.exchange-container{max-width:600px;margin:40px auto;padding:25px;background-color:#f9f9f9;border-radius:12px;box-shadow:0 4px 12px rgba(0,0,0,0.1);font-family:"Helvetica Neue", Arial, sans-serif}.exchange-container h2{text-align:center;margin-bottom:20px;color:#333}.form-group{display:flex;flex-direction:column;margin-bottom:15px}.form-group label{margin-bottom:5px;font-weight:600;color:#555}.form-group select,.form-group input[type="date"]{padding:6px 10px;border:1px solid #ccc;border-radius:6px;font-size:14px;transition:border 0.2s, box-shadow 0.2s}.form-group select:focus,.form-group input[type="date"]:focus{border-color:#007bff;box-shadow:0 0 5px rgba(0,123,255,0.3);outline:none}#date_picker.invalid{border-color:red;background-color:#ffe6e6}#get_rate{width:100%;padding:10px 0;font-size:14px;font-weight:600;color:white;background-color:#007bff;border:none;border-radius:8px;cursor:pointer;transition:background-color 0.2s, transform 0.1s}#get_rate:disabled{background-color:#aaa;cursor:not-allowed}#get_rate:hover:not(:disabled){background-color:#0056b3}#get_rate:active:not(:disabled){transform:scale(0.98)}.exchange-container__result{margin-top:20px;font-weight:bold;font-size:18px;text-align:center;color:#333;min-height:24px;position:relative}.skeleton{display:inline-block;height:20px;width:100px;background:linear-gradient(90deg, #eee 25%, #ddd 50%, #eee 75%);background-size:200% 100%;border-radius:6px;animation:shimmer 1.2s infinite}@keyframes shimmer{0%{background-position:-200% 0}100%{background-position:200% 0}}