/* ============================================================
   immersion-reader.css — Titan Book Reader
   Paginated e-book reader (CSS columns) + page-turn + audio dock
   ============================================================ */

/* ── mode switches ───────────────────────────────────────── */
#imm-content.bk-mode { overflow: hidden !important; padding: 0 !important; position: relative; display: block; scroll-behavior: auto; }
#titan-immersion-overlay.bk-active .imm-topbar,
#titan-immersion-overlay.bk-active .imm2-nav { display: none !important; }
body.bk-reading #imm-dynamic-island { display: none !important; }

/* ── themes ──────────────────────────────────────────────── */
.bk-root {
    --bk-page: #f3e9d2; --bk-ink: #2e2418; --bk-muted: #7a6a55; --bk-accent: #9a5b1f;
    --bk-desk: #1d1611; --bk-chrome-ink: #eadfca; --bk-rule: rgba(70,45,10,.16);
    --bk-hl: rgba(154,91,31,.30); --bk-pop: #fbf5e6; --bk-pop-ink: #2e2418;
    --bk-font: "Literata","Amiri","Noto Naskh Arabic",Georgia,"Times New Roman",serif;
    --bk-ui: "Tajawal","Cairo",system-ui,-apple-system,"Segoe UI",sans-serif;
    --bk-size: 19px; --bk-lh: 1.85; --bk-align: justify;
    position: absolute; inset: 0; display: flex; flex-direction: column;
    background: var(--bk-desk); color: var(--bk-chrome-ink); font-family: var(--bk-ui);
    -webkit-tap-highlight-color: transparent; user-select: none; -webkit-user-select: none;
}
.bk-root[data-bk-theme="paper"] { }
.bk-root[data-bk-theme="light"] { --bk-page:#fbfaf7; --bk-ink:#1d1c1a; --bk-muted:#6b6a66; --bk-accent:#6d28d9; --bk-desk:#dedbd4; --bk-chrome-ink:#2b2a27; --bk-rule:rgba(0,0,0,.12); --bk-hl:rgba(109,40,217,.22); --bk-pop:#fff; --bk-pop-ink:#1d1c1a; }
.bk-root[data-bk-theme="sepia"] { --bk-page:#e6d5b0; --bk-ink:#3a2c18; --bk-muted:#7b6844; --bk-accent:#8a4b12; --bk-desk:#2a2014; --bk-chrome-ink:#ead9b4; --bk-rule:rgba(80,50,10,.2); --bk-hl:rgba(138,75,18,.32); --bk-pop:#f1e4c4; --bk-pop-ink:#3a2c18; }
.bk-root[data-bk-theme="night"] { --bk-page:#1c1916; --bk-ink:#d9d0c1; --bk-muted:#8d8474; --bk-accent:#e3a455; --bk-desk:#0d0b0a; --bk-chrome-ink:#cfc6b6; --bk-rule:rgba(255,235,200,.12); --bk-hl:rgba(227,164,85,.28); --bk-pop:#25211d; --bk-pop-ink:#e6dccb; }
.bk-root[data-bk-theme="black"] { --bk-page:#000; --bk-ink:#bdbdbd; --bk-muted:#7a7a7a; --bk-accent:#6ec1ff; --bk-desk:#000; --bk-chrome-ink:#b5b5b5; --bk-rule:rgba(255,255,255,.14); --bk-hl:rgba(110,193,255,.25); --bk-pop:#121212; --bk-pop-ink:#d6d6d6; }
.bk-root[data-bk-font="sans"] { --bk-font: "Tajawal","Cairo",system-ui,-apple-system,"Segoe UI",sans-serif; }
@media (max-width: 640px) { .bk-root { --bk-desk: var(--bk-page); --bk-chrome-ink: var(--bk-ink); } }

/* ── top bar ─────────────────────────────────────────────── */
.bk-top {
    flex: 0 0 auto; display: flex; align-items: center; gap: 6px; padding: 8px 10px; min-height: 52px;
    padding-top: max(8px, env(safe-area-inset-top, 0px));
    transition: transform .28s ease, opacity .25s ease, margin .28s ease; position: relative; z-index: 6;
}
.bk-root.bk-chrome-off .bk-top { transform: translateY(-110%); opacity: 0; margin-bottom: -52px; pointer-events: none; }
.bk-ibtn {
    width: 42px; height: 42px; border-radius: 12px; border: 0; background: transparent; color: var(--bk-chrome-ink);
    display: inline-grid; place-items: center; cursor: pointer; font-size: 1rem; flex-shrink: 0; transition: background .15s, transform .12s;
}
.bk-ibtn:hover { background: rgba(127,127,127,.16); }
.bk-ibtn:active { transform: scale(.92); }
.bk-ibtn.on { color: var(--bk-accent); }
.bk-titlebox { flex: 1; min-width: 0; text-align: center; line-height: 1.25; }
.bk-title { font-size: .9rem; font-weight: 800; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bk-sub { font-size: .68rem; opacity: .7; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* ── stage + sheet (the book) ────────────────────────────── */
.bk-stage { flex: 1 1 auto; min-height: 0; position: relative; display: grid; place-items: center; overflow: hidden; touch-action: pan-y pinch-zoom; }
.bk-sheet {
    position: relative; background: var(--bk-page); perspective: 2600px; perspective-origin: 50% 40%;
    box-shadow: 0 1px 0 var(--bk-rule), 2px 2px 0 -.5px var(--bk-page), 2px 2px 0 0 var(--bk-rule),
                4px 4px 0 -.5px var(--bk-page), 4px 4px 0 0 var(--bk-rule), 0 26px 50px rgba(0,0,0,.38);
    border-radius: 4px;
}
.bk-sheet::before { /* paper grain */
    content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none; opacity: .5; mix-blend-mode: multiply;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 .45  0 0 0 0 .35  0 0 0 0 .2  0 0 0 .09 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}
.bk-root[data-bk-theme="night"] .bk-sheet::before, .bk-root[data-bk-theme="black"] .bk-sheet::before { opacity: .15; mix-blend-mode: screen; }
@media (max-width: 640px) { .bk-sheet { box-shadow: none; border-radius: 0; } }
.bk-spine { position: absolute; top: 0; bottom: 0; width: 60px; margin-left: -30px; pointer-events: none; z-index: 3;
    background: linear-gradient(90deg, transparent, rgba(0,0,0,.16) 46%, rgba(0,0,0,.26) 50%, rgba(0,0,0,.14) 54%, transparent); }
.bk-clip { position: absolute; overflow: hidden; z-index: 1; }
.bk-flow {
    position: absolute; top: 0; left: 0; column-fill: auto; column-count: auto;
    font-family: var(--bk-font); font-size: var(--bk-size); line-height: var(--bk-lh); color: var(--bk-ink);
    text-rendering: optimizeLegibility; -webkit-font-smoothing: antialiased; hyphens: auto; -webkit-hyphens: auto;
    transition: transform .3s cubic-bezier(.3,.8,.3,1), opacity .18s ease; will-change: transform;
}
.bk-flow.bk-notrans { transition: none !important; }
.bk-flow.bk-fadeout { opacity: 0; }
.bk-run, .bk-pn { position: absolute; z-index: 2; font-size: .68rem; color: var(--bk-muted); letter-spacing: .3px; pointer-events: none; transition: opacity .2s; font-family: var(--bk-ui); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bk-run { top: 9px; } .bk-pn { bottom: 11px; font-variant-numeric: tabular-nums; }
.bk-sheet.bk-turning .bk-run, .bk-sheet.bk-turning .bk-pn { opacity: 0; }

/* edge hints (desktop) */
.bk-edge { position: absolute; top: 50%; transform: translateY(-50%); width: 44px; height: 88px; border: 0; border-radius: 14px; background: rgba(127,127,127,.0); color: var(--bk-chrome-ink); opacity: 0; transition: opacity .2s, background .2s; cursor: pointer; z-index: 5; font-size: 1.1rem; }
.bk-stage:hover .bk-edge { opacity: .55; } .bk-edge:hover { opacity: 1 !important; background: rgba(127,127,127,.2); }
.bk-edge[disabled] { opacity: 0 !important; pointer-events: none; }
.bk-edge.l { left: 6px; } .bk-edge.r { right: 6px; }
@media (hover: none), (max-width: 760px) { .bk-edge { display: none; } }

/* ── page turn leaf ──────────────────────────────────────── */
.bk-leaf { position: absolute; top: 0; z-index: 6; transform-style: preserve-3d; will-change: transform; pointer-events: none; }
.bk-leaf-f, .bk-leaf-b, .bk-static { position: absolute; inset: 0; overflow: hidden; background: var(--bk-page); backface-visibility: hidden; -webkit-backface-visibility: hidden; contain: layout paint; }
.bk-leaf-b { transform: rotateY(180deg); }
.bk-static { z-index: 4; backface-visibility: visible; -webkit-backface-visibility: visible; }
.bk-face-clone { position: absolute; pointer-events: none; }
.bk-leaf-sh { position: absolute; inset: 0; pointer-events: none; opacity: 0; }
.bk-leaf-f .bk-leaf-sh { background: linear-gradient(var(--bk-sh-dir,90deg), rgba(0,0,0,0) 40%, rgba(0,0,0,.35)); }
.bk-leaf-b .bk-leaf-sh { background: linear-gradient(var(--bk-sh-dir-b,270deg), rgba(0,0,0,0) 35%, rgba(0,0,0,.4)); }
.bk-under { position: absolute; inset: 0; z-index: 5; pointer-events: none; opacity: 0; background: radial-gradient(ellipse at var(--bk-under-x,50%) 50%, rgba(0,0,0,.45), rgba(0,0,0,.05) 80%); border-radius: inherit; }

/* ── typography inside pages ─────────────────────────────── */
.bk-flow .bk-sec { break-before: column; -webkit-column-break-before: always; }
.bk-flow > .bk-sec:first-child { break-before: auto; -webkit-column-break-before: auto; }
.bk-flow .bk-blank { break-before: column; -webkit-column-break-before: always; height: 40px; display: grid; place-items: center; color: var(--bk-muted); opacity: .45; font-size: 1.4rem; }
.bk-flow p, .bk-flow h1, .bk-flow h2, .bk-flow h3 { margin: 0; }
.bk-flow .imm-book-para { margin: 0 0 .85em !important; text-align: var(--bk-align) !important; text-indent: 0; orphans: 2; widows: 2; color: inherit; }
.bk-flow .imm-sentence { display: inline !important; padding: 0 !important; background: none !important; border-radius: 0 !important; }
.bk-flow .imm-sentence:hover { background: none !important; }
.bk-flow .imm-sent-replay, .bk-flow .imm-mic-btn { display: none !important; }
.bk-flow .imm-kw { opacity: 1 !important; color: inherit !important; background: none; border-radius: 5px; padding: 0 1px; margin: 0 -1px; cursor: pointer; transition: background .12s, color .12s; -webkit-box-decoration-break: clone; box-decoration-break: clone; }
.bk-flow .imm-kw-speakable:hover { background: var(--bk-hl) !important; }
.bk-flow .imm-kw-tap { background: var(--bk-hl) !important; }
.bk-flow .imm-sent-tip { display: block; margin: .4em 0 .7em; padding: .55em .8em; border-radius: 10px; font-size: .86em; line-height: 1.6; background: var(--bk-hl); color: var(--bk-ink); border: 1px solid var(--bk-rule); text-align: start; break-inside: avoid; }
.bk-flow .imm-sent-tip-speak { border: 0; background: transparent; color: var(--bk-accent); cursor: pointer; padding: 0 .4em; }
.bk-flow .imm-dropcap { float: left; font-size: 3.2em; line-height: .78; padding: .06em .1em 0 0; font-weight: 700; color: var(--bk-accent); }
.bk-flow[dir="rtl"] .imm-dropcap, .bk-flow .imm-dropcap-rtl { float: none; font-size: inherit; line-height: inherit; padding: 0; font-weight: inherit; color: inherit; }
.bk-flow .imm-inline-image-wrap { break-inside: avoid; margin: .4em 0 1em; height: calc(var(--bk-ph) * .3); border-radius: 8px; overflow: hidden; }
.bk-flow .imm-inline-image { width: 100%; height: 100%; object-fit: cover; display: block; }

/* ── desktop book polish: desk vignette, page-stack edges, corner curl, cast shadow ── */
.bk-root[data-bk-desk-style="desk"] .bk-stage { background: radial-gradient(140% 110% at 50% 34%, color-mix(in srgb, var(--bk-desk) 55%, #fff 6%) 0%, var(--bk-desk) 58%, #000 138%); }
.bk-root[data-bk-desk-style="desk"] .bk-sheet { border-radius: 6px 14px 14px 6px; }
.bk-root[data-bk-desk-style="desk"][dir="rtl"] .bk-sheet { border-radius: 14px 6px 6px 14px; }
.bk-root[data-bk-desk-style="desk"] .bk-sheet::after {
    content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none; z-index: 7;
    background: linear-gradient(to right, rgba(0,0,0,.14), rgba(0,0,0,0) 3.5%, rgba(0,0,0,0) 96.5%, rgba(0,0,0,.14));
    box-shadow: inset 2px 2px 0 -1px color-mix(in srgb, var(--bk-page) 60%, #fff),
                inset -3px -3px 0 -2px color-mix(in srgb, var(--bk-page) 55%, #000 18%);
}
.bk-root[data-bk-desk-style="desk"][dir="rtl"] .bk-sheet::after { box-shadow: inset -2px 2px 0 -1px color-mix(in srgb, var(--bk-page) 60%, #fff), inset 3px -3px 0 -2px color-mix(in srgb, var(--bk-page) 55%, #000 18%); }
.bk-curl {
    position: absolute; bottom: 0; width: 52px; height: 52px; z-index: 6; pointer-events: none;
    opacity: 0; transition: opacity .3s; border-bottom-right-radius: 8px;
    background: linear-gradient(315deg, color-mix(in srgb, var(--bk-page) 72%, #fff) 0%, var(--bk-page) 46%, rgba(0,0,0,.18) 47%, rgba(0,0,0,0) 62%);
    filter: drop-shadow(-3px -3px 5px rgba(0,0,0,.3));
}
.bk-curl[data-side="r"] { right: 0; }
.bk-curl[data-side="l"] { left: 0; transform: scaleX(-1); }
.bk-stage:hover .bk-curl { opacity: .85; }
.bk-sheet.bk-turning .bk-curl, .bk-root.bk-chrome-off .bk-curl { opacity: 0 !important; }
.bk-leaf-cast { position: absolute; top: 0; height: 100%; z-index: 5; pointer-events: none; opacity: 0; }

/* narration / karaoke states — upcoming dim, read = full, current = marker */
.bk-narrating .imm-kw:not(.bk-done):not(.imm-kw-active) { color: color-mix(in srgb, var(--bk-ink) 52%, transparent) !important; }
.bk-flow .imm-kw.imm-kw-active { background: var(--bk-hl) !important; color: var(--bk-ink) !important; box-shadow: 0 2px 0 0 var(--bk-accent); border-radius: 5px; font-weight: inherit; }
.bk-flow .bk-sent-on { background: color-mix(in srgb, var(--bk-hl) 40%, transparent); border-radius: 6px; -webkit-box-decoration-break: clone; box-decoration-break: clone; }

/* section chrome */
.bk-eyebrow { font: 800 .62rem var(--bk-ui); letter-spacing: 2.4px; color: var(--bk-accent); text-transform: uppercase; }
.bk-h2 { font: 800 1.15em var(--bk-ui); color: var(--bk-accent); display: flex; align-items: center; gap: .5em; margin-bottom: .7em !important; }
.bk-orn { display: flex; align-items: center; gap: .6em; color: var(--bk-accent); opacity: .7; margin: .8em 0; font-size: .9em; }
.bk-orn::before, .bk-orn::after { content: ""; flex: 1; height: 1px; background: currentColor; opacity: .5; }
.bk-pill { display: inline-flex; align-items: center; gap: .35em; padding: .18em .7em; border-radius: 99px; font: 700 .68rem var(--bk-ui); color: var(--bk-accent); background: var(--bk-hl); margin: 0 .4em .4em 0; }
[dir="rtl"] .bk-pill { margin: 0 0 .4em .4em; }
.bk-ui-dir { font-family: var(--bk-ui); }

/* cover */
.bk-cover { height: var(--bk-ph); display: flex; flex-direction: column; font-family: var(--bk-ui); }
.bk-cover-art { flex: 0 0 44%; border-radius: 8px; background-size: cover; background-position: center; background-color: color-mix(in srgb, var(--bk-accent) 35%, var(--bk-page)); position: relative; overflow: hidden; box-shadow: 0 10px 24px rgba(0,0,0,.25); }
.bk-cover-art::after { content: ""; position: absolute; inset: 0; background: linear-gradient(to top, rgba(0,0,0,.35), transparent 55%); }
.bk-cover-body { flex: 1; display: flex; flex-direction: column; gap: .5em; padding-top: 1.1em; min-height: 0; }
.bk-cover h1 { font: 800 1.55em/1.28 var(--bk-font); color: var(--bk-ink); }
.bk-cover-goal { font-size: .88em; line-height: 1.7; color: var(--bk-muted); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.bk-cover-meta { font-size: .72em; color: var(--bk-muted); display: flex; gap: 1em; flex-wrap: wrap; }
.bk-cover-actions { margin-top: auto; display: flex; gap: .6em; flex-wrap: wrap; }
.bk-btn { border: 0; cursor: pointer; font: 800 .82rem var(--bk-ui); padding: .75em 1.3em; border-radius: 99px; background: var(--bk-accent); color: var(--bk-page); display: inline-flex; align-items: center; gap: .55em; transition: transform .12s, filter .15s; }
.bk-btn:active { transform: scale(.96); } .bk-btn:hover { filter: brightness(1.08); }
.bk-btn.ghost { background: transparent; color: var(--bk-accent); box-shadow: inset 0 0 0 1.5px var(--bk-accent); }

/* context */
.bk-ctx .bk-p { font-size: 1em; line-height: var(--bk-lh); text-align: var(--bk-align); margin-bottom: .9em; }
.bk-goal { margin: .8em 0; padding: .7em .9em; border-radius: 12px; background: var(--bk-hl); font: 600 .84em/1.6 var(--bk-ui); color: var(--bk-ink); break-inside: avoid; }
.bk-goal b { color: var(--bk-accent); display: block; font-size: .78em; letter-spacing: .6px; margin-bottom: .2em; }
.bk-trivia { display: flex; gap: .6em; margin: .55em 0; font: 500 .82em/1.65 var(--bk-ui); color: var(--bk-muted); break-inside: avoid; }
.bk-trivia i { color: var(--bk-accent); margin-top: .35em; }

/* chapter */
.bk-ch-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: .8em; font-family: var(--bk-ui); }
.bk-ch-num { font: 800 .72rem var(--bk-ui); letter-spacing: 2px; color: var(--bk-accent); text-transform: uppercase; display: inline-flex; align-items: center; gap: .6em; }
.bk-ch-num::before { content: "❖"; font-size: .9em; }
.bk-ch-done { color: #2f9e6a; font-size: .85rem; }
.bk-figure { height: calc(var(--bk-ph) * .3); margin: 0 0 1em; border-radius: 10px; overflow: hidden; position: relative; background: color-mix(in srgb, var(--bk-accent) 25%, var(--bk-page)); break-inside: avoid; box-shadow: 0 6px 18px rgba(0,0,0,.2); }
.bk-figure img, .bk-figure video { width: 100%; height: 100%; object-fit: cover; object-position: center 30%; display: block; }
.bk-figure.bk-noimg { display: grid; place-items: center; color: var(--bk-accent); font-size: 2rem; }

/* a picture from the book itself, sitting between its paragraphs */
.bk-fig { margin: 1em auto; padding: 0; max-width: 100%; break-inside: avoid; page-break-inside: avoid;
          display: flex; flex-direction: column; gap: .45em; align-items: center; }
.bk-fig img { display: block; width: 100%; height: auto; max-width: 100%; object-fit: contain;
              border-radius: 8px; background: color-mix(in srgb, var(--bk-accent) 8%, var(--bk-page));
              border: 1px solid var(--bk-rule); opacity: 1;
              animation: bk-fig-in .38s ease .3s backwards; }
@keyframes bk-fig-in { from { opacity: 0 } to { opacity: 1 } }
.bk-fig figcaption { font: 500 .76em/1.5 var(--bk-ui); color: var(--bk-muted); text-align: center;
                     max-width: 34em; }

/* vocabulary */
.bk-vocab, .bk-quiz { font-family: var(--bk-ui); }
.bk-vrow { display: flex; align-items: flex-start; gap: .7em; padding: .6em 0; border-bottom: 1px solid var(--bk-rule); break-inside: avoid; cursor: pointer; }
.bk-vword { font: 800 1em var(--bk-font); color: var(--bk-ink); }
.bk-vmean { font: 500 .82em/1.5 var(--bk-ui); color: var(--bk-muted); margin-top: .1em; transition: filter .2s; }
.bk-vocab.bk-hide .bk-vmean { filter: blur(6px); } .bk-vocab.bk-hide .bk-vrow.shown .bk-vmean { filter: none; }
.bk-vex { font: italic 500 .76em/1.5 var(--bk-font); color: var(--bk-muted); opacity: .85; margin-top: .15em; }
.bk-vspk { margin-inline-start: auto; border: 0; background: var(--bk-hl); color: var(--bk-accent); width: 34px; height: 34px; border-radius: 50%; cursor: pointer; flex-shrink: 0; }
.bk-vtoggle { margin: .2em 0 .8em; font: 700 .72rem var(--bk-ui); color: var(--bk-accent); background: none; border: 0; cursor: pointer; padding: 0; }

/* quiz (re-skin of existing controls) */
.bk-quiz .imm-interaction { padding: 0; background: none; border: 0; }
.bk-quiz .imm-cliffhanger-label { color: var(--bk-accent); font: 800 .72rem var(--bk-ui); letter-spacing: 1.4px; margin-bottom: .7em; display: flex; gap: .5em; align-items: center; }
.bk-quiz .imm-question-row { display: flex; gap: .5em; align-items: flex-start; margin-bottom: .9em; break-inside: avoid; }
.bk-quiz .imm-question { font: 800 1.02em/1.55 var(--bk-font); color: var(--bk-ink); flex: 1; }
.bk-quiz .imm-choice-row { display: flex; gap: .4em; margin-bottom: .55em; break-inside: avoid; }
.bk-quiz .imm-choice-btn { flex: 1; text-align: start; padding: .75em .9em; border-radius: 12px; border: 1.5px solid var(--bk-rule); background: transparent; color: var(--bk-ink); font: 600 .9em/1.5 var(--bk-font); cursor: pointer; transition: .15s; }
.bk-quiz .imm-choice-btn:not(:disabled):hover { border-color: var(--bk-accent); background: var(--bk-hl); }
.bk-quiz .imm-choice-btn.imm-choice-correct { border-color: #2f9e6a; background: rgba(47,158,106,.16); }
.bk-quiz .imm-choice-btn.imm-choice-wrong { border-color: #d64545; background: rgba(214,69,69,.14); }
.bk-quiz .imm-tts-btn { border: 0; background: transparent; color: var(--bk-accent); cursor: pointer; width: 34px; flex-shrink: 0; }
.bk-quiz .imm-feedback-success { display: flex; flex-wrap: wrap; align-items: center; gap: .6em; padding: .8em; border-radius: 12px; background: rgba(47,158,106,.14); color: var(--bk-ink); font: 700 .86em var(--bk-ui); break-inside: avoid; }
.bk-quiz .imm-xp-pop { color: #2f9e6a; font-weight: 800; }
.bk-quiz .imm-unlock-hint { opacity: .7; font-weight: 500; }
.bk-quiz .imm-feedback-error-box { padding: .7em .9em; border-radius: 12px; background: rgba(214,69,69,.12); font: 600 .84em/1.6 var(--bk-ui); color: var(--bk-ink); break-inside: avoid; }
.bk-quiz .imm-btn-next-ch, .bk-quiz .imm-btn-retry-choice { margin-top: .4em; border: 0; border-radius: 99px; padding: .55em 1.1em; background: var(--bk-accent); color: var(--bk-page); font: 800 .78rem var(--bk-ui); cursor: pointer; }

/* end page */
.bk-end { height: var(--bk-ph); display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; gap: .7em; font-family: var(--bk-ui); }
.bk-end h2 { font: 800 1.6em var(--bk-font); color: var(--bk-ink); }
.bk-end p { color: var(--bk-muted); font-size: .86em; line-height: 1.7; max-width: 26em; }
.bk-end .bk-orn { width: 70%; }
.bk-end-actions { display: flex; flex-direction: column; gap: .5em; width: min(100%, 260px); margin-top: .6em; }

/* ── bottom dock: progress + player ──────────────────────── */
.bk-dock { flex: 0 0 auto; position: relative; z-index: 6; padding: 4px 14px calc(8px + env(safe-area-inset-bottom, 0px)); display: flex; flex-direction: column; gap: 6px; transition: transform .28s ease, opacity .25s ease; }
.bk-root.bk-chrome-off .bk-prog { display: none; }
.bk-prog { display: flex; flex-direction: column; gap: 5px; max-width: 760px; width: 100%; margin: 0 auto; }
.bk-scrub { position: relative; height: 26px; display: flex; align-items: center; cursor: pointer; touch-action: none; }
.bk-scrub-track { position: relative; flex: 1; height: 4px; border-radius: 4px; background: rgba(127,127,127,.28); }
.bk-scrub-fill { position: absolute; top: 0; bottom: 0; inset-inline-start: 0; width: 0; border-radius: 4px; background: var(--bk-accent); }
.bk-tick { position: absolute; top: -3px; width: 2px; height: 10px; background: var(--bk-chrome-ink); opacity: .45; border-radius: 1px; }
.bk-knob { position: absolute; top: 50%; width: 14px; height: 14px; margin: -7px -7px 0 0; border-radius: 50%; background: var(--bk-accent); box-shadow: 0 2px 6px rgba(0,0,0,.35); transition: transform .12s; inset-inline-start: 0; }
[dir="rtl"] .bk-knob { margin: -7px 0 0 -7px; }
.bk-scrub:active .bk-knob { transform: scale(1.35); }
.bk-prog-meta { display: flex; justify-content: space-between; gap: 8px; font-size: .68rem; opacity: .75; font-variant-numeric: tabular-nums; }
.bk-player { display: flex; align-items: center; gap: 8px; direction: ltr; max-width: 760px; width: 100%; margin: 0 auto; padding: 8px 10px; border-radius: 18px; background: color-mix(in srgb, var(--bk-chrome-ink) 9%, transparent); border: 1px solid color-mix(in srgb, var(--bk-chrome-ink) 14%, transparent); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }
.bk-player[hidden] { display: none; }
.bk-pl-main { width: 46px; height: 46px; border-radius: 50%; border: 0; background: var(--bk-accent); color: var(--bk-page); font-size: 1.05rem; cursor: pointer; display: grid; place-items: center; flex-shrink: 0; box-shadow: 0 4px 14px rgba(0,0,0,.3); transition: transform .12s; }
.bk-pl-main:active { transform: scale(.92); }
.bk-pl-mid { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 3px; }
.bk-pl-title { font: 800 .76rem var(--bk-ui); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; direction: auto; }
.bk-seek { position: relative; height: 22px; display: flex; align-items: center; cursor: pointer; touch-action: none; }
.bk-seek-track { position: relative; flex: 1; height: 4px; border-radius: 4px; background: rgba(127,127,127,.3); }
.bk-seek-fill { position: absolute; inset: 0 auto 0 0; width: 0; border-radius: 4px; background: var(--bk-chrome-ink); opacity: .85; }
.bk-seek-knob { position: absolute; top: 50%; left: 0; width: 12px; height: 12px; margin: -6px 0 0 -6px; border-radius: 50%; background: var(--bk-chrome-ink); }
.bk-pl-time { display: flex; justify-content: space-between; font: 600 .62rem var(--bk-ui); opacity: .7; font-variant-numeric: tabular-nums; }
.bk-pbtn { width: 38px; height: 38px; border-radius: 12px; border: 0; background: transparent; color: var(--bk-chrome-ink); cursor: pointer; display: grid; place-items: center; position: relative; font-size: .92rem; flex-shrink: 0; transition: background .15s; }
.bk-pbtn:hover { background: rgba(127,127,127,.18); }
.bk-pbtn small { position: absolute; font: 800 .5rem var(--bk-ui); top: 50%; left: 50%; transform: translate(-50%,-38%); }
.bk-pbtn.txt { font: 800 .72rem var(--bk-ui); width: 44px; }
.bk-pbtn.on { color: var(--bk-accent); }
.bk-pbtn .bk-badge { position: absolute; top: 2px; right: 0; font: 800 .5rem var(--bk-ui); background: var(--bk-accent); color: var(--bk-page); border-radius: 8px; padding: 1px 4px; }
@media (max-width: 420px) { .bk-pbtn.opt { display: none; } .bk-player { gap: 4px; padding: 7px 8px; } }

/* follow chip + resume toast */
.bk-chip { position: absolute; z-index: 7; left: 50%; bottom: 14px; transform: translateX(-50%) translateY(16px); opacity: 0; pointer-events: none; padding: .55em 1em; border-radius: 99px; border: 0; background: var(--bk-accent); color: var(--bk-page); font: 800 .74rem var(--bk-ui); box-shadow: 0 8px 22px rgba(0,0,0,.35); cursor: pointer; transition: .25s; display: inline-flex; gap: .5em; align-items: center; white-space: nowrap; }
.bk-chip.show { opacity: 1; transform: translateX(-50%) translateY(0); pointer-events: auto; }
.bk-toast { position: absolute; z-index: 8; left: 12px; right: 12px; bottom: 12px; max-width: 520px; margin: 0 auto; display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: 16px; background: var(--bk-pop); color: var(--bk-pop-ink); box-shadow: 0 14px 40px rgba(0,0,0,.4); font: 600 .8rem/1.4 var(--bk-ui); transform: translateY(140%); transition: transform .35s cubic-bezier(.3,1.2,.4,1); }
.bk-toast.show { transform: translateY(0); }
.bk-toast span { flex: 1; min-width: 0; }
.bk-toast button { border: 0; border-radius: 99px; padding: .5em 1em; font: 800 .74rem var(--bk-ui); cursor: pointer; background: var(--bk-accent); color: var(--bk-page); }
.bk-toast button.x { background: transparent; color: var(--bk-muted); padding: .5em; }

/* sentence action bar */
.bk-sentbar { position: absolute; z-index: 9; display: flex; gap: 2px; padding: 4px; border-radius: 14px; background: var(--bk-pop); box-shadow: 0 10px 30px rgba(0,0,0,.4); transform: translate(-50%, -100%); animation: bk-pop .16s ease; }
.bk-sentbar button { border: 0; background: transparent; color: var(--bk-pop-ink); padding: .55em .8em; border-radius: 10px; font: 700 .72rem var(--bk-ui); cursor: pointer; display: inline-flex; gap: .45em; align-items: center; white-space: nowrap; }
.bk-sentbar button:hover { background: var(--bk-hl); }
@keyframes bk-pop { from { opacity: 0; transform: translate(-50%, -90%) scale(.94); } }

/* bottom sheets */
.bk-pops { position: absolute; inset: 0; z-index: 20; display: flex; align-items: flex-end; justify-content: center; }
.bk-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,.5); animation: bk-fade .2s ease; }
.bk-panel { position: relative; width: 100%; max-width: 560px; max-height: 82%; display: flex; flex-direction: column; background: var(--bk-pop); color: var(--bk-pop-ink); border-radius: 22px 22px 0 0; box-shadow: 0 -10px 40px rgba(0,0,0,.35); animation: bk-up .28s cubic-bezier(.2,.9,.3,1); font-family: var(--bk-ui); padding-bottom: env(safe-area-inset-bottom, 0px); }
@media (min-width: 700px) { .bk-pops { align-items: center; } .bk-panel { border-radius: 22px; max-height: 80%; } }
.bk-grab { width: 40px; height: 4px; border-radius: 4px; background: var(--bk-rule); margin: 8px auto 0; }
.bk-panel-head { display: flex; align-items: center; justify-content: space-between; padding: 8px 16px 6px; }
.bk-panel-head h3 { margin: 0; font-size: 1rem; font-weight: 800; }
.bk-panel-body { overflow-y: auto; padding: 4px 16px 18px; -webkit-overflow-scrolling: touch; }
@keyframes bk-up { from { transform: translateY(40px); opacity: 0; } }
@keyframes bk-fade { from { opacity: 0; } }
.bk-set { padding: 12px 0; border-bottom: 1px solid var(--bk-rule); }
.bk-set:last-child { border: 0; }
.bk-set > label { display: block; font: 700 .72rem var(--bk-ui); color: var(--bk-muted); margin-bottom: 8px; }
.bk-seg { display: flex; gap: 6px; flex-wrap: wrap; }
.bk-seg button { flex: 1; min-width: 64px; padding: .6em .5em; border-radius: 12px; border: 1.5px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); font: 700 .78rem var(--bk-ui); cursor: pointer; transition: .15s; }
.bk-seg button.on { border-color: var(--bk-accent); background: var(--bk-hl); color: var(--bk-pop-ink); box-shadow: inset 0 0 0 1px var(--bk-accent); }
.bk-swatches { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; }
.bk-sw { aspect-ratio: 1; border-radius: 50%; border: 2px solid var(--bk-rule); cursor: pointer; position: relative; display: grid; place-items: center; font: 800 .7rem var(--bk-font); padding: 0; }
.bk-sw.on { border-color: var(--bk-accent); box-shadow: 0 0 0 2px var(--bk-pop), 0 0 0 4px var(--bk-accent); }
.bk-sw small { position: absolute; bottom: -17px; font: 600 .56rem var(--bk-ui); color: var(--bk-muted); white-space: nowrap; }
.bk-sizerow { display: flex; align-items: center; gap: 10px; direction: ltr; }
.bk-sizerow input[type=range] { flex: 1; accent-color: var(--bk-accent); }
.bk-sizerow button { width: 40px; height: 40px; border-radius: 12px; border: 1.5px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); font-weight: 800; cursor: pointer; }
.bk-switch { display: flex; align-items: center; justify-content: space-between; gap: 12px; font: 700 .84rem var(--bk-ui); }
.bk-switch button { width: 48px; height: 28px; border-radius: 20px; border: 0; background: rgba(127,127,127,.35); position: relative; cursor: pointer; transition: .2s; flex-shrink: 0; }
.bk-switch button::after { content: ""; position: absolute; top: 3px; left: 3px; width: 22px; height: 22px; border-radius: 50%; background: #fff; transition: .2s; }
.bk-switch button.on { background: var(--bk-accent); } .bk-switch button.on::after { left: 23px; }
.bk-toc-item { display: flex; align-items: center; gap: 12px; width: 100%; padding: 12px 6px; border: 0; border-bottom: 1px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); text-align: start; cursor: pointer; font: 700 .9rem var(--bk-ui); }
.bk-toc-item.cur { color: var(--bk-accent); }
.bk-toc-item .n { margin-inline-start: auto; font-size: .72rem; color: var(--bk-muted); font-variant-numeric: tabular-nums; }
.bk-toc-item .ic { width: 28px; text-align: center; color: var(--bk-accent); }
.bk-menu-item { display: flex; align-items: center; gap: 14px; width: 100%; padding: 14px 6px; border: 0; border-bottom: 1px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); font: 700 .9rem var(--bk-ui); cursor: pointer; text-align: start; }
.bk-menu-item i { width: 24px; text-align: center; color: var(--bk-accent); }
.bk-menu-item.on i { color: var(--bk-accent); }

@media (prefers-reduced-motion: reduce) { .bk-flow, .bk-top, .bk-chip, .bk-toast, .bk-panel, .bk-backdrop { transition: none !important; animation: none !important; } }

/* ── FIX: original reader CSS painted the text near-white (made for the dark UI) ── */
.bk-flow .imm-text-primary { color: var(--bk-ink) !important; font-size: inherit !important; line-height: inherit !important; padding: 0 !important; background: none !important; border: 0 !important; border-radius: 0 !important; animation: none !important; }
.bk-flow .imm-karaoke-container, .bk-flow .imm-book-para, .bk-flow .imm-sentence { color: var(--bk-ink) !important; }
.bk-flow .imm-kw { color: inherit !important; }
.bk-flow .imm-book-para { hyphens: auto; }
.bk-flow .imm-book-para:last-child { margin-bottom: .85em !important; }

/* ── per-paragraph translation ── */
.bk-flow .bk-ptr { display: inline-grid; place-items: center; width: 1.7em; height: 1.7em; margin-inline-start: .55em; padding: 0; border: 0; border-radius: 50%; vertical-align: middle; font-size: .62em; cursor: pointer; color: var(--bk-accent); background: var(--bk-hl); opacity: .9; transition: transform .12s, background .15s; -webkit-tap-highlight-color: transparent; }
.bk-flow .bk-ptr:hover { background: var(--bk-accent); color: var(--bk-page); }
.bk-flow .bk-ptr:active { transform: scale(.88); }
.bk-flow .bk-p-on { background: color-mix(in srgb, var(--bk-hl) 55%, transparent); border-radius: 8px; box-shadow: 0 0 0 .35em color-mix(in srgb, var(--bk-hl) 55%, transparent); }
.bk-ptcard { position: absolute; z-index: 7; inset-inline: 10px; bottom: 10px; max-width: 640px; margin: 0 auto; max-height: 46%; display: flex; flex-direction: column; border-radius: 18px; background: var(--bk-pop); color: var(--bk-pop-ink); box-shadow: 0 16px 44px rgba(0,0,0,.42); border: 1px solid var(--bk-rule); transform: translateY(24px); opacity: 0; transition: transform .26s cubic-bezier(.2,.9,.3,1), opacity .2s; font-family: var(--bk-ui); }
.bk-ptcard.top { bottom: auto; top: 10px; transform: translateY(-24px); }
.bk-ptcard.show { transform: translateY(0); opacity: 1; }
.bk-pt-head { display: flex; align-items: center; gap: 4px; padding: 8px 8px 4px 12px; direction: ltr; }
[dir="rtl"] .bk-pt-head { padding: 8px 12px 4px 8px; }
.bk-pt-lang { font: 800 .72rem var(--bk-ui); color: var(--bk-accent); margin-inline-end: auto; direction: ltr; }
.bk-pt-count { font: 700 .66rem var(--bk-ui); opacity: .55; margin: 0 6px; font-variant-numeric: tabular-nums; }
.bk-pt-b { width: 34px; height: 34px; border: 0; border-radius: 10px; background: transparent; color: var(--bk-pop-ink); cursor: pointer; display: grid; place-items: center; font-size: .85rem; }
.bk-pt-b:hover { background: var(--bk-hl); }
.bk-pt-text { overflow-y: auto; padding: 4px 16px 16px; font: 500 1rem/1.85 var(--bk-font); -webkit-overflow-scrolling: touch; user-select: text; -webkit-user-select: text; }

/* ============================================================
   PRO LAYER — mini-player, sheets, stats, review, notes, search
   ============================================================ */
/* mini-player (narration continues in the library) */
.imm2-mini { position: relative; flex-shrink: 0; display: flex; align-items: center; gap: 10px; margin: 0 10px 6px; padding: 8px 10px; border-radius: 16px; overflow: hidden; background: color-mix(in srgb, var(--imm-surface, #1b1530) 94%, transparent); border: 1px solid var(--imm-border, rgba(255,255,255,.12)); box-shadow: 0 10px 30px rgba(0,0,0,.35); backdrop-filter: blur(16px); cursor: pointer; transform: translateY(20px); opacity: 0; transition: .28s cubic-bezier(.2,.9,.3,1); color: var(--imm-text, #fff); z-index: 6; }
.imm2-mini.show { transform: none; opacity: 1; }
.imm2-mini .m-art { width: 42px; height: 42px; border-radius: 11px; flex-shrink: 0; background: linear-gradient(135deg, var(--imm-purple2, #a855f7), var(--imm-purple, #7c3aed)) center/cover; display: grid; place-items: center; color: #fff; }
.imm2-mini .m-art[style] i { display: none; }
.imm2-mini .m-info { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 1px; }
.imm2-mini .m-info b { font-size: .82rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.imm2-mini .m-info span { font-size: .68rem; opacity: .65; }
.imm2-mini .m-btn { width: 38px; height: 38px; border: 0; border-radius: 50%; background: transparent; color: inherit; cursor: pointer; display: grid; place-items: center; }
.imm2-mini .m-btn[data-m=pp] { background: var(--imm-purple, #7c3aed); color: #fff; }
.imm2-mini .m-bar { position: absolute; left: 0; right: 0; bottom: 0; height: 3px; background: rgba(127,127,127,.25); }
.imm2-mini .m-bar i { display: block; height: 100%; width: 0; background: var(--imm-purple, #7c3aed); }
#titan-immersion-overlay.bk-active .imm2-mini { display: none; }

/* offline banner */
.imm2-offline { flex-shrink: 0; display: flex; align-items: center; justify-content: center; gap: 8px; padding: 6px 12px; font: 700 .72rem var(--imm-font, inherit); background: #b45309; color: #fff; text-align: center; }
.imm2-offline[hidden] { display: none; }

/* library sheet */
.imm2-sheet { position: absolute; inset: 0; z-index: 50; display: flex; align-items: flex-end; justify-content: center; pointer-events: none; }
.imm2-sheet-bd { position: absolute; inset: 0; background: rgba(0,0,0,.55); opacity: 0; transition: opacity .25s; pointer-events: auto; }
.imm2-sheet.show .imm2-sheet-bd { opacity: 1; }
.imm2-sheet-pn { position: relative; width: 100%; max-width: 560px; max-height: 88%; display: flex; flex-direction: column; background: var(--imm-surface, #1b1530); color: var(--imm-text, #fff); border-radius: 24px 24px 0 0; transform: translateY(100%); transition: transform .3s cubic-bezier(.2,.9,.3,1); pointer-events: auto; padding-bottom: env(safe-area-inset-bottom, 0px); box-shadow: 0 -12px 40px rgba(0,0,0,.4); }
.imm2-sheet.show .imm2-sheet-pn { transform: none; }
@media (min-width: 700px) { .imm2-sheet { align-items: center; } .imm2-sheet-pn { border-radius: 24px; } }
.imm2-sheet-grab { width: 40px; height: 4px; border-radius: 4px; background: var(--imm-border, rgba(255,255,255,.2)); margin: 8px auto 0; }
.imm2-sheet-hd { display: flex; align-items: center; justify-content: space-between; padding: 8px 16px 6px; }
.imm2-sheet-hd h3 { margin: 0; font-size: 1.05rem; font-weight: 900; }
.imm2-sheet-body { overflow-y: auto; padding: 4px 16px 20px; -webkit-overflow-scrolling: touch; }

/* stats */
.st-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.st-card { padding: 14px; border-radius: 16px; background: var(--imm-card, rgba(255,255,255,.05)); border: 1px solid var(--imm-border, rgba(255,255,255,.1)); display: flex; flex-direction: column; gap: 3px; }
.st-card b { font-size: 1.5rem; font-weight: 900; }
.st-card span { font-size: .7rem; opacity: .65; }
.st-h { margin: 18px 0 8px; font-size: .85rem; opacity: .8; }
.st-chart { display: flex; gap: 8px; align-items: flex-end; height: 120px; direction: ltr; }
.st-col { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 6px; height: 100%; }
.st-bar { flex: 1; width: 100%; max-width: 34px; display: flex; flex-direction: column; justify-content: flex-end; border-radius: 8px; overflow: hidden; background: rgba(127,127,127,.12); }
.st-bar i { display: block; width: 100%; min-height: 0; }
.st-bar i.r, .st-legend i.r { background: var(--imm-purple, #7c3aed); }
.st-bar i.l, .st-legend i.l { background: var(--imm-cyan, #22d3ee); }
.st-col span { font-size: .66rem; opacity: .6; }
.st-legend { display: flex; gap: 14px; justify-content: center; margin-top: 8px; font-size: .7rem; opacity: .8; }
.st-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-inline-end: 5px; }

/* review (SRS) */
.rv-top { display: flex; align-items: center; gap: 10px; font-size: .74rem; opacity: .85; margin-bottom: 14px; }
.rv-bar { flex: 1; height: 6px; border-radius: 6px; background: rgba(127,127,127,.25); overflow: hidden; }
.rv-bar b { display: block; height: 100%; background: linear-gradient(90deg, var(--imm-purple, #7c3aed), var(--imm-cyan, #22d3ee)); transition: width .3s; }
.rv-card { text-align: center; padding: 28px 16px; border-radius: 22px; background: var(--imm-card, rgba(255,255,255,.05)); border: 1px solid var(--imm-border, rgba(255,255,255,.1)); min-height: 210px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px; }
.rv-lang { font-size: .7rem; opacity: .6; }
.rv-word { font-size: 2rem; font-weight: 900; line-height: 1.3; word-break: break-word; }
.rv-ans { margin-top: 14px; padding-top: 14px; border-top: 1px dashed var(--imm-border, rgba(255,255,255,.2)); font-size: 1.15rem; font-weight: 700; color: var(--imm-gold, #fbbf24); width: 100%; }
.rv-actions { margin-top: 14px; }
.rv-rate { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.rv-rate[hidden] { display: none; }
.rv-b { padding: 14px 6px; border: 0; border-radius: 14px; font: 800 .8rem var(--imm-font, inherit); cursor: pointer; color: #fff; }
.rv-b.again { background: #dc2626; } .rv-b.good { background: #16a34a; } .rv-b.easy { background: #7c3aed; }
.rv-done { text-align: center; padding: 20px 0; } .rv-done h3 { margin: 6px 0; font-size: 1.4rem; } .rv-done p { opacity: .75; margin: 0 0 16px; }

/* v2 home: quick-action row under the goal card */
.imm2-goal-actions { display: flex; gap: 8px; width: 100%; flex-wrap: wrap; margin-top: 2px; }
.imm2-goal-actions button { flex: 1; min-width: 120px; display: inline-flex; align-items: center; justify-content: center; gap: 7px; padding: 9px 10px; border-radius: 12px; border: 1px solid var(--imm-border, rgba(255,255,255,.12)); background: var(--glass, rgba(255,255,255,.05)); color: var(--imm-text); font: 800 .74rem var(--imm-font, inherit); cursor: pointer; position: relative; }
.imm2-goal-actions button:hover { border-color: var(--imm-purple); }
.imm2-goal-actions .dueb { background: #ef4444; color: #fff; border-radius: 99px; font-size: .62rem; padding: 1px 7px; }

/* reader: ribbon, highlights, flash */
.bk-ribbon { position: absolute; top: -2px; inset-inline-end: 22px; width: 22px; height: 46px; z-index: 6; background: var(--bk-accent); clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 78%, 0 100%); transform: translateY(-110%); transition: transform .25s cubic-bezier(.2,.9,.3,1); pointer-events: none; filter: drop-shadow(0 3px 4px rgba(0,0,0,.35)); }
.bk-ribbon.show { transform: none; }
.bk-flow .imm-sentence[data-hl] { -webkit-box-decoration-break: clone; box-decoration-break: clone; border-radius: 4px; }
.bk-flow .imm-sentence[data-hl="y"] { background: rgba(255,214,10,.34) !important; }
.bk-flow .imm-sentence[data-hl="g"] { background: rgba(52,199,89,.30) !important; }
.bk-flow .imm-sentence[data-hl="b"] { background: rgba(90,200,250,.30) !important; }
.bk-flow .imm-sentence[data-hl="p"] { background: rgba(255,111,168,.30) !important; }
.bk-flow .imm-sentence.bk-hasnote { text-decoration: underline dotted var(--bk-accent); text-underline-offset: .22em; }
.bk-flow .imm-sentence.bk-flash { animation: bk-flash 2s ease; }
@keyframes bk-flash { 0%, 55% { background: var(--bk-hl) !important; box-shadow: 0 0 0 .3em var(--bk-hl); } 100% { box-shadow: 0 0 0 .3em transparent; } }
.bk-sentbar { flex-wrap: wrap; justify-content: center; max-width: 94%; }
.bk-sentbar button { padding: .5em .65em; }

/* reader sheets: highlight editor, notes list, search */
.bk-hl-quote { padding: .8em 1em; border-radius: 12px; background: var(--bk-hl); font: 500 .95rem/1.8 var(--bk-font); margin-bottom: 4px; max-height: 120px; overflow-y: auto; }
.bk-hl-colors { display: flex; gap: 12px; }
.bk-hl-colors button { width: 38px; height: 38px; border-radius: 50%; border: 3px solid transparent; cursor: pointer; }
.bk-hl-colors button.on { border-color: var(--bk-pop-ink); box-shadow: 0 0 0 2px var(--bk-pop); }
.bk-note { width: 100%; box-sizing: border-box; border-radius: 12px; border: 1.5px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); font: 500 .9rem/1.6 var(--bk-ui); padding: .7em .9em; resize: vertical; outline: 0; }
.bk-note:focus { border-color: var(--bk-accent); }
.bk-note-item { display: flex; gap: 10px; align-items: flex-start; padding: 12px 6px; border-bottom: 1px solid var(--bk-rule); cursor: pointer; }
.bk-dot { width: 12px; height: 12px; border-radius: 50%; margin-top: .4em; flex-shrink: 0; }
.bk-ni-b { flex: 1; min-width: 0; } .bk-ni-t { font: 500 .88rem/1.7 var(--bk-font); } .bk-ni-n { font: 600 .76rem/1.6 var(--bk-ui); color: var(--bk-muted); margin-top: 3px; }
.bk-ni-x { border: 0; background: transparent; color: var(--bk-muted); cursor: pointer; padding: 6px; }
.bk-search { display: flex; align-items: center; gap: 10px; padding: 0 14px; height: 44px; border-radius: 14px; border: 1.5px solid var(--bk-rule); margin-bottom: 10px; }
.bk-search:focus-within { border-color: var(--bk-accent); }
.bk-search input { flex: 1; border: 0; outline: 0; background: transparent; color: var(--bk-pop-ink); font: 600 .92rem var(--bk-ui); }
.bk-sr { display: block; width: 100%; text-align: start; padding: 11px 6px; border: 0; border-bottom: 1px solid var(--bk-rule); background: transparent; color: var(--bk-pop-ink); font: 500 .88rem/1.7 var(--bk-font); cursor: pointer; }
.bk-sr mark { background: var(--bk-hl); color: inherit; border-radius: 3px; padding: 0 2px; }
.bk-badge2 { margin-inline-start: auto; background: #ef4444; color: #fff; border-radius: 99px; font: 800 .65rem var(--bk-ui); padding: 2px 8px; }

/* first-run coach */
.bk-coach { position: absolute; inset: 0; z-index: 30; display: grid; place-items: center; padding: 18px; background: rgba(0,0,0,.6); animation: bk-fade .25s ease; }
.bk-coach-card { width: 100%; max-width: 380px; background: var(--bk-pop); color: var(--bk-pop-ink); border-radius: 22px; padding: 20px; font-family: var(--bk-ui); box-shadow: 0 20px 60px rgba(0,0,0,.5); }
.bk-coach-card h3 { margin: 0 0 12px; font-size: 1.05rem; }
.bk-coach-row { display: flex; gap: 12px; align-items: flex-start; padding: 9px 0; font: 600 .84rem/1.6 var(--bk-ui); }
.bk-coach-row i { width: 22px; text-align: center; color: var(--bk-accent); margin-top: .25em; }

/* ── sentence translate button (replaces the old per-sentence microphone) ── */
.bk-flow .imm-sent-translate { position: relative; display: inline-flex !important; align-items: center; justify-content: center; width: 1.7em; height: 1.7em; margin-inline-start: .3em; padding: 0; vertical-align: .05em; border: 0; border-radius: 50%; background: transparent; color: var(--bk-accent); opacity: .45; font-size: .66em; line-height: 1; cursor: pointer; transition: opacity .15s, background .15s; -webkit-tap-highlight-color: transparent; }
.bk-flow .imm-sent-translate::after { content: ""; position: absolute; inset: -9px; }          /* finger-sized hit area */
.bk-flow .imm-sent-translate:hover, .bk-flow .imm-sent-translate-active { opacity: 1; background: color-mix(in srgb, var(--bk-accent) 16%, transparent); }
.bk-flow .imm-sent-translate:focus-visible { outline: 2px solid var(--bk-accent); outline-offset: 2px; opacity: 1; }
.bk-root[data-bk-trans="off"] .imm-sent-translate { display: none !important; }
.bk-flow .imm-sent-tip.bk-blur .imm-sent-tip-text { filter: blur(6px); cursor: pointer; transition: filter .2s; }
.bk-flow .imm-sent-tip.bk-tip-err { color: var(--bk-muted); }
.bk-flow .bk-looping { outline: 2px dashed var(--bk-accent); outline-offset: 2px; border-radius: 6px; }

/* ── live translation caption (follows the narrated sentence) ── */
.bk-cap { position: absolute; z-index: 6; left: 12px; right: 12px; bottom: 10px; max-width: 640px; margin: 0 auto; padding: .6em .95em; border-radius: 14px; background: color-mix(in srgb, var(--bk-pop) 95%, transparent); color: var(--bk-pop-ink); box-shadow: 0 6px 24px rgba(0,0,0,.25); font: 600 .95rem/1.6 var(--bk-ui); text-align: center; -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); animation: bk-cap-in .18s ease; }
.bk-cap.wait { opacity: .7; }
.bk-cap.blur .bk-cap-t { filter: blur(6px); cursor: pointer; }
@keyframes bk-cap-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ── car mode ── */
.bk-car { position: absolute; inset: 0; z-index: 15; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: clamp(18px, 5vh, 34px); padding: 24px; background: #000; color: #fff; font-family: var(--bk-ui); }
.bk-car-x { position: absolute; top: calc(14px + env(safe-area-inset-top, 0px)); inset-inline-end: 14px; width: 56px; height: 56px; border-radius: 50%; border: 2px solid rgba(255,255,255,.3); background: transparent; color: #fff; font-size: 1.3rem; cursor: pointer; }
.bk-car-title { font-size: clamp(1.15rem, 5vw, 1.6rem); font-weight: 800; text-align: center; line-height: 1.45; max-width: 92%; }
.bk-car-time { display: flex; gap: 14px; font-size: 1.35rem; font-variant-numeric: tabular-nums; color: #bdbdbd; direction: ltr; }
.bk-car-time .d::before { content: "/ "; }
.bk-car-row { display: flex; align-items: center; justify-content: center; gap: clamp(6px, 2vw, 18px); direction: ltr; width: 100%; }
.bk-car-row button { position: relative; flex: 0 0 auto; width: clamp(52px, 16vw, 84px); height: clamp(52px, 16vw, 84px); border-radius: 50%; border: 2px solid rgba(255,255,255,.28); background: #161616; color: #fff; font-size: clamp(1.1rem, 4.5vw, 1.7rem); cursor: pointer; -webkit-tap-highlight-color: transparent; }
.bk-car-row button:active { transform: scale(.95); }
.bk-car-row button.main { width: clamp(84px, 26vw, 128px); height: clamp(84px, 26vw, 128px); background: var(--bk-accent, #e3a455); color: #000; border-color: transparent; font-size: clamp(2rem, 9vw, 2.8rem); }
.bk-car-row button small { position: absolute; bottom: 12%; left: 0; right: 0; font-size: .6rem; font-weight: 800; }
.bk-car-row.two button { width: auto; min-width: 96px; padding: 0 22px; height: 64px; border-radius: 32px; font-size: 1.25rem; font-weight: 800; }
.bk-car button:focus-visible { outline: 3px solid #fff; outline-offset: 3px; }
@media (prefers-reduced-motion: reduce) { .bk-cap { animation: none; } .bk-flow .imm-sent-translate, .bk-flow .imm-sent-tip.bk-blur .imm-sent-tip-text { transition: none; } }
.bk-approx { display: inline-block; margin-inline-start: .5em; padding: 0 .45em; border-radius: 999px; font: 700 .62rem/1.6 var(--bk-ui); opacity: .7; border: 1px solid currentColor; vertical-align: middle; }