body{font-family:Arial,Helvetica,sans-serif;margin:0;background:#f7f7f7;height:100vh;display:flex;flex-direction:column}
main{padding:20px}
#doc-list ul{list-style:none;padding:0}
#doc-list li{margin:8px 0}
#controls{display:flex;gap:8px;padding:10px;background:#fff;z-index:10}
#viewer-wrapper{flex:1;display:flex;justify-content:center;align-items:center;padding:10px;overflow:hidden}
/* Flipbook: wir setzen variable Breite/Höhe via JS, innen sind zwei Seiten (je 50%) */
#flipbook{transform-origin: left top; /* wichtig für Skalierung */}
#flipbook .page{background:#fff;display:flex;align-items:center;justify-content:center;overflow:hidden}
#flipbook img{max-width:100%;max-height:100%;display:block;transition:transform .2s ease}
a#back{align-self:center;text-decoration:none;padding:6px 8px;border:1px solid #ddd;background:#fff;border-radius:4px}