:root{--color-bg-primary: #f8fafc;--color-bg-secondary: #ffffff;--color-bg-tertiary: #f1f5f9;--color-bg-card: rgba(255, 255, 255, .98);--color-bg-hover: rgba(22, 45, 80, .05);--color-accent-primary: #162d50;--color-accent-secondary: #00b4d8;--color-accent-tertiary: #0077b6;--color-accent-gradient: linear-gradient(135deg, #162d50 0%, #00b4d8 100%);--color-accent-glow: rgba(0, 180, 216, .25);--color-text-primary: #0f172a;--color-text-secondary: #475569;--color-text-muted: #64748b;--color-success: #059669;--color-warning: #d97706;--color-error: #dc2626;--color-info: #0284c7;--color-admin: #162d50;--color-professor: #0077b6;--color-student: #059669;--border-color: rgba(22, 45, 80, .1);--border-color-hover: rgba(0, 180, 216, .4);--shadow-sm: 0 2px 8px rgba(22, 45, 80, .06);--shadow-md: 0 4px 16px rgba(22, 45, 80, .1);--shadow-lg: 0 8px 32px rgba(22, 45, 80, .14);--shadow-glow: 0 0 40px var(--color-accent-glow);--spacing-xs: .25rem;--spacing-sm: .5rem;--spacing-md: 1rem;--spacing-lg: 1.5rem;--spacing-xl: 2rem;--spacing-2xl: 3rem;--radius-sm: .375rem;--radius-md: .5rem;--radius-lg: .75rem;--radius-xl: 1rem;--radius-2xl: 1.5rem;--radius-full: 9999px;--font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-size-xs: .75rem;--font-size-sm: .875rem;--font-size-base: 1rem;--font-size-lg: 1.125rem;--font-size-xl: 1.25rem;--font-size-2xl: 1.5rem;--font-size-3xl: 2rem;--font-size-4xl: 2.5rem;--transition-fast: .15s ease;--transition-base: .2s ease;--transition-slow: .3s ease;--sidebar-width: 280px;--header-height: 70px}*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}html{font-size:16px;scroll-behavior:smooth}body{font-family:var(--font-family);background:var(--color-bg-primary);color:var(--color-text-primary);line-height:1.6;min-height:100vh;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{min-height:100vh}h1,h2,h3,h4,h5,h6{font-weight:600;line-height:1.3;color:var(--color-text-primary)}h1{font-size:var(--font-size-4xl)}h2{font-size:var(--font-size-3xl)}h3{font-size:var(--font-size-2xl)}h4{font-size:var(--font-size-xl)}h5{font-size:var(--font-size-lg)}h6{font-size:var(--font-size-base)}p{color:var(--color-text-secondary)}a{color:var(--color-accent-primary);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--color-accent-secondary)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-lg);font-family:var(--font-family);font-size:var(--font-size-sm);font-weight:500;border:none;border-radius:var(--radius-lg);cursor:pointer;transition:all var(--transition-base);white-space:nowrap}.btn-primary{background:var(--color-accent-gradient);color:#fff;box-shadow:var(--shadow-sm),0 0 20px #6366f14d}.btn-primary:hover{transform:translateY(-2px);box-shadow:var(--shadow-md),0 0 30px #6366f180}.btn-secondary{background:var(--color-bg-tertiary);color:var(--color-text-primary);border:1px solid var(--border-color)}.btn-secondary:hover{background:var(--color-bg-hover);border-color:var(--border-color-hover)}.btn-danger{background:var(--color-error);color:#fff}.btn-danger:hover{background:#dc2626;transform:translateY(-2px)}.btn-icon{padding:var(--spacing-sm);background:transparent;color:var(--color-text-secondary)}.btn-icon:hover{background:var(--color-bg-hover);color:var(--color-text-primary)}.card{background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);padding:var(--spacing-xl);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);transition:all var(--transition-base)}.card:hover{border-color:var(--border-color-hover);box-shadow:var(--shadow-md)}.card-gradient{background:linear-gradient(135deg,rgba(99,102,241,.1) 0%,rgba(168,85,247,.1) 100%);border-color:#6366f133}.input{width:100%;padding:var(--spacing-md);font-family:var(--font-family);font-size:var(--font-size-base);color:var(--color-text-primary);background:var(--color-bg-tertiary);border:1px solid var(--border-color);border-radius:var(--radius-lg);transition:all var(--transition-base)}.input:focus{outline:none;border-color:var(--color-accent-primary);box-shadow:0 0 0 3px #1a365d1f}.input::placeholder{color:var(--color-text-muted)}.input-group{display:flex;flex-direction:column;gap:var(--spacing-sm)}.input-group label{font-size:var(--font-size-sm);font-weight:500;color:var(--color-text-secondary)}.select{width:100%;padding:var(--spacing-md);font-family:var(--font-family);font-size:var(--font-size-base);color:var(--color-text-primary);background:var(--color-bg-tertiary);border:1px solid var(--border-color);border-radius:var(--radius-lg);cursor:pointer;-webkit-appearance:none;-moz-appearance:none;appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%2371717a' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right var(--spacing-md) center;background-size:16px;padding-right:40px}.select:focus{outline:none;border-color:var(--color-accent-primary);box-shadow:0 0 0 3px #1a365d1f}.table-container{overflow-x:auto;border-radius:var(--radius-xl);border:1px solid var(--border-color)}.table{width:100%;border-collapse:collapse}.table th,.table td{padding:var(--spacing-md) var(--spacing-lg);text-align:left;border-bottom:1px solid var(--border-color)}.table th{background:var(--color-bg-tertiary);font-weight:600;font-size:var(--font-size-sm);color:var(--color-text-secondary);text-transform:uppercase;letter-spacing:.05em}.table tr:last-child td{border-bottom:none}.table tr:hover td{background:var(--color-bg-hover)}.badge{display:inline-flex;align-items:center;gap:var(--spacing-xs);padding:var(--spacing-xs) var(--spacing-sm);font-size:var(--font-size-xs);font-weight:500;border-radius:var(--radius-full);text-transform:uppercase;letter-spacing:.05em}.badge-admin{background:rgba(239,68,68,.15);color:var(--color-admin)}.badge-professor{background:rgba(59,130,246,.15);color:var(--color-professor)}.badge-student{background:rgba(34,197,94,.15);color:var(--color-student)}.badge-success{background:rgba(34,197,94,.15);color:var(--color-success)}.badge-warning{background:rgba(245,158,11,.15);color:var(--color-warning)}.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-center{justify-content:center}.justify-between{justify-content:space-between}.gap-xs{gap:var(--spacing-xs)}.gap-sm{gap:var(--spacing-sm)}.gap-md{gap:var(--spacing-md)}.gap-lg{gap:var(--spacing-lg)}.gap-xl{gap:var(--spacing-xl)}.text-center{text-align:center}.text-right{text-align:right}.text-muted{color:var(--color-text-muted)}.text-secondary{color:var(--color-text-secondary)}.w-full{width:100%}.h-full{height:100%}.grid{display:grid;gap:var(--spacing-lg)}.grid-cols-2{grid-template-columns:repeat(2,1fr)}.grid-cols-3{grid-template-columns:repeat(3,1fr)}.grid-cols-4{grid-template-columns:repeat(4,1fr)}@media (max-width: 1200px){.grid-cols-4{grid-template-columns:repeat(3,1fr)}}@media (max-width: 900px){.grid-cols-4,.grid-cols-3{grid-template-columns:repeat(2,1fr)}}@media (max-width: 600px){.grid-cols-4,.grid-cols-3,.grid-cols-2{grid-template-columns:1fr}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}@keyframes slideIn{0%{opacity:0;transform:translate(-20px)}to{opacity:1;transform:translate(0)}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.5}}@keyframes shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.animate-fadeIn{animation:fadeIn var(--transition-slow) ease forwards}.animate-slideIn{animation:slideIn var(--transition-slow) ease forwards}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(26,54,93,.5);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);display:flex;align-items:center;justify-content:center;z-index:1000;padding:var(--spacing-lg)}.modal{background:var(--color-bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-2xl);max-width:500px;width:100%;max-height:90vh;overflow-y:auto;animation:fadeIn var(--transition-base) ease}.modal-header{display:flex;align-items:center;justify-content:space-between;padding:var(--spacing-xl);border-bottom:1px solid var(--border-color)}.modal-header h3{font-size:var(--font-size-xl)}.modal-body{padding:var(--spacing-xl)}.modal-footer{display:flex;gap:var(--spacing-md);justify-content:flex-end;padding:var(--spacing-xl);border-top:1px solid var(--border-color)}.page-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:var(--spacing-xl);flex-wrap:wrap;gap:var(--spacing-md)}.page-header h1{font-size:var(--font-size-2xl);background:var(--color-accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--spacing-2xl);text-align:center;color:var(--color-text-muted)}.empty-state svg{width:64px;height:64px;margin-bottom:var(--spacing-lg);opacity:.5}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--color-bg-secondary)}::-webkit-scrollbar-thumb{background:var(--color-bg-tertiary);border-radius:var(--radius-full)}::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}::selection{background:var(--color-accent-primary);color:#fff}.sidebar{position:fixed;left:0;top:0;bottom:0;width:var(--sidebar-width);background:var(--color-bg-secondary);border-right:1px solid var(--border-color);display:flex;flex-direction:column;z-index:100}.sidebar-header{padding:var(--spacing-xl);border-bottom:1px solid var(--border-color)}.logo{display:flex;align-items:center;justify-content:center}.logo-image{max-width:180px;height:auto}.sidebar-user{padding:var(--spacing-lg);margin:var(--spacing-md);background:var(--color-bg-tertiary);border-radius:var(--radius-lg);display:flex;align-items:center;gap:var(--spacing-md)}.user-avatar{width:44px;height:44px;border-radius:var(--radius-full);overflow:hidden;flex-shrink:0}.user-avatar img{width:100%;height:100%;object-fit:cover}.user-info{display:flex;flex-direction:column;min-width:0}.user-name{font-weight:600;font-size:var(--font-size-sm);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.user-role{font-size:var(--font-size-xs);font-weight:500;text-transform:uppercase;letter-spacing:.05em}.sidebar-nav{flex:1;padding:var(--spacing-md);display:flex;flex-direction:column;gap:var(--spacing-xs);overflow-y:auto}.nav-item{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-md) var(--spacing-lg);color:var(--color-text-secondary);border-radius:var(--radius-lg);transition:all var(--transition-base);text-decoration:none}.nav-item:hover{background:var(--color-bg-hover);color:var(--color-text-primary)}.nav-item.active{background:rgba(0,180,216,.12);color:var(--color-accent-secondary)}.nav-item.active .nav-icon{color:var(--color-accent-secondary)}.nav-icon{flex-shrink:0;opacity:.8}.nav-label{font-weight:500;font-size:var(--font-size-sm)}.sidebar-footer{padding:var(--spacing-lg);border-top:1px solid var(--border-color)}.version-info{text-align:center;font-size:var(--font-size-xs);color:var(--color-text-muted)}.header{position:fixed;top:0;left:var(--sidebar-width);right:0;height:var(--header-height);background:rgba(255,255,255,.9);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-bottom:1px solid var(--border-color);display:flex;align-items:center;justify-content:space-between;padding:0 var(--spacing-xl);z-index:90}.header-left{flex:1}.header-title{font-size:var(--font-size-xl);font-weight:600;background:var(--color-accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.header-center{flex:2;display:flex;justify-content:center}.search-box{position:relative;width:100%;max-width:400px}.search-icon{position:absolute;left:var(--spacing-md);top:50%;transform:translateY(-50%);color:var(--color-text-muted)}.search-input{width:100%;padding:var(--spacing-sm) var(--spacing-lg);padding-left:44px;background:var(--color-bg-tertiary);border:1px solid var(--border-color);border-radius:var(--radius-full);color:var(--color-text-primary);font-size:var(--font-size-sm);transition:all var(--transition-base)}.search-input:focus{outline:none;border-color:var(--color-accent-primary);box-shadow:0 0 0 3px #1a365d26}.search-input::placeholder{color:var(--color-text-muted)}.header-right{flex:1;display:flex;align-items:center;justify-content:flex-end;gap:var(--spacing-md)}.header-btn{position:relative;width:40px;height:40px;display:flex;align-items:center;justify-content:center;background:transparent;border:none;border-radius:var(--radius-lg);color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition-base)}.header-btn:hover{background:var(--color-bg-hover);color:var(--color-text-primary)}.notification-btn{position:relative}.notification-badge{position:absolute;top:4px;right:4px;width:18px;height:18px;background:var(--color-accent-gradient);border-radius:var(--radius-full);font-size:10px;font-weight:600;display:flex;align-items:center;justify-content:center;color:#fff}.header-user{display:flex;align-items:center;gap:var(--spacing-md);padding-left:var(--spacing-md);border-left:1px solid var(--border-color)}.header-user-name{font-weight:500;font-size:var(--font-size-sm);color:var(--color-text-secondary)}.logout-btn:hover{background:rgba(239,68,68,.15);color:var(--color-error)}.main-layout{display:flex;min-height:100vh}.main-content-wrapper{flex:1;margin-left:var(--sidebar-width);display:flex;flex-direction:column}.main-content{flex:1;padding:var(--spacing-xl);padding-top:calc(var(--header-height) + var(--spacing-xl));background:var(--color-bg-primary);min-height:100vh}.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:var(--spacing-xl);position:relative;overflow:hidden;background:linear-gradient(135deg,#f5f7fa 0%,#e4e8ec 100%)}.login-background{position:absolute;top:0;right:0;bottom:0;left:0;z-index:0}.bg-gradient-1{position:absolute;width:600px;height:600px;background:radial-gradient(circle,rgba(26,54,93,.15) 0%,transparent 70%);top:-200px;left:-200px;animation:float 20s ease-in-out infinite}.bg-gradient-2{position:absolute;width:500px;height:500px;background:radial-gradient(circle,rgba(0,188,212,.15) 0%,transparent 70%);bottom:-150px;right:-150px;animation:float 25s ease-in-out infinite reverse}.bg-gradient-3{position:absolute;width:400px;height:400px;background:radial-gradient(circle,rgba(44,82,130,.1) 0%,transparent 70%);top:50%;left:50%;transform:translate(-50%,-50%);animation:pulse 15s ease-in-out infinite}@keyframes float{0%,to{transform:translate(0)}50%{transform:translate(30px,30px)}}@keyframes pulse{0%,to{transform:translate(-50%,-50%) scale(1)}50%{transform:translate(-50%,-50%) scale(1.1)}}.login-container{position:relative;z-index:1;max-width:450px;width:100%;background:white;border-radius:24px;padding:48px 40px;box-shadow:0 20px 60px #1a365d26}.login-header{margin-bottom:32px;text-align:center}.login-logo{display:flex;justify-content:center;margin-bottom:24px}.login-logo-image{max-width:220px;height:auto}.login-header h1{font-size:1.75rem;font-weight:700;color:#1a365d;margin-bottom:8px}.login-header p{font-size:1rem;color:#64748b}.email-login-form{display:flex;flex-direction:column;gap:20px;width:100%}.form-group{display:flex;flex-direction:column;gap:8px}.form-group label{display:flex;align-items:center;gap:8px;color:#374151;font-size:.875rem;font-weight:600}.form-group label svg{color:#1a365d}.form-group input{width:100%;padding:14px 16px;background:#f8fafc;border:2px solid #e2e8f0;border-radius:12px;color:#1e293b;font-size:1rem;transition:all .2s ease;box-sizing:border-box}.form-group input:hover{border-color:#cbd5e1}.form-group input:focus{outline:none;border-color:#1a365d;background:white;box-shadow:0 0 0 4px #1a365d1a}.form-group input::placeholder{color:#94a3b8}.login-btn{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;padding:16px 24px;margin-top:8px;background:linear-gradient(135deg,#1a365d 0%,#00bcd4 100%);border:none;border-radius:12px;color:#fff;font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s ease;box-shadow:0 4px 15px #1a365d4d}.login-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 8px 25px #1a365d66}.login-btn:active:not(:disabled){transform:translateY(0)}.login-btn:disabled{opacity:.6;cursor:not-allowed;transform:none}.login-error{text-align:center;color:#dc2626;font-size:.875rem;margin-top:16px;padding:12px 16px;background:#fef2f2;border-radius:8px;border:1px solid #fecaca}.login-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;gap:16px;color:#1a365d}@media (max-width: 500px){.login-container{padding:32px 24px;margin:16px;border-radius:20px}.login-header h1{font-size:1.5rem}.login-logo-image{max-width:180px}}.book-reader{height:100vh;display:flex;flex-direction:column;background:var(--color-background);overflow:hidden}.book-reader.fullscreen{position:fixed;top:0;left:0;right:0;bottom:0;z-index:9999}.reader-header{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-md) var(--spacing-lg);background:var(--color-surface-elevated);border-bottom:1px solid var(--color-border);z-index:10}.reader-title{flex:1;min-width:0}.reader-title h1{font-size:1.125rem;font-weight:600;color:var(--color-text-primary);margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.reader-author{font-size:.875rem;color:var(--color-text-secondary)}.reader-controls{display:flex;gap:var(--spacing-sm)}.reader-content{flex:1;position:relative;overflow:hidden;background:#1a1a2e}.pdf-viewer{width:100%;height:100%;border:none;display:block}.pdf-overlay{position:absolute;top:0;left:0;right:0;bottom:0;pointer-events:none}.reader-footer{display:flex;align-items:center;justify-content:space-between;padding:var(--spacing-sm) var(--spacing-lg);background:var(--color-surface-elevated);border-top:1px solid var(--color-border)}.reader-info{display:flex;align-items:center;gap:var(--spacing-md)}.book-reader-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;gap:var(--spacing-md);color:var(--color-text-secondary);background:var(--color-background)}.book-reader-loading .spin{color:var(--color-accent-primary);animation:spin 1s linear infinite}.book-reader-error{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;gap:var(--spacing-md);color:var(--color-text-secondary);background:var(--color-background);text-align:center;padding:var(--spacing-xl)}.book-reader-error svg{color:var(--color-text-muted)}.book-reader-error h2{color:var(--color-text-primary);margin:0}.book-reader-error p{color:var(--color-text-secondary);margin:0}.book-reader{user-select:none;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none}.pdf-viewer::-webkit-download-button{display:none!important}@media (max-width: 768px){.reader-header{padding:var(--spacing-sm) var(--spacing-md)}.reader-title h1{font-size:1rem}.reader-footer{padding:var(--spacing-xs) var(--spacing-md)}}.book-filters{margin-bottom:var(--spacing-xl)}.filters-main{display:flex;gap:var(--spacing-md);align-items:center;flex-wrap:wrap}.search-filter{position:relative;flex:1;min-width:250px;max-width:400px}.search-filter .search-icon{position:absolute;left:var(--spacing-md);top:50%;transform:translateY(-50%);color:var(--color-text-muted)}.search-filter .search-input{width:100%;padding:var(--spacing-sm) var(--spacing-lg);padding-left:44px;background:var(--color-bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-lg);color:var(--color-text-primary);font-size:var(--font-size-sm);transition:all var(--transition-base)}.search-filter .search-input:focus{outline:none;border-color:var(--color-accent-primary);box-shadow:0 0 0 3px #1a365d1f}.filter-toggle{display:flex;align-items:center;gap:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-lg);background:var(--color-bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-lg);color:var(--color-text-secondary);font-size:var(--font-size-sm);font-weight:500;cursor:pointer;transition:all var(--transition-base);position:relative}.filter-toggle:hover{border-color:var(--color-accent-primary);color:var(--color-accent-primary)}.filter-toggle.active{background:var(--color-accent-primary);border-color:var(--color-accent-primary);color:#fff}.filter-toggle.has-filters .filter-badge{position:absolute;top:-4px;right:-4px;width:10px;height:10px;background:var(--color-accent-tertiary);border-radius:50%}.clear-filters{display:flex;align-items:center;gap:var(--spacing-xs);padding:var(--spacing-sm) var(--spacing-md);background:transparent;border:none;color:var(--color-error);font-size:var(--font-size-sm);font-weight:500;cursor:pointer;transition:all var(--transition-base)}.clear-filters:hover{text-decoration:underline}.filters-expanded{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:var(--spacing-md);margin-top:var(--spacing-lg);padding:var(--spacing-lg);background:var(--color-bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-xl);animation:fadeIn var(--transition-base) ease}.filter-group{display:flex;flex-direction:column;gap:var(--spacing-xs)}.filter-group label{font-size:var(--font-size-xs);font-weight:600;color:var(--color-text-secondary);text-transform:uppercase;letter-spacing:.05em}.filter-group .select{padding:var(--spacing-sm) var(--spacing-md);font-size:var(--font-size-sm)}.manage-books{max-width:1400px;margin:0 auto}.books-table-container{background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);overflow:hidden}.book-cell{display:flex;align-items:center;gap:var(--spacing-md)}.book-thumb{width:50px;height:70px;object-fit:cover;border-radius:var(--radius-sm)}.book-details{display:flex;flex-direction:column}.book-name{font-weight:600;font-size:var(--font-size-sm)}.book-desc{font-size:var(--font-size-xs);color:var(--color-text-muted)}.assignees{display:flex;align-items:center}.assignee-avatar{width:28px;height:28px;border-radius:var(--radius-full);border:2px solid var(--color-bg-secondary);margin-left:-8px}.assignee-avatar:first-child{margin-left:0}.assignee-more{width:28px;height:28px;background:var(--color-bg-tertiary);border-radius:var(--radius-full);border:2px solid var(--color-bg-secondary);margin-left:-8px;display:flex;align-items:center;justify-content:center;font-size:var(--font-size-xs);color:var(--color-text-muted)}.textarea{resize:vertical;min-height:80px}.upload-area{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--spacing-sm);padding:var(--spacing-xl);border:2px dashed var(--border-color);border-radius:var(--radius-lg);color:var(--color-text-muted);cursor:pointer;transition:all var(--transition-base)}.upload-area:hover{border-color:var(--color-accent-primary);color:var(--color-accent-primary)}.assign-book-title{margin-bottom:var(--spacing-lg);padding-bottom:var(--spacing-lg);border-bottom:1px solid var(--border-color)}.assign-list{display:flex;flex-direction:column;gap:var(--spacing-sm);max-height:400px;overflow-y:auto}.assign-item{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-md);background:var(--color-bg-tertiary);border:2px solid transparent;border-radius:var(--radius-lg);cursor:pointer;transition:all var(--transition-base)}.assign-item:hover{background:var(--color-bg-hover)}.assign-item.assigned{border-color:var(--color-success);background:rgba(34,197,94,.1)}.assign-avatar{width:40px;height:40px;border-radius:var(--radius-full)}.assign-info{flex:1;display:flex;flex-direction:column;gap:var(--spacing-xs)}.assign-name{font-weight:500;font-size:var(--font-size-sm)}.assign-check{width:24px;height:24px;border:2px solid var(--border-color);border-radius:var(--radius-full);display:flex;align-items:center;justify-content:center;font-size:12px;color:var(--color-success);transition:all var(--transition-base)}.assign-item.assigned .assign-check{background:var(--color-success);border-color:var(--color-success);color:#fff}.badge-component{background:rgba(26,54,93,.12);color:var(--color-accent-primary);padding:var(--spacing-xs) var(--spacing-sm);border-radius:var(--radius-full);font-size:var(--font-size-xs);font-weight:500}.badge-student{background:rgba(34,197,94,.15);color:var(--color-success);padding:var(--spacing-xs) var(--spacing-sm);border-radius:var(--radius-full);font-size:var(--font-size-xs);font-weight:500}.badge-professor{background:rgba(139,92,246,.15);color:#8b5cf6;padding:var(--spacing-xs) var(--spacing-sm);border-radius:var(--radius-full);font-size:var(--font-size-xs);font-weight:500}.class-tags{display:flex;flex-wrap:wrap;gap:var(--spacing-xs)}.class-tag{background:rgba(201,162,39,.15);color:var(--color-accent-tertiary);padding:2px var(--spacing-sm);border-radius:var(--radius-sm);font-size:var(--font-size-xs);font-weight:500}.class-tag-more{background:var(--color-bg-tertiary);color:var(--color-text-muted);padding:2px var(--spacing-sm);border-radius:var(--radius-sm);font-size:var(--font-size-xs)}.book-author{font-size:var(--font-size-xs);color:var(--color-text-muted)}.modal-lg{max-width:700px}.form-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:var(--spacing-md)}@media (max-width: 600px){.form-grid{grid-template-columns:1fr}}.class-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:var(--spacing-sm)}.class-checkbox{display:flex;align-items:center;gap:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-md);background:var(--color-bg-tertiary);border:2px solid transparent;border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);font-size:var(--font-size-sm)}.class-checkbox:hover{border-color:var(--color-accent-primary)}.class-checkbox.checked{border-color:var(--color-accent-tertiary);background:rgba(201,162,39,.1)}.class-checkbox input{display:none}.class-checkbox span{white-space:nowrap}.pdf-upload-container{display:flex;flex-direction:column;gap:var(--spacing-sm)}.pdf-selected{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-md);background:rgba(26,54,93,.05);border:2px solid var(--color-accent-primary);border-radius:var(--radius-lg)}.pdf-selected svg{color:var(--color-accent-primary);flex-shrink:0}.pdf-filename{flex:1;font-size:var(--font-size-sm);font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.pdf-size{font-size:var(--font-size-xs);color:var(--color-text-muted)}.pdf-uploaded{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-md);background:rgba(34,197,94,.08);border:2px solid var(--color-success);border-radius:var(--radius-lg)}.pdf-uploaded .text-success{color:var(--color-success)}.pdf-uploaded span{flex:1;font-size:var(--font-size-sm);font-weight:500;color:var(--color-success)}.upload-hint{font-size:var(--font-size-xs);color:var(--color-text-muted)}.upload-error{color:var(--color-error);font-size:var(--font-size-sm);margin-top:var(--spacing-xs)}.upload-success{color:var(--color-success);font-size:var(--font-size-sm);margin-top:var(--spacing-xs)}.btn-sm{padding:var(--spacing-xs) var(--spacing-md);font-size:var(--font-size-sm)}.manage-users{max-width:1400px;margin:0 auto}.filter-tabs{display:flex;gap:var(--spacing-sm);margin-bottom:var(--spacing-xl)}.filter-tab{padding:var(--spacing-sm) var(--spacing-lg);background:transparent;border:1px solid var(--border-color);border-radius:var(--radius-full);color:var(--color-text-secondary);font-size:var(--font-size-sm);font-weight:500;cursor:pointer;transition:all var(--transition-base)}.filter-tab:hover{background:var(--color-bg-hover);border-color:var(--border-color-hover)}.filter-tab.active{background:var(--color-accent-gradient);border-color:transparent;color:#fff}.users-table-container{background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);overflow:hidden}.user-cell{display:flex;align-items:center;gap:var(--spacing-md)}.user-avatar{width:40px;height:40px;border-radius:var(--radius-full);object-fit:cover}.user-name{font-weight:500}.books-count{display:inline-flex;align-items:center;gap:var(--spacing-xs);padding:var(--spacing-xs) var(--spacing-sm);background:var(--color-bg-tertiary);border-radius:var(--radius-full);font-size:var(--font-size-sm);color:var(--color-text-secondary)}.actions{display:flex;gap:var(--spacing-xs)}.actions .btn-icon.danger:hover{background:rgba(239,68,68,.15);color:var(--color-error)}.manage-curriculum{max-width:1200px;margin:0 auto}.loading-container{display:flex;flex-direction:column;align-items:center;justify-content:center;height:300px;gap:var(--spacing-md);color:var(--color-text-muted)}.curriculum-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:var(--spacing-lg)}.curriculum-card{display:flex;align-items:center;gap:var(--spacing-md);padding:var(--spacing-lg);background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);transition:all var(--transition-base)}.curriculum-card:hover{border-color:var(--color-accent-primary);box-shadow:0 4px 12px #1a365d1a}.curriculum-icon{width:48px;height:48px;background:linear-gradient(135deg,var(--color-accent-primary),var(--color-accent-secondary));border-radius:var(--radius-lg);display:flex;align-items:center;justify-content:center;color:#fff;flex-shrink:0}.curriculum-info{flex:1;min-width:0}.curriculum-info h3{font-size:var(--font-size-md);font-weight:600;margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.curriculum-actions{display:flex;gap:var(--spacing-xs)}.curriculum-actions .btn-icon.danger:hover{background:rgba(239,68,68,.15);color:var(--color-error)}.empty-state{grid-column:1 / -1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--spacing-3xl);color:var(--color-text-muted);gap:var(--spacing-md)}.empty-state svg{opacity:.5}.form-error{color:var(--color-error);font-size:var(--font-size-sm);margin-top:var(--spacing-sm)}.spin{animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.book-card{display:flex;align-items:center;gap:var(--spacing-lg);padding:var(--spacing-md);background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);cursor:pointer;transition:all var(--transition-base);animation:fadeIn var(--transition-slow) ease forwards}.book-card:hover{border-color:var(--border-color-hover);transform:translate(4px);box-shadow:var(--shadow-md)}.book-cover{position:relative;width:80px;height:110px;flex-shrink:0;border-radius:var(--radius-md);overflow:hidden}.book-cover img{width:100%;height:100%;object-fit:cover}.book-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:rgba(0,0,0,.7);display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity var(--transition-base)}.book-card:hover .book-overlay{opacity:1}.read-btn{display:flex;align-items:center;gap:var(--spacing-xs);padding:var(--spacing-xs) var(--spacing-sm);background:var(--color-accent-gradient);border:none;border-radius:var(--radius-md);color:#fff;font-size:var(--font-size-xs);font-weight:500;cursor:pointer;transition:transform var(--transition-fast)}.read-btn:hover{transform:scale(1.05)}.book-info{flex:1;min-width:0}.book-title{font-size:var(--font-size-base);font-weight:600;margin-bottom:var(--spacing-xs);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.book-author{font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-bottom:var(--spacing-sm)}.book-progress{display:flex;flex-direction:column;gap:var(--spacing-xs)}.progress-bar{height:6px;background:var(--color-bg-tertiary);border-radius:var(--radius-full);overflow:hidden}.progress-fill{height:100%;background:var(--color-accent-gradient);border-radius:var(--radius-full);transition:width var(--transition-slow)}.progress-text{font-size:var(--font-size-xs);color:var(--color-text-muted)}.book-meta{display:flex;align-items:center;gap:var(--spacing-xs);font-size:var(--font-size-xs);color:var(--color-text-muted)}.book-arrow{color:var(--color-text-muted);transition:all var(--transition-base)}.book-card:hover .book-arrow{color:var(--color-accent-primary);transform:translate(4px)}.book-card-grid{flex-direction:column;padding:0;overflow:hidden}.book-card-grid .book-cover{width:100%;height:200px;border-radius:0}.book-card-grid .book-info{padding:var(--spacing-lg)}.book-card-grid .book-arrow{display:none}.my-books{max-width:1200px;margin:0 auto}.books-section{margin-bottom:var(--spacing-2xl)}.books-section h2{font-size:var(--font-size-xl);margin-bottom:var(--spacing-lg);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--border-color)}.books-list{display:flex;flex-direction:column;gap:var(--spacing-md)}.student-books-group{background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);padding:var(--spacing-lg);margin-bottom:var(--spacing-lg)}.student-header{display:flex;align-items:center;gap:var(--spacing-md);margin-bottom:var(--spacing-lg);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--border-color)}.student-avatar{width:48px;height:48px;border-radius:var(--radius-full);object-fit:cover}.student-info{display:flex;flex-direction:column}.student-name{font-weight:600;font-size:var(--font-size-base)}.student-count{font-size:var(--font-size-sm);color:var(--color-text-muted)}.empty-message{color:var(--color-text-muted);font-style:italic;padding:var(--spacing-lg);text-align:center}.students-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:var(--spacing-lg)}.student-card{background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);padding:var(--spacing-xl);transition:all var(--transition-base)}.student-card:hover{border-color:var(--border-color-hover);transform:translateY(-2px);box-shadow:var(--shadow-md)}.student-card .student-header{border-bottom:none;margin-bottom:var(--spacing-lg);padding-bottom:0}.student-card .student-avatar{width:56px;height:56px}.student-email{font-size:var(--font-size-xs);color:var(--color-text-muted)}.student-stats{display:flex;gap:var(--spacing-xl);margin-bottom:var(--spacing-md)}.student-stat{display:flex;flex-direction:column;align-items:center}.student-stat .stat-value{font-size:var(--font-size-xl);font-weight:700;color:var(--color-text-primary)}.student-stat .stat-label{font-size:var(--font-size-xs);color:var(--color-text-muted)}.student-card .progress-bar{height:8px;background:var(--color-bg-tertiary);border-radius:var(--radius-full);overflow:hidden}.student-card .progress-fill{height:100%;background:var(--color-accent-gradient);border-radius:var(--radius-full);transition:width var(--transition-slow)}.my-library{max-width:1200px;margin:0 auto}.library-filters{display:flex;align-items:center;gap:var(--spacing-md);margin-bottom:var(--spacing-xl);padding:var(--spacing-md) var(--spacing-lg);background:var(--color-bg-card);border:1px solid var(--border-color);border-radius:var(--radius-xl);color:var(--color-text-muted)}.filter-btn{padding:var(--spacing-sm) var(--spacing-lg);background:transparent;border:none;border-radius:var(--radius-full);color:var(--color-text-secondary);font-size:var(--font-size-sm);font-weight:500;cursor:pointer;transition:all var(--transition-base)}.filter-btn:hover{background:var(--color-bg-hover);color:var(--color-text-primary)}.filter-btn.active{background:var(--color-accent-gradient);color:#fff}.library-grid{display:flex;flex-direction:column;gap:var(--spacing-md)}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--spacing-2xl);text-align:center;color:var(--color-text-muted);background:var(--color-bg-card);border:1px dashed var(--border-color);border-radius:var(--radius-xl);margin-top:var(--spacing-xl)}.empty-state h3{margin-top:var(--spacing-lg);margin-bottom:var(--spacing-sm);color:var(--color-text-secondary)}.empty-state p{max-width:400px}