:root{--sidebar-bg: #2c2f3a;--sidebar-hover: #3a3e4d;--sidebar-active: #4a6fa5;--sidebar-text: #c8cdd8;--sidebar-text-dim: #7a8098;--main-bg: #f5f2ed;--card-bg: #ffffff;--card-shadow: 0 2px 8px rgba(0, 0, 0, .12);--card-hover-shadow: 0 6px 20px rgba(0, 0, 0, .18);--accent: #4a6fa5;--accent-hover: #3a5f95;--danger: #e05252;--text-main: #2c2f3a;--text-dim: #7a8098;--border: #e0ddd7;--topbar-bg: #ffffff;--overlay-bg: rgba(44, 47, 58, .6)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,微软雅黑,PingFang SC,sans-serif;background:var(--main-bg);color:var(--text-main);display:flex;height:100vh;overflow:hidden;font-size:14px}#sidebar{width:220px;min-width:220px;background:var(--sidebar-bg);display:flex;flex-direction:column;height:100vh;-webkit-user-select:none;user-select:none}#sidebar-header{display:flex;align-items:center;gap:10px;padding:20px 16px 16px;border-bottom:1px solid rgba(255,255,255,.07)}#sidebar-header .logo{font-size:22px}#sidebar-header .logo-text{font-size:16px;font-weight:600;color:#f0f0f0;letter-spacing:.5px}#category-list{list-style:none;flex:1;overflow-y:auto;padding:8px 0}#category-list::-webkit-scrollbar{width:4px}#category-list::-webkit-scrollbar-thumb{background:#ffffff26;border-radius:2px}.cat-item{display:flex;align-items:center;gap:8px;padding:10px 16px;cursor:pointer;color:var(--sidebar-text);border-radius:0;transition:background .15s;position:relative}.cat-item:hover{background:var(--sidebar-hover)}.cat-item.active{background:var(--sidebar-active);color:#fff}.cat-item .cat-icon{font-size:15px;flex-shrink:0}.cat-item .cat-name{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13.5px}.cat-actions{display:none;gap:4px}.cat-item:hover .cat-actions,.cat-item.active .cat-actions{display:flex}.cat-actions button{background:none;border:none;cursor:pointer;padding:2px 4px;border-radius:3px;font-size:13px;color:var(--sidebar-text-dim);line-height:1;transition:background .12s,color .12s}.cat-actions button:hover{background:#ffffff26;color:#fff}.cat-actions .cat-delete:hover{color:#e05252}#sidebar-footer{padding:12px 16px;border-top:1px solid rgba(255,255,255,.07)}#add-cat-btn{width:100%;padding:8px 12px;background:#ffffff14;border:1px dashed rgba(255,255,255,.2);color:var(--sidebar-text);cursor:pointer;border-radius:6px;font-size:13px;transition:background .15s,border-color .15s}#add-cat-btn:hover{background:#ffffff21;border-color:#ffffff59}#main{flex:1;display:flex;flex-direction:column;overflow:hidden}#top-bar{background:var(--topbar-bg);border-bottom:1px solid var(--border);padding:0 24px;height:56px;display:flex;align-items:center;gap:16px;flex-shrink:0}#top-bar h2{font-size:16px;font-weight:600;flex:1}#book-count{color:var(--text-dim);font-size:13px}#add-book-btn{padding:8px 16px;background:var(--accent);color:#fff;border:none;border-radius:6px;cursor:pointer;font-size:13.5px;font-weight:500;transition:background .15s}#add-book-btn:hover{background:var(--accent-hover)}#content{flex:1;overflow-y:auto;padding:24px}#content::-webkit-scrollbar{width:6px}#content::-webkit-scrollbar-thumb{background:#ccc;border-radius:3px}#book-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:20px}.book-card{background:var(--card-bg);border-radius:10px;box-shadow:var(--card-shadow);cursor:pointer;transition:transform .18s,box-shadow .18s;overflow:hidden;-webkit-user-select:none;user-select:none}.book-card:hover{transform:translateY(-4px);box-shadow:var(--card-hover-shadow)}.book-cover{position:relative;aspect-ratio:2/3;background:#e8e4dc;overflow:hidden}.book-cover img{width:100%;height:100%;object-fit:cover;display:block}.book-cover-placeholder{width:100%;height:100%;display:flex;align-items:center;justify-content:center;font-size:36px;background:linear-gradient(135deg,#e8e4dc,#d4cfc5)}.book-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:#2c2f3a8c;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .18s}.book-card:hover .book-overlay{opacity:1}.btn-read{padding:8px 20px;background:#fff;color:var(--text-main);border:none;border-radius:20px;font-size:13px;font-weight:600;cursor:pointer;transition:background .12s}.btn-read:hover{background:#f0f0f0}.book-info{padding:10px 10px 12px}.book-title{font-size:13px;font-weight:600;line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:4px}.hidden{display:none!important}.book-author{font-size:11.5px;color:var(--text-dim);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.book-ghost{opacity:.4}#empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:60vh;color:var(--text-dim);text-align:center}.empty-icon{font-size:56px;margin-bottom:16px}#empty-state p{margin-bottom:6px;font-size:15px}#empty-state .empty-hint{font-size:13px;color:#b0aaa0}#drop-overlay{display:none;position:fixed;top:0;right:0;bottom:0;left:0;background:#4a6fa540;border:3px dashed var(--accent);z-index:1000;align-items:center;justify-content:center;pointer-events:none}#drop-overlay.active{display:flex}.drop-hint{text-align:center;color:var(--accent)}.drop-hint span{font-size:56px;display:block;margin-bottom:12px}.drop-hint p{font-size:18px;font-weight:600}#context-menu{display:none;position:fixed;z-index:2000;background:#fff;border:1px solid var(--border);border-radius:8px;box-shadow:0 4px 20px #00000026;padding:4px 0;min-width:160px;font-size:13.5px}#context-menu.visible{display:block}.ctx-item{padding:8px 16px;cursor:pointer;color:var(--text-main);transition:background .12s;position:relative}.ctx-item:hover{background:#f5f5f5}.ctx-danger{color:var(--danger)}.ctx-sep{height:1px;background:var(--border);margin:3px 0}.ctx-submenu-trigger:after{content:"▶";position:absolute;right:12px;font-size:10px;color:var(--text-dim)}.ctx-submenu{display:none;position:absolute;left:calc(100% + 2px);top:-4px;background:#fff;border:1px solid var(--border);border-radius:8px;box-shadow:0 4px 20px #00000026;padding:4px 0;min-width:140px;z-index:2001}.ctx-submenu-trigger:hover .ctx-submenu{display:block}.ctx-submenu .ctx-item{font-size:13px}.modal-overlay{display:none;position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-bg);z-index:3000;align-items:center;justify-content:center}.modal-overlay.visible{display:flex}.modal-box{background:#fff;border-radius:12px;padding:24px;width:320px;box-shadow:0 8px 32px #0003}.modal-box h3{margin-bottom:16px;font-size:16px}.confirm-modal-box p,.notice-modal-box p{margin-bottom:18px;line-height:1.6;color:var(--text-main);white-space:pre-line}.modal-box input{width:100%;padding:10px 12px;border:1px solid var(--border);border-radius:6px;font-size:14px;outline:none;margin-bottom:16px;transition:border-color .15s}.modal-box input:focus{border-color:var(--accent)}.modal-btns{display:flex;justify-content:flex-end;gap:10px}.btn-primary{padding:8px 20px;background:var(--accent);color:#fff;border:none;border-radius:6px;cursor:pointer;font-size:13.5px;transition:background .15s}.btn-primary:hover{background:var(--accent-hover)}.btn-primary.btn-danger{background:var(--danger)}.btn-primary.btn-danger:hover{background:#c94444}.btn-secondary{padding:8px 20px;background:#f0f0f0;color:var(--text-main);border:none;border-radius:6px;cursor:pointer;font-size:13.5px;transition:background .15s}.btn-secondary:hover{background:#e4e4e4}#loading-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-bg);z-index:4000;display:flex;flex-direction:column;align-items:center;justify-content:center;color:#fff;gap:16px;font-size:15px}.spinner{width:36px;height:36px;border:4px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}