@media (max-width:900px){#book-container,.hamburger-btn{flex-direction:column;padding:0}#book,#toc-list,body,html{overflow-x:hidden}#book-container{gap:0;min-height:calc(100dvh - 60px);position:relative;overflow:hidden}#book,#toc-list,.book-page{overflow-y:auto}.hamburger-btn{position:fixed;top:15px;left:15px;width:44px;height:44px;background:rgba(255,255,255,.95);border:none;border-radius:8px;box-shadow:0 2px 8px rgba(0,0,0,.15);cursor:pointer;z-index:1001;display:flex;justify-content:center;align-items:center;gap:5px;transition:.3s}.hamburger-btn:hover{background:#fff;box-shadow:0 4px 12px rgba(0,0,0,.2)}.hamburger-btn:active{transform:scale(.95)}.hamburger-btn span{width:22px;height:2px;background:#333;border-radius:2px;transition:.3s;display:block}.hamburger-btn.sidebar-open{display:none}.book-page img,.book-page.active{display:block!important}.sidebar-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.5);z-index:999;opacity:0;visibility:hidden;transition:opacity .3s,visibility .3s}#toc.toc-sidebar,.toc-header{background:#fff;display:flex;box-sizing:border-box}.sidebar-overlay.active{opacity:1;visibility:visible}#toc.toc-sidebar{position:fixed;top:0;left:0;width:85%;max-width:320px;height:100dvh!important;max-height:100dvh!important;box-shadow:2px 0 10px rgba(0,0,0,.2);padding:0;margin:0;overflow:hidden;z-index:1000;transform:translateX(-100%);transition:transform .3s;flex-direction:column}#toc.toc-sidebar.sidebar-open{transform:translateX(0)}.toc-header{justify-content:space-between;align-items:center;padding:20px;border-bottom:1px solid #ddd;flex-shrink:0;min-height:60px}.book-page,.hardcover-cover{min-height:calc(100vh - 60px)!important}.toc-header h2{margin:0;font-size:1.2em;font-weight:600;color:#000;font-family:Georgia,'Times New Roman',serif;flex:1}.close-toc-btn{width:36px;height:36px;background:0 0;border:none;font-size:24px;color:#666;cursor:pointer;display:flex;align-items:center;justify-content:center;border-radius:4px;transition:.2s;padding:0;line-height:1;flex-shrink:0;margin-left:10px}#book,.book-page,.book-page img{width:100%!important}.book-page,.nav-btn{display:none!important}.bottom-nav-btn:hover:not(:disabled),.close-toc-btn:hover{background:#f5f5f5;color:#000}.close-toc-btn:active{transform:scale(.9)}#toc-list{flex:1 1 auto;padding:15px 20px 20px;margin:0;min-height:0;height:0}#toc-list::-webkit-scrollbar{width:6px}#toc-list::-webkit-scrollbar-track{background:#f1f1f1}#toc-list::-webkit-scrollbar-thumb{background:#888;border-radius:3px}#toc-list::-webkit-scrollbar-thumb:hover{background:#555}#book{height:calc(100dvh - 60px)!important;margin:0;padding:0;box-shadow:none;box-sizing:border-box;-webkit-overflow-scrolling:touch;scroll-behavior:smooth;position:relative}.book-page{position:relative!important;top:0!important;left:0!important;background:#fff;margin:0;padding:0 0 80px!important;overflow-x:hidden!important}.book-page img{height:100%!important;object-fit:contain!important;margin:0;padding:0;transform:scale(1.3);transform-origin:top center}.bottom-nav{position:fixed;bottom:0;left:0;width:100%;height:60px;background:#fff;border-top:1px solid #ddd;display:flex;justify-content:space-between;align-items:center;padding:0;z-index:998;box-shadow:0 -2px 8px rgba(0,0,0,.1)}.bottom-nav-btn{flex:1;height:100%;background:0 0;border:none;color:#333;font-size:1em;font-weight:500;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:.2s;font-family:system-ui,-apple-system,'Segoe UI',sans-serif;padding:0}.bottom-nav-btn:not(:last-child){border-right:1px solid #eee}#toc-list a:active,.bottom-nav-btn:active:not(:disabled){background:#e8e8e8}.bottom-nav-btn:disabled{opacity:.4;cursor:not-allowed;color:#999}.bottom-nav-btn span{display:block}.hardcover-cover{padding:40px 30px 80px!important}.cover-title{font-size:1.2em!important;margin-bottom:30px!important}.cover-subtitle{font-size:1em!important;margin-bottom:20px!important}.cover-program{font-size:.9em!important;margin-bottom:30px!important}.cover-details{font-size:.9em!important;margin-bottom:15px!important}.cover-author{font-size:1em!important;margin-top:10px!important}.cover-reviewers{font-size:.85em!important;padding-top:10px!important;margin-top:10px!important;flex-direction:column!important;gap:15px!important}#toc-list a{padding:8px 10px;font-size:.9em}#toc-list .toc-level-1{margin-left:15px}#toc-list .toc-level-2{margin-left:30px}}