*{box-sizing:border-box}body{color:#fff;background:#0d1b2a;margin:0;font-family:Arial,Helvetica,sans-serif}.app{z-index:1;flex-direction:column;justify-content:center;align-items:center;height:100vh;display:flex;position:relative}h1{margin-bottom:40px}.timer{margin-bottom:20px;font-size:5rem;font-weight:700}.exercise{margin-bottom:40px;font-size:1.6rem}button{color:#fff;cursor:pointer;background:#00a8e8;border:none;border-radius:10px;padding:15px 35px;font-size:1.2rem}button:hover{background:#0077b6}.panel{text-align:center;width:320px;margin-bottom:25px}.label{color:#7aa6c2;text-transform:uppercase;letter-spacing:2px;margin-bottom:8px;font-size:.9rem}.panel div:last-child{font-size:2rem;font-weight:700}.video-background{z-index:0;opacity:0;pointer-events:none;transition:opacity .6s;position:fixed;inset:0}.video-background.is-visible{opacity:1}.video-background__media{object-fit:cover;width:100%;height:100%;display:block}.video-background__overlay{background:#050c1499;position:absolute;inset:0}.button-row{gap:12px;display:flex}#pauseButton{background:#3a3a3a}#pauseButton:hover{background:#2a2a2a}#pauseButton:disabled,button:disabled{opacity:.5;cursor:not-allowed}.pause-status{letter-spacing:2px;color:#ffd166;text-transform:uppercase;margin-bottom:16px;font-size:1.1rem}