:root{--bg:#0A0F1C;--card-bg:#151B2E;--gradient1:linear-gradient(45deg, #FF3CAC 0%, #784BA0 50%, #2B86C5 100%);--gradient2:linear-gradient(45deg, #FA8BFF 0%, #2BD2FF 50%, #2BFF88 100%);--text:#FFFFFF;--text-secondary:rgba(255, 255, 255, 0.8);--nav-bg:rgba(21, 27, 46, 0.98);--border-color:rgba(255, 255, 255, 0.15);--button-bg:rgba(255, 255, 255, 0.15);--button-hover:rgba(255, 255, 255, 0.25);--button-shadow:0 5px 15px rgba(0, 0, 0, 0.2);--button-text:#FFFFFF;--input-bg:rgba(255, 255, 255, 0.08);--placeholder-color:rgba(255, 255, 255, 0.6);--result-item-bg:rgba(255, 255, 255, 0.08);--result-item-hover:rgba(255, 255, 255, 0.15);--result-item-active:rgba(255, 255, 255, 0.2);--selected-bg:#4a6bc0;--selected-border:#FF3CAC;--focus-color:#4A90D9}[data-theme=light]{--bg:#e8ecf0;--card-bg:#ffffff;--text:#1a202c;--text-secondary:#4a5568;--nav-bg:rgba(255, 255, 255, 0.98);--border-color:rgba(0, 0, 0, 0.12);--button-bg:#2c4a8c;--button-hover:#3a5db1;--button-shadow:0 4px 12px rgba(44, 74, 140, 0.25);--button-text:#ffffff;--yt-color:#FF0000;--yt-hover:#CC0000;--input-bg:#ffffff;--placeholder-color:#718096;--result-item-bg:#e2e8f0;--result-item-hover:#cbd5e0;--result-item-active:#a0aec0;--selected-bg:#2c4a8c;--selected-border:#784BA0;--focus-color:#2563eb}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Heebo,sans-serif;background:var(--bg);color:var(--text);min-height:100vh;line-height:1.6;transition:background-color .3s}nav{background:var(--nav-bg);backdrop-filter:blur(10px);width:100%;z-index:100;padding:1rem 2rem;border-bottom:1px solid var(--border-color);transition:background-color .3s,border-color .3s}.nav-content{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;height:64px}.nav-logo{font-size:1.5rem;font-weight:700;background:var(--gradient1);-webkit-background-clip:text;-webkit-text-fill-color:transparent;text-decoration:none;display:flex;align-items:center}.nav-logo-image{width:50px;height:50px;object-fit:contain}.nav-links{display:flex;gap:2rem;align-items:center}.nav-links a{color:var(--text);text-decoration:none;transition:color .3s;font-weight:500}.nav-links a:hover{color:var(--text)}.nav-links a.active{font-weight:700;position:relative}.nav-links a.active::after{content:'';position:absolute;bottom:-8px;left:0;right:0;height:3px;background:var(--gradient1);border-radius:3px}.theme-toggle{background:var(--button-bg);border:1px solid 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.3s}.nav-links.active{max-height:600px;opacity:1;padding:1rem;overflow-y:auto}.nav-links a{padding:12px 8px;width:100%;text-align:right;border-bottom:1px solid var(--border-color)}.nav-links a:last-of-type{border-bottom:none}.nav-links a.active::after{display:none}.theme-toggle{width:40px!important;height:40px!important;min-width:40px!important;min-height:40px!important;max-width:40px!important;max-height:40px!important;border-radius:50%!important;padding:0!important;margin:1rem 0!important;align-self:flex-start;flex-shrink:0}}.container{max-width:1200px;margin:0 auto;padding:2rem}header{text-align:center;padding:1rem 0 2rem;position:relative;max-width:800px;margin:0 auto}.title{font-size:3rem;font-weight:700;background:var(--gradient1);-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:1rem;line-height:1.2}.subtitle{font-size:1.2rem;color:var(--text-secondary);margin-bottom:1.5rem;font-weight:500;transition:color .3s}.search-container{margin-bottom:1.5rem;position:relative}.search-input{width:100%;padding:1rem 1.5rem;border-radius:12px;border:1px solid var(--border-color);background:var(--input-bg);color:var(--text);font-size:1.1rem;font-family:Heebo,sans-serif;transition:.3s}.search-input::placeholder{color:var(--placeholder-color)}.search-input:focus{outline:0;box-shadow:0 0 0 3px rgba(120,75,160,.2);border-color:rgba(120,75,160,.5)}.search-examples{margin-top:.5rem;font-size:.9rem;color:var(--text-secondary)}.topics-row{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:.5rem;margin-bottom:1rem;justify-content:center}.topic-tag{background:var(--button-bg);color:var(--button-text);border-radius:20px;padding:.5rem 1rem;font-size:.9rem;cursor:pointer;transition:.2s;border:1px solid var(--border-color);font-family:Heebo,sans-serif}.topic-tag.active{background:var(--selected-bg);border:2px solid var(--selected-border);font-weight:700;box-shadow:0 0 10px rgba(120,75,160,.5)}.topic-tag:hover{background:var(--button-hover);transform:translateY(-2px)}.videos-list-container{margin-top:2rem}.videos-list-title{font-size:1.8rem;font-weight:700;margin-bottom:1.5rem;background:var(--gradient1);-webkit-background-clip:text;-webkit-text-fill-color:transparent;position:relative;display:inline-block;padding-bottom:.25rem}.videos-list-title::after{content:'';position:absolute;left:0;right:0;bottom:0;height:3px;background:var(--gradient1);border-radius:3px}.videos-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1.5rem}.video-card{background:var(--card-bg);border-radius:12px;overflow:hidden;box-shadow:0 5px 15px rgba(0,0,0,.1);transition:transform .3s,box-shadow .3s;border:1px solid var(--border-color);height:100%;display:flex;flex-direction:column}.video-card:hover{transform:translateY(-5px);box-shadow:0 8px 25px rgba(0,0,0,.15)}.video-thumbnail{width:100%;aspect-ratio:16/9;background:#111;position:relative;overflow:hidden;display:flex;align-items:center;justify-content:center}.video-thumbnail::before{content:'▶';position:absolute;width:60px;height:60px;background:rgba(255,0,0,.8);border-radius:50%;color:#fff;display:flex;align-items:center;justify-content:center;font-size:1.5rem;opacity:0;transition:opacity .3s;z-index:2}.video-card:hover .video-thumbnail::before{opacity:1}.video-thumbnail img{width:100%;height:100%;object-fit:cover;transition:transform .3s}.video-card:hover .video-thumbnail img{transform:scale(1.05)}.video-info{padding:1rem;flex-grow:1;display:flex;flex-direction:column}.video-title{font-size:1rem;font-weight:700;margin-bottom:.5rem;line-height:1.4}.video-topic{font-size:.85rem;color:var(--text-secondary);margin-top:auto;display:flex;align-items:center;gap:.5rem}.no-results{text-align:center;padding:3rem;font-size:1.2rem;color:var(--text-secondary);display:none}.skip-link{position:absolute;top:-100px;right:0;background:#000;color:#fff;padding:12px 24px;z-index:10000;text-decoration:none;font-weight:600;border-radius:0 0 8px 8px;transition:top .3s}.skip-link:focus{top:0}.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}[tabindex]:focus-visible,a:focus-visible,button:focus-visible,input:focus-visible{outline:3px solid var(--focus-color);outline-offset:2px}a:focus:not(:focus-visible),button:focus:not(:focus-visible),input:focus:not(:focus-visible){outline:0}.site-footer{display:block;width:100%;text-align:center;padding:1.5rem 1rem;border-top:1px solid var(--border-color);margin-top:2rem;background:var(--card-bg)}.site-footer-nav{display:block;margin-bottom:.5rem}.site-footer-nav a{color:var(--text);text-decoration:none;font-size:.9rem;transition:opacity .3s}.site-footer-nav a:hover{text-decoration:underline}.footer-separator{margin:0 .75rem;color:var(--text-secondary)}.footer-copyright{font-size:.85rem;color:var(--text-secondary);margin-top:.5rem}.footer-privacy-btn{background:0 0;border:none;color:var(--text);font-size:.9rem;font-family:inherit;cursor:pointer;padding:0;transition:opacity .3s}.footer-privacy-btn:hover{text-decoration:underline}@media (max-width:768px){.container{padding:1rem}.title{font-size:2.2rem}.subtitle{font-size:1rem}.videos-grid{grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:1rem}}@media (max-width:480px){.videos-grid{grid-template-columns:1fr}.title{font-size:1.8rem}.site-footer{padding:1rem .5rem}.footer-privacy-btn,.site-footer-nav a{font-size:.8rem}.footer-separator{margin:0 .4rem}.footer-copyright{font-size:.75rem}}