/* ===================================================================
   Lumen — Generative Reading
   A gorgeous, minimal, literary reading surface.
   =================================================================== */

:root {
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --measure: 34rem;          /* ideal line length for prose */
  --font-serif: "Spectral", Georgia, "Times New Roman", serif;
  --font-display: "Fraunces", Georgia, serif;
  --font-ui: "Inter", system-ui, -apple-system, sans-serif;
  --reader-size: 1.22rem;
  --reader-leading: 1.78;
  --reader-face: var(--font-serif);
}

/* ---- Themes ---- */
body[data-theme="paper"] {
  --bg: #f4f1ea;
  --bg2: #efeae0;
  --ink: #211d18;
  --ink-soft: #5c5346;
  --ink-faint: #8a7f6e;
  --accent: #9a6a3c;
  --line: #ddd5c6;
  --card: #fbf9f4;
  --shadow: 0 22px 60px -28px rgba(60, 45, 25, 0.45);
  --grain-opacity: 0.04;
}
body[data-theme="sepia"] {
  --bg: #ece0cb;
  --bg2: #e6d8bf;
  --ink: #3a2f23;
  --ink-soft: #6b5a44;
  --ink-faint: #9b876a;
  --accent: #a8662f;
  --line: #d8c6a6;
  --card: #f1e7d4;
  --shadow: 0 22px 60px -28px rgba(80, 55, 25, 0.5);
  --grain-opacity: 0.05;
}
body[data-theme="night"] {
  --bg: #11100e;
  --bg2: #0c0b0a;
  --ink: #e9e2d4;
  --ink-soft: #b3a892;
  --ink-faint: #7d735f;
  --accent: #d6a360;
  --line: #2a2620;
  --card: #1a1815;
  --shadow: 0 30px 70px -30px rgba(0, 0, 0, 0.8);
  --grain-opacity: 0.045;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }

body {
  background:
    radial-gradient(120% 80% at 50% -10%, var(--bg2) 0%, var(--bg) 55%) fixed;
  color: var(--ink);
  font-family: var(--font-ui);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background 0.6s var(--ease), color 0.4s var(--ease);
  overscroll-behavior: none;
}

.grain {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  opacity: var(--grain-opacity);
  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='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: multiply;
}
body[data-theme="night"] .grain { mix-blend-mode: screen; }

/* ---- Views ---- */
.view { position: fixed; inset: 0; z-index: 2; opacity: 0; pointer-events: none;
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
  transform: translateY(8px); overflow-y: auto; -webkit-overflow-scrolling: touch; }
.view.is-active { opacity: 1; pointer-events: auto; transform: none; }

.btn { font-family: var(--font-ui); font-weight: 500; border: none; cursor: pointer;
  border-radius: 999px; transition: transform 0.25s var(--ease), background 0.25s var(--ease), opacity 0.25s; }
.btn--primary { background: var(--ink); color: var(--bg); }
.btn--primary:hover { transform: translateY(-2px); }
.btn--primary:disabled { opacity: 0.35; cursor: default; transform: none; }
.btn--lg { padding: 1rem 2.4rem; font-size: 1.05rem; }
.btn--ghost { background: transparent; color: var(--ink-soft); border: 1px solid var(--line); padding: 0.7rem 1.1rem; }
.ghost { background: transparent; border: none; color: var(--ink-soft); cursor: pointer;
  font-family: var(--font-ui); font-size: 0.95rem; transition: color 0.2s; }
.ghost:hover { color: var(--ink); }

/* ============ LIBRARY (home) ============ */
.view--home { padding: 0 0 3rem; }
.lib__head { position: sticky; top: 0; z-index: 8; display: flex; align-items: center;
  justify-content: space-between; padding: max(1rem, env(safe-area-inset-top)) clamp(1rem,4vw,2.4rem) 0.9rem;
  background: linear-gradient(var(--bg) 70%, transparent); }
.lib__head .brand { display: inline-flex; align-items: baseline; gap: 0.45rem; }
.brand__mark { color: var(--accent); font-size: 1.2rem; }
.brand__name { font-family: var(--font-display); font-weight: 400; font-size: 1.7rem;
  letter-spacing: -0.02em; line-height: 1; }
.lib__new { background: transparent; border: 1px solid var(--line); color: var(--ink-soft);
  border-radius: 999px; padding: 0.5rem 1rem; font-family: var(--font-ui); font-size: 0.9rem;
  cursor: pointer; transition: all 0.2s; }
.lib__new:hover { color: var(--ink); border-color: var(--ink-soft); }
.lib__tag { padding: 0 clamp(1rem,4vw,2.4rem); margin: 0.2rem 0 1.4rem; max-width: 44rem;
  color: var(--ink-soft); font-family: var(--font-serif); font-style: italic; font-size: 1.02rem; }

.lib-mine { margin-bottom: 0.5rem; }
.row { margin-bottom: 1.6rem; }
.row__title { font-family: var(--font-display); font-weight: 400; font-size: 1.25rem;
  padding: 0 clamp(1rem,4vw,2.4rem); margin-bottom: 0.8rem; display: flex; align-items: baseline; gap: 0.6rem; }
.row__title .row__count { font-family: var(--font-ui); font-size: 0.72rem; color: var(--ink-faint);
  letter-spacing: 0.04em; }
.row__track { display: flex; gap: clamp(0.7rem, 2vw, 1.1rem); overflow-x: auto; overflow-y: hidden;
  padding: 0.3rem clamp(1rem,4vw,2.4rem) 0.8rem; scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch; scrollbar-width: none; }
.row__track::-webkit-scrollbar { display: none; }

.cover-card { flex: 0 0 auto; width: clamp(124px, 30vw, 158px); background: none; border: none;
  padding: 0; cursor: pointer; scroll-snap-align: start; text-align: left;
  transition: transform 0.28s var(--ease); }
.cover-card:hover { transform: translateY(-6px); }
.cover-card__art { width: 100%; aspect-ratio: 2/3; border-radius: 7px; overflow: hidden;
  box-shadow: var(--shadow); background: var(--card);
  position: relative; outline: 1px solid rgba(0,0,0,0.06); }
.cover-ph, .cover-img, .cover-tt { position: absolute; inset: 0; width: 100%; height: 100%; }
.cover-ph svg, .cover-tt svg { display: block; width: 100%; height: 100%; }
.cover-ph { transition: opacity 0.5s var(--ease); }
.cover-img { object-fit: cover; opacity: 0; transition: opacity 0.6s var(--ease); }
.cover-card__art.img-ready .cover-img { opacity: 1; }
.cover-card__art.img-ready .cover-ph { opacity: 0; }
.cover-tt { z-index: 2; pointer-events: none; }
.cover-card__heart { z-index: 3; }
.cover-card__art::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 7px;
  background: linear-gradient(90deg, rgba(0,0,0,0.28), rgba(0,0,0,0) 60%); pointer-events: none; }
.cover-card__cap { margin-top: 0.5rem; font-family: var(--font-serif); font-size: 0.8rem;
  color: var(--ink-soft); line-height: 1.25; display: -webkit-box; -webkit-line-clamp: 2;
  -webkit-box-orient: vertical; overflow: hidden; }
.cover-card__heart { position: absolute; top: 6px; right: 6px; z-index: 2; font-size: 0.9rem;
  color: #fff; opacity: 0; filter: drop-shadow(0 1px 2px rgba(0,0,0,0.5)); }
.cover-card.is-hearted .cover-card__heart { opacity: 1; color: var(--accent); }

.cover-skel { flex: 0 0 auto; width: clamp(124px, 30vw, 158px); }
.cover-skel__art { width: 100%; aspect-ratio: 2/3; border-radius: 7px;
  background: linear-gradient(100deg, var(--card) 30%, var(--bg2) 50%, var(--card) 70%);
  background-size: 200% 100%; animation: shimmer 1.4s infinite; }
@keyframes shimmer { from { background-position: 200% 0; } to { background-position: -200% 0; } }

.home__foot { padding: 3rem clamp(1rem,4vw,2.4rem) 0; color: var(--ink-faint);
  font-size: 0.8rem; text-align: center; }

/* ============ GENRE PICKER ============ */
.view--pick { padding: clamp(1.2rem, 4vh, 3rem) 1.2rem 5rem; }
.picker { max-width: 52rem; margin: 0 auto; }
.picker__back { position: sticky; top: 0.5rem; margin-bottom: 1rem; }
.picker__h { font-family: var(--font-display); font-weight: 400; font-size: clamp(1.8rem, 5vw, 2.6rem);
  letter-spacing: -0.02em; }
.picker__sub { color: var(--ink-soft); font-family: var(--font-serif); font-style: italic;
  margin: 0.5rem 0 2rem; }
.genre-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(11rem, 1fr));
  gap: 0.8rem; }
.genre { background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 1.1rem 1.1rem; cursor: pointer; text-align: left;
  transition: transform 0.25s var(--ease), border-color 0.25s, background 0.25s; position: relative; }
.genre:hover { transform: translateY(-3px); }
.genre.is-sel { border-color: var(--accent); background: var(--bg2);
  box-shadow: inset 0 0 0 1px var(--accent); }
.genre__name { font-family: var(--font-display); font-size: 1.12rem; }
.genre__mood { font-size: 0.82rem; color: var(--ink-faint); margin-top: 0.3rem;
  font-family: var(--font-serif); line-height: 1.35; }

.sub { margin-top: 2rem; }
.sub__h, .tune h3 { font-family: var(--font-ui); font-weight: 600; font-size: 0.8rem;
  text-transform: uppercase; letter-spacing: 0.12em; color: var(--ink-faint); margin-bottom: 0.9rem; }
.sub__chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chip { background: transparent; border: 1px solid var(--line); color: var(--ink-soft);
  border-radius: 999px; padding: 0.5rem 1rem; font-size: 0.9rem; cursor: pointer;
  font-family: var(--font-serif); transition: all 0.2s; }
.chip:hover { border-color: var(--ink-soft); color: var(--ink); }
.chip.is-sel { background: var(--ink); color: var(--bg); border-color: var(--ink); }

.tune { margin-top: 2.2rem; background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 1.3rem; }
.tune__row { display: flex; gap: 1.2rem; align-items: center; justify-content: space-between; }
.tune__text p { color: var(--ink-soft); font-size: 0.88rem; line-height: 1.5; margin-top: 0.4rem;
  font-family: var(--font-serif); }
.tune__status { margin-top: 0.9rem; font-size: 0.82rem; color: var(--accent); }

.switch { position: relative; flex: none; width: 52px; height: 30px; cursor: pointer; }
.switch input { position: absolute; opacity: 0; }
.switch__track { position: absolute; inset: 0; background: var(--line); border-radius: 999px;
  transition: background 0.3s; }
.switch__thumb { position: absolute; top: 3px; left: 3px; width: 24px; height: 24px;
  background: var(--card); border-radius: 50%; box-shadow: 0 1px 4px rgba(0,0,0,0.25);
  transition: transform 0.3s var(--ease); }
.switch input:checked + .switch__track { background: var(--accent); }
.switch input:checked + .switch__track .switch__thumb { transform: translateX(22px); }

#btn-begin { margin-top: 2.4rem; width: 100%; }

/* ============ LOADING / CONJURE ============ */
.view--loading { display: flex; align-items: center; justify-content: center; }
.conjure { text-align: center; }
.conjure__orb { width: 90px; height: 90px; margin: 0 auto 1.8rem; border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, var(--accent), transparent 70%);
  animation: breathe 2.6s var(--ease) infinite; filter: blur(2px); }
@keyframes breathe { 0%,100% { transform: scale(0.8); opacity: 0.5; }
  50% { transform: scale(1.15); opacity: 1; } }
.conjure__line { font-family: var(--font-serif); font-style: italic; font-size: 1.15rem;
  color: var(--ink-soft); transition: opacity 0.5s; min-height: 1.5em; }

/* ============ READER ============ */
.view--reader { overflow: hidden; display: flex; flex-direction: column; }

.reader__chrome { position: absolute; top: 0; left: 0; right: 0; z-index: 6;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: max(0.9rem, env(safe-area-inset-top)) 1.2rem 0.9rem;
  background: linear-gradient(var(--bg), transparent);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease); }
.reader__chrome.is-hidden { opacity: 0; transform: translateY(-100%); pointer-events: none; }
.chrome__center { text-align: center; overflow: hidden; }
.chrome__title { display: block; font-family: var(--font-display); font-size: 0.98rem;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 60vw; }
.chrome__author { display: block; font-family: var(--font-serif); font-style: italic;
  font-size: 0.78rem; color: var(--ink-faint); }
.chrome__right { display: flex; align-items: center; gap: 0.6rem; }
.chrome__btn { font-size: 0.95rem; padding: 0.4rem 0.6rem; }
#btn-settings { font-family: var(--font-display); }
.bio-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent);
  box-shadow: 0 0 0 0 rgba(154,106,60,0.5); animation: pulse 2.4s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(154,106,60,0.45);} 70%{ box-shadow:0 0 0 7px rgba(154,106,60,0);} 100%{box-shadow:0 0 0 0 rgba(154,106,60,0);} }

.reader__stage { flex: 1; display: flex; justify-content: center; align-items: flex-start;
  overflow-y: auto; -webkit-overflow-scrolling: touch; padding: 0 1.4rem;
  scroll-behavior: smooth; }
.page { width: 100%; max-width: var(--measure);
  padding: clamp(4.5rem, 12vh, 8rem) 0 clamp(5rem, 14vh, 8rem);
  font-family: var(--reader-face); font-size: var(--reader-size); line-height: var(--reader-leading);
  color: var(--ink); transition: opacity 0.42s var(--ease), transform 0.42s var(--ease);
  letter-spacing: 0.003em; }
.page.is-turning { opacity: 0; transform: translateY(10px); }
.page p { margin: 0 0 1.15em; text-align: justify; -webkit-hyphens: auto; hyphens: auto; }
.page p:first-of-type { margin-top: 0; }
/* drop-cap & no-indent on the first paragraph of a chapter */
.page.chapter-open p:first-of-type::first-letter {
  font-family: var(--font-display); font-size: 3.1em; line-height: 0.74; float: left;
  padding: 0.06em 0.09em 0 0; color: var(--accent); font-weight: 500; }
.page p + p { text-indent: 1.3em; }
.page.chapter-open p:first-of-type { text-indent: 0; }

.chapter-head { text-align: center; margin: 0 0 2.6rem; }
.chapter-head__eyebrow { font-family: var(--font-ui); font-size: 0.72rem; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--ink-faint); }
.chapter-head__title { font-family: var(--font-display); font-weight: 400; font-size: 1.8rem;
  margin-top: 0.5rem; letter-spacing: -0.01em; }
.chapter-head__rule { width: 44px; height: 1px; background: var(--accent); margin: 1.3rem auto 0;
  opacity: 0.6; }

.the-end { text-align: center; margin-top: 3rem; }
.the-end__mark { font-family: var(--font-display); font-style: italic; font-size: 1.5rem;
  color: var(--ink-soft); }
.the-end__rule { width: 60px; height: 1px; background: var(--line); margin: 1.4rem auto; }
.the-end .btn { margin-top: 0.5rem; }

/* page footer / nav */
.reader__foot { position: absolute; bottom: 0; left: 0; right: 0; z-index: 6;
  display: flex; align-items: center; justify-content: center; gap: 1.2rem;
  padding: 0.7rem 1.2rem max(0.7rem, env(safe-area-inset-bottom));
  background: linear-gradient(transparent, var(--bg) 60%);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease); }
.reader__foot.is-hidden { opacity: 0; transform: translateY(100%); pointer-events: none; }
.nav { width: 44px; height: 44px; border-radius: 50%; border: 1px solid var(--line);
  background: var(--card); color: var(--ink-soft); font-size: 1.4rem; cursor: pointer;
  display: grid; place-items: center; transition: all 0.2s; flex: none; line-height: 1; }
.nav:hover:not(:disabled) { color: var(--ink); transform: scale(1.06); }
.nav:disabled { opacity: 0.3; cursor: default; }
.progress { display: flex; flex-direction: column; align-items: center; gap: 0.45rem;
  width: min(22rem, 50vw); }
.progress__label { font-size: 0.75rem; color: var(--ink-faint); letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums; }
.progress__bar { width: 100%; height: 3px; background: var(--line); border-radius: 2px; overflow: hidden; }
.progress__fill { height: 100%; width: 0; background: var(--accent); border-radius: 2px;
  transition: width 0.5s var(--ease); }

/* loading shimmer for next-page wait */
.page.is-loading { display: flex; flex-direction: column; gap: 1.1em; }
.page.is-loading::after { content: "writing the next page…"; font-family: var(--font-serif);
  font-style: italic; color: var(--ink-faint); text-align: center; margin-top: 30vh;
  animation: fade 1.4s ease-in-out infinite alternate; }
@keyframes fade { from { opacity: 0.35; } to { opacity: 0.85; } }

.tapzone { position: absolute; top: 12%; bottom: 12%; width: 28%; z-index: 4;
  background: transparent; border: none; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.tapzone--left { left: 0; }
.tapzone--right { right: 0; }
@media (min-width: 820px) { .tapzone { display: none; } }

/* ============ SETTINGS SHEET ============ */
.sheet { position: fixed; inset: 0; z-index: 20; display: flex; align-items: flex-end;
  justify-content: center; }
.sheet[hidden] { display: none; }

/* ---- book detail sheet ---- */
.sheet--book { align-items: center; }
.sheet__panel--book { width: min(40rem, 100%); border-radius: 20px; padding: 1.6rem;
  max-height: 92vh; overflow-y: auto; position: relative; }
@media (max-width: 560px) { .sheet--book { align-items: flex-end; }
  .sheet__panel--book { border-radius: 20px 20px 0 0; } }
.bd-close { position: absolute; top: 0.8rem; right: 1rem; font-size: 1.1rem; z-index: 3; }
.book-detail { display: flex; gap: 1.4rem; }
@media (max-width: 560px) { .book-detail { flex-direction: column; align-items: center; text-align: center; } }
.book-detail__cover { flex: 0 0 auto; width: 160px; }
.book-detail__cover .cover-card__art { width: 100%; aspect-ratio: 2/3; position: relative;
  border-radius: 8px; overflow: hidden; box-shadow: var(--shadow); }
.book-detail__info { flex: 1; min-width: 0; }
.bd-genre { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.14em;
  color: var(--accent); font-weight: 600; }
.bd-title { font-family: var(--font-display); font-weight: 400; font-size: 1.7rem; line-height: 1.1;
  margin: 0.4rem 0 0.3rem; }
.bd-author { font-family: var(--font-serif); font-style: italic; color: var(--ink-soft); }
.bd-tones { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0.9rem 0; }
@media (max-width: 560px) { .bd-tones { justify-content: center; } }
.bd-tone { font-size: 0.72rem; text-transform: capitalize; color: var(--ink-soft);
  border: 1px solid var(--line); border-radius: 999px; padding: 0.2rem 0.7rem; }
.bd-blurb { font-family: var(--font-serif); font-size: 1.02rem; line-height: 1.6; color: var(--ink);
  margin: 0.6rem 0 1.4rem; }
.bd-actions { display: flex; gap: 0.6rem; align-items: center; }
@media (max-width: 560px) { .bd-actions { justify-content: center; } }
.bd-heart { font-size: 1.2rem; line-height: 1; padding: 0.7rem 0.95rem; }
.bd-heart.is-on { color: var(--accent); border-color: var(--accent); }
.bd-dismiss { margin-top: 0.9rem; font-size: 0.82rem; color: var(--ink-faint); }
.sheet__scrim { position: absolute; inset: 0; background: rgba(0,0,0,0.4); z-index: 1;
  animation: fadein 0.3s; }
.sheet__panel { position: relative; z-index: 2; width: min(34rem, 100%); background: var(--card);
  border-radius: 20px 20px 0 0; padding: 1.6rem 1.6rem max(2rem, env(safe-area-inset-bottom));
  box-shadow: var(--shadow); animation: slideup 0.4s var(--ease); border: 1px solid var(--line); }
@media (min-width: 640px){ .sheet { align-items: center; } .sheet__panel { border-radius: 20px; } }
@keyframes slideup { from { transform: translateY(100%);} to { transform: none; } }
@keyframes fadein { from { opacity: 0; } to { opacity: 1; } }
.sheet__h { font-family: var(--font-display); font-weight: 400; font-size: 1.3rem; margin-bottom: 1.3rem; }
.set-row { display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  margin-bottom: 1.2rem; font-size: 0.95rem; color: var(--ink-soft); }
.seg { display: inline-flex; background: var(--bg2); border: 1px solid var(--line);
  border-radius: 999px; padding: 3px; }
.seg button { border: none; background: transparent; color: var(--ink-soft); cursor: pointer;
  padding: 0.4rem 0.85rem; border-radius: 999px; font-family: var(--font-ui); transition: all 0.2s; }
.seg button.is-sel { background: var(--ink); color: var(--bg); }
#size-seg button[data-size="s"]{font-size:0.8rem} #size-seg button[data-size="m"]{font-size:0.95rem}
#size-seg button[data-size="l"]{font-size:1.1rem} #size-seg button[data-size="xl"]{font-size:1.25rem}
#face-seg button[data-face="spectral"]{font-family:var(--font-serif)}
#face-seg button[data-face="fraunces"]{font-family:var(--font-display)}
#sheet-close { width: 100%; margin-top: 0.6rem; padding: 0.9rem; }

/* ============ TOAST ============ */
.toast { position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%) translateY(1rem);
  background: var(--ink); color: var(--bg); padding: 0.8rem 1.3rem; border-radius: 999px;
  font-size: 0.9rem; z-index: 40; opacity: 0; transition: all 0.3s var(--ease);
  box-shadow: var(--shadow); max-width: 90vw; text-align: center; }
.toast.is-show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.12s !important; }
}