:root{--primary-bg:#eef2f7;--card-bg:#fff;--text-color:#333;--primary-color:#007bff;--secondary-color:#37474f;--error-color:#e53935;--footer-color:#888;--input-bg:#fff;--hover-color:#0056b3;--shadow-color:rgba(0,0,0,.1)}@media (prefers-color-scheme:dark){:root{--primary-bg:#121212;--card-bg:#1f1f1f;--text-color:#f1f1f1;--primary-color:#bb86fc;--secondary-color:#bb86fc;--error-color:#cf6679;--footer-color:#888;--input-bg:#333;--hover-color:#3700b3;--shadow-color:hsla(0,0%,100%,.1)}}body{font-family:Roboto,sans-serif;background-color:var(--primary-bg);margin:0;padding:0;color:var(--text-color);transition:background-color .3s ease}.container{width:90%;max-width:900px;margin:30px auto;background-color:var(--card-bg);padding:25px 30px;border-radius:15px;box-shadow:0 8px 20px var(--shadow-color)}h1,h2{text-align:center;color:var(--secondary-color);margin-bottom:10px}.intro-text{text-align:center;color:#616161;font-size:18px;line-height:1.6}.intro-text,table{margin-bottom:30px}table{width:100%;border-collapse:collapse;font-size:14px}td,th{padding:14px 20px;text-align:center;border:1px solid #e0e0e0}th{background-color:var(--primary-color);color:#fff;font-weight:700}tr:nth-child(2n){background-color:#f7f9fc}.btn{background-color:var(--primary-color);color:#fff;border:none;padding:12px 24px;border-radius:8px;cursor:pointer;display:block;width:100%;font-size:16px;transition:background-color .3s ease}.btn:hover{background-color:var(--hover-color)}.form-group{margin-bottom:20px}label{font-weight:500;color:var(--secondary-color)}input,select{width:100%;padding:10px;margin-top:8px;border:1px solid #ccc;border-radius:5px;font-size:14px;background-color:var(--input-bg);color:var(--text-color)}input.error,select.error{border-color:var(--error-color);background-color:#ffe4e4}.error-message{color:var(--error-color);font-size:12px;margin-top:5px;display:none}.output{margin-top:30px;font-weight:700;color:var(--primary-color);font-size:18px}.footer,.output{text-align:center}.footer{margin-top:40px;font-size:14px;color:var(--footer-color)}.info-box{background-color:#f1f8e9;border:1px solid #c5e1a5;color:#558b2f;padding:15px;border-radius:8px;margin-bottom:20px}@media (max-width:768px){.container{padding:15px}h1{font-size:24px}.btn{font-size:14px}.intro-text{font-size:16px;margin-bottom:20px}table{font-size:12px}td,th{padding:12px 16px}.output{font-size:16px}.footer{font-size:12px}}@media (max-width:480px){h1{font-size:22px}.intro-text{font-size:14px}.btn{font-size:12px}table{font-size:10px}td,th{padding:10px 14px}.output{font-size:14px}}