:root{--primary: #2563eb;--primary-dark: #1d4ed8;--secondary: #9333ea;--accent: #f59e0b;--dark: #111827;--gray-dark: #374151;--gray: #6b7280;--gray-light: #e5e7eb;--light: #f9fafb;--danger: #dc2626;--success: #16a34a;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow: 0 4px 6px rgba(0, 0, 0, .1);--shadow-lg: 0 10px 15px rgba(0, 0, 0, .1);--font-sans: "Inter", system-ui, -apple-system, sans-serif}*{margin:0;padding:0;box-sizing:border-box}body{font-family:var(--font-sans);color:var(--dark);line-height:1.5;background-color:var(--light)}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 1rem}.section{padding:4rem 0}h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.2;margin-bottom:1rem}h1{font-size:2.5rem}h2{font-size:2rem}h3{font-size:1.75rem}p{margin-bottom:1rem}a{color:var(--primary);text-decoration:none;transition:color .3s}a:hover{color:var(--primary-dark)}.btn{display:inline-block;padding:.75rem 1.5rem;border-radius:.25rem;font-weight:600;text-align:center;cursor:pointer;transition:all .3s;border:none;font-size:1rem}.btn-primary{background-color:var(--primary);color:#fff}.btn-primary:hover{background-color:var(--primary-dark);color:#fff}.btn-secondary{background-color:var(--secondary);color:#fff}.btn-secondary:hover{background-color:#7e22ce;color:#fff}.btn-accent{background-color:var(--accent);color:#fff}.btn-accent:hover{background-color:#d97706;color:#fff}.btn-outline{background-color:transparent;border:2px solid var(--primary);color:var(--primary)}.btn-outline:hover{background-color:var(--primary);color:#fff}.header{background-color:#fff;box-shadow:var(--shadow-sm);position:sticky;top:0;z-index:100}.header-container{display:flex;justify-content:space-between;align-items:center;height:70px}.logo{font-size:1.5rem;font-weight:700;color:var(--primary)}.nav-menu{display:flex;gap:2rem;list-style:none}.nav-link{color:var(--gray-dark);font-weight:500}.nav-link:hover,.nav-link.active{color:var(--primary)}.hero{padding:6rem 0;background:linear-gradient(135deg,#f0f9ff,#e0f2fe)}.hero-content{max-width:600px}.hero-title{font-size:3rem;margin-bottom:1.5rem;color:var(--dark)}.hero-subtitle{font-size:1.25rem;color:var(--gray);margin-bottom:2rem}.hero-btns{display:flex;gap:1rem}.features{background-color:#fff;padding:5rem 0}.section-title{text-align:center;margin-bottom:3rem}.features-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:2rem}.feature-card{background-color:#fff;border-radius:.5rem;overflow:hidden;box-shadow:var(--shadow);transition:transform .3s,box-shadow .3s}.feature-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg)}.feature-card-content{padding:1.5rem}.feature-icon{background-color:#e0f2fe;color:var(--primary);width:3rem;height:3rem;border-radius:50%;display:flex;align-items:center;justify-content:center;margin-bottom:1rem;font-size:1.5rem}.cta{background-color:var(--primary);color:#fff;padding:5rem 0;text-align:center}.cta-title{font-size:2.5rem;margin-bottom:1rem}.cta-subtitle{font-size:1.25rem;margin-bottom:2rem;opacity:.9}.footer{background-color:var(--dark);color:#fff;padding:4rem 0 2rem}.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:2rem}.footer-column h3{font-size:1.25rem;margin-bottom:1.5rem}.footer-menu{list-style:none}.footer-menu li{margin-bottom:.75rem}.footer-menu a{color:var(--gray-light)}.footer-menu a:hover{color:#fff}.copyright{text-align:center;padding-top:2rem;margin-top:2rem;border-top:1px solid rgba(255,255,255,.1);color:var(--gray);font-size:.875rem}.voice-cmd-btn{position:fixed;bottom:2rem;right:2rem;width:4rem;height:4rem;border-radius:50%;background-color:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;cursor:pointer;box-shadow:var(--shadow);transition:all .3s;z-index:90;border:none}.voice-cmd-btn:hover{background-color:var(--primary-dark);transform:scale(1.05)}.voice-cmd-btn.active{background-color:var(--danger);animation:pulse 1.5s infinite}@keyframes pulse{0%{box-shadow:0 0 #dc2626b3}70%{box-shadow:0 0 0 10px #dc262600}to{box-shadow:0 0 #dc262600}}.course-card{background-color:#fff;border-radius:.5rem;overflow:hidden;box-shadow:var(--shadow);transition:transform .3s,box-shadow .3s}.course-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg)}.course-card-img{width:100%;height:200px;object-fit:cover}.course-card-content{padding:1.5rem}.course-card-title{font-size:1.25rem;margin-bottom:.5rem}.course-card-description{color:var(--gray);margin-bottom:1.5rem}.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:2rem}.course-header{background-color:var(--dark);color:#fff;padding:4rem 0}.course-content{display:grid;grid-template-columns:2fr 1fr;gap:2rem;margin-top:2rem}.sidebar{background-color:#fff;border-radius:.5rem;padding:1.5rem;box-shadow:var(--shadow);height:fit-content}.sidebar-title{margin-bottom:1rem;padding-bottom:.5rem;border-bottom:1px solid var(--gray-light)}.sidebar-menu{list-style:none}.sidebar-menu li{margin-bottom:.5rem}.sidebar-menu a{display:block;padding:.5rem;border-radius:.25rem;color:var(--gray-dark);transition:all .3s}.sidebar-menu a:hover,.sidebar-menu a.active{background-color:var(--primary);color:#fff}.video-container{position:relative;padding-bottom:56.25%;height:0;overflow:hidden;max-width:100%;border-radius:.5rem;margin-bottom:2rem;box-shadow:var(--shadow)}.video-container iframe,.video-container video{position:absolute;top:0;left:0;width:100%;height:100%;border:none}.material-content{background-color:#fff;border-radius:.5rem;padding:2rem;box-shadow:var(--shadow)}@media (max-width: 768px){.hero{padding:4rem 0}.hero-title{font-size:2.5rem}.course-content{grid-template-columns:1fr}.hero-btns{flex-direction:column;gap:.5rem}.header-container{flex-direction:column;height:auto;padding:1rem 0}.nav-menu{margin-top:1rem;flex-wrap:wrap;justify-content:center;gap:1rem}}