none;
}
.primary.big { display: flex; width: 100%; height: 48px; margin: 6px 0 4px; }

/* table of contents */
#toc-list ol { list-style: none; margin: 0; padding: 0; }
#toc-list li > .row { display: flex; align-items: stretch; }
#toc-list a {
  flex: 1; display: block; padding: 10px 16px; color: var(--fg); text-decoration: none;
  line-height: 1.35;
}
#toc-list a:hover { background: var(--chip); }
#toc-list a.current { color: var(--accent); font-weight: 600; }
#toc-list .lvl0 > .row > a { font-weight: 600; }
#toc-list .lvl1 a { padding: 8px 16px 8px 30px; font-size: 14px; color: var(--muted); }
#toc-list .lvl1 a:hover { color: var(--fg); }
#toc-list .lvl2 a { padding-left: 44px; font-size: 13.5px; }
#toc-list .toggle {
  width: 44px; flex: none; border: 0; background: transparent; color: var(--muted);
  display: inline-flex; align-items: center; justify-content: center;
}
#toc-list .toggle svg { width: 18px; height: 18px; transition: transform .15s; }
#toc-list li.open > .row .toggle svg { transform: rotate(90deg); }
#toc-list li:not(.open) > ol { display: none; }
#toc-list mark, #search-results mark { background: color-mix(in srgb, var(--accent) 25%, transparent); color: inherit; border-radius: 2px; }

/* search */
#search-results .hint, #search-results .status { color: var(--muted); padding: 8px 16px; margin: 0; font-size: 14px; }
#search-results .group { padding: 12px 16px 4px; font-size: 12.5px; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; }
#search-results button.hit {
  display: block; width: 100%; text-align: left; border: 0; background: transparent;
  padding: 9px 16px; line-height: 1.45; font-size: 14px; color: var(--fg);
}
#search-results button.hit:hover { background: var(--chip); }

/* settings popover */
.popover {
  position: fixed; z-index: 30;
  top: calc(var(--bar-h) + var(--safe-t) + 6px);
  right: max(8px, var(--safe-r));
  width: min(340px, calc(100vw - 16px));
  padding: 10px 14px; border-radius: 14px;
  background: var(--page); box-shadow: var(--shadow); border: 1px solid var(--line);
}
.popover .row { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 8px 0; }
.popover .label { color: var(--muted); font-size: 14px; }
.seg { display: inline-flex; align-items: center; background: var(--chip); border-radius: 10px; padding: 3px; gap: 2px; }
.seg button { height: 36px; min-width: 44px; padding: 0 10px; border: 0; border-radius: 8px; background: transparent; font-size: 14px; }
.seg button.on { background: var(--page); box-shadow: 0 1px 3px rgba(0, 0, 0, .15); font-weight: 600; }
.seg output { min-width: 52px; text-align: center; font-size: 14px; font-variant-numeric: tabular-nums; }

/* download modal */
.modal { position: fixed; inset: 0; z-index: 40; display: flex; align-items: center; justify-content: center; padding: 16px; background: rgba(0, 0, 0, .35); }
.modal-card { width: min(460px, 100%); max-height: calc(100% - 16px); overflow-y: auto; background: var(--page); border-radius: 16px; box-shadow: var(--shadow); padding: 4px 18px 18px; }
.modal-card .drawer-head { padding: 6px 0 2px; }
.modal-card p { margin: 8px 0; color: var(--fg); }
.modal-card .inapp { padding: 10px 12px; border-radius: 10px; background: var(--chip); }
.howto { margin: 12px 0 0; padding-left: 18px; color: var(--muted); font-size: 14px; }
.howto li { margin: 6px 0; }
.howto b { color: var(--fg); }

/* loader */
.overlay { position: fixed; inset: 0; z-index: 50; display: flex; align-items: center; justify-content: center; background: var(--bg); padding: 24px; }
.loader-card { text-align: center; width: min(360px, 100%); }
.loader-card img { border-radius: 14px; box-shadow: var(--shadow); }
.loader-card h1 { font-size: 20px; margin: 16px 0 6px; }
.loader-card p { color: var(--muted); margin: 0 0 14px; }
.loader-card .track { margin: 0 auto; }
.loader-actions { margin-top: 18px; display: flex; gap: 16px; align-items: center; justify-content: center; }
.loader-actions a { color: var(--accent); }
#app:not(.loading) .overlay { opacity: 0; pointer-events: none; transition: opacity .25s; }

.toast {
  position: fixed; left: 50%; transform: translateX(-50%);
  bottom: calc(var(--foot-h) + var(--safe-b) + 12px);
  max-width: calc(100vw - 32px);
  padding: 10px 16px; border-radius: 10px; z-index: 60;
  background: var(--fg); color: var(--bg); font-size: 14px; box-shadow: var(--shadow);
}

@media (max-width: 520px) {
  :root { --bar-h: 50px; }
  .nav span { display: none; }
  .nav { width: 44px; padding: 0; justify-content: center; }
  .title .book { display: none; }
  .title .chapter { font-size: 14.5px; }
  .icon { width: 42px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }