: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;--sql-color:#e95420;--java-color:#007396;--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)}.mobile-menu-btn{display:none;font-size:1.5rem;background:none;border:none;color:white;cursor:pointer}main{padding:40px 0}.tool-section{display:none;animation:fadeIn 0.5s ease}.tool-section.active{display:block}@keyframes fadeIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(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}.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)}.converter-container{display:flex;flex-direction:column;gap:20px}.converter-row{display:flex;flex-wrap:wrap;gap:20px}.converter-col{flex:1;min-width:300px}.converter-col h3{margin-bottom:10px;color:var(--dark-color);font-size:1.2rem;display:flex;align-items:center;gap:8px}.px-label{color:#e95420}.rem-label{color:#007396}.input-group{margin-bottom:20px}.input-group label{display:block;margin-bottom:8px;font-weight:600;color:var(--dark-color)}.input-group input{width:100%;padding:15px;border:2px solid #e0e0e0;border-radius:var(--border-radius);font-size:1.1rem;transition:var(--transition)}.input-group input:focus{outline:none;border-color:var(--primary-color)}.px-input{border-left:4px solid #e95420}.rem-input{border-left:4px solid #007396}.base-size-input{border-left:4px solid var(--primary-color)}.converter-actions{display:flex;gap:15px;flex-wrap:wrap}.action-btn{padding:12px 24px;border-radius:6px;border:none;font-weight:600;cursor:pointer;transition:var(--transition);display:flex;align-items:center;gap:8px}.btn-primary{background-color:var(--primary-color);color:white}.btn-primary:hover{background-color:var(--secondary-color)}.btn-secondary{background-color:#e9ecef;color:var(--dark-color)}.btn-secondary:hover{background-color:#dee2e6}.btn-warning{background-color:var(--warning-color);color:white}.btn-warning:hover{background-color:#d1146a}.result-container{display:flex;flex-direction:column;gap:15px;margin-top:20px}.result-row{display:flex;flex-wrap:wrap;gap:15px}.result-box{background:#f8f9fa;padding:20px;border-radius:var(--border-radius);flex:1;min-width:200px;text-align:center;border:1px solid #e9ecef}.result-label{font-size:0.9rem;color:var(--gray-color);margin-bottom:5px}.result-value{font-size:2rem;font-weight:700;color:var(--primary-color)}.result-unit{font-size:1rem;color:var(--gray-color);margin-left:5px}.config-options{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:20px;margin-top:25px}.option-group{background:#f8f9fa;padding:20px;border-radius:var(--border-radius)}.option-group h4{margin-bottom:15px;color:var(--secondary-color);font-size:1.1rem;display:flex;align-items:center;gap:8px}.checkbox-label{display:flex;align-items:center;gap:8px;margin-bottom:10px;cursor:pointer;font-size:0.95rem}.checkbox-label input[type="checkbox"]{width:16px;height:16px;cursor:pointer}.radio-group{display:flex;flex-direction:column;gap:8px;margin-top:10px}.radio-label{display:flex;align-items:center;gap:8px;cursor:pointer}.radio-label input[type="radio"]{width:16px;height:16px;cursor:pointer}.history-container{margin-top:30px}.history-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px}.history-header h3{font-size:1.2rem;color:var(--secondary-color)}.history-table{width:100%;border-collapse:collapse;background:white;border-radius:var(--border-radius);overflow:hidden;box-shadow:0 4px 12px rgba(0,0,0,0.05)}.history-table th{background-color:#f8f9fa;padding:12px 15px;text-align:left;font-weight:600;color:var(--dark-color);border-bottom:2px solid #e9ecef}.history-table td{padding:12px 15px;border-bottom:1px solid #eee}.history-table tr:hover{background-color:#f9f9f9}.formula-container{background:#f0f7ff;border-radius:var(--border-radius);padding:20px;margin-top:25px;border-left:4px solid var(--primary-color)}.formula-container h3{margin-bottom:10px;color:var(--secondary-color);font-size:1.2rem}.formula-content{font-family:'Consolas','Monaco','Courier New',monospace;background:white;padding:15px;border-radius:8px;margin-top:10px}.common-values{margin-top:30px}.common-values h3{margin-bottom:15px;color:var(--secondary-color);font-size:1.2rem}.common-values-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:15px}.common-value-btn{background:white;border:1px solid #e0e0e0;border-radius:8px;padding:12px;text-align:center;cursor:pointer;transition:var(--transition)}.common-value-btn:hover{background-color:var(--primary-color);color:white;border-color:var(--primary-color)}.common-value-btn .value{font-size:1.2rem;font-weight:600;margin-bottom:5px}.common-value-btn .label{font-size:0.85rem;color:var(--gray-color)}footer{background-color:var(--dark-color);color:white;padding:40px 0;margin-top:60px}.footer-content{display:flex;flex-wrap:wrap;justify-content:space-between;gap:40px}.footer-section{flex:1;min-width:250px}.footer-section h3{font-size:1.3rem;margin-bottom:20px;color:var(--success-color)}.footer-links{list-style:none}.footer-links li{margin-bottom:10px}.footer-links a{color:#ddd;text-decoration:none;transition:var(--transition)}.footer-links a:hover{color:var(--success-color)}.copyright{text-align:center;margin-top:40px;padding-top:20px;border-top:1px solid #444;color:#aaa;font-size:0.9rem}@media (max-width:768px){.header-content{flex-direction:column;gap:20px}nav ul{flex-direction:column;gap:10px;text-align:center}.mobile-menu-btn{display:block;position:absolute;top:25px;right:20px}.mobile-menu{display:none;width:100%;margin-top:15px}.mobile-menu.show{display:block}.converter-row{flex-direction:column}.converter-col{min-width:100%}.converter-actions{flex-direction:column}.action-btn{width:100%;justify-content:center}.config-options{grid-template-columns:1fr}.result-row{flex-direction:column}.common-values-grid{grid-template-columns:repeat(auto-fill,minmax(120px,1fr))}}