.stc-calculator {
    max-width: 600px;
    margin: 0 auto;
    padding: 25px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    font-family: 'Segoe UI', sans-serif;
}

.stc-calculator h2 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
    font-size: 24px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 10px;
}

.stc-row {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
}

.stc-group {
    flex: 1;
    margin-bottom: 15px;
}

.stc-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.stc-group input,
.stc-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
    transition: all 0.3s;
}

.stc-group input:focus,
.stc-group select:focus {
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
    outline: none;
}

.stc-submit-btn {
    width: 100%;
    padding: 14px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    margin-top: 10px;
}

.stc-submit-btn:hover {
    background: #2980b9;
    transform: translateY(-2px);
}

.stc-results {
    margin-top: 20px;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
    border-left: 4px solid #3498db;
    display: none;
}

.stc-result-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px dashed #e0e0e0;
}

.stc-result-item.stc-total {
    border-bottom: none;
    margin-top: 10px;
    font-size: 18px;
}

.stc-label {
    font-weight: 600;
    color: #555;
}

.stc-value {
    font-weight: 700;
    color: #2ecc71;
}

.stc-total .stc-value {
    color: #e74c3c;
    font-size: 20px;
}

/* Responsive */
@media (max-width: 768px) {
    .stc-row {
        flex-direction: column;
        gap: 0;
    }
}