.backward-inflation-tool * {box-sizing: border-box;font-family: "Segoe UI",sans-serif;}
.backward-inflation-container {max-width: 600px;margin: 30px auto;padding: 25px;background: #fff;border-radius: 12px;box-shadow: 0 10px 25px rgba(0,0,0,.1);}
.backward-inflation-container h2 {text-align: center;color: #2c3e50;margin-bottom: 20px;}
.backward-row {display: flex;gap: 15px;flex-wrap: wrap;}
.input-group {flex: 1;min-width: 150px;}
.input-group label {font-weight: 600;display: block;margin-bottom: 6px;}
.input-group input {width: 100%;padding: 10px;border-radius: 6px;border: 1px solid #ccc;font-size: 15px;}
.backward-buttons {margin-top: 20px;display: flex;justify-content: space-between;}
.backward-buttons button {flex: 1;margin: 0 5px;padding: 12px;font-size: 16px;border: none;border-radius: 8px;color: white;cursor: pointer;transition: background .3s;}
.backward-buttons button:first-child {background-color: #4caf50;}
.backward-buttons button:first-child:hover {background-color: #388e3c;}
.backward-buttons button:last-child {background-color: #a6acaf;}
.backward-buttons button:last-child:hover {background-color: #7b8387;}
#back-result {margin-top: 20px;font-size: 18px;font-weight: 500;color: #333;}
#back-chart {margin-top: 30px;}