/* Huellas de Tinta — una pantalla fija: barra fina arriba, ventana de lectura centrada, cuatro botones grandes abajo. */
:root{
  --bg:#F3F5F2; --surface:#FFFFFF; --ink:#1B2126; --muted:#5F6B70; --line:#D7DDDA;
  --accent:#1F5F8B; --accent-ink:#FFFFFF; --mark:#E4EEF3;
  --serif:"Literata", Georgia, "Times New Roman", serif;
  --sans:"Atkinson Hyperlegible", system-ui, -apple-system, "Segoe UI", sans-serif;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){:root{
  --bg:#121518; --surface:#1B1F23; --ink:#E8E4DA; --muted:#98A2A6; --line:#2D3338;
  --accent:#7DB7DD; --accent-ink:#0E1A22; --mark:#1D2A33; color-scheme:dark}}

*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{background:var(--bg);color:var(--ink);font-family:var(--sans);font-size:15px;overflow:hidden;-webkit-tap-highlight-color:transparent;
  padding-top:env(safe-area-inset-top,0px)}
[hidden]{display:none!important}
.app{height:100%;display:flex;flex-direction:column}

.top{display:flex;align-items:center;gap:10px;padding:10px 16px;border-bottom:1px solid var(--line)}
.title{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-weight:700}
.pct{color:var(--muted);font-variant-numeric:tabular-nums;font-size:13px}
.tbtn{font:inherit;font-size:14px;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:8px;padding:7px 12px;cursor:pointer}
.tbtn:disabled{opacity:.5;cursor:default}
.tbtn:focus-visible,.nav:focus-visible,.seg button:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.tbtn.primary{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.bar{height:3px;background:var(--line)}
.bar i{display:block;height:100%;width:0;background:var(--accent);transition:width .2s}

.panel{padding:12px 16px 14px;border-bottom:1px solid var(--line);background:var(--surface);display:grid;gap:12px}
.row{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.row label{color:var(--muted);font-size:13px;letter-spacing:.02em}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:8px;overflow:hidden;flex-wrap:wrap}
.seg button{font:inherit;font-size:14px;border:0;background:transparent;color:var(--ink);padding:7px 12px;cursor:pointer}
.seg button[aria-pressed="true"]{background:var(--accent);color:var(--accent-ink)}
.stepper{display:inline-flex;align-items:center;gap:6px}
.stepper output{min-width:2ch;text-align:center;font-variant-numeric:tabular-nums;font-weight:700}

.stage{flex:1;min-height:0;display:flex;align-items:center;justify-content:center;padding-inline:16px;position:relative}
.window{width:100%;max-width:1000px;overflow:hidden;position:relative;background:var(--mark);border-radius:10px;padding-inline:clamp(10px,3vw,24px)}
.window.imgmode{overflow:auto;padding:12px;-webkit-overflow-scrolling:touch;overscroll-behavior:contain}
.col{font-family:var(--serif);line-height:1.5;will-change:transform;transition:transform .18s ease, opacity .18s ease;overflow-wrap:break-word;hyphens:auto}
.col.sans{font-family:var(--sans)}
.col.flash{opacity:.25}
.imgwrap{display:flex;flex-direction:column;align-items:center;gap:8px;min-height:100%;justify-content:center}
.imgwrap img{display:block;max-width:none;height:auto;border-radius:4px;background:#fff}
.cap{margin:0;color:var(--muted);font-size:14px;text-align:center;max-width:60ch}
.skipped{color:var(--muted);font-style:italic;text-align:center;padding:16px}
.msg{position:absolute;inset:auto 16px 12px;text-align:center;color:var(--muted);font-size:13px}

.controls{display:grid;grid-template-columns:1.35fr 1fr 1fr 1.35fr;gap:10px;padding:12px 16px calc(14px + env(safe-area-inset-bottom,0px));border-top:1px solid var(--line);background:var(--surface)}
.nav{font:inherit;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;min-height:76px;border-radius:14px;border:1px solid var(--line);background:var(--bg);color:var(--ink);cursor:pointer;touch-action:manipulation;user-select:none;-webkit-user-select:none}
.nav svg{width:30px;height:30px}
.nav span{font-size:13px;color:var(--muted)}
.nav.go{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.nav.go span{color:var(--accent-ink);opacity:.85}
.nav:active{transform:scale(.97)}
.nav:disabled{opacity:.35}
input[type=file]{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}

/* Hojas: Ritmo, Club, Biblioteca */
.sheet{position:fixed;inset:0;z-index:10;background:var(--bg);overflow-y:auto;padding:calc(14px + env(safe-area-inset-top,0px)) 16px calc(24px + env(safe-area-inset-bottom,0px))}
.sheet-in{max-width:640px;margin:0 auto;display:grid;gap:22px}
.sheet h2{font-family:var(--serif);font-weight:600;font-size:26px;margin:0;text-wrap:balance}
.sheet h3{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 10px}
.shead{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px}
.kpi{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:12px}
.kpi b{display:block;font-family:var(--serif);font-size:28px;font-weight:600;font-variant-numeric:tabular-nums;line-height:1.1}
.kpi small{color:var(--muted);font-size:13px}
.week{display:grid;grid-template-columns:repeat(7,1fr);gap:8px;align-items:end;height:120px}
.week div{display:flex;flex-direction:column;align-items:center;gap:6px;height:100%;justify-content:flex-end}
.week i{display:block;width:100%;max-width:34px;background:var(--accent);border-radius:4px 4px 0 0;min-height:2px}
.week i.zero{background:var(--line)}
.week span{font-size:12px;color:var(--muted)}
.week em{font-style:normal;font-size:11px;font-variant-numeric:tabular-nums}
.splits{display:grid;gap:6px}
.split{display:grid;grid-template-columns:5.5em 1fr 4.5em;gap:10px;align-items:center;font-size:13px;font-variant-numeric:tabular-nums}
.split .track{height:10px;background:var(--line);border-radius:5px;overflow:hidden}
.split .track i{display:block;height:100%;background:var(--accent)}
.split .r{text-align:right;color:var(--muted)}
.note{color:var(--muted);font-size:13px;line-height:1.5;margin:0}
.empty{color:var(--muted);font-size:14px;margin:0}

.tabs{margin-top:-6px}
.cbody{display:grid;gap:18px}
.field{font:inherit;font-size:16px;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:8px;padding:9px 10px;min-width:0}
.field:focus-visible{outline:3px solid var(--accent);outline-offset:1px}
.formrow{display:flex;gap:8px;flex-wrap:wrap}
.formrow .field{flex:1 1 160px}
.join{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:16px;display:grid;gap:12px}
.join p{margin:0;line-height:1.5}
.feed{display:grid;gap:2px}
.post{display:grid;grid-template-columns:38px 1fr auto;gap:12px;align-items:center;padding:10px 0;border-bottom:1px solid var(--line)}
.av{width:38px;height:38px;border-radius:50%;display:grid;place-items:center;font-weight:700;color:var(--accent-ink);background:var(--accent);font-size:16px;flex:none}
.post .txt{min-width:0;line-height:1.4;overflow-wrap:anywhere}
.post .when{display:block;color:var(--muted);font-size:12px;margin-top:2px}
.kbtn{font:inherit;font-size:13px;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:999px;padding:6px 11px;cursor:pointer;white-space:nowrap;font-variant-numeric:tabular-nums}
.kbtn[aria-pressed="true"]{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.kbtn:disabled{cursor:default;opacity:.7}
.group h3 span{color:var(--ink);font-weight:700;margin-left:4px}
.bk{display:grid;grid-template-columns:1fr auto;gap:6px 12px;align-items:center;padding:10px 0;border-bottom:1px solid var(--line)}
.bk .t{min-width:0;font-family:var(--serif);font-size:17px;line-height:1.3;overflow-wrap:anywhere}
.bk .a{color:var(--muted);font-size:13px}
.bk .meta{grid-column:1/-1;display:flex;align-items:center;gap:10px;color:var(--muted);font-size:13px;font-variant-numeric:tabular-nums}
.bk .meta .track{flex:1;max-width:220px;height:6px;background:var(--line);border-radius:3px;overflow:hidden}
.bk .meta .track i{display:block;height:100%;background:var(--accent)}
.bk .acts{display:flex;gap:6px;align-items:center;flex-wrap:wrap;justify-content:flex-end}
.bk select{padding:6px 8px;font-size:13px}
.linkbtn{font:inherit;font-size:13px;background:none;border:0;color:var(--accent);cursor:pointer;padding:4px}
.reader{display:grid;grid-template-columns:38px 1fr;gap:12px;align-items:center;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--surface);cursor:pointer;text-align:left;font:inherit;color:var(--ink);width:100%}
.reader:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.reader .nm{font-weight:700}
.reader .ln{color:var(--muted);font-size:13px;line-height:1.45;overflow-wrap:anywhere}
.readers{display:grid;gap:8px}
.me-tag{font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--accent);margin-left:6px}
.lib{display:grid;gap:8px}
.libitem{display:grid;grid-template-columns:1fr auto;gap:10px;align-items:center;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.libitem .t{font-family:var(--serif);font-size:17px;overflow-wrap:anywhere;min-width:0}
.libitem small{color:var(--muted)}

/* Bienvenida */
.intro{position:fixed;inset:0;z-index:20;background:var(--bg);display:flex;flex-direction:column;padding:calc(20px + env(safe-area-inset-top,0px)) 16px calc(20px + env(safe-area-inset-bottom,0px))}
.intro-in{flex:1;min-height:0;max-width:520px;width:100%;margin:0 auto;display:flex;flex-direction:column;justify-content:center;gap:22px;overflow-y:auto}
.intro .eyebrow{font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:var(--accent);font-weight:700;margin:0}
.intro h2{font-family:var(--serif);font-weight:600;font-size:clamp(26px,7vw,34px);line-height:1.15;margin:0;text-wrap:balance}
.intro p{margin:0;line-height:1.55;font-size:16px}
.intro .demo{background:var(--mark);border-radius:12px;padding:18px;font-family:var(--serif);font-size:22px;line-height:1.5}
.intro .demo .dim{opacity:.25;font-size:15px;display:block}
.keys{display:grid;grid-template-columns:1.35fr 1fr 1fr 1.35fr;gap:8px}
.keys div{border:1px solid var(--line);border-radius:10px;padding:10px 4px;text-align:center;font-size:12px;color:var(--muted);background:var(--surface)}
.keys div b{display:block;color:var(--ink);font-size:14px;margin-bottom:2px}
.keys .go{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.keys .go b{color:var(--accent-ink)}
.facts{display:grid;gap:12px;margin:0;padding:0;list-style:none}
.facts li{display:grid;grid-template-columns:22px 1fr;gap:10px;line-height:1.5}
.facts li::before{content:"";width:10px;height:10px;border-radius:50%;background:var(--accent);margin-top:7px}
.intro-foot{max-width:520px;width:100%;margin:0 auto;display:flex;align-items:center;justify-content:space-between;gap:12px;padding-top:12px}
.dots{display:flex;gap:6px}
.dots i{width:8px;height:8px;border-radius:50%;background:var(--line)}
.dots i.on{background:var(--accent)}
@media (max-width:520px){.pct{display:none}.tbtn{padding:7px 9px;font-size:13px}.top{gap:6px}}
@media (prefers-reduced-motion: reduce){.col,.bar i{transition:none}}