:root {
  --bg: #faf7f0;
  --panel: #fffdf8;
  --ink: #2b2620;
  --muted: #8a8172;
  --line: #e7e0d3;
  --accent: #b23a2e;
  --accent-soft: #f4e0dc;
  --good: #3f7d4f;
  --shadow: 0 2px 10px rgba(60, 45, 20, .10);
  --drawer-shadow: 0 0 40px rgba(40, 30, 10, .28);
  --header-h: 54px;
  --footer-h: 40px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17140f;
    --panel: #201c16;
    --ink: #ece6da;
    --muted: #9a9080;
    --line: #332d23;
    --accent: #e0796b;
    --accent-soft: #3a241f;
    --good: #7fb98c;
    --shadow: 0 2px 12px rgba(0, 0, 0, .4);
    --drawer-shadow: 0 0 40px rgba(0, 0, 0, .6);
  }
}

* { box-sizing: border-box; }

html, body { height: 100%; }
html { overflow-x: hidden; }     /* never allow a sideways pan on mobile */
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  height: 100vh;
  height: 100dvh;               /* track the real viewport on mobile */
  overflow: hidden;
  display: flex;
  flex-direction: column;
  -webkit-text-size-adjust: 100%;
}

/* thin scrollbars on the scrolling regions */
.drawer, main#reader {
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}
.drawer::-webkit-scrollbar, main#reader::-webkit-scrollbar { width: 8px; height: 8px; }
.drawer::-webkit-scrollbar-thumb,
main#reader::-webkit-scrollbar-thumb { background: var(--line); border-radius: 8px; }
.drawer::-webkit-scrollbar-thumb:hover,
main#reader::-webkit-scrollbar-thumb:hover { background: var(--muted); }
.drawer::-webkit-scrollbar-track, main#reader::-webkit-scrollbar-track { background: transparent; }

/* header -------------------------------------------------------------------- */
header {
  flex: 0 0 var(--header-h);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 14px;
  padding-top: env(safe-area-inset-top);
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  z-index: 40;
}
.brand { font-weight: 700; letter-spacing: .2px; font-size: 17px; white-space: nowrap; }
.i-plus {
  font-size: 11px;
  color: #fff;
  background: var(--accent);
  padding: 1px 7px;
  border-radius: 999px;
  vertical-align: middle;
  margin-left: 2px;
}
.spacer { flex: 1 1 auto; }

.icon-btn {
  flex: 0 0 auto;
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  padding: 0;
}
.bars, .bars::before, .bars::after {
  content: "";
  display: block;
  width: 18px; height: 2px;
  background: currentColor;
  border-radius: 2px;
  position: relative;
}
.bars::before { position: absolute; top: -6px; }
.bars::after  { position: absolute; top: 6px; }

.toggle {
  flex: 0 0 auto;
  font: inherit;
  font-size: 14px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
  white-space: nowrap;
}
.toggle[aria-pressed="true"] { background: var(--accent); color: #fff; border-color: var(--accent); }
a.toggle { text-decoration: none; display: inline-flex; align-items: center; }

/* app body ------------------------------------------------------------------ */
.app {
  flex: 1 1 auto;
  min-height: 0;
  position: relative;      /* drawers are positioned against this */
  display: flex;
  overflow: hidden;        /* clip the off-canvas drawers so the page can't scroll sideways */
}

/* reader -------------------------------------------------------------------- */
main#reader {
  flex: 1 1 auto;
  min-width: 0;
  min-height: 0;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  touch-action: manipulation;   /* kill double-tap zoom + 300ms delay */
  padding: 18px 20px 48px;
}
.lesson-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin: 0 0 4px; }
.lesson-head h2 { font-size: 21px; margin: 0; }
.lesson-track { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; margin: 0 0 6px; }
.mark-btn {
  font: inherit;
  font-size: 13px;
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  color: var(--muted);
  cursor: pointer;
}
.mark-btn:hover { border-color: var(--good); color: var(--good); }
.mark-btn.done { background: var(--good); border-color: var(--good); color: #fff; }
.note { color: var(--muted); font-size: 14px; margin: 2px 0 18px; max-width: 60ch; }

.para { margin: 0 0 20px; }
.text { font-size: 23px; line-height: 2.1; }
.sentence { cursor: pointer; border-radius: 4px; }
.sentence:hover { background: var(--accent-soft); }
.word { border-radius: 4px; padding: 0 1px; }
.punct { color: var(--muted); }

.lesson-nav-btns { display: flex; gap: 10px; margin: 28px 0 0; }
.lesson-nav-btns button {
  font: inherit; font-size: 14px;
  padding: 9px 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
}
.lesson-nav-btns button:hover { border-color: var(--accent); color: var(--accent); }
.lesson-nav-btns button[disabled] { opacity: .4; cursor: default; }
.lesson-nav-btns .next { margin-left: auto; }

/* drawers (nav + dictionary) ------------------------------------------------ */
.drawer {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 82vw;
  max-width: 320px;
  background: var(--panel);
  z-index: 30;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  transition: transform .22s ease;
  box-shadow: var(--drawer-shadow);
}
.drawer.left  { left: 0;  transform: translateX(-102%); border-right: 1px solid var(--line); padding: 14px 12px calc(24px + env(safe-area-inset-bottom)); }
.drawer.right { right: 0; transform: translateX(102%);  border-left: 1px solid var(--line);  padding: 16px 14px calc(28px + env(safe-area-inset-bottom)); }
body.nav-open  .drawer.left  { transform: translateX(0); }
body.dict-open .drawer.right { transform: translateX(0); }

.scrim {
  position: fixed;
  inset: 0;
  background: rgba(20, 15, 5, .38);
  z-index: 25;
  border: 0;
}

/* progress ------------------------------------------------------------------ */
.progress { margin: 4px 8px 14px; }
.progress-bar { height: 6px; border-radius: 6px; background: var(--line); overflow: hidden; }
.progress-fill { height: 100%; width: 0; background: var(--good); transition: width .25s ease; }
.progress-text { font-size: 12px; color: var(--muted); margin-top: 5px; }

/* track accordion ----------------------------------------------------------- */
.track { margin-bottom: 4px; }
.track-head {
  display: flex; align-items: center; gap: 8px;
  width: 100%;
  font: inherit;
  text-align: left;
  padding: 9px 10px;
  border: none;
  border-radius: 9px;
  background: none;
  color: var(--ink);
  cursor: pointer;
}
.track-head:hover { background: var(--accent-soft); }
.track-head .caret { flex: 0 0 12px; font-size: 11px; color: var(--muted); transition: transform .18s ease; }
.track.open .track-head .caret { transform: rotate(90deg); }
.track-head .t-title { font-weight: 700; font-size: 14px; flex: 1 1 auto; }
.track-head .t-count { font-size: 11px; color: var(--muted); }
.track.done-all .track-head .t-count { color: var(--good); }
.track-lessons { display: none; padding: 2px 0 6px 6px; }
.track.open .track-lessons { display: block; }

button.lesson {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  font: inherit;
  font-size: 13.5px;
  text-align: left;
  padding: 7px 10px;
  border: none;
  border-radius: 8px;
  background: none;
  color: var(--ink);
  cursor: pointer;
}
button.lesson:hover { background: var(--accent-soft); }
button.lesson.active { background: var(--accent); color: #fff; font-weight: 600; }
.tick {
  flex: 0 0 15px;
  width: 15px; height: 15px;
  border: 1.5px solid var(--line);
  border-radius: 50%;
  font-size: 10px;
  line-height: 12px;
  text-align: center;
  color: transparent;
}
button.lesson.done .tick { background: var(--good); border-color: var(--good); color: #fff; }
button.lesson.active.done .tick { background: #fff; border-color: #fff; color: var(--accent); }
.lesson .l-title { flex: 1 1 auto; }
.lvl { flex: 0 0 auto; letter-spacing: 1px; font-size: 9px; color: var(--muted); opacity: .8; }
button.lesson.active .lvl { color: rgba(255,255,255,.85); }

/* settings ------------------------------------------------------------------ */
.settings {
  margin-top: 18px;
  padding: 14px 8px 4px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.settings label { font-size: 12px; color: var(--muted); display: flex; flex-direction: column; gap: 5px; }
.settings select {
  font: inherit; font-size: 14px;
  padding: 8px 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
  color: var(--ink);
  width: 100%;
}

/* dictionary ---------------------------------------------------------------- */
.dict-head { font-size: 17px; font-weight: 700; margin: 0 0 2px; }
.dict-sub { font-size: 12px; color: var(--muted); margin: 0 0 12px; }
.dict-section {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--accent);
  margin: 16px 0 6px;
  padding-bottom: 3px;
  border-bottom: 1px solid var(--line);
}
.dict-section:first-of-type { margin-top: 2px; }
.dict-entry { display: flex; gap: 8px; align-items: baseline; padding: 4px 0; }
.dict-entry .word {
  cursor: pointer;
  font-size: 16px;
  min-width: 5em;
  flex-shrink: 0;
  border-radius: 4px;
  padding: 1px 3px;
}
.dict-entry .word:hover { background: var(--accent-soft); }
.dict-gloss { color: var(--muted); font-size: 13px; line-height: 1.35; }

/* footer -------------------------------------------------------------------- */
footer#help {
  flex: 0 0 auto;
  padding: 9px 16px calc(9px + env(safe-area-inset-bottom));
  font-size: 12px;
  color: var(--muted);
  background: var(--panel);
  border-top: 1px solid var(--line);
  text-align: center;
}
footer#help b { font-weight: 600; color: var(--ink); }

/* popup + status ------------------------------------------------------------ */
.popup {
  position: fixed;
  z-index: 50;
  max-width: min(280px, 90vw);
  padding: 11px 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow);
  font-size: 14px;
}
.popup .pu-head { font-size: 18px; font-weight: 600; line-height: 1.35; }
.popup .pu-gloss { color: var(--muted); margin-top: 4px; }

.status {
  position: fixed;
  bottom: calc(var(--footer-h) + 16px + env(safe-area-inset-bottom));
  left: 50%;
  transform: translateX(-50%);
  background: var(--ink);
  color: var(--bg);
  padding: 8px 15px;
  border-radius: 999px;
  font-size: 13px;
  z-index: 45;
  opacity: .94;
}

/* ===========================================================================
   Desktop / wide: drawers become persistent columns, no scrim, no hamburger
   =========================================================================== */
@media (min-width: 900px) {
  header { padding: 0 22px; }
  #menuToggle { display: none; }

  .app {
    display: grid;
    grid-template-columns: 264px minmax(0, 1fr);
    max-width: 1360px;
    width: 100%;
    margin: 0 auto;
  }
  body.dict-open .app { grid-template-columns: 264px minmax(0, 1fr) 340px; }

  .drawer {
    position: static;
    width: auto;
    max-width: none;
    transform: none !important;
    box-shadow: none;
    transition: none;
  }
  .drawer.left { border-right: 1px solid var(--line); padding-bottom: 24px; }
  .drawer.right { display: none; }
  body.dict-open .drawer.right { display: block; }

  .scrim { display: none !important; }

  main#reader { padding: 22px 34px 44px; }
  .text { font-size: 24px; }
}