* { margin: 0; } html, body { font-size: 18px; } .container { max-width: 1200px; margin: 30px auto; background: #f1f1f1; padding: 30px; } h1 { text-align: center; margin-bottom: 40px; } button { background: none; border: 1px solid black; border-radius: 4px; padding: 10px 20px; font-size: .9rem; } button:hover { background: orangered; } button:active { background: black; color: white; } .slider { width: 256px; height: 256px; border: 2px solid black; margin: 30px auto; overflow: hidden; } .slider-line { height: 256px; width: 1024px; background: orangered; position: relative; display: flex; left: 0; transition: all ease 1s; }