/* ============================================================
   E-book reader — ledger-style chrome around a StPageFlip stage
   ============================================================ */
.ebook {
    --ebook-bar-h: 64px;
    position: relative;
    margin-top: 78px;                      /* below the fixed site header */
    padding: 0;                            /* override the global section padding */
    min-height: calc(100vh - 78px);
    display: grid;
    grid-template-rows: var(--ebook-bar-h) 1fr auto auto;
    background:
        radial-gradient(1200px 600px at 50% 0%, var(--accent-soft), transparent 60%),
        var(--bg-soft);
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}
.ebook.is-fullscreen { margin-top: 0; min-height: 100vh; background: var(--bg); }
/* iOS / no Fullscreen API: pin the reader over everything and hide the site chrome */
html.ebook-fs, html.ebook-fs body { overflow: hidden !important; height: 100%; overscroll-behavior: none; }
html.ebook-fs .site-header, html.ebook-fs .site-footer, html.ebook-fs .cookie-bar, html.ebook-fs .nav.is-open { display: none !important; }
.ebook.is-fake-fullscreen {
    position: fixed; inset: 0; z-index: 3000;
    margin: 0; min-height: 0; height: 100vh; height: 100dvh;
    display: grid; grid-template-rows: auto minmax(0, 1fr) auto;
    overflow: hidden;
    padding-top: env(safe-area-inset-top); padding-bottom: env(safe-area-inset-bottom);
}
.ebook.is-fake-fullscreen .ebook__protected { display: none; }
.ebook.is-fake-fullscreen .ebook__body { min-height: 0; }
.ebook.is-fake-fullscreen .ebook__stage { min-height: 0; height: 100%; }
.ebook.is-fake-fullscreen .ebook__toc { top: 0; }

/* ---- top bar ---- */
.ebook__bar {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 1rem;
    padding: 0 clamp(1rem, 3vw, 2.5rem);
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}
.ebook__kicker {
    display: block;
    font-family: 'Space Grotesk', monospace;
    font-size: .68rem;
    letter-spacing: .24em;
    text-transform: uppercase;
    color: var(--accent);
}
.ebook__title {
    margin: .1rem 0 0;
    font-size: 1rem;
    line-height: 1.2;
    letter-spacing: -.01em;
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.ebook__counter {
    display: inline-flex; align-items: baseline; gap: .35rem;
    font-family: 'Space Grotesk', monospace;
    font-variant-numeric: tabular-nums;
    color: var(--text-soft);
    font-size: .85rem;
    letter-spacing: .08em;
}
.ebook__counter-label { font-size: .65rem; text-transform: uppercase; letter-spacing: .2em; margin-right: .4rem; }
.ebook__counter-input {
    width: 3.4em; padding: .1rem .2rem;
    font: 700 1.35rem 'Space Grotesk', monospace; letter-spacing: .02em; text-align: center;
    color: var(--heading); background: transparent;
    border: 0; border-bottom: 1px solid transparent; border-radius: 0;
    transition: border-color .2s;
}
.ebook__counter-input:hover { border-bottom-color: var(--border); }
.ebook__counter-input:focus { outline: none; border-bottom-color: var(--accent); }
.ebook__counter i  { font-style: normal; opacity: .5; }
.ebook__tools { display: flex; justify-content: flex-end; align-items: center; gap: .5rem; }
.ebook__zoom { display: inline-flex; }
.ebook__zoom .ebook__tool { padding: 0 .55rem; }
.ebook__zoom .ebook__tool + .ebook__tool { margin-left: -1px; }
.ebook__zoom-level { min-width: 58px; justify-content: center; font-family: 'Space Grotesk', monospace; font-size: .74rem; letter-spacing: .06em; }
.ebook__tool:disabled { opacity: .35; pointer-events: none; }
.ebook__free {
    font-family: 'Space Grotesk', monospace;
    font-size: .7rem; letter-spacing: .12em; text-transform: uppercase;
    color: var(--accent);
    border: 1px solid var(--accent-shadow);
    padding: .35rem .6rem;
    margin-right: .4rem;
}
.ebook__tool {
    display: inline-flex; align-items: center; gap: .4rem;
    height: 38px; padding: 0 .75rem;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text);
    font: 600 .82rem 'Inter', sans-serif;
    cursor: pointer;
    transition: border-color .2s, color .2s, background-color .2s;
}
.ebook__tool:hover, .ebook__tool[aria-expanded="true"] { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.ebook__tool .material-symbols-outlined { font-size: 20px; }

/* ---- body: stage + optional TOC column ---- */
.ebook__body { display: grid; grid-template-columns: 1fr; min-height: 0; }
.ebook.has-toc .ebook__body { grid-template-columns: 1fr 320px; }

.ebook__stage {
    position: relative;
    display: grid;
    place-items: center;
    min-height: max(520px, min(78vh, 900px));
    padding: 40px 0;
    overflow: hidden;
    isolation: isolate;
    transition: filter .25s ease;
}
.ebook.is-fullscreen .ebook__stage { min-height: calc(100vh - var(--ebook-bar-h) - 60px); }
/* Veiled = the bitmap is hidden outright and a solid black sheet covers the stage, so a capture
   taken while the window is unfocused (Snipping Tool, Win+Shift+S, alt-tab) contains nothing. */
.ebook.is-veiled .ebook__stage > .ebook__sizer,
.ebook.is-wiped  .ebook__stage > .ebook__sizer { visibility: hidden; }
.ebook.is-veiled .ebook__stage, .ebook.is-wiped .ebook__stage { background: #000; }
.ebook__sizer { position: relative; margin: 0 auto; transform-origin: center center; will-change: transform; }
.ebook__book { position: relative; width: 100%; height: 100%; }

/* ---- mobile engine: horizontal snap pager, one page per screen, pinch-zoom per page ---- */
.ebook.is-mobile .ebook__stage { padding: 0; min-height: 0; }
.ebook.is-mobile .ebook__arrow { display: none; }
.ebook.is-mobile .ebook__sizer { width: 100%; height: 100%; margin: 0; }
.ebook__pager {
    position: absolute; inset: 0;
    display: flex;
    overflow-x: auto; overflow-y: hidden;
    scroll-snap-type: x mandatory;
    overscroll-behavior-x: contain;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    touch-action: pan-x pan-y;          /* the browser handles swiping; pinch is ours */
}
.ebook__pager::-webkit-scrollbar { display: none; }
.ebook__pager.is-zoomed { overflow: hidden; scroll-snap-type: none; touch-action: none; }
.ebook-slide {
    flex: 0 0 100%; width: 100%; height: 100%;
    scroll-snap-align: center; scroll-snap-stop: always;
    display: grid; place-items: center;
    overflow: hidden;
}
.ebook-slide__frame {
    position: relative;
    background: #fff;
    box-shadow: 0 14px 40px -20px rgba(0,0,0,.55);
    transform-origin: center center;
    will-change: transform;
}
.ebook-slide__frame.is-animating { transition: transform .22s cubic-bezier(.2,.7,.2,1); }
.ebook-slide__frame .ebook-page { width: 100%; height: 100%; }
.ebook-slide__frame .ebook-page--hard { background: #fff; }
.ebook.is-zoomed .ebook__sizer { cursor: grab; }
.ebook.is-zoomed.is-panning .ebook__sizer { cursor: grabbing; }
.ebook.is-zoomed .ebook__book .stf__block { pointer-events: none; }
.ebook.is-zoomed .ebook__arrow { opacity: .55; }


.ebook__arrow {
    position: absolute; top: 50%; transform: translateY(-50%);
    width: 52px; height: 52px;
    display: grid; place-items: center;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 50%;
    color: var(--heading);
    cursor: pointer;
    z-index: 5;
    transition: transform .2s, border-color .2s, color .2s, opacity .2s;
    box-shadow: 0 10px 30px -18px rgba(0,0,0,.45);
}
.ebook__arrow--prev { left: clamp(.5rem, 2vw, 2rem); }
.ebook__arrow--next { right: clamp(.5rem, 2vw, 2rem); }
.ebook__arrow:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-50%) scale(1.06); }
.ebook__arrow:disabled { opacity: .25; pointer-events: none; }

.ebook.is-veiled .ebook__veil { transition: none; }
.ebook__veil, .ebook__notice {
    position: absolute; inset: 0;
    display: grid; place-items: center; text-align: center;
    pointer-events: none;
    opacity: 0; transition: opacity .25s ease;
    z-index: 6;
}
.ebook__veil { color: #fff; background: #000; }
.ebook__veil .material-symbols-outlined { font-size: 44px; color: var(--accent); }
.ebook__veil p { margin: .4rem 0 0; font-weight: 600; }
.ebook.is-veiled .ebook__veil { opacity: 1; }
.ebook__notice {
    inset: auto 0 1.2rem 0;
    padding: .55rem 1rem;
    justify-self: center;
    place-items: unset;
    width: max-content; max-width: 90%;
    background: var(--heading); color: var(--bg);
    font-size: .82rem; font-weight: 600;
    transform: translateY(6px);
}
.ebook__notice.is-visible { opacity: 1; transform: translateY(0); }

/* ---- pages ---- */
.ebook-page {
    background: #fff;
    overflow: hidden;
    box-shadow: inset 0 0 0 1px rgba(0,0,0,.05);
}
.ebook-page--hard { background: #1A2731; }
.ebook-page__inner { position: relative; width: 100%; height: 100%; }
.ebook-page canvas {
    display: block;
    width: 100%; height: 100%;
    object-fit: contain;
    pointer-events: none;
}
.ebook-page__skeleton {
    position: absolute; inset: 0;
    background: linear-gradient(100deg, #f3f4f4 20%, #e6e9e9 40%, #f3f4f4 60%);
    background-size: 220% 100%;
    animation: ebook-shimmer 1.4s linear infinite;
}
.ebook-page--hard .ebook-page__skeleton { background: linear-gradient(100deg, #22323f 20%, #2b3d4b 40%, #22323f 60%); background-size: 220% 100%; }
.ebook-page.is-ready .ebook-page__skeleton { display: none; }
.ebook-page.is-error .ebook-page__skeleton { animation: none; background: repeating-linear-gradient(45deg, #f6f7f7 0 12px, #ecefef 12px 24px); }
@keyframes ebook-shimmer { to { background-position: -120% 0; } }


/* Locked page (anonymous readers, beyond the free allowance) */
.ebook-page--locked { background: #fff; }
.ebook-page--locked .ebook-page__inner { display: flex; align-items: center; justify-content: center; overflow: hidden; }
/* the real page, shrunk to 60x85 on the server and blurred here: recognisable as a page, never legible */
.ebook-locked__bg {
    position: absolute; inset: 0; width: 100%; height: 100%;
    object-fit: cover;
    filter: blur(6px) saturate(.85);
    transform: scale(1.04);
    pointer-events: none; user-select: none;
}
.ebook-locked {
    position: relative; z-index: 1;
    width: min(86%, 400px); max-height: 92%; scrollbar-width: thin;
    display: flex; flex-direction: column; justify-content: center;
    overflow: auto;
    padding: clamp(.9rem, 5%, 1.8rem);
    background: rgba(255,255,255,.94);
    border: 1px solid rgba(26,39,49,.12);
    box-shadow: 0 30px 60px -30px rgba(0,0,0,.45);
    backdrop-filter: blur(3px);
    color: #25343F;
    text-align: left;
}
.ebook-locked__index {
    flex-shrink: 0;
    display: flex; justify-content: space-between; align-items: baseline;
    font-family: 'Space Grotesk', monospace; font-size: .68rem; letter-spacing: .2em; text-transform: uppercase;
    color: #FF9B51;
    border-bottom: 1px solid #BFC9D1; padding-bottom: .6rem; margin-bottom: 1.4rem;
}
.ebook-locked__index b { color: #1A2731; letter-spacing: .06em; }
.ebook-locked h3 { font-size: clamp(1rem, 2.2vw, 1.35rem); line-height: 1.25; color: #1A2731; margin: 0 0 .9rem; }
.ebook-locked p  { color: #54636F; font-size: .9rem; margin-bottom: 1.4rem; }
.ebook-unlock { display: grid; gap: .8rem; margin: 0 0 1rem; }
.ebook-unlock__field { display: grid; gap: .3rem; }
.ebook-unlock__field span { font-family: 'Space Grotesk', monospace; font-size: .64rem; letter-spacing: .2em; text-transform: uppercase; color: #54636F; }
.ebook-unlock__field input {
    width: 100%; padding: .65rem 0;
    border: 0; border-bottom: 1px solid #BFC9D1; border-radius: 0; background: transparent;
    color: #1A2731; font: 500 1rem 'Inter', sans-serif;
}
.ebook-unlock__field input[name="code"] { font-family: 'Space Grotesk', monospace; font-size: 1.25rem; letter-spacing: .28em; text-transform: uppercase; }
.ebook-unlock__field input:focus { outline: none; border-bottom-color: #FF9B51; box-shadow: 0 1px 0 0 #FF9B51; }
.ebook-unlock__field input.is-invalid { border-bottom-color: #C2410C; }
.ebook-unlock__error { margin: 0; font-size: .82rem; color: #C2410C; }
.ebook-unlock .btn { border-radius: 0; justify-content: space-between; }
.ebook-unlock .btn[disabled] { opacity: .6; cursor: progress; }
.ebook-locked__support { font-size: .8rem; color: #54636F; margin: 0; }
.ebook-locked__support a { color: #FF9B51; font-weight: 600; }

/* ---- TOC ---- */
.ebook__toc {
    border-left: 1px solid var(--border);
    background: var(--surface);
    display: flex; flex-direction: column;
    max-height: min(78vh, 900px);
}
.ebook__toc-head {
    display: flex; justify-content: space-between; align-items: center;
    padding: 1rem 1.2rem;
    border-bottom: 1px solid var(--border);
    font-family: 'Space Grotesk', monospace; font-size: .7rem; letter-spacing: .22em; text-transform: uppercase;
    color: var(--text-soft);
}
.ebook__toc-head button { background: none; border: 0; color: var(--text-soft); cursor: pointer; display: grid; }
.ebook__toc-list { list-style: none; margin: 0; padding: .4rem 0; overflow: auto; }
.ebook__toc-list button {
    width: 100%; display: flex; justify-content: space-between; gap: 1rem; align-items: baseline;
    padding: .65rem 1.2rem;
    background: none; border: 0; border-bottom: 1px dashed var(--border);
    color: var(--text); text-align: left; cursor: pointer;
    font: 500 .84rem/1.35 'Inter', sans-serif;
    transition: background-color .15s, color .15s;
}
.ebook__toc-list button:hover { background: var(--accent-soft); color: var(--accent); }
.ebook__toc-list button.is-locked { color: var(--text-soft); }
.ebook__toc-page { font-family: 'Space Grotesk', monospace; font-size: .75rem; letter-spacing: .08em; display: inline-flex; align-items: center; gap: .25rem; flex-shrink: 0; }
.ebook__toc-page .material-symbols-outlined { font-size: 14px; }

/* ---- progress rail ---- */
.ebook__rail {
    position: relative; height: 6px; margin: 0 clamp(1rem, 3vw, 2.5rem);
    background: var(--border); cursor: pointer; outline-offset: 6px;
}
.ebook__rail-fill { position: absolute; inset: 0 auto 0 0; background: var(--accent); transition: width .35s ease; z-index: 2; }
.ebook__rail-free { position: absolute; inset: 0 auto 0 0; background: repeating-linear-gradient(90deg, var(--accent-shadow) 0 4px, transparent 4px 8px); opacity: .6; }
.ebook__protected {
    display: flex; align-items: center; gap: .5rem;
    margin: 0; padding: .9rem clamp(1rem, 3vw, 2.5rem) 1.3rem;
    font-size: .74rem; color: var(--text-soft);
}
.ebook__protected .material-symbols-outlined { font-size: 16px; color: var(--accent); }

.ebook__print { display: none; }
@media print {
    body * { visibility: hidden !important; }
    .ebook__print { display: block !important; visibility: visible !important; position: fixed; inset: 0; padding: 4rem; font: 700 2rem/1.3 sans-serif; }
}

/* ---- responsive ---- */
@media (max-width: 900px) {
    .ebook { --ebook-bar-h: auto; min-width: 0; }
    .ebook__bar { grid-template-columns: minmax(0, 1fr) auto; grid-template-rows: auto auto; padding: .6rem .9rem; gap: .4rem .6rem; }
    .ebook__bar > * { min-width: 0; }
    .ebook__title { font-size: .9rem; }
    .ebook__kicker { font-size: .6rem; letter-spacing: .18em; }
    .ebook__counter { grid-column: 1 / -1; order: 3; }
    .ebook__free { display: none; }
    .ebook__tools { flex-wrap: wrap; justify-content: flex-end; gap: .3rem; }
    .ebook__tool { height: 34px; padding: 0 .5rem; }
    .ebook__tool .material-symbols-outlined { font-size: 18px; }
    .ebook__zoom-level { min-width: 44px; font-size: .68rem; }
    .ebook__tool span:not(.material-symbols-outlined):not([data-zoom-level]) { display: none; }
    .ebook__stage { min-height: max(360px, 62vh); padding: 12px 0; }
    .ebook__arrow { width: 38px; height: 38px; opacity: .8; }
    .ebook__arrow--prev { left: .35rem; }
    .ebook__arrow--next { right: .35rem; }
    .ebook-locked { width: min(92%, 400px); padding: .9rem; }
    .ebook-locked h3 { font-size: .98rem; }
    .ebook-unlock__field input[name="code"] { font-size: 1.05rem; letter-spacing: .18em; }
    .ebook-locked__support { font-size: .74rem; }
    .ebook.has-toc .ebook__body { grid-template-columns: 1fr; }
    .ebook__toc { position: fixed; inset: 78px 0 0 auto; width: min(92vw, 360px); z-index: 1200; max-height: none; box-shadow: -20px 0 60px rgba(0,0,0,.25); }
    .ebook.is-fullscreen .ebook__toc { top: 0; }
}
@media (max-width: 380px) {
    .ebook__zoom { display: none; }   /* pinch and double-tap still zoom */
    .ebook__counter b, .ebook__counter-input { font-size: 1.1rem; }
}
@media (prefers-reduced-motion: reduce) {
    .ebook-page__skeleton { animation: none; }
    .ebook__rail-fill { transition: none; }
}