body {
    background-color: #2b3a48; /* Dark background for the whole page */
    color: #ffffff; /* White text by default */
}

.card {
    border-radius: 12px; /* Soften the card edges */
    border: none; /* Remove default border */
}

.screen {
    background-color: #f5f5f5; /* Light grey background for screen */
    color: #333; /* Dark text for better readability */
    border-radius: 8px;
}

.btn {
    font-weight: bold;
    border-radius: 6px;
}

.btn-primary {
    background-color: #3b82f6; /* Blue for financial function buttons */
    border: none;
}

.btn-warning {
    background-color: #f59e0b; /* Orange for arithmetic operators */
    border: none;
}

.btn-danger {
    background-color: #e11d48; /* Red for clear buttons */
    border: none;
}

.btn-success {
    background-color: #10b981; /* Green for compute buttons */
    border: none;
}

.btn-light {
    background-color: #ffffff; /* White for numeric buttons */
    color: #333;
    border: none;
}

.btn-secondary {
    background-color: #6b7280; /* Gray for special buttons like +/- and backspace */
    border: none;
}

.list-group-item {
    border: none; /* Remove borders from list items */
}

ul.list-group {
    border-radius: 8px;
}

.card-body {
    padding: 1.5rem; /* Provide more space for the contents */
}

/* Optional: Additional Custom Styles */
.screen {
    transition: background-color 0.3s, color 0.3s;
}

.card-body {
    transition: background-color 0.3s, color 0.3s;
}

body {
    transition: background-color 0.3s, color 0.3s;
}

.btn {
    transition: background-color 0.3s, color 0.3s;
}