:root{--navy:#0E1A2B;--navy2:#15253B;--gold:#C9A45C;--ivory:#F4F1EA;--muted:#9FB0C6}
*{box-sizing:border-box}
html,body{margin:0;height:100%;overflow:hidden;background:var(--navy);color:var(--ivory);font-family:Poppins,'Noto Sans Bengali',system-ui,sans-serif}
body.ictd-reader{-webkit-user-select:none;user-select:none;-webkit-touch-callout:none;-webkit-tap-highlight-color:transparent;overscroll-behavior:none}
img{-webkit-user-drag:none;user-drag:none;pointer-events:none}

/* top bar */
.rb-top{height:52px;display:flex;align-items:center;gap:12px;padding:0 14px;padding-top:env(safe-area-inset-top);border-bottom:1px solid rgba(201,164,92,.25);background:rgba(14,26,43,.96)}
.rb-back{color:var(--gold);text-decoration:none;font-size:22px;width:36px;height:36px;display:grid;place-items:center;border-radius:8px}
.rb-back:hover{background:rgba(255,255,255,.06)}
.rb-title{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:14px}
.rb-title strong{font-family:Lora,serif;font-weight:700;font-size:16px;letter-spacing:.2px}
.rb-title span{color:var(--muted)}

/* stage */
.rb-stage{position:relative;height:calc(100% - 52px - 58px);display:flex;align-items:center;justify-content:center;padding:18px 56px;overflow:hidden}
.rb-stage.zoomed{overflow:auto;align-items:flex-start;justify-content:flex-start}
.rb-zoom{width:100%;max-width:1500px;margin:auto}
.rb-book{width:100%;margin:0 auto}
.page{background:#fff}
.pg{position:relative;width:100%;height:100%;background:#fdfdfb;overflow:hidden}
.pg img{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;opacity:0;transition:opacity .25s}
.pg.ready img{opacity:1}
.pg:not(.ready):not(.locked)::before{content:"";position:absolute;left:50%;top:50%;width:28px;height:28px;margin:-14px;border:2px solid #d8d2c4;border-top-color:var(--gold);border-radius:50%;animation:spin 1s linear infinite}
.page.err .pg::before{border-color:#c33;animation:none}
.pg .wm{position:absolute;inset:0;pointer-events:none;opacity:.045;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='360' height='240'%3E%3Ctext x='20' y='140' transform='rotate(-28 180 120)' font-family='Georgia,serif' font-size='18' fill='%230E1A2B'%3E%C2%A9 Pranab B Nath%3C/text%3E%3C/svg%3E");background-repeat:repeat}
.pg .pn{position:absolute;bottom:6px;left:0;right:0;text-align:center;font-size:10px;color:rgba(14,26,43,.0)}
.pg.locked{display:grid;place-items:center;background:linear-gradient(#fbfaf6,#f1ede3);color:var(--navy);text-align:center}
.pg.locked{cursor:pointer}
.lock{padding:24px;max-width:320px}.lock-ico{font-size:34px;margin-bottom:10px}
.lock-t{margin:0 0 4px;font-family:Lora,serif;font-weight:700;font-size:18px}.lock-s{margin:0 0 18px;font-size:13px;color:#5b6474}
.lock a{display:block;text-decoration:none;font-size:14px;margin:0 auto 10px}
.lock-buy{padding:11px 18px;background:var(--navy);color:var(--ivory)!important;border-radius:999px;font-weight:600}
.lock-login{color:#8a6d2f!important}

/* big invisible tap zones for prev/next */
.rb-edge{position:absolute;top:50%;transform:translateY(-50%);width:44px;height:120px;border:0;background:transparent;color:rgba(244,241,234,.55);font-size:44px;cursor:pointer;z-index:5;border-radius:10px}
.rb-edge:hover{color:var(--gold);background:rgba(255,255,255,.04)}
.rb-edge:disabled{opacity:.15;cursor:default}
.rb-edge-l{left:6px}.rb-edge-r{right:6px}

/* bottom toolbar */
.rb-bar{height:58px;display:flex;align-items:center;justify-content:center;gap:6px;padding:0 10px;padding-bottom:env(safe-area-inset-bottom);border-top:1px solid rgba(201,164,92,.25);background:rgba(14,26,43,.97)}
.rb-btn{min-width:40px;height:40px;padding:0 10px;border:1px solid rgba(201,164,92,.35);background:transparent;color:var(--ivory);border-radius:10px;font-size:18px;line-height:1;cursor:pointer;font-family:inherit}
.rb-btn:hover:not(:disabled){border-color:var(--gold);color:var(--gold)}
.rb-btn:disabled{opacity:.3;cursor:default}
.rb-pageinfo{display:flex;align-items:center;gap:6px;font-size:14px;color:var(--muted);margin:0 4px}
.rb-pageinfo input{width:58px;height:36px;text-align:center;border:1px solid rgba(201,164,92,.35);background:var(--navy2);color:var(--ivory);border-radius:8px;font:inherit;-webkit-user-select:text;user-select:text}
.rb-pageinfo input::-webkit-inner-spin-button{display:none}
.rb-zoomval{font-size:13px;color:var(--muted);min-width:44px;text-align:center}
.rb-sep{width:1px;height:26px;background:rgba(201,164,92,.25);margin:0 6px}

/* toc drawer */
.rb-toc{position:fixed;top:0;right:0;bottom:0;width:min(420px,92vw);background:#fbfaf6;color:var(--navy);transform:translateX(100%);transition:transform .28s ease;z-index:30;display:flex;flex-direction:column;box-shadow:-10px 0 40px rgba(0,0,0,.35)}
.rb-toc.open{transform:none}
.rb-toc-head{display:flex;align-items:center;justify-content:space-between;padding:16px 18px;border-bottom:1px solid #e6e0d2;font-family:Lora,serif;font-size:18px}
.rb-toc-head .rb-btn{color:var(--navy);border-color:#d8d0bd}
.rb-toc ol{list-style:none;margin:0;padding:8px 0 30px;overflow:auto;flex:1}
.rb-toc li a{display:flex;gap:12px;justify-content:space-between;padding:9px 18px 9px 30px;color:var(--navy);text-decoration:none;font-size:14px;line-height:1.4}
.rb-toc li a:hover{background:#f0ebdf}
.rb-toc li a em{font-style:normal;color:#8a7a55;font-variant-numeric:tabular-nums}
.rb-toc li.part a{padding-left:18px;margin-top:10px;font-weight:600;font-family:Lora,serif;color:#1a2b44;border-top:1px solid #ece6d8}
.rb-scrim{position:fixed;inset:0;background:rgba(0,0,0,.45);opacity:0;pointer-events:none;transition:opacity .25s;z-index:25}
.rb-scrim.on{opacity:1;pointer-events:auto}

.rb-copy{position:fixed;left:0;right:0;bottom:60px;text-align:center;font-size:10.5px;color:rgba(159,176,198,.55);pointer-events:none;letter-spacing:.2px}
.rb-loading{position:absolute;inset:0;display:grid;place-content:center;text-align:center;color:var(--muted);background:var(--navy);z-index:10;transition:opacity .3s}
.rb-loading.hide{opacity:0;pointer-events:none}
.rb-spin{width:36px;height:36px;margin:0 auto 12px;border:2px solid rgba(201,164,92,.25);border-top-color:var(--gold);border-radius:50%;animation:spin 1s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

/* fullscreen & pseudo-fullscreen (iPhone) */
:fullscreen .rb-top,.pseudo-full .rb-top{display:none}
:fullscreen .rb-stage,.pseudo-full .rb-stage{height:calc(100% - 58px)}

/* mobile */
@media (max-width:760px){
  .rb-stage{padding:10px 6px}
  .rb-edge{width:34px;font-size:34px;height:90px;color:rgba(244,241,234,.35)}
  .rb-sep,.rb-zoomval,#btnZoomOut,#btnZoomIn{display:none}
  .rb-title span{display:none}
  .rb-copy{font-size:9px}
}
@media print{body *{display:none!important}body::after{content:"Printing is disabled for this book.";display:block;padding:40px;color:#000}}

/* ================= Sales screen (paywall) ================= */
.pw{position:fixed;inset:0;z-index:50;display:grid;place-items:center;padding:18px;background:rgba(6,12,22,.78);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);animation:pwIn .35s ease}
.pw[hidden]{display:none}
@keyframes pwIn{from{opacity:0}to{opacity:1}}
.pw-card{position:relative;width:min(920px,100%);max-height:calc(100vh - 36px);overflow:auto;background:linear-gradient(160deg,#13233A 0%,#0E1A2B 60%);border:1px solid rgba(201,164,92,.45);border-radius:18px;box-shadow:0 40px 90px rgba(0,0,0,.55);color:var(--ivory);-webkit-user-select:none;user-select:none;animation:pwUp .45s cubic-bezier(.2,.8,.2,1)}
@keyframes pwUp{from{transform:translateY(18px);opacity:0}to{transform:none;opacity:1}}
.pw-x{position:absolute;top:12px;right:14px;width:36px;height:36px;border:0;border-radius:50%;background:rgba(255,255,255,.06);color:var(--muted);font-size:22px;cursor:pointer;z-index:2}
.pw-x:hover{color:var(--ivory);background:rgba(255,255,255,.12)}
.pw-grid{display:grid;grid-template-columns:230px 1fr;gap:34px;padding:38px 40px 26px}
.pw-coverbox{align-self:start;position:relative}
.pw-cover{width:100%;display:block;border-radius:6px;box-shadow:0 22px 44px rgba(0,0,0,.55),0 0 0 1px rgba(201,164,92,.35);transform:rotate(-2deg)}
.pw-kick{margin:0 0 8px;color:var(--gold);font-size:13px;letter-spacing:1.5px;font-weight:600}
.pw-h{text-wrap:balance;margin:0 0 10px;font-family:'Noto Serif Bengali',Lora,serif;font-size:clamp(24px,3.2vw,32px);line-height:1.3;font-weight:700}
.pw-h span{color:var(--gold);font-size:.78em;text-wrap:balance;display:inline-block;margin-top:4px}
.pw-list li strong{color:var(--ivory);font-weight:700}
.pw-sub{margin:0 0 16px;color:#C9D1DD;font-size:15.5px;line-height:1.6}
.pw-list{list-style:none;margin:0 0 20px;padding:0}
.pw-list li{position:relative;padding:0 0 9px 28px;font-size:15px;line-height:1.55;color:#E7E3D9}
.pw-list li::before{content:"✓";position:absolute;left:0;top:0;width:19px;height:19px;border-radius:50%;background:rgba(201,164,92,.18);color:var(--gold);font-size:12px;display:grid;place-items:center;font-weight:700}
.pw-price{display:flex;align-items:baseline;gap:12px;flex-wrap:wrap;margin:0 0 14px}
.pw-price del{color:#8C98AA;font-size:18px}
.pw-price strong{font-family:'Noto Serif Bengali',Lora,serif;font-size:38px;line-height:1;color:var(--ivory)}
.pw-badge{background:var(--gold);color:var(--navy);font-size:12.5px;font-weight:700;padding:4px 10px;border-radius:999px;letter-spacing:.3px}
.pw-buy{display:block;text-align:center;padding:16px 22px;border-radius:12px;background:linear-gradient(180deg,#D8B56B,#C29A4F);color:#0E1A2B!important;font-weight:700;font-size:18px;text-decoration:none;box-shadow:0 10px 26px rgba(201,164,92,.28);transition:transform .15s,box-shadow .15s}
.pw-buy:hover{transform:translateY(-1px);box-shadow:0 14px 32px rgba(201,164,92,.38)}
.pw-trust{margin:12px 0 4px;text-align:center;font-size:13px;color:#AEB9C8}
.pw-pay{margin:0 0 10px;text-align:center;font-size:12.5px;color:#8C98AA}
.pw-links{margin:6px 0 0;text-align:center;font-size:14px;color:#8C98AA}
.pw-links a{color:var(--gold);text-decoration:none}
.pw-links a:hover{text-decoration:underline}
.pw-course{margin:0 40px 34px;padding-top:22px;border-top:1px dashed rgba(201,164,92,.35)}
.pwc-kick{margin:0 0 12px;font-family:'Noto Serif Bengali',serif;font-size:18px;font-weight:700}
.pwc-list{display:grid;gap:12px}
.pwc{display:flex;gap:14px;align-items:center;padding:12px;border:1px solid rgba(201,164,92,.3);border-radius:12px;text-decoration:none;color:var(--ivory)!important;background:rgba(255,255,255,.03)}
.pwc:hover{border-color:var(--gold)}
.pwc img{width:110px;height:70px;object-fit:cover;border-radius:8px;flex:none}
.pwc span{display:flex;flex-direction:column;gap:3px}
.pwc small,.pwc-soon small{color:var(--gold);font-size:12px;letter-spacing:1px}
.pwc strong,.pwc-soon strong{font-size:16px;line-height:1.35}
.pwc em{font-style:normal;color:#C9D1DD;font-size:13.5px}
.pwc-soon{display:flex;gap:16px;align-items:center;justify-content:space-between;flex-wrap:wrap;padding:16px 18px;border-radius:12px;background:rgba(201,164,92,.08);border:1px solid rgba(201,164,92,.3)}
.pwc-soon span{display:flex;flex-direction:column;gap:4px}
.pwc-soon a{white-space:nowrap;padding:10px 16px;border-radius:999px;border:1.5px solid var(--gold);color:var(--gold)!important;text-decoration:none;font-weight:600;font-size:14px}
.pwc-soon a:hover{background:rgba(201,164,92,.12)}

/* slim bar during preview */
.pv-bar{position:fixed;left:50%;transform:translateX(-50%);bottom:72px;z-index:20;display:flex;align-items:center;gap:14px;padding:8px 8px 8px 18px;border-radius:999px;background:rgba(14,26,43,.94);border:1px solid rgba(201,164,92,.45);box-shadow:0 10px 30px rgba(0,0,0,.4);font-size:14px;color:#D5DCE6;white-space:nowrap}
.pv-bar[hidden]{display:none}
.pv-bar b{color:var(--gold);font-weight:600}
.pv-buy{padding:8px 16px;border-radius:999px;background:var(--gold);color:var(--navy)!important;text-decoration:none;font-weight:700}
.has-pv .rb-copy{display:none}
.pw-open .pv-bar{display:none}

@media (max-width:760px){
  .pw{padding:0;align-items:end}
  .pw-card{border-radius:18px 18px 0 0;max-height:92vh}
  .pw-grid{grid-template-columns:1fr;gap:14px;padding:26px 20px 18px}
  .pw-coverbox{width:118px;margin:0 auto}
  .pw-main{text-align:center}
  .pw-list{text-align:left}
  .pw-price{justify-content:center}
  .pw-price strong{font-size:34px}
  .pw-course{margin:0 20px 24px}
  .pwc-soon{flex-direction:column;align-items:stretch;text-align:center}
  .pv-bar{bottom:66px;font-size:13px;gap:10px;padding:6px 6px 6px 14px}
}
.has-pv .rb-stage{padding-bottom:62px}
@media (max-width:760px){.has-pv .rb-stage{padding-bottom:56px}}

.rb-toast{position:fixed;top:66px;left:50%;transform:translateX(-50%);z-index:60;padding:12px 22px;border-radius:999px;background:#C9A45C;color:#0E1A2B;font-weight:700;font-size:15px;box-shadow:0 12px 30px rgba(0,0,0,.4);animation:pwUp .4s ease;transition:opacity .6s}
.rb-toast.out{opacity:0}