.spd-container {
    max-width: 500px;
    background: #fff;
    padding: 25px;
    border: 1px solid #eee;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    border-radius: 8px;
    margin: 20px 0;
    font-family: sans-serif;
}
.spd-container h3 { margin-top: 0; border-bottom: 2px solid #0073aa; padding-bottom: 15px; margin-bottom: 20px; color:#333; }
.spd-form-group { margin-bottom: 15px; }
.spd-form-group label { display: block; margin-bottom: 8px; font-weight: 600; color: #555; }
.spd-form-group select { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 4px; background:#fafafa; }
.spd-action button { 
    background: #0073aa; color: white; border: none; padding: 12px; cursor: pointer; 
    font-size: 16px; width: 100%; border-radius: 4px; font-weight:bold; transition:all 0.3s; 
}
.spd-action button:hover:not(:disabled) { background: #005177; }
.spd-action button:disabled { background: #ccc; cursor: not-allowed; }
#spd-result-display { margin-top: 20px; padding: 20px; background: #eef9ee; border: 1px solid #cceccc; color: #2e5c2e; text-align: center; border-radius: 4px; }
.spd-price-value { font-size: 28px; font-weight: bold; display: block; margin-top: 5px; color:#1e7b1e; }