*{margin:0;padding:0;box-sizing:border-box;}:root{--bg-primary:#ffffff;--bg-secondary:#f8fafc;--bg-tertiary:#e2e8f0;--text-primary:#2d3748;--text-secondary:#4a5568;--text-tertiary:#718096;--border-color:#e2e8f0;--shadow-light:rgba(0,0,0,0.1);--shadow-medium:rgba(0,0,0,0.15);--gradient-bg:linear-gradient(135deg,#f5f7fa 0%,#c3cfe2 100%);--card-bg:#ffffff;--input-bg:#f8fafc;--footer-bg:#2d3748;--footer-text:#ffffff;}[data-theme="dark"]{--bg-primary:#1a202c;--bg-secondary:#2d3748;--bg-tertiary:#4a5568;--text-primary:#f7fafc;--text-secondary:#e2e8f0;--text-tertiary:#cbd5e0;--border-color:#4a5568;--shadow-light:rgba(0,0,0,0.3);--shadow-medium:rgba(0,0,0,0.4);--gradient-bg:linear-gradient(135deg,#2d3748 0%,#4a5568 100%);--card-bg:#2d3748;--input-bg:#4a5568;--footer-bg:#1a202c;--footer-text:#f7fafc;}body{font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;line-height:1.6;color:var(--text-primary);background:var(--bg-primary);overflow-x:hidden;transition:background-color 0.3s ease,color 0.3s ease;}.container{max-width:1200px;margin:0 auto;padding:0 20px;}.header{background:linear-gradient(135deg,#ff4757 0%,#3742fa 100%);padding:20px 0;box-shadow:0 4px 20px var(--shadow-light);border-bottom:3px solid #3742fa;transition:box-shadow 0.3s ease;}.header-content{display:flex;justify-content:space-between;align-items:center;}.logo{font-size:1.8rem;font-weight:600;font-style:italic;color:white;text-shadow:0 2px 4px rgba(0,0,0,0.2);letter-spacing:-0.3px;margin:0;}.theme-toggle{background:rgba(255,255,255,0.2);border:2px solid rgba(255,255,255,0.3);border-radius:50%;width:50px;height:50px;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all 0.3s ease;backdrop-filter:blur(10px);}.theme-toggle:hover{background:rgba(255,255,255,0.3);border-color:rgba(255,255,255,0.5);transform:scale(1.05);}.theme-icon{font-size:1.5rem;transition:transform 0.3s ease;}.theme-toggle:hover .theme-icon{transform:rotate(15deg);}.hero-section{background:var(--gradient-bg);padding:80px 0;position:relative;transition:background 0.3s ease;}.hero-content{text-align:center;max-width:800px;margin:0 auto;}.hero-title{font-size:3rem;font-weight:700;color:var(--text-primary);margin-bottom:16px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;transition:color 0.3s ease;}.hero-subtitle{font-size:1.25rem;color:var(--text-secondary);margin-bottom:40px;font-weight:500;transition:color 0.3s ease;}.tool-container{background:var(--card-bg);border-radius:24px;padding:40px;box-shadow:0 20px 60px var(--shadow-light);border:1px solid red;backdrop-filter:blur(10px);transition:all 0.3s ease;}.input-group{display:flex;gap:16px;margin-bottom:30px;flex-wrap:wrap;}.video-input{flex:1;min-width:300px;padding:16px 20px;border:2px solid var(--border-color);border-radius:16px;font-size:1rem;font-weight:500;transition:all 0.3s ease;background:var(--input-bg);color:var(--text-primary);}.video-input::placeholder{color:var(--text-tertiary);transition:color 0.3s ease;}.video-input:focus{outline:none;border-color:#667eea;box-shadow:0 0 0 3px rgba(102,126,234,0.1);background:var(--card-bg);}.generate-btn{padding:16px 32px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:white;border:none;border-radius:16px;font-size:1rem;font-weight:600;cursor:pointer;transition:all 0.3s ease;box-shadow:0 8px 25px rgba(102,126,234,0.3);min-width:150px;}.generate-btn:hover{transform:translateY(-2px);box-shadow:0 12px 35px rgba(102,126,234,0.4);}.generate-btn:active{transform:translateY(0);}.output-area{background:var(--bg-secondary);border-radius:16px;padding:24px;border:2px solid var(--border-color);transition:all 0.3s ease;}.output-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;flex-wrap:wrap;gap:16px;}.output-header h2{font-size:1.25rem;font-weight:600;color:var(--text-primary);transition:color 0.3s ease;}.copy-all-btn{padding:10px 20px;background:linear-gradient(135deg,#48bb78 0%,#38a169 100%);color:white;border:none;border-radius:12px;font-size:0.9rem;font-weight:600;cursor:pointer;transition:all 0.3s ease;box-shadow:0 4px 15px rgba(72,187,120,0.3);}.copy-all-btn:hover{transform:translateY(-1px);box-shadow:0 6px 20px rgba(72,187,120,0.4);}.tags-container{display:flex;flex-wrap:wrap;gap:8px;}.tag{background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:white;padding:8px 16px;border-radius:20px;font-size:0.9rem;font-weight:500;cursor:pointer;transition:all 0.3s ease;box-shadow:0 2px 8px rgba(102,126,234,0.2);}.tag:hover{transform:translateY(-1px);box-shadow:0 4px 12px rgba(102,126,234,0.3);}.section-title{font-size:2.5rem;font-weight:700;text-align:center;margin-bottom:50px;color:var(--text-primary);background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;transition:color 0.3s ease;}.how-to-use{padding:80px 0;background:var(--bg-primary);transition:background 0.3s ease;}.steps-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:30px;margin-bottom:50px;}.step{text-align:center;padding:30px 20px;background:var(--bg-secondary);border-radius:20px;box-shadow:0 8px 25px var(--shadow-light);transition:all 0.3s ease;border:1px solid var(--border-color);}.step:hover{transform:translateY(-5px);box-shadow:0 15px 40px var(--shadow-medium);}.step-number{width:50px;height:50px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:white;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.25rem;font-weight:700;margin:0 auto 20px;box-shadow:0 4px 15px rgba(102,126,234,0.3);}.step h3{font-size:1.25rem;font-weight:600;color:var(--text-primary);margin-bottom:12px;transition:color 0.3s ease;}.step p{color:var(--text-secondary);line-height:1.6;transition:color 0.3s ease;}.tips-section{background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:white;padding:40px;border-radius:20px;box-shadow:0 15px 40px rgba(102,126,234,0.2);}.key-benefits h4{font-size:1.3rem;font-weight:600;color:var(--text-primary);margin-bottom:15px;display:flex;align-items:center;gap:8px;}.tips-list{list-style:none;display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:15px;}.tips-list li{padding:12px 0;position:relative;padding-left:30px;}.tips-list li::before{content:'✓';position:absolute;left:0;top:12px;color:#48bb78;font-weight:bold;font-size:1.1rem;}.features{padding:80px 0;background:var(--gradient-bg);transition:background 0.3s ease;}.features-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:30px;}.feature-card{background:var(--card-bg);padding:40px 30px;border-radius:20px;text-align:center;box-shadow:0 10px 30px var(--shadow-light);transition:all 0.3s ease;border:1px solid var(--border-color);}.feature-card:hover{transform:translateY(-8px);box-shadow:0 20px 50px var(--shadow-medium);}.feature-icon{font-size:3rem;margin-bottom:20px;display:block;}.feature-card h3{font-size:1.25rem;font-weight:600;color:var(--text-primary);margin-bottom:15px;transition:color 0.3s ease;}.feature-card p{color:var(--text-secondary);line-height:1.6;transition:color 0.3s ease;}.featured-content{padding:80px 0;background:var(--bg-primary);transition:background 0.3s ease;}.content-wrapper{max-width:800px;margin:0 auto;}.content-text{font-size:1.1rem;line-height:1.8;color:var(--text-secondary);transition:color 0.3s ease;}.content-text p{margin-bottom:20px;}.content-text strong{color:var(--text-primary);font-weight:600;transition:color 0.3s ease;}.key-benefits{background:linear-gradient(135deg,#f8fafc 0%,#e2e8f0 100%);padding:30px;border-radius:16px;margin-top:30px;border-left:4px solid #667eea;}.key-benefits h3{font-size:1.25rem;font-weight:600;color:#2d3748;margin-bottom:15px;}.key-benefits ul{list-style:none;}.key-benefits li{padding:8px 0;position:relative;padding-left:25px;color:#4a5568;}.key-benefits li::before{content:'•';position:absolute;left:0;color:#667eea;font-weight:bold;font-size:1.2rem;}.footer{background:var(--footer-bg);color:var(--footer-text);padding:40px 0;text-align:center;transition:all 0.3s ease;}.footer-content{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:20px;}.footer-links{display:flex;gap:30px;flex-wrap:wrap;}.footer-links a{color:white;text-decoration:none;font-weight:500;font-size:0.85em;transition:color 0.3s ease;}.footer-links a:hover{color:#667eea;}.footer-copyright{font-weight:bold;font-size:0.85em;}.popup-modal{display:none;position:fixed;z-index:1000;left:0;top:0;width:100%;height:100%;background-color:rgba(0,0,0,0.5);backdrop-filter:blur(5px);}.popup-content{background-color:var(--card-bg);margin:5% auto;padding:40px;border-radius:20px;width:90%;max-width:600px;position:relative;box-shadow:0 25px 60px var(--shadow-medium);animation:slideIn 0.3s ease;border:1px solid var(--border-color);}@keyframes slideIn{from{opacity:0;transform:translateY(-50px);}to{opacity:1;transform:translateY(0);}}.close-btn{position:absolute;top:15px;right:20px;font-size:2rem;font-weight:bold;color:var(--text-tertiary);cursor:pointer;transition:color 0.3s ease;}.close-btn:hover{color:#667eea;}#popupTitle{font-size:1.5rem;font-weight:600;color:var(--text-primary);margin-bottom:20px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;transition:color 0.3s ease;}#popupText{color:var(--text-secondary);line-height:1.6;transition:color 0.3s ease;}.loading{display:inline-block;width:20px;height:20px;border:3px solid rgba(255,255,255,0.3);border-radius:50%;border-top-color:#fff;animation:spin 1s ease-in-out infinite;}@keyframes spin{to{transform:rotate(360deg);}}@media (max-width:768px){.hero-title{font-size:2.5rem;}.section-title{font-size:2rem;}.tool-container{padding:30px 20px;}.input-group{flex-direction:column;}.video-input{min-width:auto;}.generate-btn{width:100%;}.output-header{flex-direction:column;align-items:stretch;}.copy-all-btn{width:100%;}.footer-content{flex-direction:column;text-align:center;}.footer-links{justify-content:center;}.popup-content{margin:10% auto;padding:30px 20px;}.tips-list{grid-template-columns:1fr;}}@media (max-width:480px){.hero-title{font-size:2rem;}.logo{font-size:2rem;}.container{padding:0 15px;}.tool-container{padding:20px 15px;}.steps-grid{grid-template-columns:1fr;}.features-grid{grid-template-columns:1fr;}}.faq-section{padding:80px 0;background:var(--bg-secondary);}.faq-container{max-width:800px;margin:0 auto;display:flex;flex-direction:column;gap:20px;}.faq-item{background:var(--card-bg);border-radius:12px;padding:30px;box-shadow:0 4px 6px var(--shadow-light);transition:transform 0.3s ease,box-shadow 0.3s ease;border:1px solid var(--border-color);}.faq-item:hover{transform:translateY(-2px);box-shadow:0 8px 25px var(--shadow-medium);}.faq-question{font-size:1.25rem;font-weight:600;color:var(--text-primary);margin-bottom:15px;line-height:1.4;}.faq-answer{font-size:1rem;color:var(--text-secondary);line-height:1.6;margin:0;}@media (max-width:768px){.faq-section{padding:60px 0;}.faq-item{padding:25px 20px;}.faq-question{font-size:1.1rem;}.faq-answer{font-size:0.95rem;}}@media (max-width:480px){.faq-section{padding:40px 0;}.faq-item{padding:20px 15px;}.faq-question{font-size:1rem;}}.video-demo-section{padding:80px 0;background:var(--bg-primary);transition:background 0.3s ease;}.video-demo-content{text-align:center;max-width:900px;margin:0 auto;}.video-subtitle{font-size:1.125rem;color:var(--text-secondary);margin-bottom:40px;line-height:1.6;transition:color 0.3s ease;}.video-container{position:relative;max-width:900px;margin:0 auto;}.video-wrapper{position:relative;width:100%;aspect-ratio:16 / 9;border-radius:20px;overflow:hidden;box-shadow:0 20px 50px var(--shadow-medium);transition:all 0.3s ease;background:var(--card-bg);border:1px solid var(--border-color);}.video-wrapper:hover{transform:translateY(-5px);box-shadow:0 25px 60px var(--shadow-medium);}.video-wrapper:focus-within{outline:none;box-shadow:0 0 0 3px rgba(102,126,234,0.3),0 25px 60px var(--shadow-medium);}.video-poster{position:relative;width:100%;height:100%;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all 0.3s ease;}.poster-image{width:100%;height:100%;object-fit:cover;transition:transform 0.3s ease;}.video-poster:hover .poster-image{transform:scale(1.02);}.play-button{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:80px;height:80px;background:linear-gradient(135deg,rgba(102,126,234,0.95) 0%,rgba(118,75,162,0.95) 100%);border:none;border-radius:50%;color:white;cursor:pointer;transition:all 0.3s ease;display:flex;align-items:center;justify-content:center;box-shadow:0 8px 25px rgba(102,126,234,0.4);backdrop-filter:blur(10px);}.play-button:hover{transform:translate(-50%,-50%) scale(1.1);box-shadow:0 12px 35px rgba(102,126,234,0.5);background:linear-gradient(135deg,rgba(102,126,234,1) 0%,rgba(118,75,162,1) 100%);}.play-button:focus{outline:none;box-shadow:0 0 0 3px rgba(102,126,234,0.3),0 12px 35px rgba(102,126,234,0.5);}.play-button:active{transform:translate(-50%,-50%) scale(0.95);}.play-icon{width:32px;height:32px;margin-left:4px;}.video-iframe{position:absolute;top:0;left:0;width:100%;height:100%;border:none;border-radius:20px;opacity:0;transform:scale(0.9);transition:all 0.3s ease;}.video-iframe.loaded{opacity:1;transform:scale(1);}.video-caption{margin-top:20px;font-size:0.95rem;color:var(--text-tertiary);font-style:italic;transition:color 0.3s ease;}.video-fallback-link{display:inline-block;margin-top:20px;padding:12px 24px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:white;text-decoration:none;border-radius:12px;font-weight:500;transition:all 0.3s ease;box-shadow:0 4px 15px rgba(102,126,234,0.3);}.video-fallback-link:hover{transform:translateY(-2px);box-shadow:0 8px 25px rgba(102,126,234,0.4);text-decoration:none;color:white;}@media (max-width:768px){.video-demo-section{padding:60px 0;}.video-subtitle{font-size:1rem;margin-bottom:30px;}.video-wrapper{border-radius:16px;}.play-button{width:60px;height:60px;}.play-icon{width:24px;height:24px;}.video-caption{font-size:0.9rem;margin-top:15px;}}@media (max-width:480px){.video-demo-section{padding:40px 0;}.video-wrapper{border-radius:12px;}.play-button{width:50px;height:50px;}.play-icon{width:20px;height:20px;}.video-subtitle{font-size:0.95rem;}.video-caption{font-size:0.85rem;}}