:root{--primary: #6366f1;--primary-dark: #4f46e5;--secondary: #8b5cf6;--bg-dark: #0f172a;--bg-card: #1e293b;--bg-hover: #334155;--text-primary: #f1f5f9;--text-secondary: #cbd5e1;--border-color: #334155;--success: #10b981;--danger: #ef4444}*{margin:0;padding:0;box-sizing:border-box}body{background:var(--bg-dark);color:var(--text-primary);font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;min-height:100vh;overflow-x:hidden}.navbar{background:#0f172af2;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid var(--border-color);padding:1rem 0}.navbar-brand{font-size:1.5rem;font-weight:700;background:linear-gradient(135deg,var(--primary),var(--secondary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.nav-link{color:var(--text-secondary)!important;font-weight:500;margin:0 .5rem;transition:color .3s ease}.nav-link:hover{color:var(--primary)!important}.btn-download-header{background:linear-gradient(135deg,var(--primary),var(--secondary));border:none;padding:.5rem 1.5rem;border-radius:8px;font-weight:600;transition:transform .2s ease,box-shadow .3s ease}.btn-download-header:hover{transform:translateY(-2px);box-shadow:0 10px 25px #6366f166}.hero{padding:6rem 0 4rem;text-align:center}.hero h1{font-size:clamp(2rem,5vw,3.5rem);font-weight:800;margin-bottom:1rem;background:linear-gradient(135deg,#fff,var(--text-secondary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero p{font-size:1.25rem;color:var(--text-secondary);margin-bottom:3rem}.url-input-container{max-width:800px;margin:0 auto 3rem;position:relative}.url-input{background:var(--bg-card);border:2px solid var(--border-color);color:var(--text-primary);padding:1.25rem 1.5rem;border-radius:12px;font-size:1rem;transition:border-color .3s ease,box-shadow .3s ease}.url-input:focus{background:var(--bg-card);border-color:var(--primary);color:var(--text-primary);box-shadow:0 0 0 4px #6366f11a;outline:none}.url-input::placeholder{color:#64748b}.btn-fetch{background:linear-gradient(135deg,var(--primary),var(--secondary));border:none;padding:1rem 3rem;font-size:1.1rem;font-weight:600;border-radius:12px;margin-top:1rem;transition:transform .2s ease,box-shadow .3s ease}.btn-fetch:hover{transform:translateY(-2px);box-shadow:0 15px 35px #6366f180}.btn-fetch:disabled{opacity:.6;cursor:not-allowed;transform:none}.platforms{display:flex;justify-content:center;gap:2rem;flex-wrap:wrap;margin-top:3rem}.platform-icon{width:60px;height:60px;background:var(--bg-card);border:1px solid var(--border-color);border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:1.8rem;transition:transform .3s ease,border-color .3s ease;cursor:pointer}.platform-icon:hover{transform:translateY(-5px);border-color:var(--primary)}.preview-section{max-width:900px;margin:4rem auto;opacity:0;transform:translateY(30px);transition:opacity .5s ease,transform .5s ease;display:none}.preview-section.active{opacity:1;transform:translateY(0);display:block}@keyframes fadeInUp{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.preview-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:16px;padding:2rem;box-shadow:0 10px 40px #0000004d}.video-thumbnail{width:100%;border-radius:12px;margin-bottom:1.5rem;aspect-ratio:16/9;object-fit:cover;background:var(--bg-hover)}.video-info h4{font-size:1.5rem;font-weight:700;margin-bottom:1rem}.platform-badge{display:inline-block;padding:.4rem 1rem;background:linear-gradient(135deg,var(--primary),var(--secondary));border-radius:20px;font-size:.85rem;font-weight:600;margin-right:.5rem;color:#fff}.duration-badge{display:inline-block;padding:.4rem 1rem;background:var(--bg-hover);border-radius:20px;font-size:.85rem;font-weight:600}.download-options{margin-top:2rem}.form-select{background:var(--bg-dark);border:1px solid var(--border-color);color:var(--text-primary);padding:.75rem 1rem;border-radius:8px;transition:border-color .3s ease}.form-select:focus{background:var(--bg-dark);border-color:var(--primary);color:var(--text-primary);box-shadow:0 0 0 3px #6366f11a;outline:none}.form-select option{background:var(--bg-dark);color:var(--text-primary)}.btn-download{background:var(--success);border:none;padding:1rem;font-size:1.1rem;font-weight:600;border-radius:8px;width:100%;margin-top:1rem;transition:transform .2s ease,box-shadow .3s ease}.btn-download:hover{background:#059669;transform:translateY(-2px);box-shadow:0 10px 25px #10b98166}.loading-spinner{text-align:center;padding:3rem 0}.spinner-border{width:4rem;height:4rem;border-width:4px}.progress-container{margin-top:1.5rem}.progress{height:8px;background:var(--bg-dark);border-radius:10px;overflow:hidden}.progress-bar{background:linear-gradient(90deg,var(--primary),var(--secondary));transition:width .3s ease}.alert-custom{max-width:800px;margin:2rem auto;border-radius:12px}.features{padding:6rem 0;background:linear-gradient(180deg,transparent,rgba(99,102,241,.03))}.section-title{text-align:center;font-size:2.5rem;font-weight:800;margin-bottom:1rem}.section-subtitle{text-align:center;color:var(--text-secondary);font-size:1.1rem;margin-bottom:4rem}.feature-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:16px;padding:2rem;text-align:center;transition:transform .3s ease,border-color .3s ease;height:100%}.feature-card:hover{transform:translateY(-10px);border-color:var(--primary)}.feature-icon{width:80px;height:80px;background:linear-gradient(135deg,var(--primary),var(--secondary));border-radius:20px;display:flex;align-items:center;justify-content:center;font-size:2.5rem;margin:0 auto 1.5rem}.feature-card h4{font-size:1.3rem;font-weight:700;margin-bottom:1rem}.feature-card p{color:var(--text-secondary);line-height:1.6}.footer{background:var(--bg-card);border-top:1px solid var(--border-color);padding:3rem 0 2rem;margin-top:6rem}.footer-links{display:flex;justify-content:center;gap:2rem;margin-bottom:1.5rem;flex-wrap:wrap}.footer-links a{color:var(--text-secondary);text-decoration:none;transition:color .3s ease}.footer-links a:hover{color:var(--primary)}.copyright{text-align:center;color:var(--text-secondary);font-size:.9rem}@media(max-width:768px){.hero{padding:4rem 0 2rem}.platforms{gap:1rem}.platform-icon{width:50px;height:50px;font-size:1.5rem}.preview-card{padding:1.5rem}}