:root {
    --primary-green: #1dbf73; /* Yazılım Yeşili */
    --primary-blue: #0077ff; /* Yazılım Mavisi */
    --bg-light: #f4f6f8;
    --text-dark: #212529;
    --text-light: #ffffff;
    --shadow: 0 8px 24px rgba(0,0,0,0.06);
    --radius: 12px;
    --transition: 0.3s ease;
}

body {
    font-family: 'Segoe UI', 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
}

/* Ana başlık alanı */
header {
    background: linear-gradient(135deg, var(--primary-green), var(--primary-blue));
    color: var(--text-light);
    padding: 80px 20px;
    text-align: center;
    box-shadow: var(--shadow);
    border-bottom-left-radius: var(--radius);
    border-bottom-right-radius: var(--radius);
}

    header h1 {
        font-size: 3rem;
        margin-bottom: 15px;
    }

    header p {
        font-size: 1.2rem;
        opacity: 0.9;
    }

/* Sayfa bölümleri */
main {
    padding: 60px 20px;
}

.row {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: center;
}

.col-md-4 {
    background-color: white;
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: transform var(--transition), box-shadow var(--transition);
    flex: 1 1 300px;
    max-width: 350px;
}

    .col-md-4:hover {
        transform: translateY(-5px);
        box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    }

    .col-md-4 h2 {
        color: var(--primary-blue);
        font-size: 1.4rem;
        margin-bottom: 10px;
    }

/* Butonlar */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    transition: background-color var(--transition), color var(--transition);
}

.btn-primary {
    background-color: var(--primary-green);
    color: white;
    border: none;
}

    .btn-primary:hover {
        background-color: #17a263;
    }

.btn-outline-dark {
    background-color: transparent;
    border: 2px solid var(--primary-blue);
    color: var(--primary-blue);
}

    .btn-outline-dark:hover {
        background-color: var(--primary-blue);
        color: white;
    }

/* Footer */
footer {
    background-color: #e0e0e0;
    padding: 30px 20px;
    text-align: center;
    font-size: 0.95rem;
    color: #555;
    border-top: 2px solid #ccc;
    margin-top: 60px;
    border-radius: 8px 8px 0 0;
}

/* Başlıklar */
h1, h2, h3 {
    margin-top: 0;
    line-height: 1.2;
}