:root{--color-primary: #2563eb;--color-primary-hover: #1d4ed8;--color-secondary: #64748b;--color-background: #f8fafc;--color-surface: #ffffff;--color-text-main: #0f172a;--color-text-muted: #64748b;--color-border: #e2e8f0;--color-danger: #ef4444;--color-success: #22c55e;--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 16px;--spacing-lg: 24px;--spacing-xl: 32px;--radius-sm: 4px;--radius-md: 8px;--radius-lg: 12px;--font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif}*{box-sizing:border-box}body{margin:0;padding:0;font-family:var(--font-family);background-color:var(--color-background);color:var(--color-text-main);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}h1,h2,h3,h4,h5,h6{margin:0;font-weight:600}button{font-family:inherit}a{text-decoration:none;color:inherit}ul,ol{margin:0;padding:0;list-style:none}.layout{min-height:100vh;display:flex;flex-direction:column}.layout-nav{height:64px;background-color:var(--color-surface);border-bottom:1px solid var(--color-border);display:flex;align-items:center;padding:0 var(--spacing-lg);position:sticky;top:0;z-index:10}.layout-logo{font-size:1.25rem;font-weight:700;color:var(--color-primary);display:flex;align-items:center;gap:8px}.layout-main{flex:1;background-color:var(--color-background)}.btn{display:inline-flex;align-items:center;justify-content:center;border:1px solid transparent;padding:var(--spacing-sm) var(--spacing-md);font-size:1rem;font-weight:500;border-radius:var(--radius-md);cursor:pointer;transition:all .2s ease;gap:var(--spacing-sm);background-color:transparent}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-primary{background-color:var(--color-primary);color:#fff;border-color:var(--color-primary)}.btn-primary:hover:not(:disabled){background-color:var(--color-primary-hover);border-color:var(--color-primary-hover)}.btn-secondary{background-color:#fff;color:var(--color-text-main);border-color:var(--color-border)}.btn-secondary:hover:not(:disabled){background-color:var(--color-background);border-color:var(--color-text-muted)}.btn-danger{background-color:transparent;color:var(--color-danger);border-color:var(--color-danger)}.btn-danger:hover:not(:disabled){background-color:var(--color-danger);color:#fff}.btn-ghost{color:var(--color-text-muted)}.btn-ghost:hover:not(:disabled){background-color:var(--color-background);color:var(--color-text-main)}.btn-sm{padding:var(--spacing-xs) var(--spacing-sm);font-size:.875rem}.btn-lg{padding:var(--spacing-md) var(--spacing-lg);font-size:1.125rem}.btn-full{width:100%}.card{background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);box-shadow:0 1px 3px #0000001a,0 1px 2px -1px #0000001a;overflow:hidden;transition:box-shadow .2s ease,border-color .2s ease}.card-padding-sm{padding:var(--spacing-sm)}.card-padding-md{padding:var(--spacing-md)}.card-padding-lg{padding:var(--spacing-lg)}.card-interactive:hover{cursor:pointer;box-shadow:0 4px 6px -1px #0000001a,0 2px 4px -2px #0000001a;border-color:var(--color-primary)}.card-selected{border-color:var(--color-primary);box-shadow:0 0 0 2px var(--color-primary-hover)}.modal-overlay{position:fixed;inset:0;background-color:#00000080;display:flex;align-items:center;justify-content:center;z-index:50;padding:var(--spacing-md)}.modal-content{background-color:var(--color-surface);border-radius:var(--radius-lg);box-shadow:0 20px 25px -5px #0000001a,0 8px 10px -6px #0000001a;width:100%;max-width:600px;max-height:90vh;display:flex;flex-direction:column;animation:modal-in .2s ease-out}@keyframes modal-in{0%{opacity:0;transform:scale(.95)}to{opacity:1;transform:scale(1)}}.modal-header{padding:var(--spacing-lg);border-bottom:1px solid var(--color-border);display:flex;align-items:center;justify-content:space-between}.modal-title{font-size:1.25rem;font-weight:600;color:var(--color-text-main)}.modal-body{padding:var(--spacing-lg);overflow-y:auto}.modal-footer{padding:var(--spacing-lg);border-top:1px solid var(--color-border);display:flex;justify-content:flex-end;gap:var(--spacing-sm)}.modal-close-btn{background:none;border:none;cursor:pointer;color:var(--color-text-muted);padding:4px;border-radius:4px}.modal-close-btn:hover{background-color:var(--color-background);color:var(--color-text-main)}.tag{display:inline-flex;align-items:center;padding:2px 8px;border-radius:9999px;font-size:.75rem;font-weight:500;line-height:1.25rem;white-space:nowrap}.tag-default{background-color:#f1f5f9;color:#475569}.tag-primary{background-color:#eff6ff;color:#1d4ed8}.tag-success{background-color:#f0fdf4;color:#15803d}.tag-warning{background-color:#fefce8;color:#854d0e}.tag-danger{background-color:#fef2f2;color:#b91c1c}.dashboard{padding:var(--spacing-lg);max-width:800px;margin:0 auto}.dashboard-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:var(--spacing-xl)}.dashboard-empty{text-align:center;padding:var(--spacing-xl);color:var(--color-text-muted)}.session-list{display:flex;flex-direction:column;gap:var(--spacing-md)}.session-list-item{display:flex;justify-content:space-between;align-items:center;text-decoration:none;color:inherit}.session-list-item:hover{border-color:var(--color-primary)}.session-info h3{font-size:1.125rem;margin-bottom:var(--spacing-xs)}.session-meta{display:flex;gap:var(--spacing-md);font-size:.875rem;color:var(--color-text-muted);margin-bottom:var(--spacing-sm)}.session-tags{display:flex;flex-wrap:wrap;gap:var(--spacing-xs)}.slot-item{display:flex;gap:var(--spacing-sm);margin-bottom:var(--spacing-md);align-items:stretch}.slot-controls{display:flex;flex-direction:column;width:90px;gap:8px;align-items:center;background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:8px}.slot-time-display{font-size:.75rem;font-weight:600;color:var(--color-text-muted)}.slot-duration-display{font-size:.875rem;font-weight:600;color:var(--color-text-main);padding:4px;background:#f1f5f9;border-radius:4px;width:100%;text-align:center}.slot-reorder{display:flex;gap:4px;margin-top:auto}.slot-content{flex:1;display:flex;gap:var(--spacing-sm);background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:var(--spacing-sm)}.slot-group{flex:1;display:flex;flex-direction:column;border:1px dashed var(--color-border);border-radius:var(--radius-sm);position:relative;background-color:var(--color-background)}.slot-group.filled{border-style:solid;background-color:var(--color-surface);overflow:hidden}.slot-group-header{display:flex;justify-content:space-between;align-items:center;padding:4px 8px;background-color:#f1f5f9;border-bottom:1px solid var(--color-border)}.slot-group-label-input{font-size:.75rem;font-weight:600;text-transform:uppercase;border:1px solid transparent;background:transparent;color:var(--color-text-main);width:100px;padding:2px 4px;border-radius:4px}.slot-group-label-input:focus{outline:none;border-color:var(--color-primary);background-color:#fff}.slot-group-remove{background:none;border:none;color:#ef4444;cursor:pointer;font-size:1.2rem;line-height:1;padding:0 4px}.slot-group-body{flex:1;cursor:pointer;display:flex;flex-direction:column;justify-content:center;min-height:80px}.slot-group-body:hover{background-color:#f8fafc}.slot-placeholder{color:var(--color-text-muted);font-size:.875rem;display:flex;flex-direction:column;align-items:center;gap:4px;padding:8px}.slot-actions{display:flex;flex-direction:column;gap:var(--spacing-xs);justify-content:center}.slot-exercise-preview{display:flex;flex-direction:row;align-items:center;width:100%;height:100%;padding:var(--spacing-sm);text-align:left}.slot-exercise-img{width:60px;height:60px;object-fit:cover;border-radius:var(--radius-sm);margin-right:var(--spacing-sm)}.exercise-card{display:flex;flex-direction:column;height:100%;min-height:250px}.exercise-card-image{width:100%;height:150px;object-fit:cover;border-radius:var(--radius-md) var(--radius-md) 0 0;background-color:var(--color-background)}.exercise-card-content{flex:1;display:flex;flex-direction:column;gap:var(--spacing-sm)}.exercise-card-title{font-size:1.125rem;font-weight:600;margin-bottom:var(--spacing-xs)}.exercise-card-description{font-size:.875rem;color:var(--color-text-muted);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:var(--spacing-sm)}.exercise-card-tags{display:flex;flex-wrap:wrap;gap:var(--spacing-xs);margin-top:auto}.exercise-card-meta{display:flex;align-items:center;gap:var(--spacing-md);font-size:.75rem;color:var(--color-text-muted);margin-top:var(--spacing-sm)}.exercise-card-meta-item{display:flex;align-items:center;gap:4px}.exercise-detail{padding:var(--spacing-lg)}.exercise-detail-header{margin-bottom:var(--spacing-lg)}.exercise-detail-title{font-size:1.5rem;font-weight:700;margin-bottom:var(--spacing-sm)}.exercise-detail-meta{display:flex;gap:var(--spacing-lg);color:var(--color-text-muted);margin-bottom:var(--spacing-md)}.exercise-detail-meta-item{display:flex;align-items:center;gap:8px}.exercise-detail-tags{display:flex;flex-wrap:wrap;gap:var(--spacing-sm)}.exercise-detail-content{line-height:1.6}.exercise-detail-content iframe{max-width:100%;aspect-ratio:16 / 9;height:auto;border-radius:var(--radius-md);margin:var(--spacing-md) 0}.exercise-detail-content img{max-width:100%;border-radius:var(--radius-md);margin:var(--spacing-md) 0}.exercise-detail-content h1,.exercise-detail-content h2,.exercise-detail-content h3{margin-top:var(--spacing-lg);margin-bottom:var(--spacing-sm)}.exercise-detail-content ul,.exercise-detail-content ol{margin-left:var(--spacing-lg);margin-bottom:var(--spacing-md)}.exercise-picker{display:flex;flex-direction:column;height:70vh}.picker-filters{display:flex;gap:var(--spacing-lg);margin-bottom:var(--spacing-lg);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--color-border)}.filter-group{display:flex;flex-direction:column;gap:var(--spacing-xs)}.filter-group label{font-size:.875rem;font-weight:500;color:var(--color-text-muted)}.filter-select{padding:var(--spacing-sm);border:1px solid var(--color-border);border-radius:var(--radius-sm);background-color:var(--color-surface);font-family:inherit;color:var(--color-text-main)}.picker-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:var(--spacing-md);overflow-y:auto;padding-bottom:var(--spacing-lg)}.picker-empty{display:flex;align-items:center;justify-content:center;height:100%;color:var(--color-text-muted);font-style:italic}.session-timeline,.timeline-slots{display:flex;flex-direction:column}.timeline-total{padding:var(--spacing-md);text-align:right;font-weight:600;color:var(--color-text-main);border-top:2px solid var(--color-border);margin-top:var(--spacing-sm)}.timeline-empty{padding:var(--spacing-xl);text-align:center;color:var(--color-text-muted);border:2px dashed var(--color-border);border-radius:var(--radius-md);margin-bottom:var(--spacing-lg)}.session-builder{padding:var(--spacing-lg);max-width:900px;margin:0 auto}.builder-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:var(--spacing-xl);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--color-border)}.builder-settings{display:flex;align-items:center;gap:12px}.builder-name-input{font-size:1.5rem;font-weight:600;border:none;background:transparent;border-bottom:2px solid transparent;padding:4px;color:var(--color-text-main);width:300px}.builder-name-input:focus{outline:none;border-bottom-color:var(--color-primary)}.builder-age-select{font-size:1rem;padding:8px 12px;border-radius:var(--radius-md);border:1px solid var(--color-border);background-color:var(--color-surface)}.builder-content{background-color:var(--color-surface);border-radius:var(--radius-lg);padding:var(--spacing-lg);box-shadow:0 1px 3px #0000001a}.session-viewer{padding:var(--spacing-lg);max-width:900px;margin:0 auto}.viewer-header{display:flex;align-items:flex-start;justify-content:space-between;margin-bottom:var(--spacing-xl);padding-bottom:var(--spacing-md);border-bottom:1px solid var(--color-border)}.viewer-title{text-align:center}.viewer-meta{color:var(--color-text-muted);margin-top:var(--spacing-xs)}.viewer-timeline{display:flex;flex-direction:column;gap:var(--spacing-xl)}.viewer-slot{display:flex;gap:var(--spacing-lg);align-items:flex-start}.viewer-slot-time{width:80px;flex-shrink:0;display:flex;flex-direction:column;align-items:center;justify-content:center;background-color:var(--color-primary);color:#fff;padding:var(--spacing-sm);border-radius:var(--radius-md);font-weight:600;text-align:center;font-size:.9rem}.viewer-slot-activities{flex:1;display:flex;flex-direction:column;gap:var(--spacing-md)}.viewer-activity{background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden}.viewer-group-label{background-color:var(--color-background);padding:var(--spacing-sm) var(--spacing-lg);font-weight:600;border-bottom:1px solid var(--color-border)}.viewer-empty-slot{padding:var(--spacing-xl);text-align:center;color:var(--color-text-muted);font-style:italic}.viewer-activity-header{padding:var(--spacing-md);cursor:pointer;display:flex;justify-content:space-between;align-items:center;background-color:var(--color-surface)}.viewer-activity-header:hover{background-color:var(--color-background)}.viewer-thumb{width:60px;height:40px;object-fit:cover;border-radius:4px}.viewer-activity-title{font-weight:600;font-size:1.1rem}.viewer-activity-tags{font-size:.8rem;color:var(--color-text-muted)}