:root{--primary-color: #2c3e50;--secondary-color: #3498db;--accent-color: #e74c3c;--light-color: #ecf0f1;--dark-color: #34495e}*{box-sizing:border-box;margin:0;padding:0;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}body{background-color:#f5f7fa;color:var(--dark-color);line-height:1.6;padding:20px}.container{max-width:800px;margin:0 auto;background-color:#fff;border-radius:10px;box-shadow:0 0 20px #0000001a;padding:30px;position:relative}header{text-align:center;margin-bottom:30px;border-bottom:2px solid var(--light-color);padding-bottom:20px;position:relative}.lang-switcher{position:absolute;top:0;right:0}.lang-switcher select{padding:5px;border-radius:4px;border:1px solid var(--light-color);font-size:.8rem;cursor:pointer;background:#fff}h1{color:var(--primary-color);margin-bottom:10px;padding-right:80px;font-size:1.5rem}.description{color:#7f8c8d;font-size:1.1rem}.formula-container{background-color:#f8f9fa;border-left:4px solid var(--secondary-color);padding:20px;margin:20px 0;font-size:1.1rem;overflow-x:auto;text-align:center}.formula-main{display:flex;align-items:center;justify-content:center;gap:15px;flex-wrap:wrap}.formula-variable{font-size:1.8rem;font-weight:700;font-family:Courier New,monospace}.fraction{display:inline-flex;flex-direction:column;text-align:center;font-family:Courier New,monospace}.numerator{padding:5px 10px;border-bottom:2px solid var(--dark-color)}.denominator{padding:5px 10px}.toggle-btn{background-color:transparent;border:1px solid var(--secondary-color);color:var(--secondary-color);padding:6px 12px;border-radius:4px;cursor:pointer;font-size:.9rem;margin-top:20px;transition:all .3s}.toggle-btn:hover{background-color:var(--secondary-color);color:#fff}.explanation-content{margin-top:15px;padding:15px;background-color:#ecf0f1;border-radius:5px;text-align:left;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;font-size:.95rem}.explanation-content h4{margin-bottom:10px;color:var(--primary-color)}.explanation-content ul{list-style-position:inside;padding-left:0}.explanation-content li{margin-bottom:5px}.input-group{margin-bottom:20px}label{display:block;margin-bottom:8px;font-weight:600;color:var(--primary-color)}input[type=number],select{width:100%;padding:10px;border:1px solid #ddd;border-radius:4px;font-size:1rem;transition:border-color .3s}input[type=number]:focus,select:focus{border-color:var(--secondary-color);outline:none;box-shadow:0 0 0 2px #3498db33}.slider-container{display:flex;align-items:center;gap:15px}.slider-container input[type=range]{flex:1}.slider-value{min-width:60px;text-align:center;font-weight:700;color:var(--secondary-color)}.button-group{display:flex;gap:10px;margin-top:30px}button{padding:12px 20px;border:none;border-radius:4px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s}#calculate-btn{background-color:var(--secondary-color);color:#fff;flex:2}#calculate-btn:hover{background-color:#2980b9}#reset-btn{background-color:var(--light-color);color:var(--dark-color);flex:1}#reset-btn:hover{background-color:#d5dbdb}.result-container{margin-top:30px;padding:20px;background-color:#e8f4fc;border-radius:6px;display:none}.result-container h3{color:var(--primary-color);margin-bottom:10px}#result{font-size:1.5rem;font-weight:700;color:var(--accent-color)}.explanation{margin-top:15px;font-size:.9rem;color:#7f8c8d}footer{margin-top:30px;text-align:center;font-size:.9rem;color:#95a5a6;border-top:1px solid var(--light-color);padding-top:20px}.tooltip-container{position:relative;display:inline-flex;align-items:center;cursor:help}.info-icon{margin-left:8px;width:16px;height:16px;background-color:#bdc3c7;color:#fff;border-radius:50%;text-align:center;font-size:12px;line-height:16px;font-style:italic;font-weight:700;font-family:Georgia,serif;transition:background-color .3s}.tooltip-container:hover .info-icon{background-color:var(--secondary-color)}.tooltip-text{visibility:hidden;width:250px;background-color:var(--dark-color);color:#fff;text-align:left;border-radius:6px;padding:10px;position:absolute;z-index:10;bottom:135%;left:50%;transform:translate(-50%);opacity:0;transition:opacity .3s;font-size:.85rem;font-weight:400;box-shadow:0 2px 5px #0003;pointer-events:none}.tooltip-text:after{content:"";position:absolute;top:100%;left:50%;margin-left:-5px;border-width:5px;border-style:solid;border-color:var(--dark-color) transparent transparent transparent}.tooltip-container:hover .tooltip-text{visibility:visible;opacity:1}@media(max-width:600px){.container{padding:15px}.button-group{flex-direction:column}h1{font-size:1.2rem;padding-right:0;margin-top:30px}}.oirsa-ip-notice{position:fixed;left:0;right:0;bottom:0;z-index:9999;padding:10px 14px;text-align:center;font-size:12px;line-height:1.3;color:#e5e7eb;background:#0b1220eb;border-top:1px solid rgba(255,255,255,.18);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.oirsa-ip-notice a{color:#bfdbfe;text-decoration:underline;font-weight:600}.oirsa-ip-notice a:hover{color:#fff}body{padding-bottom:56px!important}