/* =========================
   Base & Responsive Fonts
========================= */
:root {
    --accent: #0d6efd;
    --accent-light: rgba(13, 110, 253, 0.08);
    --accent-lighter: rgba(13, 110, 253, 0.02);
    --bg-dark: #0f1724;
    --text-dark: #fff;
    --card-shadow: rgba(0, 0, 0, 0.08);
}

html {
    font-size: 14px;
    position: relative;
    min-height: 100%;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

body {
    margin: 0;
    scroll-behavior: smooth;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #fff;
    color: #000;
    transition: background-color 0.3s, color 0.3s;
}

/* =========================
   Focus & Accessibility
========================= */
.btn:focus,
.btn:active:focus,
.btn-link.nav-link:focus,
.form-control:focus,
.form-check-input:focus {
    box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem var(--accent);
    outline: none;
}

/* =========================
   Hero Section
========================= */
.hero {
    background: linear-gradient(90deg, var(--accent-light), var(--accent-lighter));
    padding: 80px 20px;
    text-align: center;
}

@media (min-width: 768px) {
    .hero {
        padding: 100px 40px;
    }
}

/* =========================
   Card Hover Effect
========================= */
.card-hover {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

    .card-hover:hover {
        transform: translateY(-6px);
        box-shadow: 0 10px 30px var(--card-shadow);
    }

/* =========================
   Course Badge
========================= */
.course-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--accent);
    color: #fff;
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: bold;
}

/* =========================
   Instructor Image
========================= */
.instructor-img {
    width: 96px;
    height: 96px;
    object-fit: cover;
    border-radius: 50%;
    border: 2px solid var(--accent);
}

/* =========================
   Footer
========================= */
footer {
    background: var(--bg-dark);
    color: var(--text-dark);
    padding: 40px 20px;
    text-align: center;
}

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

        footer a:hover {
            color: #ff69b4; /* Accent hover */
        }

/* =========================
   Dark Mode Support
========================= */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #0a0a0a;
        color: #f1f1f1;
    }

    .hero {
        background: linear-gradient(90deg, rgba(13,110,253,0.2), rgba(13,110,253,0.05));
    }

    .card-hover:hover {
        box-shadow: 0 10px 30px rgba(255,255,255,0.05);
    }

    footer {
        background: #05080f;
    }
}