body {
    background-color: #f8f9fa;
    font-family: 'Inter', system-ui, sans-serif;
}
.calc-container {
    background: #ffffff;
    border-radius: 14px;
    box-shadow: 0 12px 35px rgba(0,0,0,0.06);
}
.result-display {
    background: #fff4f4;
    border: 2px dashed #dc3545;
    border-radius: 12px;
}