:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #475569;
    --accent-nn: #8b5cf6;
    --accent-mml: #0ea5e9;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: #1e293b;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    letter-spacing: -0.025em;
}

/* Custom Card Styles */
.card {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05) !important;
}

.card-header-icon {
    font-size: 3rem;
    color: white;
}

/* Course Specific Colors */
.bg-gradient-mml {
    background: linear-gradient(135deg, #0ea5e9 0%, #0369a1 100%);
}

.bg-gradient-nn {
    background: linear-gradient(135deg, #8b5cf6 0%, #6d28d9 100%);
}

.text-mml {
    color: #0284c7;
}

.text-nn {
    color: #7c3aed;
}

.bg-mml-light {
    background-color: #e0f2fe;
}

.bg-nn-light {
    background-color: #f3e8ff;
}

/* Concept & Example Boxes (Bootstrap Alerts) */
.alert-concept {
    border-left: 5px solid #0ea5e9;
    background-color: #f0f9ff;
    color: #0c4a6e;
}

.alert-example {
    border-left: 5px solid #22c55e;
    background-color: #f0fdf4;
    color: #14532d;
}

/* Math Block */
.math-block {
    background-color: #f8fafc;
    padding: 1.5rem;
    border-radius: 0.5rem;
    border: 1px solid #e2e8f0;
    margin: 1.5rem 0;
    overflow-x: auto;
    text-align: center;
}

/* Mermaid Container */
.diagram-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    margin: 2rem 0;
    display: flex;
    justify-content: center;
    border: 1px solid #e2e8f0;
}

/* Navigation Links */
.nav-link.active {
    font-weight: 600;
    color: var(--primary-color) !important;
}