.reading-progress{position:fixed;top:0;left:0;height:3px;background:#f55000;width:0%;z-index:9999;opacity:0;transition:opacity .3s ease}.reading-progress.show{opacity:1}.book-layout{display:flex;align-items:flex-start;max-width:1100px;margin:0 auto;padding:0 16px;gap:0}.book-toc{width:260px;flex-shrink:0;position:sticky;top:72px;max-height:calc(100vh - 88px);overflow-y:auto;padding:24px 0;scrollbar-width:thin;scrollbar-color:#e7e5e4 transparent}.book-toc::-webkit-scrollbar{width:4px}.book-toc::-webkit-scrollbar-track{background:transparent}.book-toc::-webkit-scrollbar-thumb{background:#e7e5e4;border-radius:4px}.book-toc-inner{padding:0 20px 0 0;border-right:1px solid #e7e5e4}.book-toc-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px;padding-bottom:12px;border-bottom:1px solid #f0eeec}.book-toc-series{font-size:13px;font-weight:700;color:#1c1917;letter-spacing:.02em}.book-toc-count{font-size:12px;color:#fff;background:#f55000;padding:4px 10px;border-radius:5px;font-weight:600;letter-spacing:.06em}.book-toc-nav{display:flex;flex-direction:column;gap:2px}.book-toc-item{display:flex;align-items:flex-start;gap:8px;padding:7px 10px;border-radius:8px;text-decoration:none;border:none;color:#57534e;font-size:13px;line-height:1.5;transition:background .15s,color .15s}.book-toc-item:hover{background:#f5f5f4;color:#1c1917;border:none}.book-toc-section.active .book-toc-item{background:#f5500014;color:#f55000;font-weight:600;border-radius:8px 8px 0 0}.book-toc-order{flex-shrink:0;width:18px;height:18px;font-size:11px;line-height:18px;text-align:center;border-radius:4px;background:#f0eeec;color:#a8a29e;margin-top:1px}.book-toc-item.active .book-toc-order,.book-toc-section.active .book-toc-order{background:#f5500026;color:#f55000}.book-toc-sub{display:flex;flex-direction:column;gap:1px;padding:4px 0 6px 36px;border-radius:0 0 8px 8px;background:#f550000a}.book-toc-sub-item{display:block;padding:5px 10px;font-size:12px;line-height:1.5;color:#78716c;text-decoration:none;border:none;border-radius:5px;transition:color .15s,background .15s;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.book-toc-sub-item:hover{color:#f55000;background:#f550000f}.book-toc-title{flex:1;min-width:0}.book-toc-back{display:flex;align-items:center;gap:6px;margin-top:20px;padding:8px 10px;font-size:12px;color:#a8a29e;text-decoration:none;border:none;border-radius:6px;transition:color .15s,background .15s}.book-toc-back:hover{color:#57534e;background:#f5f5f4;border:none}.article-nav{display:flex;justify-content:space-between;align-items:stretch;gap:16px;margin-top:48px;padding-top:32px;border-top:1px solid #e7e5e4}.article-nav-link{display:flex;flex-direction:column;gap:4px;padding:14px 18px;border-radius:10px;background:#fff;border:1px solid #e7e5e4;text-decoration:none;transition:border-color .2s,box-shadow .2s;flex:1;max-width:280px;box-shadow:0 1px 3px #0000000a}.article-nav-link:hover{border-color:#f55000;box-shadow:0 4px 12px #f5500014}.article-nav-prev{align-items:flex-start}.article-nav-next{align-items:flex-end;text-align:right}.article-nav-label{display:flex;align-items:center;gap:6px;font-size:12px;color:#a8a29e;font-weight:500}.article-nav-title{font-size:14px;font-weight:600;color:#1c1917;line-height:1.4}.article-nav-link:hover .article-nav-title{color:#f55000}.book-main{flex:1;min-width:0;padding-left:40px}.book-main .prose{max-width:680px;margin:0;padding:0}@media(max-width:768px){.book-layout{flex-direction:column;padding:0}.book-toc{width:100%;position:static;max-height:none;padding:0;border-bottom:none;margin-bottom:0;background:#fafaf9}.book-toc-inner{padding:0;border-right:none}.book-toc-nav{display:none}.book-toc.expanded .book-toc-nav{display:flex;padding:0 16px 16px}.book-toc-header{cursor:pointer;display:flex;align-items:center;justify-content:space-between;padding:16px;margin-bottom:0;border-bottom:1px solid #e7e5e4;background:#f5f5f4;-webkit-tap-highlight-color:transparent;min-height:48px}.book-toc-header:after{content:"▾";font-size:16px;color:#78716c;transition:transform .2s;flex-shrink:0;margin-left:8px}.book-toc.expanded .book-toc-header{border-bottom:none;padding:16px}.book-toc.expanded .book-toc-header:after{transform:rotate(180deg)}.book-toc-item{padding:12px 10px;font-size:14px;border-radius:8px;min-height:44px;align-items:center}.book-toc-order{width:22px;height:22px;font-size:12px;line-height:22px}.book-toc-back{padding:14px 16px;margin-top:0;border-top:1px solid #e7e5e4;font-size:13px;min-height:44px;align-items:center}.book-main{padding:0 16px}.book-main .prose{max-width:100%}}