/* ════════════════════════════════════════════════════════════════════
   assets/flipbook.css — หน้าอ่านหนังสือพลิกหน้า (viewer.php)
   ตัวแปรสีมาจาก assets/showcase.css (body.pub)
   โครง: แถบบน (.rd-top) · เวที (.rd-stage มีเล่มอยู่กลาง) · แถบล่าง (.rd-bar) · ลิ้นชักภาพย่อ (.rd-thumbs)
   ════════════════════════════════════════════════════════════════════ */

.reader{position:relative;display:flex;flex-direction:column;height:calc(100vh - 68px);height:calc(100dvh - 68px);min-height:520px;
    color:var(--on-night);overflow:hidden;isolation:isolate;
    background:
        radial-gradient(55% 60% at 50% 45%,rgba(255,236,200,.08),transparent 70%),
        radial-gradient(80% 50% at 50% 100%,rgba(176,138,60,.10),transparent 70%),
        linear-gradient(180deg,#15161b,#1c1d23 60%,#16171c)}
@media(max-width:1023px){.reader{height:calc(100dvh - 104px)}}
.reader:fullscreen{height:100vh;height:100dvh}
.reader::-webkit-backdrop{background:#15161b}

/* แถบความคืบหน้าการโหลดเบื้องหลัง (บางมาก ชิดขอบบน) */
.rd-net{position:absolute;left:0;right:0;top:0;height:2px;z-index:6;pointer-events:none;transition:opacity .5s}
.rd-net span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--gold),var(--gold-3));transition:width .3s}
.rd-net.is-done{opacity:0}

/* ── แถบบน ── */
.rd-top{position:relative;z-index:5;display:flex;align-items:center;gap:var(--s4);padding:var(--s3) var(--s5);
    border-bottom:1px solid var(--night-line);background:rgba(18,19,24,.55);backdrop-filter:blur(10px)}
.rd-heading{min-width:0;flex:1}
.rd-crumb{display:flex;align-items:center;gap:var(--s2);font-size:12.5px;color:var(--on-night-2);line-height:1.4}
.rd-dot{width:7px;height:7px;border-radius:50%}
.rd-title{font-size:17px!important;font-weight:600;color:#fff!important;line-height:1.45;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.rd-actions{display:flex;align-items:center;gap:var(--s2);flex-shrink:0}
.rd-actions [aria-pressed="true"]{background:rgba(214,185,113,.16);border-color:rgba(214,185,113,.5);color:var(--gold-3)}
@media(max-width:640px){.rd-top{padding:var(--s2) var(--s4);gap:var(--s3)}.rd-title{font-size:15px!important}.rd-crumb{display:none}}

/* ── ตัวเวที ── */
.rd-body{position:relative;flex:1;min-height:0;display:flex}
.rd-stage{position:relative;flex:1;min-width:0;display:flex;align-items:center;justify-content:center;overflow:hidden}
.rd-view{position:absolute;inset:var(--s6) 88px;display:flex;align-items:center;justify-content:center}
@media(max-width:767px){.rd-view{inset:var(--s4) var(--s3)}}
.rd-zoom{position:relative;display:flex;align-items:center;justify-content:center;width:100%;height:100%;
    transform-origin:0 0;will-change:transform}
.rd-zoom.is-animating{transition:transform .32s var(--ease)}
.rd-book{position:relative;margin:auto;transition:transform .7s var(--ease);filter:drop-shadow(0 26px 30px rgba(0,0,0,.5)) drop-shadow(0 4px 6px rgba(0,0,0,.35))}
.rd-book.is-hidden{visibility:hidden}

/* หน้ากระดาษ */
.rd-book .pg{background:#fff;overflow:hidden}
.pg-in{position:absolute;inset:0;background:#fffefa}
.pg-in img{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;opacity:0;transition:opacity .35s ease;user-select:none;-webkit-user-drag:none}
.pg.is-loaded .pg-in img{opacity:1}
.pg-skel{position:absolute;inset:8%;display:flex;flex-direction:column;gap:7%;justify-content:center;transition:opacity .3s}
.pg-skel i{display:block;height:3.2%;border-radius:3px;background:linear-gradient(90deg,#f1ede4 25%,#e6e1d6 50%,#f1ede4 75%);background-size:300% 100%;animation:pgShimmer 1.6s linear infinite}
.pg-skel i:nth-child(2){width:82%}.pg-skel i:nth-child(4){width:64%}
.pg-skel b{position:absolute;right:0;bottom:0;font-size:12px;font-weight:500;color:#b8b2a6;font-variant-numeric:tabular-nums}
.pg.is-loaded .pg-skel{opacity:0}
@keyframes pgShimmer{to{background-position:-150% 0}}
/* เงาใกล้สันเล่ม — ทำให้กระดาษดูโค้งเข้าสัน */
.pg-shade{position:absolute;inset:0;pointer-events:none}
.pg.is-left .pg-shade{background:linear-gradient(270deg,rgba(0,0,0,.20),rgba(0,0,0,.05) 4%,transparent 11%,transparent 96%,rgba(0,0,0,.04))}
.pg.is-right .pg-shade{background:linear-gradient(90deg,rgba(0,0,0,.20),rgba(0,0,0,.05) 4%,transparent 11%,transparent 96%,rgba(0,0,0,.04))}
.pg.is-cover .pg-shade{background:linear-gradient(90deg,rgba(0,0,0,.25),rgba(255,255,255,.12) 2.5%,transparent 6%),linear-gradient(115deg,rgba(255,255,255,.10),transparent 40%)}
.pg.is-back .pg-shade{background:linear-gradient(270deg,rgba(0,0,0,.25),rgba(255,255,255,.12) 2.5%,transparent 6%)}

/* ลูกศรข้างเล่ม */
.rd-arrow{position:absolute;top:50%;z-index:3;width:56px;height:96px;transform:translateY(-50%);border:0;border-radius:var(--r-lg);
    display:grid;place-items:center;background:transparent;color:rgba(242,239,232,.55);cursor:pointer;transition:background .2s,color .2s,opacity .2s}
.rd-arrow .material-symbols-outlined{font-size:40px}
.rd-arrow:hover:not(:disabled){background:rgba(255,255,255,.06);color:#fff}
.rd-arrow:disabled{opacity:0;pointer-events:none}
.rd-arrow.is-prev{left:var(--s4)}.rd-arrow.is-next{right:var(--s4)}
@media(max-width:767px){.rd-arrow{display:none}}

/* ซูม: แผ่นใสคลุมเวทีไว้ลากเลื่อน (ปิดการพลิกหน้าชั่วคราว) */
.rd-pan{position:absolute;inset:0;z-index:2;display:none;cursor:grab;touch-action:none}
.rd-stage.is-zoomed .rd-pan{display:block}
.rd-stage.is-zoomed .rd-pan.is-grabbing{cursor:grabbing}
.rd-stage.is-zoomed .rd-arrow{opacity:0;pointer-events:none}

/* ── ระหว่างโหลด ── */
.rd-loading{position:absolute;z-index:4;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--s3);
    text-align:center;padding:var(--s5);transition:opacity .5s,visibility .5s}
.rd-loading.is-done{opacity:0;visibility:hidden}
.rd-loading-book{position:relative;width:64px;height:46px;margin-bottom:var(--s3);perspective:300px}
.rd-loading-book span{position:absolute;left:50%;top:0;width:30px;height:46px;transform-origin:left center;border-radius:0 3px 3px 0;
    background:linear-gradient(90deg,#d9cfbb,#f6f1e6);box-shadow:0 2px 6px rgba(0,0,0,.4);animation:ldFlip 1.8s var(--ease) infinite}
.rd-loading-book span:nth-child(2){animation-delay:.25s}.rd-loading-book span:nth-child(3){animation-delay:.5s}
@keyframes ldFlip{0%,15%{transform:rotateY(0)}55%,100%{transform:rotateY(-180deg)}}
.rd-loading-title{font-family:var(--f-serif);font-size:18px;font-weight:600;color:#fff}
.rd-loading-bar{width:min(340px,80vw);height:4px;border-radius:4px;background:rgba(255,255,255,.1);overflow:hidden}
.rd-loading-bar span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--gold),var(--gold-3));transition:width .25s}
.rd-loading-bar.is-indeterminate span{width:35%!important;animation:ldSlide 1.2s ease-in-out infinite}
@keyframes ldSlide{from{transform:translateX(-100%)}to{transform:translateX(290%)}}
.rd-loading-meta{display:flex;flex-wrap:wrap;justify-content:center;gap:var(--s1) var(--s4);font-size:13px;color:var(--on-night-2);font-variant-numeric:tabular-nums}
.rd-loading-meta [data-k="pct"]{color:var(--gold-3);font-weight:600}
.rd-loading-meta [hidden]{display:none}

.rd-error{position:absolute;z-index:4;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--s3);text-align:center;padding:var(--s5)}
.rd-error[hidden]{display:none}
.rd-error>.material-symbols-outlined{font-size:44px;color:#d98b7a}
.rd-error-title{font-family:var(--f-serif);font-size:19px;font-weight:600;color:#fff}
.rd-error-sub{font-size:14px;color:var(--on-night-2);max-width:46ch;margin-bottom:var(--s3)}

.rd-resume{position:absolute;z-index:4;left:50%;bottom:var(--s5);transform:translateX(-50%);display:flex;align-items:center;gap:var(--s3);
    padding:var(--s2) var(--s2) var(--s2) var(--s4);border-radius:999px;background:rgba(27,29,36,.92);border:1px solid var(--night-line);
    box-shadow:0 18px 40px -16px rgba(0,0,0,.8);font-size:14px;white-space:nowrap;animation:rdUp .4s var(--ease)}
.rd-resume[hidden]{display:none}
.rd-resume>.material-symbols-outlined{color:var(--gold-2);font-size:19px}
@keyframes rdUp{from{opacity:0;transform:translate(-50%,10px)}}

/* ── แถบล่าง ── */
.rd-bar{position:relative;z-index:5;display:flex;align-items:center;gap:var(--s4);padding:var(--s3) var(--s5);
    border-top:1px solid var(--night-line);background:rgba(18,19,24,.6);backdrop-filter:blur(10px)}
.rd-bar-group{display:flex;align-items:center;gap:var(--s2);flex-shrink:0}
.rd-sep{width:1px;height:22px;background:var(--night-line);margin:0 var(--s1)}
.rd-scrub{position:relative;flex:1;display:flex;align-items:center;gap:var(--s4);min-width:0}
.rd-page{font-size:13.5px;color:var(--on-night);white-space:nowrap;font-variant-numeric:tabular-nums;min-width:118px}
.rd-scrub input{flex:1;min-width:60px;-webkit-appearance:none;appearance:none;height:28px;background:transparent;cursor:pointer}
.rd-scrub input:disabled{cursor:default;opacity:.4}
.rd-scrub input::-webkit-slider-runnable-track{height:3px;border-radius:3px;background:linear-gradient(90deg,var(--gold-2) var(--fill,0%),rgba(255,255,255,.14) var(--fill,0%))}
.rd-scrub input::-moz-range-track{height:3px;border-radius:3px;background:rgba(255,255,255,.14)}
.rd-scrub input::-moz-range-progress{height:3px;border-radius:3px;background:var(--gold-2)}
.rd-scrub input::-webkit-slider-thumb{-webkit-appearance:none;width:15px;height:15px;margin-top:-6px;border-radius:50%;background:#fff;
    box-shadow:0 0 0 4px rgba(214,185,113,.25),0 2px 6px rgba(0,0,0,.5);transition:transform .15s}
.rd-scrub input::-moz-range-thumb{width:15px;height:15px;border:0;border-radius:50%;background:#fff;box-shadow:0 0 0 4px rgba(214,185,113,.25)}
.rd-scrub input:active::-webkit-slider-thumb{transform:scale(1.2)}
.rd-scrub-tip{position:absolute;bottom:calc(100% + 10px);transform:translateX(-50%);padding:var(--s1) var(--s3);border-radius:var(--r-sm);
    background:#fff;color:var(--ink);font-size:12.5px;font-weight:600;white-space:nowrap;pointer-events:none;box-shadow:var(--sh-2)}
.rd-scrub-tip[hidden]{display:none}
.rd-zoom-val{min-width:52px;height:36px;border:0;border-radius:var(--r);background:transparent;color:var(--on-night);font-size:13px;
    font-variant-numeric:tabular-nums;cursor:pointer}
.rd-zoom-val:hover{background:rgba(255,255,255,.08)}
.rd-bar [aria-pressed="true"]{color:var(--gold-3);border-color:rgba(214,185,113,.5)}
@media(max-width:640px){
    .rd-bar{padding:var(--s2) var(--s3);gap:var(--s2)}
    .rd-page{min-width:0;font-size:12.5px}
    .rd-scrub{gap:var(--s2);flex-direction:column;align-items:stretch}
    .rd-scrub input{height:20px}
    .rd-sep{display:none}
}

/* ── ลิ้นชักภาพย่อ ── */
.rd-thumbs{position:relative;z-index:4;width:300px;flex-shrink:0;display:flex;flex-direction:column;
    border-right:1px solid var(--night-line);background:rgba(18,19,24,.86);backdrop-filter:blur(12px);animation:rdSlide .3s var(--ease)}
.rd-thumbs[hidden]{display:none}
@keyframes rdSlide{from{transform:translateX(-24px);opacity:0}}
@media(max-width:767px){.rd-thumbs{position:absolute;inset:0;width:auto}}
.rd-thumbs-head{display:flex;align-items:center;justify-content:space-between;padding:var(--s3) var(--s3) var(--s3) var(--s5);
    font-size:14px;font-weight:600;border-bottom:1px solid var(--night-line)}
.rd-thumbs-grid{position:relative;flex:1;overflow-y:auto;overscroll-behavior:contain;padding:var(--s4);display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--s4) var(--s3);
    align-content:start;scrollbar-width:thin;scrollbar-color:rgba(255,255,255,.18) transparent}
@media(max-width:767px){.rd-thumbs-grid{grid-template-columns:repeat(auto-fill,minmax(110px,1fr))}}
.th{display:flex;flex-direction:column;align-items:center;gap:var(--s2);border:0;background:none;padding:0;cursor:pointer;color:var(--on-night-2);font-size:12px;font-variant-numeric:tabular-nums}
.th-img{position:relative;width:100%;background:#2a2c34;border-radius:3px;overflow:hidden;box-shadow:0 6px 14px -6px rgba(0,0,0,.7);
    outline:2px solid transparent;outline-offset:3px;transition:outline-color .2s,transform .2s var(--ease)}
.th-img img{display:block;width:100%;height:100%;object-fit:contain;background:#fff;opacity:0;transition:opacity .3s}
.th.is-loaded .th-img img{opacity:1}
.th:hover .th-img{transform:translateY(-2px)}
.th.is-current{color:var(--gold-3)}
.th.is-current .th-img{outline-color:var(--gold-2)}

/* ── ข้อมูลเอกสารใต้เวที ── */
.rd-info{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:var(--s5) var(--s8);padding-top:var(--s7);padding-bottom:var(--s7)}
@media(max-width:1023px){.rd-info{grid-template-columns:1fr}}
.rd-info .eyebrow a{text-decoration:none;color:inherit}
.rd-info .eyebrow a:hover{text-decoration:underline}
.rd-info-title{font-size:clamp(24px,2.6vw,34px);line-height:1.35;font-weight:700;margin-top:var(--s2)}
.rd-info-desc{margin-top:var(--s4);color:var(--ink-2);font-size:16px;line-height:1.8;max-width:68ch}
.rd-facts{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid var(--line);align-self:start}
.rd-facts div{padding:var(--s3) 0;border-bottom:1px solid var(--line)}
.rd-facts div:nth-child(odd){padding-right:var(--s4)}
.rd-facts dt{font-size:12.5px;color:var(--ink-3)}
.rd-facts dd{font-size:15px;font-weight:600;color:var(--ink);font-variant-numeric:tabular-nums}
.rd-keys{grid-column:1/-1;display:flex;flex-wrap:wrap;gap:var(--s2) var(--s5);font-size:13px;color:var(--ink-3)}
.rd-keys kbd{display:inline-grid;place-items:center;min-width:24px;height:24px;padding:0 6px;margin-right:3px;border-radius:5px;
    border:1px solid var(--line-2);border-bottom-width:2px;background:var(--card);font-family:var(--f-sans);font-size:12px;color:var(--ink-2)}
@media(hover:none){.rd-keys{display:none}}

@media(prefers-reduced-motion:reduce){
    html:not([data-motion="on"]) .pg-skel i,
    html:not([data-motion="on"]) .rd-loading-book span{animation:none}
}