* { margin: 0px; padding: 0px; box-sizing: border-box; font-family: 'Courier', monospace; } .sec { position: absolute; width: 100%; height: 100%; overflow: hidden; display: flex; justify-content: center; align-items: center; background: #0099ff; } .sec .dot { position: absolute; width: 40px; height: 40px; background: #fff; border-radius: 50%; transform: translate(-50%,-50%); cursor: default; transition: box-shadow 0.5s; } .sec .dot:active { box-shadow: 0 0 0 200vh #fff; border: 2px solid #000; } .sec .dot.active { background-color: #000; border: 2px solid black; } .sec .dot.active:active { box-shadow: 0 0 0 200vh rgb(0, 0, 0); border: 2px solid #fff; } .sec .dot::before { content:'Light Mode'; position: absolute; top: 50%; left:50px; white-space: nowrap; transform: translateY( -50%); color: #fff; font-size: 1.5em; font-weight: 600; } .sec .dot.active::before { content:'Dark Mode'; color: #000; } .sec h2 { position: absolute; width: 100%; height: 100%; display: flex; justify-content: center; align-items: center; font-size: 80vh ; color: #fff; background: #000; user-select: none; font-weight: 900; text-transform: uppercase; text-align: center; mix-blend-mode: multiply; } .sec.active h2 { color:#000; background: #fff; mix-blend-mode: screen; } .sec video { position: absolute; top: 0; left: 0; width: 100%; height: 100%; object-fit: cover; /* z-index: 1; */ }