:root{--color-primary: #3b82f6;--color-primary-dark: #2563eb;--color-secondary: #6b7280;--color-secondary-dark: #4b5563;--color-success: #10b981;--color-success-dark: #059669;--color-danger: #ef4444;--color-danger-dark: #dc2626;--color-text: #1f2937;--color-text-secondary: #6b7280;--color-text-light: #9ca3af;--color-bg: #ffffff;--color-bg-secondary: #f9fafb;--color-bg-hover: #f3f4f6;--color-border: #e5e7eb;--spacing-xs: .25rem;--spacing-sm: .5rem;--spacing-md: 1rem;--spacing-lg: 1.5rem;--spacing-xl: 2rem;--spacing-2xl: 3rem;--font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;--font-size-xs: .75rem;--font-size-sm: .875rem;--font-size-md: 1rem;--font-size-lg: 1.125rem;--font-size-xl: 1.25rem;--font-size-2xl: 1.5rem;--font-size-3xl: 1.875rem;--sidebar-width: 260px;--header-height: 64px;--shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .05);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .1);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1);--radius-sm: 4px;--radius-md: 6px;--radius-lg: 8px;--radius-xl: 12px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:var(--font-family);color:var(--color-text);background-color:var(--color-bg-secondary);line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{min-height:100vh}button{font-family:inherit}a{color:var(--color-primary);text-decoration:none}a:hover{text-decoration:underline}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 var(--spacing-md)}.card{background:#fff;border-radius:var(--radius-lg);padding:var(--spacing-lg);box-shadow:var(--shadow-sm);border:1px solid var(--color-border)}.card-title{font-size:var(--font-size-lg);font-weight:600;margin-bottom:var(--spacing-md);color:var(--color-text)}.error-boundary{display:flex;align-items:center;justify-content:center;min-height:400px;padding:2rem}.error-boundary-content{text-align:center;max-width:500px}.error-boundary-content h2{color:var(--color-danger);margin-bottom:1rem}.error-boundary-content p{color:var(--color-text-secondary);margin-bottom:1.5rem}.error-boundary-button{padding:.5rem 1rem;background-color:var(--color-primary);color:#fff;border:none;border-radius:6px;cursor:pointer;font-size:1rem}.error-boundary-button:hover{background-color:var(--color-primary-dark)}.sidebar{position:fixed;left:0;top:0;bottom:0;width:var(--sidebar-width);background:#fff;border-right:1px solid var(--color-border);display:flex;flex-direction:column;z-index:100}.sidebar-header{padding:var(--spacing-lg);border-bottom:1px solid var(--color-border)}.sidebar-logo{font-size:var(--font-size-xl);font-weight:700;color:var(--color-text);margin:0}.sidebar-nav{flex:1;overflow-y:auto;padding:var(--spacing-md)}.sidebar-nav-item{display:flex;align-items:center;gap:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-md);border-radius:var(--radius-md);color:var(--color-text);margin-bottom:var(--spacing-xs);transition:all .2s;text-decoration:none}.sidebar-nav-item:hover{background-color:var(--color-bg-hover);text-decoration:none}.sidebar-nav-item-active{background-color:var(--color-primary);color:#fff}.sidebar-nav-item-active:hover{background-color:var(--color-primary-dark)}.sidebar-nav-icon{font-size:var(--font-size-lg)}@media(max-width:768px){.sidebar{transform:translate(-100%);transition:transform .3s}.sidebar-open{transform:translate(0)}}.header{position:fixed;top:0;left:var(--sidebar-width);right:0;height:var(--header-height);background:#fff;border-bottom:1px solid var(--color-border);z-index:99}.header-content{display:flex;align-items:center;justify-content:space-between;padding:0 var(--spacing-lg);height:100%}.header-title h2{margin:0;font-size:var(--font-size-xl);font-weight:600;color:var(--color-text)}.header-actions{display:flex;align-items:center;gap:var(--spacing-md)}.header-user{color:var(--color-text);font-weight:500}@media(max-width:768px){.header{left:0}}.logout-btn{margin-left:12px;padding:8px 12px;border-radius:6px;border:1px solid #ef4444;background:#ef4444;color:#fff;font-weight:600;cursor:pointer;transition:transform .05s ease,box-shadow .2s ease,background .2s ease;box-shadow:0 2px 8px #ef444440}.logout-btn:hover{background:#dc2626;border-color:#dc2626}.logout-btn:active{transform:translateY(1px);box-shadow:0 1px 4px #ef444440}.dashboard-layout{display:flex;min-height:100vh}.dashboard-main{margin-left:var(--sidebar-width);margin-top:var(--header-height);flex:1;padding:var(--spacing-lg);background-color:var(--color-bg-secondary);min-height:calc(100vh - var(--header-height))}.dashboard-content{max-width:1400px;margin:0 auto}@media(max-width:768px){.dashboard-main{margin-left:0}}.loading{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1rem;padding:2rem}.loading-fullscreen{position:fixed;inset:0;background-color:#ffffffe6;z-index:9999}.loading-spinner{width:3rem;height:3rem;border:4px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .8s linear infinite}.loading-message{color:var(--color-text-secondary);font-size:.875rem}.stats-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:var(--spacing-lg);margin-bottom:var(--spacing-xl)}.stat-card{background:#fff;border-radius:var(--radius-lg);padding:var(--spacing-lg);display:flex;align-items:center;gap:var(--spacing-md);box-shadow:var(--shadow-sm);border:1px solid var(--color-border);transition:transform .2s,box-shadow .2s}.stat-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}.stat-card-icon{font-size:2.5rem;width:4rem;height:4rem;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-md);flex-shrink:0}.stat-card-blue .stat-card-icon{background-color:#dbeafe}.stat-card-green .stat-card-icon{background-color:#d1fae5}.stat-card-purple .stat-card-icon{background-color:#e9d5ff}.stat-card-yellow .stat-card-icon{background-color:#fef3c7}.stat-card-orange .stat-card-icon{background-color:#fed7aa}.stat-card-pink .stat-card-icon{background-color:#fce7f3}.stat-card-content{flex:1}.stat-card-value{font-size:var(--font-size-2xl);font-weight:700;color:var(--color-text);margin-bottom:var(--spacing-xs)}.stat-card-label{font-size:var(--font-size-sm);color:var(--color-text-secondary)}.dashboard-page{padding:var(--spacing-lg)}.dashboard-title{font-size:var(--font-size-2xl);font-weight:700;margin-bottom:var(--spacing-xl);color:var(--color-text)}.dashboard-error{padding:var(--spacing-lg);background:#fff;border-radius:var(--radius-lg);color:var(--color-danger)}.table-wrapper{overflow-x:auto;border:1px solid var(--color-border);border-radius:8px;background:#fff}.table{width:100%;border-collapse:collapse;font-size:.875rem}.table thead{background-color:var(--color-bg-secondary)}.table th{padding:.75rem 1rem;text-align:left;font-weight:600;color:var(--color-text);border-bottom:2px solid var(--color-border)}.table th.sortable{cursor:pointer;-webkit-user-select:none;user-select:none}.table th.sortable:hover{background-color:var(--color-bg-hover)}.table td{padding:.75rem 1rem;border-bottom:1px solid var(--color-border);color:var(--color-text)}.table tbody tr:hover{background-color:var(--color-bg-hover)}.table-row-clickable{cursor:pointer}.table-empty,.table-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:3rem;color:var(--color-text-secondary)}.table-loading-spinner{width:2rem;height:2rem;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .6s linear infinite;margin-bottom:1rem}.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;border:none;border-radius:6px;font-weight:500;cursor:pointer;transition:all .2s;font-family:inherit}.btn:focus{outline:2px solid var(--color-primary);outline-offset:2px}.btn-sm{padding:.375rem .75rem;font-size:.875rem}.btn-md{padding:.5rem 1rem;font-size:1rem}.btn-lg{padding:.75rem 1.5rem;font-size:1.125rem}.btn-primary{background-color:var(--color-primary);color:#fff}.btn-primary:hover:not(:disabled){background-color:var(--color-primary-dark)}.btn-secondary{background-color:var(--color-secondary);color:#fff}.btn-secondary:hover:not(:disabled){background-color:var(--color-secondary-dark)}.btn-danger{background-color:var(--color-danger);color:#fff}.btn-danger:hover:not(:disabled){background-color:var(--color-danger-dark)}.btn-success{background-color:var(--color-success);color:#fff}.btn-success:hover:not(:disabled){background-color:var(--color-success-dark)}.btn:disabled,.btn-disabled{opacity:.6;cursor:not-allowed}.btn-spinner{width:1em;height:1em;border:2px solid currentColor;border-top-color:transparent;border-radius:50%;animation:spin .6s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.badge{display:inline-flex;align-items:center;gap:.25rem;padding:.25rem .5rem;border-radius:4px;font-size:.875rem;font-weight:500}.badge-green{background-color:#d1fae5;color:#065f46}.badge-yellow{background-color:#fef3c7;color:#92400e}.badge-red{background-color:#fee2e2;color:#991b1b}.badge-gray{background-color:#f3f4f6;color:#374151}.badge-orange{background-color:#fed7aa;color:#9a3412}.modal-overlay{position:fixed;inset:0;background-color:#00000080;display:flex;align-items:center;justify-content:center;z-index:1000;padding:1rem}.modal{background:#fff;border-radius:8px;box-shadow:0 10px 25px #0003;max-height:90vh;display:flex;flex-direction:column;max-width:100%}.modal-sm{width:100%;max-width:400px}.modal-md{width:100%;max-width:600px}.modal-lg{width:100%;max-width:900px}.modal-xl{width:100%;max-width:1200px}.modal-header{display:flex;align-items:center;justify-content:space-between;padding:1.5rem;border-bottom:1px solid var(--color-border)}.modal-title{margin:0;font-size:1.25rem;font-weight:600;color:var(--color-text)}.modal-close{background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--color-text-secondary);padding:0;width:2rem;height:2rem;display:flex;align-items:center;justify-content:center;border-radius:4px;transition:background-color .2s}.modal-close:hover{background-color:var(--color-bg-hover)}.modal-body{padding:1.5rem;overflow-y:auto;flex:1}.modal-footer{padding:1.5rem;border-top:1px solid var(--color-border);display:flex;gap:.75rem;justify-content:flex-end}.books-list-page{padding:var(--spacing-lg)}.books-list-header{margin-bottom:var(--spacing-lg)}.books-list-header h1{font-size:var(--font-size-2xl);font-weight:700;color:var(--color-text);margin:0}.book-title-cell{display:flex;flex-direction:column;gap:var(--spacing-xs)}.book-isbn{font-size:var(--font-size-xs);color:var(--color-text-secondary)}.book-actions{display:flex;gap:var(--spacing-sm);flex-wrap:wrap}.modal-warning{color:var(--color-text-secondary);font-size:var(--font-size-sm);margin-top:var(--spacing-sm)}.book-detail-page{padding:var(--spacing-lg)}.book-detail-header{margin-bottom:var(--spacing-lg)}.book-detail-content{background:#fff;border-radius:var(--radius-lg);padding:var(--spacing-xl);box-shadow:var(--shadow-sm)}.book-detail-main h1{font-size:var(--font-size-3xl);margin-bottom:var(--spacing-lg);color:var(--color-text)}.book-detail-meta{display:flex;flex-direction:column;gap:var(--spacing-sm);margin-bottom:var(--spacing-xl);padding-bottom:var(--spacing-lg);border-bottom:1px solid var(--color-border)}.book-detail-author{margin-top:var(--spacing-xs)}.book-detail-description{margin-top:var(--spacing-lg)}.book-detail-description h3{font-size:var(--font-size-lg);margin-bottom:var(--spacing-md);color:var(--color-text)}.book-detail-actions{display:flex;gap:var(--spacing-md);margin-top:var(--spacing-xl);padding-top:var(--spacing-lg);border-top:1px solid var(--color-border)}.book-detail-error{padding:var(--spacing-xl);text-align:center;color:var(--color-danger)}.chapters-list-page{padding:var(--spacing-lg)}.chapter-actions{display:flex;gap:var(--spacing-sm)}.modal-footer{display:flex;gap:var(--spacing-sm);justify-content:flex-end;margin-top:var(--spacing-lg)}.toaster{position:fixed;top:16px;right:16px;display:flex;flex-direction:column;gap:8px;z-index:9999}.toast{padding:10px 12px;border-radius:6px;color:#fff;box-shadow:0 4px 14px #00000026;font-size:14px}.toast-success{background:#16a34a}.toast-error{background:#dc2626}.toast-info{background:#2563eb}.app{min-height:100vh}