:root{font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#ffffffde;background-color:#242424;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{font-weight:500;color:#646cff;text-decoration:inherit}a:hover{color:#535bf2}body{margin:0;display:flex;place-items:center;min-width:320px;min-height:100vh}h1{font-size:3.2em;line-height:1.1}button{border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;background-color:#1a1a1a;cursor:pointer;transition:border-color .25s}button:hover{border-color:#646cff}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}@media (prefers-color-scheme: light){:root{color:#213547;background-color:#fff}a:hover{color:#747bff}button{background-color:#f9f9f9}}:root{--color-primary: #2563eb;--color-primary-hover: #1d4ed8;--color-secondary: #64748b;--color-success: #10b981;--color-warning: #f59e0b;--color-error: #ef4444;--color-bg: #ffffff;--color-bg-secondary: #f8fafc;--color-bg-tertiary: #f1f5f9;--color-border: #e2e8f0;--color-text: #0f172a;--color-text-secondary: #475569;--color-text-muted: #94a3b8;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .1);--shadow-xl: 0 20px 25px -5px rgb(0 0 0 / .1);--radius-sm: .375rem;--radius-md: .5rem;--radius-lg: .75rem;--radius-xl: 1rem;--spacing-unit: 8px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;color:var(--color-text);background-color:var(--color-bg-secondary);line-height:1.6}.app{min-height:100vh;display:flex;flex-direction:column}.header{background:linear-gradient(135deg,#1e40af,#3b82f6);color:#fff;padding:calc(var(--spacing-unit) * 6) calc(var(--spacing-unit) * 4);box-shadow:var(--shadow-lg)}.header-content{max-width:1200px;margin:0 auto}.header-title h1{font-size:2.5rem;font-weight:700;margin-bottom:calc(var(--spacing-unit) * 1.5);line-height:1.2}.header-subtitle{font-size:1.125rem;opacity:.95;margin-bottom:calc(var(--spacing-unit) * 4)}.header-description{background:#ffffff1a;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 3);margin-bottom:calc(var(--spacing-unit) * 4);line-height:1.7;max-width:900px}.header-description p{margin-bottom:calc(var(--spacing-unit) * 2)}.header-description p:last-of-type{margin-bottom:calc(var(--spacing-unit) * 3)}.header-links{display:flex;align-items:center;gap:calc(var(--spacing-unit) * 2);flex-wrap:wrap}.header-links a{color:#fff;text-decoration:none;font-weight:500;transition:opacity .2s}.header-links a:hover{opacity:.8}.header-stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:calc(var(--spacing-unit) * 3);margin-top:calc(var(--spacing-unit) * 4)}.stat{text-align:center;background:#ffffff26;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 3)}.stat-value{font-size:2.5rem;font-weight:700;line-height:1}.stat-label{font-size:.875rem;opacity:.9;margin-top:calc(var(--spacing-unit) * 1)}.tabs{background:var(--color-bg);border-bottom:1px solid var(--color-border);padding:0 calc(var(--spacing-unit) * 4);display:flex;gap:calc(var(--spacing-unit) * 1);overflow-x:auto;position:sticky;top:0;z-index:10;box-shadow:var(--shadow-sm)}.tab{background:none;border:none;padding:calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);font-size:1rem;font-weight:500;color:var(--color-text-secondary);cursor:pointer;border-bottom:2px solid transparent;transition:all .2s;white-space:nowrap;display:flex;align-items:center;gap:calc(var(--spacing-unit) * 1)}.tab:focus-visible,.btn:focus-visible,.presenter-link:focus-visible,.header-links a:focus-visible{outline:3px solid var(--color-primary);outline-offset:2px;border-radius:var(--radius-sm)}.tab:hover{color:var(--color-primary);background-color:var(--color-bg-secondary)}.tab.active{color:var(--color-primary);border-bottom-color:var(--color-primary)}.tab-icon{font-size:1.25rem}.share-hint{color:var(--color-text-secondary);font-size:.875rem;margin-left:calc(var(--spacing-unit) * 2);align-self:center}.main-content{flex:1;max-width:1200px;width:100%;margin:0 auto;padding:calc(var(--spacing-unit) * 4)}.section-header{margin-bottom:calc(var(--spacing-unit) * 4)}.section-header h2{font-size:1.875rem;font-weight:700;color:var(--color-text);margin-bottom:calc(var(--spacing-unit) * 1)}.section-header p{color:var(--color-text-secondary);font-size:1.125rem}.search-bar{margin-bottom:calc(var(--spacing-unit) * 3)}.search-input{width:100%;padding:calc(var(--spacing-unit) * 2);font-size:1rem;border:2px solid var(--color-border);border-radius:var(--radius-lg);outline:none;transition:all .2s}.search-input:focus{border-color:var(--color-primary);box-shadow:0 0 0 3px #2563eb1a}.results-count{margin-bottom:calc(var(--spacing-unit) * 3);color:var(--color-text-secondary);font-size:.875rem}.controls-row{display:flex;gap:calc(var(--spacing-unit) * 2);align-items:center;margin-bottom:calc(var(--spacing-unit) * 2)}.sort-control select{padding:8px 10px;border-radius:var(--radius-md);border:1px solid var(--color-border);background:var(--color-bg)}mark{background:#fef08a;padding:0 2px;border-radius:2px}.videos-grid{display:grid;gap:calc(var(--spacing-unit) * 3);grid-template-columns:repeat(auto-fill,minmax(320px,1fr))}.video-card{background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden;transition:all .2s}.video-card:hover{box-shadow:var(--shadow-md);border-color:var(--color-primary)}.video-card-header{display:flex;justify-content:space-between;align-items:flex-start;padding:calc(var(--spacing-unit) * 3);cursor:pointer;gap:calc(var(--spacing-unit) * 2)}.video-card-header h3{font-size:1.25rem;font-weight:600;color:var(--color-text);line-height:1.4;flex:1}.expand-btn{background:var(--color-bg-secondary);border:1px solid var(--color-border);border-radius:var(--radius-md);width:32px;height:32px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;cursor:pointer;transition:all 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.2s}.presenter-link:hover{color:var(--color-primary-hover);text-decoration:underline}.affiliation{color:var(--color-text-muted);font-size:.875rem}.summary{background:var(--color-bg-secondary);border-left:4px solid var(--color-primary);padding:calc(var(--spacing-unit) * 2);border-radius:var(--radius-md);margin-bottom:calc(var(--spacing-unit) * 3)}.summary strong{display:block;margin-bottom:calc(var(--spacing-unit) * 1);color:var(--color-text)}.summary p{color:var(--color-text-secondary);line-height:1.7;margin-bottom:calc(var(--spacing-unit) * 1)}.summary-note{display:block;font-size:.75rem;color:var(--color-text-muted);font-style:italic}.video-actions{display:flex;gap:calc(var(--spacing-unit) * 2);flex-wrap:wrap}.btn{padding:calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 3);font-size:.875rem;font-weight:500;border-radius:var(--radius-md);cursor:pointer;transition:all .2s;text-decoration:none;display:inline-flex;align-items:center;gap:calc(var(--spacing-unit) * 1);border:none;min-height:44px}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--color-primary-hover);transform:translateY(-1px);box-shadow:var(--shadow-md)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{background:var(--color-bg-secondary);color:var(--color-text);border:1px solid var(--color-border)}.btn-secondary:hover{background:var(--color-bg-tertiary);border-color:var(--color-text-muted)}.no-results{text-align:center;padding:calc(var(--spacing-unit) * 8);color:var(--color-text-secondary)}.no-results p{margin-bottom:calc(var(--spacing-unit) * 2)}.chat-header{display:flex;justify-content:space-between;align-items:flex-start;gap:calc(var(--spacing-unit) * 3);margin-bottom:calc(var(--spacing-unit) * 3);padding-bottom:calc(var(--spacing-unit) * 3);border-bottom:1px solid var(--color-border)}.chat-header h2{font-size:1.5rem;font-weight:600;color:var(--color-text);margin-bottom:calc(var(--spacing-unit) * 1)}.chat-meta{display:flex;align-items:center;gap:calc(var(--spacing-unit) * 2);color:var(--color-text-secondary);font-size:.875rem;flex-wrap:wrap}.chat-meta a{color:var(--color-primary);text-decoration:none}.chat-meta a:hover{text-decoration:underline}.chat-container{display:flex;flex-direction:column;height:calc(100vh - 400px);min-height:500px;background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden}.chat-messages{flex:1;overflow-y:auto;padding:calc(var(--spacing-unit) * 3);display:flex;flex-direction:column;gap:calc(var(--spacing-unit) * 2)}.chat-message{display:flex;max-width:80%;animation:fadeIn .3s ease-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.chat-message.user{align-self:flex-end}.chat-message.assistant{align-self:flex-start}.message-content{padding:calc(var(--spacing-unit) * 2);border-radius:var(--radius-lg);line-height:1.6}.chat-message.user .message-content{background:var(--color-primary);color:#fff;border-bottom-right-radius:var(--radius-sm)}.chat-message.assistant .message-content{background:var(--color-bg-secondary);color:var(--color-text);border-bottom-left-radius:var(--radius-sm);border:1px solid var(--color-border)}.message-content p{margin-bottom:calc(var(--spacing-unit) * 1.5)}.message-content p:last-child{margin-bottom:0}.message-content strong{font-weight:600}.message-content em{font-style:italic}.message-content code{background:#00000014;padding:2px 6px;border-radius:var(--radius-sm);font-family:Courier New,monospace;font-size:.9em}.chat-message.user .message-content code{background:#fff3}.message-content pre{background:#0000000d;padding:calc(var(--spacing-unit) * 2);border-radius:var(--radius-md);overflow-x:auto;margin:calc(var(--spacing-unit) * 1.5) 0}.message-content pre code{background:none;padding:0}.message-content ul,.message-content ol{margin:calc(var(--spacing-unit) * 1.5) 0;padding-left:calc(var(--spacing-unit) * 3)}.message-content li{margin-bottom:calc(var(--spacing-unit) * .5)}.message-content blockquote{border-left:3px solid var(--color-primary);padding-left:calc(var(--spacing-unit) * 2);margin:calc(var(--spacing-unit) * 1.5) 0;color:var(--color-text-secondary);font-style:italic}.message-content a{color:var(--color-primary);text-decoration:underline}.message-content a:hover{color:var(--color-primary-hover)}.chat-message.user .message-content a{color:#fff;text-decoration:underline}.message-content h1,.message-content h2,.message-content h3{font-weight:600;margin-top:calc(var(--spacing-unit) * 2);margin-bottom:calc(var(--spacing-unit) * 1)}.message-content h1{font-size:1.5rem}.message-content h2{font-size:1.25rem}.message-content h3{font-size:1.1rem}.chat-input-form{display:flex;gap:calc(var(--spacing-unit) * 2);padding:calc(var(--spacing-unit) * 3);border-top:1px solid var(--color-border);background:var(--color-bg-secondary)}.chat-input{flex:1;padding:calc(var(--spacing-unit) * 2);font-size:1rem;border:2px solid var(--color-border);border-radius:var(--radius-md);outline:none;transition:all .2s}.chat-input:focus{border-color:var(--color-primary)}.video-selector{background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 4)}.video-selector h3{font-size:1.25rem;font-weight:600;margin-bottom:calc(var(--spacing-unit) * 3)}.video-list{display:grid;gap:calc(var(--spacing-unit) * 2);grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}.video-select-btn{width:100%;padding:calc(var(--spacing-unit) * 3);background:var(--color-bg-secondary);border:2px solid var(--color-border);border-radius:var(--radius-md);cursor:pointer;text-align:left;transition:all .2s;display:flex;flex-direction:column;gap:calc(var(--spacing-unit) * 1)}.video-select-btn:hover{border-color:var(--color-primary);background:var(--color-bg);transform:translate(4px)}.video-select-title{font-weight:600;color:var(--color-text);font-size:1rem}.video-select-meta{font-size:.875rem;color:var(--color-text-secondary)}.suggestions{background:var(--color-bg-secondary);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 4)}.suggestions h3{font-size:1.125rem;font-weight:600;margin-bottom:calc(var(--spacing-unit) * 2);color:var(--color-text)}.suggestions ul{list-style:none;display:flex;flex-direction:column;gap:calc(var(--spacing-unit) * 1.5)}.suggestion-btn{background:var(--color-bg);border:1px solid var(--color-border);padding:calc(var(--spacing-unit) * 2);border-radius:var(--radius-md);cursor:pointer;text-align:left;transition:all .2s;color:var(--color-text-secondary);font-size:.9375rem}.suggestion-btn:hover{border-color:var(--color-primary);color:var(--color-primary);transform:translate(4px)}.available-videos{margin-top:calc(var(--spacing-unit) * 4);background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 3)}.available-videos summary{cursor:pointer;font-weight:600;color:var(--color-text);padding:calc(var(--spacing-unit) * 1);transition:color .2s}.available-videos summary:hover{color:var(--color-primary)}.available-videos ul{margin-top:calc(var(--spacing-unit) * 2);padding-left:calc(var(--spacing-unit) * 3)}.available-videos li{padding:calc(var(--spacing-unit) * 1) 0;color:var(--color-text-secondary)}.available-videos a{color:var(--color-primary);text-decoration:none}.available-videos a:hover{text-decoration:underline}.presenters-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:calc(var(--spacing-unit) * 3)}.presenter-card{background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:calc(var(--spacing-unit) * 3);transition:all .2s}.presenter-card:hover{box-shadow:var(--shadow-md);transform:translateY(-2px);border-color:var(--color-primary)}.presenter-header{display:flex;justify-content:space-between;align-items:flex-start;gap:calc(var(--spacing-unit) * 2);margin-bottom:calc(var(--spacing-unit) * 1)}.presenter-header h3{font-size:1.125rem;font-weight:600;color:var(--color-text);line-height:1.3}.scholar-link{font-size:1.25rem;text-decoration:none;transition:transform .2s}.scholar-link:hover{transform:scale(1.2)}.presenter-card .affiliation{display:block;margin-bottom:calc(var(--spacing-unit) * 2)}.presenter-meta{padding-top:calc(var(--spacing-unit) * 2);border-top:1px solid var(--color-border)}.video-count{font-size:.875rem;color:var(--color-text-secondary);font-weight:500}.footer{background:var(--color-bg);border-top:1px solid var(--color-border);padding:calc(var(--spacing-unit) * 4);margin-top:auto}.footer-content{max-width:1200px;margin:0 auto;display:flex;justify-content:center;align-items:center;gap:calc(var(--spacing-unit) * 4);flex-wrap:wrap;color:var(--color-text-secondary);font-size:.875rem}.loading-container,.error-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:60vh;gap:calc(var(--spacing-unit) * 3)}.loading-spinner{width:48px;height:48px;border:4px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}@media (max-width: 768px){.header-title h1{font-size:1.875rem}.header-subtitle{font-size:1rem}.tabs{padding:0 calc(var(--spacing-unit) * 2)}.tab{padding:calc(var(--spacing-unit) * 2);font-size:.875rem}.main-content{padding:calc(var(--spacing-unit) * 2)}.chat-container{height:calc(100vh - 350px)}.chat-message{max-width:90%}.video-actions{flex-direction:column}.video-actions .btn{width:100%;justify-content:center}.footer-content{flex-direction:column;gap:calc(var(--spacing-unit) * 2);text-align:center}.presenters-grid{grid-template-columns:1fr}}@media (prefers-reduced-motion: reduce){*{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}}.tabs-spacer{flex:1}.search-bar{position:relative}.search-clear{position:absolute;right:12px;top:50%;transform:translateY(-50%);background:transparent;border:none;font-size:1.25rem;color:var(--color-text-secondary);cursor:pointer}.typing{color:var(--color-text-secondary)}