* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f4f8;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1100px;
    width: 100%;
    text-align: center;
}

.back-btn {
    display: inline-block;
    text-decoration: none;
    color: #3498db;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 20px;
}
.back-btn:hover { color: #2980b9; }

h1 {
    font-size: 2.3rem;
    color: #2c3e50;
    margin-bottom: 10px;
}

.subtitle {
    color: #7f8c8d;
    margin-bottom: 40px;
    font-size: 1.05rem;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 20px;
}

.card {
    background: #ffffff;
    border-radius: 12px;
    padding: 30px 20px;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.1);
}

.card-icon {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 15px;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.course-card .card-icon {
    background-color: #fde8d8;
    color: #e67e22;
}

.sub-card .card-icon {
    background-color: #fdecea;
    color: #c0392b;
}

.card h2 {
    font-size: 1.3rem;
    margin-bottom: 8px;
    color: #2c3e50;
}

.card p {
    font-size: 0.9rem;
    color: #95a5a6;
}