.navbar{background:var(--color-white);border-bottom:1px solid var(--color-border);position:sticky;top:0;z-index:100;box-shadow:var(--shadow-sm);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);background:#ffffffeb}.navbar-inner{display:flex;align-items:center;justify-content:space-between;height:56px;gap:var(--space-4)}.navbar-brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--color-text);flex-shrink:0}.navbar-logo-icon{color:var(--color-primary)}.navbar-title{font-size:var(--font-size-lg);font-weight:700;letter-spacing:-.02em}.navbar-links{display:flex;gap:var(--space-1)}.navbar-link{display:flex;align-items:center;gap:6px;padding:6px 14px;border-radius:var(--radius-sm);font-size:var(--font-size-sm);font-weight:500;color:var(--color-text-secondary);text-decoration:none;transition:all var(--transition)}.navbar-link:hover{color:var(--color-text);background:var(--color-bg)}.navbar-link.active{color:var(--color-primary);background:var(--color-primary-light)}.navbar-right{display:flex;align-items:center;gap:var(--space-3);flex-shrink:0}.navbar-user{display:flex;align-items:center;gap:var(--space-2)}.navbar-email{font-size:var(--font-size-sm);color:var(--color-text-secondary)}.navbar-role-badge{display:inline-flex;align-items:center;padding:2px 8px;font-size:10px;font-weight:600;text-transform:uppercase;letter-spacing:.05em;border-radius:999px;background:linear-gradient(135deg,var(--color-primary),#7c3aed);color:#fff}.navbar-logout{display:inline-flex;align-items:center;gap:6px}.navbar-theme-toggle{padding:6px 10px;font-size:16px;line-height:1}.navbar-hamburger{display:none;flex-direction:column;gap:4px;padding:8px;background:none;border:none;cursor:pointer}.hamburger-line{display:block;width:20px;height:2px;background:var(--color-text);border-radius:2px;transition:all .2s ease}.hamburger-line.open:nth-child(1){transform:rotate(45deg) translate(4px,4px)}.hamburger-line.open:nth-child(2){opacity:0}.hamburger-line.open:nth-child(3){transform:rotate(-45deg) translate(4px,-4px)}.navbar-mobile-bottom{display:none}@media (max-width: 640px){.navbar-hamburger{display:flex}.navbar-right{display:none}.navbar-links{display:none;position:absolute;top:56px;left:0;right:0;flex-direction:column;background:var(--color-white);border-bottom:1px solid var(--color-border);padding:var(--space-2);box-shadow:var(--shadow-md);gap:0}[data-theme=dark] .navbar-links{background:var(--color-surface)}.navbar-links.open{display:flex}.navbar-link{padding:12px 16px;border-radius:var(--radius-md)}.navbar-link span{display:inline}.navbar-mobile-bottom{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-2) var(--space-3);border-top:1px solid var(--color-border);margin-top:var(--space-2);flex-wrap:wrap}.navbar-mobile-bottom .navbar-user{flex:1;min-width:0}.navbar-mobile-bottom .navbar-email{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.navbar-mobile-bottom .navbar-role-badge{display:inline-flex}}.auth-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:var(--space-4);background:linear-gradient(135deg,#f0f4ff,#f5f5f7,#faf5ff)}.auth-card{width:100%;max-width:420px;padding:var(--space-5) var(--space-5) var(--space-4);background:var(--color-white);border-radius:var(--radius-xl);box-shadow:0 8px 32px #00000014,0 2px 8px #0000000a;border:1px solid rgba(0,0,0,.04)}.auth-header{text-align:center;margin-bottom:var(--space-4)}.auth-logo-wrapper{display:inline-flex;align-items:center;justify-content:center;width:56px;height:56px;border-radius:16px;background:linear-gradient(135deg,var(--color-primary),#7c3aed);margin-bottom:var(--space-3)}.auth-logo-icon{color:#fff}.auth-title{font-size:var(--font-size-2xl);font-weight:700;color:var(--color-text);letter-spacing:-.02em}.auth-subtitle{font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-top:var(--space-1)}.auth-form{display:flex;flex-direction:column;gap:var(--space-3)}.form-input-icon{padding-left:42px}.auth-submit{width:100%;margin-top:var(--space-2);padding:12px;font-size:var(--font-size-base)}.auth-footer{text-align:center;font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-top:var(--space-4);padding-top:var(--space-3);border-top:1px solid var(--color-border)}.auth-footer a{font-weight:500}.card-form{display:flex;flex-direction:column;gap:var(--space-3)}.card-form-title{font-size:var(--font-size-lg);font-weight:600;color:var(--color-text)}.char-count{font-size:var(--font-size-xs);color:var(--color-text-secondary);text-align:right;margin-top:-4px}.topic-select-row{display:flex;gap:8px;align-items:center}.topic-select-row .form-input,.topic-select-row select{flex:1;min-width:0}.card-form-toggle{display:flex;flex-direction:column;gap:var(--space-2)}.toggle-buttons{display:flex;gap:0;border:1px solid var(--color-border);border-radius:var(--radius-md);overflow:hidden}.toggle-btn{flex:1;padding:10px 16px;font-family:var(--font-family);font-size:var(--font-size-sm);font-weight:500;border:none;background:var(--color-white);color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition)}.toggle-btn:first-child{border-right:1px solid var(--color-border)}.toggle-btn.active{background:var(--color-primary);color:var(--color-white)}.toggle-btn:hover:not(.active):not(:disabled){background:var(--color-bg);color:var(--color-text)}.toggle-btn:disabled{opacity:.5;cursor:not-allowed}.folder-picker-display{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;background:var(--color-white);border:1px solid var(--color-border);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition);font-size:var(--font-size-sm);min-height:42px}.folder-picker-display:hover{border-color:var(--color-primary)}.folder-picker-display.open{border-color:var(--color-primary);border-bottom-left-radius:0;border-bottom-right-radius:0}.folder-picker-path{display:flex;align-items:center;gap:4px;color:var(--color-text);font-weight:500}.folder-picker-placeholder{color:var(--color-text-secondary)}.folder-picker-clear{padding:2px 6px;background:none;border:none;color:var(--color-text-secondary);cursor:pointer;font-size:16px;line-height:1;border-radius:var(--radius-sm)}.folder-picker-clear:hover{background:var(--color-bg);color:var(--color-text)}.folder-picker-sep{color:var(--color-text-secondary);opacity:.5;flex-shrink:0}.folder-picker-panel{display:flex;flex-direction:column;border:1px solid var(--color-primary);border-top:none;border-radius:0 0 var(--radius-md) var(--radius-md);background:var(--color-white);max-height:280px;overflow-y:auto}.folder-picker-breadcrumb{display:flex;align-items:center;flex-wrap:wrap;gap:2px;padding:8px 12px;background:var(--color-bg);border-bottom:1px solid var(--color-border);font-size:var(--font-size-xs)}.folder-picker-crumb{padding:2px 6px;background:none;border:none;font-family:var(--font-family);font-size:var(--font-size-xs);color:var(--color-primary);cursor:pointer;border-radius:var(--radius-sm);display:inline-flex;align-items:center;gap:3px}.folder-picker-crumb:hover{background:var(--color-white)}.folder-picker-item{display:flex;align-items:center;gap:var(--space-2);padding:10px 12px;background:none;border:none;border-bottom:1px solid var(--color-border);font-family:var(--font-family);font-size:var(--font-size-sm);color:var(--color-text);cursor:pointer;transition:background var(--transition);text-align:left;width:100%}.folder-picker-item:last-child{border-bottom:none}.folder-picker-item:hover{background:var(--color-bg)}.folder-picker-item svg:first-child{color:var(--color-primary);flex-shrink:0}.folder-picker-arrow{margin-left:auto;color:var(--color-text-secondary)}.folder-picker-select{background:var(--color-primary-light, #eff6ff);font-weight:500}.folder-picker-select:hover{background:var(--color-primary);color:var(--color-white)}.folder-picker-select:hover svg{color:var(--color-white)}.folder-picker-add{color:var(--color-primary);font-weight:500}.folder-picker-new{display:flex;gap:var(--space-2);align-items:center;padding:8px 12px;border-bottom:1px solid var(--color-border)}.folder-picker-new .form-input{flex:1;min-width:0;padding:6px 10px;font-size:var(--font-size-sm)}.file-upload{display:flex;flex-direction:column;gap:var(--space-3)}.file-upload-title{font-size:var(--font-size-lg);font-weight:600;color:var(--color-text)}.file-upload-desc{font-size:var(--font-size-sm);color:var(--color-text-secondary);line-height:1.6}.file-upload-dropzone{border:2px dashed var(--color-border);border-radius:var(--radius-lg);padding:var(--space-5);text-align:center;transition:all var(--transition);background:var(--color-bg)}.file-upload-dropzone.drag-over{border-color:var(--color-primary);background:var(--color-primary-light)}.file-upload-dropzone.has-file{border-style:solid;border-color:var(--color-primary);background:var(--color-primary-light)}.file-upload-input{display:none}.file-upload-label{display:flex;flex-direction:column;align-items:center;gap:var(--space-2);cursor:pointer;padding:var(--space-3)}.file-upload-icon{color:var(--color-text-secondary);opacity:.5}.file-upload-label-text{font-size:var(--font-size-sm);font-weight:500;color:var(--color-text)}.file-upload-label-formats{font-size:var(--font-size-xs);color:var(--color-text-secondary)}.file-upload-selected{display:flex;align-items:center;justify-content:center;gap:var(--space-2);color:var(--color-primary)}.file-upload-name{font-size:var(--font-size-sm);font-weight:500}.file-upload-remove{background:none;border:none;font-size:1.25rem;color:var(--color-text-secondary);cursor:pointer;padding:0 4px;line-height:1}.file-upload-remove:hover{color:var(--color-danger)}.file-upload-info{font-size:var(--font-size-sm);color:var(--color-text-secondary);font-style:italic;text-align:center}@media (max-width: 640px){.file-upload-dropzone{padding:var(--space-4)}}.file-upload .folder-select-row{display:flex;gap:var(--space-2);align-items:center}.file-upload .folder-select-row .form-input{flex:1;min-width:0}.file-upload .folder-select-row select.form-input{-webkit-appearance:auto;-moz-appearance:auto;appearance:auto}.card-list{display:flex;flex-direction:column;gap:var(--space-3)}.folder-breadcrumbs{display:flex;align-items:center;flex-wrap:wrap;gap:2px;padding:8px 12px;background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-md);font-size:var(--font-size-sm)}.breadcrumb-item{padding:4px 8px;background:none;border:none;border-radius:var(--radius-sm);font-family:var(--font-family);font-size:var(--font-size-sm);color:var(--color-primary);cursor:pointer;transition:all var(--transition);display:inline-flex;align-items:center;gap:4px}.breadcrumb-item:hover{background:var(--color-white)}.breadcrumb-item.active{color:var(--color-text);font-weight:600;cursor:default}.breadcrumb-item.active:hover{background:none}.breadcrumb-segment{display:inline-flex;align-items:center}.breadcrumb-sep{color:var(--color-text-secondary);opacity:.5}.card-list-search{position:relative;max-width:400px}.card-list-search .search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);color:var(--color-text-secondary);pointer-events:none}.card-list-search .form-input{padding-left:36px}.folder-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:var(--space-3)}.folder-card{display:flex;flex-direction:column;gap:var(--space-2);padding:var(--space-4);background:var(--color-white);border:1px solid var(--color-border);border-radius:var(--radius-lg);cursor:pointer;transition:all var(--transition);box-shadow:var(--shadow-sm)}.folder-card:hover{border-color:var(--color-primary);box-shadow:var(--shadow-md);transform:translateY(-2px)}.folder-card-icon{color:var(--color-primary);opacity:.8}.folder-card-info{display:flex;flex-direction:column;gap:2px}.folder-card-name{font-size:var(--font-size-base);font-weight:600;color:var(--color-text)}.folder-card-count{font-size:var(--font-size-xs);color:var(--color-text-secondary)}.folder-card-progress{display:flex;align-items:center;gap:var(--space-2);margin-top:var(--space-1)}.folder-progress-bar{flex:1;height:4px;background:var(--color-border);border-radius:999px;overflow:hidden}.folder-progress-fill{height:100%;background:var(--color-success);border-radius:999px;transition:width .3s ease}.folder-progress-text{font-size:var(--font-size-xs);color:var(--color-text-secondary);white-space:nowrap}.folder-detail-header{display:flex;align-items:center;gap:var(--space-2);color:var(--color-primary)}.folder-detail-title{font-size:var(--font-size-lg);font-weight:600;color:var(--color-text)}.folder-detail-count{font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-left:auto}.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:var(--space-3)}.card-preview{position:relative;display:flex;flex-direction:column;gap:var(--space-2);padding:var(--space-3);background:var(--color-white);border:1px solid var(--color-border);border-radius:var(--radius-md);box-shadow:var(--shadow-sm);transition:all var(--transition)}.card-preview:hover{box-shadow:var(--shadow-md)}.card-preview.card-known{border-left:3px solid var(--color-success)}.card-preview.card-unknown{border-left:3px solid var(--color-danger)}.card-preview-status{position:absolute;top:12px;right:12px}.status-dot{display:inline-block;width:8px;height:8px;border-radius:50%}.status-known{background:var(--color-success)}.status-unknown{background:var(--color-danger)}.card-preview-question{font-size:var(--font-size-sm);font-weight:500;color:var(--color-text);line-height:1.5}.card-preview-answer{font-size:var(--font-size-xs);color:var(--color-text-secondary);line-height:1.4}.card-preview-footer{display:flex;align-items:center;justify-content:space-between;margin-top:auto;padding-top:var(--space-2);border-top:1px solid var(--color-border)}.card-preview-date{font-size:var(--font-size-xs);color:var(--color-text-secondary)}@media (max-width: 640px){.card-list-search{max-width:100%}.folder-grid,.card-grid{grid-template-columns:1fr}}.topic-card{cursor:default}.topic-card .folder-card-top{display:flex;flex-direction:column;gap:var(--space-2);cursor:pointer}.topic-move-btn{padding:4px 10px;background:none;border:1px solid var(--color-border);border-radius:var(--radius-md);font-family:var(--font-family);font-size:var(--font-size-xs);color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition);align-self:flex-start}.topic-move-btn:hover{background:var(--color-bg);color:var(--color-primary);border-color:var(--color-primary)}.move-folder-list{display:flex;flex-direction:column;gap:var(--space-2);margin:var(--space-3) 0}.move-folder-option{display:flex;align-items:center;gap:var(--space-2);width:100%;text-align:left;justify-content:flex-start}.move-new-folder{display:flex;gap:var(--space-2);align-items:center}.move-new-folder .form-input{flex:1;min-width:0}.move-folder-select-group{margin:var(--space-3) 0}.move-folder-select-group select,.move-folder-select-group .form-input{width:100%}.card-detail-modal{max-width:600px;width:90vw;max-height:80vh;overflow-y:auto;position:relative;padding:var(--space-5)}.card-detail-close{position:absolute;top:12px;right:16px;background:none;border:none;font-size:24px;color:var(--color-text-secondary);cursor:pointer;padding:4px 8px;border-radius:var(--radius-sm);line-height:1;transition:all var(--transition)}.card-detail-close:hover{color:var(--color-text);background:var(--color-bg-hover)}.card-detail-section{padding:var(--space-2) 0}.card-detail-label{font-size:var(--font-size-sm);font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-text-secondary);margin:0 0 var(--space-2) 0}.card-detail-text{font-size:var(--font-size-base);line-height:1.7;color:var(--color-text);margin:0;white-space:pre-wrap;word-break:break-word}.card-detail-divider{height:1px;background:var(--color-border);margin:var(--space-2) 0}.card-detail-footer{display:flex;justify-content:space-between;align-items:center;padding-top:var(--space-3);margin-top:var(--space-2);border-top:1px solid var(--color-border)}.card-detail-status{font-size:var(--font-size-sm);font-weight:500;padding:2px 10px;border-radius:var(--radius-full)}.card-detail-status.status-known{background:var(--color-success-bg, rgba(34, 197, 94, .1));color:var(--color-success, #22c55e)}.card-detail-status.status-unknown{background:var(--color-danger-bg, rgba(239, 68, 68, .1));color:var(--color-danger, #ef4444)}.card-preview-actions{display:flex;gap:4px}.create-folder-row{margin-top:var(--space-2)}.create-folder-btn{display:inline-flex;align-items:center;gap:6px}.create-folder-input{display:flex;gap:6px;align-items:center}.create-folder-input .form-input{flex:1;min-width:0;max-width:300px}.dashboard-tabs{display:flex;gap:var(--space-1);margin-bottom:var(--space-4);border-bottom:1px solid var(--color-border);padding-bottom:var(--space-1)}.dashboard-tab{display:inline-flex;align-items:center;gap:6px;padding:10px 18px;font-family:var(--font-family);font-size:var(--font-size-sm);font-weight:500;color:var(--color-text-secondary);background:none;border:none;border-bottom:2px solid transparent;cursor:pointer;transition:all var(--transition);border-radius:var(--radius-sm) var(--radius-sm) 0 0}.dashboard-tab:hover{color:var(--color-text);background:var(--color-bg)}.dashboard-tab.active{color:var(--color-primary);border-bottom-color:var(--color-primary)}.dashboard-content{min-height:300px}@media (max-width: 640px){.dashboard-tabs{overflow-x:auto;-webkit-overflow-scrolling:touch}.dashboard-tab{white-space:nowrap;padding:8px 14px;font-size:var(--font-size-xs)}}.flip-card{perspective:1000px;width:100%;max-width:560px;height:340px;margin:0 auto;cursor:pointer;outline:none}.flip-card:focus-visible{outline:2px solid var(--color-primary);outline-offset:4px;border-radius:var(--radius-lg)}.flip-card-inner{position:relative;width:100%;height:100%;transform-style:preserve-3d;transition:transform .6s cubic-bezier(.4,0,.2,1)}.flip-card.flipped .flip-card-inner{transform:rotateY(180deg)}.flip-card-front,.flip-card-back{position:absolute;top:0;right:0;bottom:0;left:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--space-5);border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);border:1px solid var(--color-border);text-align:center;gap:var(--space-3)}.flip-card-front{background:var(--color-white)}.flip-card-back{background:var(--color-primary-light);transform:rotateY(180deg)}.flip-card-badge{padding:4px 14px;font-size:var(--font-size-xs);font-weight:600;text-transform:uppercase;letter-spacing:.05em;border-radius:999px;background:var(--color-bg);color:var(--color-text-secondary)}.flip-card-badge-answer{background:var(--color-primary);color:var(--color-white)}.flip-card-text{font-size:var(--font-size-lg);line-height:1.6;color:var(--color-text);max-height:200px;overflow-y:auto;padding:0 var(--space-2)}.flip-card-answer-content{text-align:left;font-size:var(--font-size-sm);line-height:1.7}.flip-card-answer-content p{margin-bottom:.5em}.flip-card-answer-content p:last-child{margin-bottom:0}.flip-card-answer-content ul,.flip-card-answer-content ol{padding-left:1.2em;margin-bottom:.5em}.flip-card-answer-content li{margin-bottom:.2em}.flip-card-answer-content strong{font-weight:600}.flip-card-answer-content h1,.flip-card-answer-content h2,.flip-card-answer-content h3{font-size:var(--font-size-base);font-weight:600;margin-bottom:.3em}.flip-card-answer-content 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var(--transition)}.folder-back-btn:hover{background:var(--color-bg);color:var(--color-text)}.study-content{display:flex;flex-direction:column;gap:var(--space-5)}.study-progress{display:flex;flex-direction:column;gap:var(--space-2)}.study-progress-text{font-size:var(--font-size-sm);font-weight:500;color:var(--color-text-secondary);text-align:center}.study-flip-hint{text-align:center;font-size:var(--font-size-sm);color:var(--color-text-secondary);opacity:.7}.study-mark-buttons{display:flex;justify-content:center;gap:var(--space-4)}.study-btn{display:flex;align-items:center;gap:var(--space-2);padding:14px 28px;font-size:var(--font-size-base);font-weight:600;border-radius:var(--radius-lg);cursor:pointer;transition:all var(--transition);border:2px solid 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var(--transition)}.study-folder-card:hover{border-color:var(--color-primary);box-shadow:var(--shadow-sm)}.study-folder-card.selected{border-color:var(--color-primary);background:var(--color-primary-light)}.study-folder-check{flex-shrink:0}.study-checkbox{width:22px;height:22px;border:2px solid var(--color-border);border-radius:6px;display:flex;align-items:center;justify-content:center;transition:all 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#6366f11a}.documents-categories{display:flex;gap:4px;flex-wrap:wrap}.documents-cat-btn{display:inline-flex;align-items:center;gap:4px;padding:5px 12px;border:1px solid var(--color-border);border-radius:20px;background:var(--color-surface);color:var(--color-text-secondary);font-size:.78rem;font-family:var(--font-family);cursor:pointer;transition:all .2s}.documents-cat-btn:hover{border-color:var(--color-primary);color:var(--color-primary)}.documents-cat-btn.active{background:var(--color-primary);color:#fff;border-color:var(--color-primary)}.documents-empty{text-align:center;padding:var(--space-8) var(--space-4);color:var(--color-text-secondary)}.documents-empty-icon{opacity:.3;margin-bottom:var(--space-3)}.documents-empty h3{color:var(--color-text);font-size:1.1rem;margin:0 0 6px}.documents-empty p{font-size:var(--font-size-sm);margin:0 0 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span{font-size:var(--font-size-sm);color:var(--color-text-secondary);font-weight:500}.settings-save-bar .btn{display:inline-flex;align-items:center;gap:6px}@media (max-width: 768px){.settings-stats{grid-template-columns:repeat(2,1fr)}.settings-field{grid-template-columns:1fr;gap:4px}.settings-field-label{padding-top:0}.settings-header{flex-direction:column}}@media (max-width: 480px){.settings-stats{grid-template-columns:1fr}}@keyframes slideUp{0%{transform:translateY(100%);opacity:0}to{transform:translateY(0);opacity:1}}*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}:root{--color-white: #ffffff;--color-bg: #f5f5f7;--color-surface: #ffffff;--color-border: #e2e2e7;--color-text: #1d1d1f;--color-text-secondary: #6e6e73;--color-primary: #2563eb;--color-primary-hover: #1d4ed8;--color-primary-light: #eff6ff;--color-danger: #dc2626;--color-danger-hover: #b91c1c;--color-success: #16a34a;--color-warning: #f59e0b;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .04);--shadow-md: 0 4px 12px 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10px;font-size:var(--font-size-xs);font-weight:500;border-radius:999px;background:var(--color-primary-light);color:var(--color-primary)}.alert{padding:12px 16px;border-radius:var(--radius-md);font-size:var(--font-size-sm);font-weight:500}.alert-error{background:#fef2f2;color:var(--color-danger);border:1px solid #fecaca}.alert-success{background:#f0fdf4;color:var(--color-success);border:1px solid #bbf7d0}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0006;display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.modal{background:var(--color-white);border-radius:var(--radius-lg);padding:var(--space-4);max-width:400px;width:90%;box-shadow:var(--shadow-lg)}.modal-title{font-size:var(--font-size-lg);font-weight:600;margin-bottom:var(--space-2)}.modal-text{font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-bottom:var(--space-4);line-height:1.5}.modal-actions{display:flex;gap:var(--space-2);justify-content:flex-end}.progress-bar{width:100%;height:6px;background:var(--color-border);border-radius:999px;overflow:hidden}.progress-fill{height:100%;background:var(--color-primary);border-radius:999px;transition:width .3s ease}.empty-state{text-align:center;padding:var(--space-7) var(--space-4);color:var(--color-text-secondary)}.empty-state-icon{font-size:3rem;margin-bottom:var(--space-3);opacity:.4}.empty-state-title{font-size:var(--font-size-lg);font-weight:600;color:var(--color-text);margin-bottom:var(--space-2)}.empty-state-text{font-size:var(--font-size-sm);max-width:320px;margin:0 auto}.spinner{display:inline-block;width:20px;height:20px;border:2px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .6s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.loading-center{display:flex;align-items:center;justify-content:center;padding:var(--space-7)}@media (max-width: 640px){.container{padding:0 var(--space-3)}.page-title{font-size:var(--font-size-xl)}th,td{padding:8px 12px}.modal{width:95%;padding:var(--space-3)}.btn{padding:10px 16px}}[data-theme=dark]{--color-white: #1c1c1e;--color-bg: #0e0e10;--color-surface: #1c1c1e;--color-border: #38383a;--color-text: #f5f5f7;--color-text-secondary: #98989d;--color-primary: #4a90e2;--color-primary-hover: #5ba0f2;--color-primary-light: rgba(74, 144, 226, .12);--color-danger: #ff453a;--color-danger-hover: #ff6961;--color-success: #30d158;--color-warning: #ffd60a;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 12px rgba(0, 0, 0, .4);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .5);--shadow-card: 0 2px 8px rgba(0, 0, 0, .3)}[data-theme=dark] .navbar{background:#1c1c1eeb}[data-theme=dark] .study-btn-known{background:#30d1581f;border-color:#30d1584d}[data-theme=dark] .study-btn-unknown{background:#ff453a1f;border-color:#ff453a4d}[data-theme=dark] .summary-stat-known{background:#30d1581f}[data-theme=dark] .summary-stat-unknown{background:#ff453a1f}[data-theme=dark] .alert-error{background:#ff453a1f;border-color:#ff453a4d}[data-theme=dark] .alert-success{background:#30d1581f;border-color:#30d1584d}