:root{--primary-color:#4361ee;--secondary-color:#3a0ca3;--accent-color:#7209b7;--light-color:#f8f9fa;--dark-color:#212529;--gray-color:#6c757d;--success-color:#4cc9f0;--warning-color:#f72585;--seo-primary:#0d9488;--seo-gradient:linear-gradient(135deg,#14b8a6 0%,#0f766e 100%);--border-radius:12px;--box-shadow:0 8px 24px rgba(0,0,0,0.1);--transition:all 0.3s ease}*{margin:0;padding:0;box-sizing:border-box;font-family:'Segoe UI','Microsoft YaHei',sans-serif}body{background-color:#f0f2f5;color:var(--dark-color);line-height:1.6}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 20px}header{background:linear-gradient(135deg,var(--primary-color),var(--secondary-color));color:white;padding:20px 0;box-shadow:0 4px 12px rgba(0,0,0,0.1);position:sticky;top:0;z-index:100}.header-content{display:flex;justify-content:space-between;align-items:center}.logo{display:flex;align-items:center;gap:15px}.logo i{font-size:2.5rem}.logo h1{font-size:1.8rem;font-weight:700}.logo span{color:var(--success-color)}nav ul{display:flex;list-style:none;gap:25px}nav a{color:white;text-decoration:none;font-weight:600;font-size:1.1rem;padding:8px 12px;border-radius:6px;transition:var(--transition)}nav a:hover,nav a.active{background-color:rgba(255,255,255,0.2)}main{padding:40px 0}.section-title{font-size:1.8rem;margin-bottom:25px;color:var(--secondary-color);display:flex;align-items:center;gap:10px}.section-title i{color:var(--accent-color)}.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:25px;margin-bottom:40px}.tool-card{background:white;border-radius:var(--border-radius);padding:25px;box-shadow:var(--box-shadow);transition:var(--transition);cursor:pointer;border:2px solid transparent}.tool-card:hover{transform:translateY(-5px);border-color:var(--primary-color)}.tool-card i{font-size:2.5rem;color:var(--primary-color);margin-bottom:15px}.tool-card h3{font-size:1.4rem;margin-bottom:10px;color:var(--dark-color)}.tool-card p{color:var(--gray-color);margin-bottom:20px}.use-tool-btn{background-color:var(--primary-color);color:white;border:none;padding:10px 20px;border-radius:6px;font-weight:600;cursor:pointer;transition:var(--transition);width:100%}.use-tool-btn:hover{background-color:var(--secondary-color)}.tool-detail{background:white;border-radius:var(--border-radius);padding:30px;box-shadow:var(--box-shadow);margin-top:30px;display:none}.tool-detail.active{display:block}.tool-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:25px;padding-bottom:15px;border-bottom:2px solid #f0f2f5}.tool-header h2{font-size:1.6rem;color:var(--secondary-color)}.close-tool{background:none;border:none;font-size:1.5rem;color:var(--gray-color);cursor:pointer;transition:var(--transition)}.close-tool:hover{color:var(--warning-color)}.density-wrapper{display:grid;grid-template-columns:1fr 1fr;gap:30px}@media (max-width:900px){.density-wrapper{grid-template-columns:1fr}}.input-panel{display:flex;flex-direction:column;gap:15px}.options-bar{display:flex;align-items:center;gap:20px;background:#f0fdfa;padding:10px 15px;border-radius:8px;border:1px solid #ccfbf1}.checkbox-label{display:flex;align-items:center;gap:8px;cursor:pointer;font-weight:600;color:var(--dark-color);font-size:0.95rem}.keyword-input{flex:1;padding:8px 12px;border:1px solid #cbd5e1;border-radius:6px;font-size:0.9rem}.keyword-input:focus{border-color:var(--seo-primary);outline:none}.content-textarea{width:100%;height:400px;padding:15px;border:2px solid #ccfbf1;border-radius:10px;font-family:'Consolas',monospace;font-size:0.9rem;resize:vertical;outline:none;background:white;transition:var(--transition)}.content-textarea:focus{border-color:var(--seo-primary);box-shadow:0 0 0 4px rgba(13,148,136,0.1)}.action-btn{background:var(--seo-gradient);color:white;border:none;padding:12px;border-radius:8px;font-weight:600;font-size:1rem;cursor:pointer;transition:var(--transition);display:flex;align-items:center;justify-content:center;gap:8px;box-shadow:0 4px 6px rgba(13,148,136,0.2)}.action-btn:hover{transform:translateY(-2px)}.result-panel{background:#f8fafc;border-radius:12px;padding:20px;border:1px solid #e2e8f0;display:flex;flex-direction:column;gap:20px}.dashboard{display:grid;grid-template-columns:1fr 1fr;gap:15px}.dash-card{background:white;padding:15px;border-radius:8px;text-align:center;box-shadow:0 2px 4px rgba(0,0,0,0.02);border-bottom:4px solid var(--seo-primary)}.dash-val{font-size:2rem;font-weight:800;color:var(--seo-primary)}.dash-label{font-size:0.85rem;color:var(--gray-color);text-transform:uppercase;margin-top:5px}.list-header{font-size:1.1rem;font-weight:700;color:var(--secondary-color);padding-bottom:10px;border-bottom:1px solid #e2e8f0}.density-list{display:flex;flex-direction:column;gap:12px;max-height:400px;overflow-y:auto;padding-right:5px}.density-list::-webkit-scrollbar{width:6px}.density-list::-webkit-scrollbar-track{background:#f1f5f9}.density-list::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:3px}.density-item{background:white;padding:12px;border-radius:8px;border:1px solid #e2e8f0;transition:var(--transition)}.density-item:hover{border-color:var(--seo-primary);transform:translateX(3px)}.item-top{display:flex;justify-content:space-between;margin-bottom:8px}.item-keyword{font-weight:700;color:var(--dark-color)}.item-stats{font-size:0.85rem;color:var(--gray-color);font-family:'Consolas',monospace}.progress-track{height:6px;background:#f1f5f9;border-radius:3px;overflow:hidden}.progress-fill{height:100%;background:var(--seo-gradient);border-radius:3px;transition:width 1s ease-out}