body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 2rem 0;
}

.container-fluid {
    max-width: 1400px;
    margin: 0 auto;
}

.calculator-container {
    background: white;
    padding: 3rem;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.calculator-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(90deg, #007bff, #28a745, #ffc107, #dc3545);
}

h1 {
    color: #333;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.form-label {
    font-weight: 600;
    color: #495057;
    margin-bottom: 0.5rem;
}

.form-select,
.form-control {
    border: 2px solid #e9ecef;
    border-radius: 10px;
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.form-select:focus,
.form-control:focus {
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.input-group-text {
    background-color: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-weight: 600;
    color: #6c757d;
}

.btn-primary {
    background: linear-gradient(45deg, #007bff, #0056b3);
    border: none;
    border-radius: 10px;
    padding: 1rem 2rem;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary:hover {
    background: linear-gradient(45deg, #0056b3, #004085);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 123, 255, 0.3);
}

.btn-outline-secondary {
    border: 2px solid #6c757d;
    border-radius: 10px;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-outline-secondary:hover {
    background-color: #6c757d;
    border-color: #6c757d;
    transform: translateY(-1px);
}

.result-container .alert,
#error .alert {
    border: none;
    border-radius: 15px;
    padding: 1.5rem;
    font-size: 1.1rem;
}

.alert-success {
    background: linear-gradient(45deg, #d4edda, #c3e6cb);
    color: #155724;
}

.alert-danger {
    background: linear-gradient(45deg, #f8d7da, #f5c6cb);
    color: #721c24;
}

.info-panel .card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
}

.info-panel .card-header {
    background: linear-gradient(45deg, #f8f9fa, #e9ecef);
    border: none;
    border-radius: 15px 15px 0 0;
    padding: 1rem 1.5rem;
}

.info-panel .card-body {
    padding: 1.5rem;
}

/* Input field state management */
.input-disabled {
    opacity: 0.6;
    pointer-events: none;
}

.input-disabled .form-control,
.input-disabled .form-select {
    background-color: #f8f9fa;
    color: #6c757d;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .calculator-container {
        padding: 2rem 1.5rem;
        margin: 1rem;
        border-radius: 15px;
    }
    
    .btn-primary {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    h1 {
        font-size: 1.75rem;
    }
}

/* Loading state */
.btn-loading {
    position: relative;
    color: transparent;
}

.btn-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    margin-left: -10px;
    margin-top: -10px;
    width: 20px;
    height: 20px;
    border: 2px solid #ffffff;
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Animation for result display */
.result-container,
#error {
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Chart container styles */
.chart-container {
    background: white;
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
    height: fit-content;
}

.chart-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(90deg, #28a745, #17a2b8, #ffc107, #dc3545);
}

.chart-wrapper {
    position: relative;
    height: 400px;
    margin: 1rem 0;
}

.chart-legend {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: #f8f9fa;
    border-radius: 20px;
    font-weight: 600;
    color: #495057;
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 50%;
}

.chart-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 400px;
    color: #6c757d;
    text-align: center;
}

.chart-empty i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

/* Responsive adjustments for chart */
@media (min-width: 992px) {
    .chart-container {
        position: sticky;
        top: 2rem;
    }
}

@media (max-width: 991px) {
    .chart-container {
        margin-top: 2rem;
        padding: 1.5rem;
    }
    
    .chart-wrapper {
        height: 300px;
    }
}