/* =================================
    CSS VARIABLES (Light & Dark Mode)
    ================================= */
:root {
    /* Light Mode */
    --body-background: #f8f8f8;
    --main-text-color: #333;
    --heading-color: #333;
    --link-color: #0066cc;
    --link-hover-color: #005fa3;
    --strong-color: #000;
}

/* Dark Mode - Activated by System Preference or Manual Toggle */
@media (prefers-color-scheme: dark) {
    :root {
        --body-background: #1a1a1a;
        --main-text-color: #e0e0e0;
        --heading-color: #e0e0e0;
        --link-color: #79a1d1;
        --link-hover-color: #62707D;
        --strong-color: #e0e0e0;
    }
}

body[data-theme='dark'] {
    --body-background: #1a1a1a;
    --main-text-color: #e0e0e0;
    --heading-color: #e0e0e0;
    --link-color: #79a1d1;
    --link-hover-color: #62707D;
    --strong-color: #e0e0e0;
}

/* =================================
    Body and Layout Styling
    ================================= */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--body-background);
    color: var(--main-text-color);
    margin: 0;
    padding-top: 80px; /* Adjust for fixed header height */
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

/* =================================
    Typography
    ================================= */
h1 {
    font-size: 2.5em;
    color: var(--heading-color);
    margin-bottom: 0.5em;
    transition: color 0.3s ease;
}

h2 {
    font-size: 1.8em;
    color: var(--heading-color);
    margin-top: 2em;
    margin-bottom: 0.8em;
    transition: color 0.3s ease;
}

p {
    line-height: 1.6;
    margin-bottom: 1em;
}

strong {
    color: var(--strong-color);
    transition: color 0.3s ease;
}

a {
    color: var(--link-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    text-decoration: underline;
    color: var(--link-hover-color);
}