.pump-calculator {
    max-width: 500px;
    margin: 0 auto;
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: #333;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.06);
}

.pump-calculator h2 {
    font-size: 25px;
    font-weight: 500;
    text-align: center;
    margin-bottom: 10px;
    color: #0086ad;
}

.calculator-subtitle {
    font-size: 14px;
    text-align: center;
    margin-top: 0;
    margin-bottom: 15px;
    color: #555;
}

.calculator-divider {
    border: 0;
    height: 0px;
    background-color: #0086ad;
    opacity: 0.3;
    margin-bottom: 20px;
}

.form-row {
    display: flex;
    align-items: center;
    margin-bottom: 8px;
    padding: 2px 0;
}

.form-row label {
    width: 40%;
    font-size: 14px;
    color: #333;
}

.form-row input {
    width: 40%;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 14px;
    transition: all 0.2s ease;
    box-sizing: border-box;
}

.form-row input:focus {
    outline: none;
    border-color: #0086ad;
    box-shadow: 0 0 0 2px rgba(0, 134, 173, 0.15);
}

.form-row span {
    width: auto;
    margin-left: 8px;
    font-size: 13px;
    color: #666;
    white-space: nowrap;
}

input[readonly] {
    background-color: #f5f5f7;
    color: #333;
    cursor: default;
}

#kwh, #horsepower {
    background-color: #fffde7;
    border-color: #ffeb3b;
}

#error-message {
    color: #ff3b30;
    font-size: 13px;
    text-align: center;
    min-height: 16px;
    margin-top: 8px;
}

.author-attribution {
    margin-top: 15px;
    text-align: center;
    font-size: 11px;
    color: #999;
}

.author-attribution a {
    color: #0086ad;
    text-decoration: none;
}

.author-attribution a:hover {
    text-decoration: underline;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .pump-calculator {
        padding: 12px;
        border-radius: 8px;
    }
    
    .form-row {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .form-row label {
        width: 100%;
        margin-bottom: 4px;
    }
    
    .form-row input {
        width: 100%;
    }
    
    .form-row span {
        margin-left: 0;
        margin-top: 4px;
    }
}