:root {
    --bs-primary: #4F2683;
    --bs-primary-rgb: 79, 38, 131; 
}
body {
    font-family: 'Inter', sans-serif;
    background-color: #f0f2f5; /* Light grey background */
}
.main-container {
    margin-top: 30px;
    margin-bottom: 30px;
    padding: 20px;
    background-color: #ffffff;
    border-radius: 15px; /* Overall rounded corners */
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}
.form-section, .graph-section {
    padding: 20px;
}
.form-control, .btn {
    border-radius: 8px; /* Rounded corners for form elements and buttons */
}
.btn-primary {
    background-color: #4F2683;
    border-color: #4F2683;
    transition: all 0.3s ease;
}
.btn-primary:hover {
    background-color: #8F55E0;
    border-color: #8F55E0;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}
.btn-primary:active {
 background-color: #4F2683 !important; 
 border-color: #4F2683 !important;
}
.btn-primary:focus {
    background-color: #8F55E0; 
    border-color: #8F55E0;
   }
.btn-primary:disabled {
    background-color: #818284;
    border-color: #818284;
}
.btn-secondary {
    background-color: #818284;
    border-color: #818284;
    transition: all 0.3s ease;
}
.btn-secondary:hover {
    background-color: #5f6061;
    border-color: #5f6061;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}
.btn-secondary:active {
 background-color: #818284 !important; 
 border-color: #818284 !important;
}
.graph-placeholder {
    min-height: 300px;
    background-color: #f0f2f4; /* Light grey for graph area */
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #6c757d;
    font-size: 1.1rem;
    text-align: center;
    padding: 20px;
    flex-direction: column;
}
.loading-spinner {
    display: none; /* Hidden by default */
}
.error-message {
    color: #dc3545;
    font-weight: bold;
    margin-top: 10px;
}
canvas {
    max-width: 100%; /* Ensure canvas is responsive */
    height: auto;
}
.accordion-button:not(.collapsed) {
    background-color: #FFFFFF; /* A light blue color */
    color: #4F2683; /* Bootstrap's primary blue color */
}