:root{--blue:#07539a;--bg:#edf2f7;--ink:#142434;--line:#dbe4ee;--muted:#6b7b8b}
*{box-sizing:border-box}html,body{margin:0;font-family:Arial,Helvetica,sans-serif;color:var(--ink);background:var(--bg)}
html{height:100%;overflow:hidden}body{height:100vh;height:100dvh;display:flex;flex-direction:column;overflow:hidden}
button,input,select,textarea{font:inherit}button:disabled{cursor:default}.btn:focus-visible,.nav:focus-visible,input:focus-visible,select:focus-visible{outline:2px solid var(--blue);outline-offset:2px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}.btn{border:1px solid #cdd9e5;background:#fff;border-radius:9px;padding:9px 12px;cursor:pointer}.btn.primary{background:var(--blue);color:#fff;border-color:var(--blue)}.btn.danger{color:#a11;border-color:#e2bcbc}.muted{color:var(--muted)}
.topbar{min-height:54px;flex-shrink:0;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:8px;padding:7px 10px}.brand{min-width:0;font-weight:700;color:var(--blue);margin-right:auto;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.view-mode{width:92px;flex-shrink:0;border:1px solid #cdd9e5;background:#fff;color:var(--ink);border-radius:9px;padding:8px 5px;font-size:13px}.topbar>.btn{flex-shrink:0;white-space:nowrap}.page-nav{display:flex;align-items:center;gap:5px;margin:0;white-space:nowrap;flex-shrink:0;font-size:13px}.page-nav label{color:var(--muted)}.page-nav input{width:55px;min-width:0;border:1px solid #cdd9e5;border-radius:7px;padding:7px 4px;text-align:center;color:var(--ink);background:#fff}.page-nav input:invalid{border-color:#be4545}.counter{text-align:center;color:var(--muted)}.page-go{padding:6px 9px}
.viewer{flex:1;min-height:0;width:100%;position:relative;display:flex;align-items:center;justify-content:center;padding:6px;overflow:hidden}.stage{position:relative;perspective:2600px;filter:drop-shadow(0 18px 26px rgba(0,0,0,.18));touch-action:none;user-select:none}.book{position:relative;display:flex;transform-style:preserve-3d;background:#fff}.basepage{position:relative;background:#fff;overflow:hidden}.basepage img{display:block;width:100%;height:100%;object-fit:contain;pointer-events:none}.basepage.left{border-right:1px solid #ddd}.spine{position:absolute;top:0;bottom:0;left:50%;width:20px;transform:translateX(-50%);background:linear-gradient(90deg,rgba(0,0,0,.10),rgba(255,255,255,.16) 43%,rgba(0,0,0,.09));z-index:4;opacity:.55;pointer-events:none}
.flip{position:absolute;top:0;width:50%;height:100%;transform-style:preserve-3d;z-index:10;display:none;will-change:transform}.flip.forward{right:0;transform-origin:left center}.flip.backward{left:0;transform-origin:right center}.face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;background:#fff;overflow:hidden}.face img{width:100%;height:100%;object-fit:contain;display:block}.face.back{transform:rotateY(180deg)}
.nav{position:absolute;top:50%;transform:translateY(-50%);height:54px;width:44px;border:0;border-radius:12px;background:rgba(255,255,255,.58);box-shadow:0 3px 12px rgba(0,0,0,.10);font-size:28px;z-index:12;cursor:pointer;opacity:.3;transition:opacity .18s,background .18s}.nav:focus-visible{opacity:1;background:rgba(255,255,255,.92)}.nav:disabled{opacity:.08}.nav.prev{left:4px}.nav.next{right:4px}
@media(hover:hover){.nav:not(:disabled):hover{opacity:1;background:rgba(255,255,255,.92)}}
.drawer{position:fixed;left:0;top:var(--toolbar-height,54px);bottom:0;width:330px;max-width:88vw;background:#fff;border-right:1px solid var(--line);transform:translateX(-102%);transition:.25s;z-index:20;padding:12px;overflow:auto}.drawer.open{transform:none}.drawer h3{font-size:16px;line-height:1.35;margin:2px 0 12px}.chapter{display:block;width:100%;text-align:left;border:0;background:#f4f7fa;margin:6px 0;padding:9px 10px;min-height:40px;font-size:13px;line-height:1.45;overflow-wrap:anywhere;border-radius:8px;cursor:pointer}
.overlay{position:fixed;inset:0;background:rgba(5,15,25,.92);display:none;align-items:center;justify-content:center;z-index:40}.overlay.open{display:flex}.overlay img{max-width:96vw;max-height:94vh}
.single-page .stage{perspective:none}.single-page .book{display:block;overflow:hidden;transform-style:flat}.single-page .basepage.left,.single-page .spine{display:none!important}.single-page .flip{width:100%!important}
@media(max-width:1100px){.desktopLabel{display:none}}
@media(max-width:800px){.topbar{gap:6px;padding:6px}.viewer{padding:3px}.brand{display:none}.nav{height:48px;background:rgba(255,255,255,.38);box-shadow:0 2px 8px rgba(0,0,0,.06)}.nav.prev{left:2px}.nav.next{right:2px}.page-nav{margin-left:auto}}
@media(max-width:420px){.topbar{gap:4px}.topbar>.btn{padding:8px}.page-nav{gap:3px;font-size:12px}.page-nav label{display:none}.page-nav input{width:48px}.page-go{padding:6px 7px}}
@media(max-width:500px){.topbar{flex-wrap:wrap}.view-mode{width:84px;font-size:12px}}

.single-turn{position:absolute;inset:0;background:#fff;z-index:10;display:none;opacity:0;pointer-events:none;transition:opacity 180ms ease-out}.single-turn img{display:block;width:100%;height:100%;object-fit:contain}.reader-notice{position:absolute;bottom:8px;left:50%;transform:translateX(-50%);max-width:90%;padding:6px 10px;background:rgba(255,255,255,.94);border-radius:7px;color:var(--ink);font-size:13px;text-align:center;z-index:15}
@media(prefers-reduced-motion:reduce){.single-turn{transition:none}}

.fullscreen-notice{position:absolute;top:8px;left:50%;transform:translateX(-50%);width:460px;max-width:calc(100% - 16px);padding:12px;background:#fff;border:1px solid var(--line);border-radius:9px;box-shadow:0 3px 16px rgba(0,0,0,.15);z-index:30;font-size:14px}.fullscreen-notice[hidden]{display:none}.fullscreen-notice p{margin:0 0 12px;line-height:1.45}.fullscreen-notice .btn{display:inline-block;text-decoration:none;color:var(--blue)}

.chapter:focus-visible{outline:2px solid var(--blue);outline-offset:2px}