:root{--bg:#111318;--panel:#191c22;--text:#f5f7fa;--muted:#9ba3af;--accent:#06b6d4;--line:rgba(255,255,255,.12)}
*{box-sizing:border-box}html,body{width:100%;height:100%}body{margin:0;overflow:hidden;background:radial-gradient(circle at 50% 35%,#29313b 0,#171a20 38%,#0d0f13 100%);color:var(--text);font-family:'Montserrat',sans-serif}
.viewer-header{position:fixed;inset:0 0 auto;z-index:10;height:68px;padding:0 clamp(16px,4vw,56px);display:grid;grid-template-columns:1fr auto 1fr;align-items:center;background:rgba(13,15,19,.82);border-bottom:1px solid var(--line);backdrop-filter:blur(15px)}.viewer-header p{margin:0;font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase}.back-link,.pdf-link{color:var(--text);text-decoration:none;font-size:13px}.back-link span{margin-left:6px}.pdf-link{justify-self:end;color:var(--accent)}
.viewer-main{position:fixed;inset:68px 0 62px;display:flex;align-items:center;justify-content:center;padding:16px;overflow:hidden}.viewer-main.zoomed{display:block;overflow:auto;cursor:grab}.viewer-main.zoomed.panning{cursor:grabbing;user-select:none}.book-stage{position:relative;flex:none;max-width:none;max-height:none;filter:drop-shadow(0 22px 24px rgba(0,0,0,.46))}.viewer-main.zoomed .book-stage{margin:0 auto}#book{position:absolute;inset:0 auto auto 0;flex:none;margin:0;transform-origin:top left;transition:transform .22s ease}.viewer-main.magnifier:not(.zoomed) #book{cursor:zoom-in}.viewer-main.zoomed #book{cursor:inherit}.stf__parent{margin:0!important}.stf__block{background:#fff}
.loading,.error{display:flex;flex-direction:column;align-items:center;text-align:center;gap:12px}.loading small{color:var(--muted)}.spinner{width:38px;height:38px;border:3px solid rgba(255,255,255,.14);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.error a{color:var(--accent)}
.viewer-controls{position:fixed;inset:auto 0 0;z-index:10;height:62px;display:flex;align-items:center;justify-content:center;gap:18px;background:rgba(13,15,19,.84);border-top:1px solid var(--line);backdrop-filter:blur(15px)}.control-group{display:flex;align-items:center;gap:14px}.control-divider{width:1px;height:26px;background:var(--line)}.zoom-hint{min-width:92px;color:var(--muted);font-size:11px}.viewer-controls button{width:38px;height:38px;border:1px solid var(--line);border-radius:50%;background:var(--panel);color:var(--text);font-size:20px;cursor:pointer;transition:.2s}.viewer-controls button:hover:not(:disabled),.viewer-controls .zoom-tool.active{background:var(--accent);border-color:var(--accent);color:#fff}.viewer-controls button:disabled{opacity:.3;cursor:default}#pageIndicator{min-width:62px;text-align:center;color:var(--muted);font-size:12px}
@media(max-width:700px){.viewer-header{grid-template-columns:1fr auto;height:58px}.viewer-header p{display:none}.back-link span{display:none}.viewer-main{inset:58px 0 56px;padding:8px}.pdf-link{font-size:12px}.viewer-controls{height:56px;gap:9px}.control-group{gap:7px}.control-divider{height:22px}.zoom-hint{min-width:88px;font-size:9px}.viewer-controls button{width:34px;height:34px;font-size:18px}#pageIndicator{min-width:48px;font-size:11px}}