.my-block { border: 1px solid #fff; border-radius: 5px; background-color: #00ff00; padding: 20px; color: #000; font-size: 16px; } .my-block h2 { font-size: 24px; margin-bottom: 10px; } .my-block p { font-size: 18px; line-height: 1.5; margin-bottom: 20px; }