body{margin:0;padding:20px;display:flex;justify-content:center;align-items:center;min-height:100vh;background:#1a1a1a;font-family:Arial,sans-serif}.container{text-align:center;background:#2a2a2a;padding:30px;border-radius:15px;box-shadow:0 0 20px #0000004d}h1{color:#fff;margin-bottom:20px}#startBtn{padding:12px 24px;font-size:18px;background:#4caf50;color:#fff;border:none;border-radius:25px;cursor:pointer;transition:background .3s}#startBtn:hover{background:#45a049}.meter{margin-top:30px;position:relative;width:300px;height:200px}.db-value{position:absolute;top:40%;left:50%;transform:translate(-50%,-50%);font-size:2.5em;color:#fff;text-shadow:0 0 10px rgba(255,255,255,.5)}.bars{position:absolute;bottom:0;width:100%;height:80px;display:flex;justify-content:space-between;align-items:flex-end}.bars:after{content:"";position:absolute;width:100%;height:10px;background:linear-gradient(90deg,#0f0,red);bottom:-20px;border-radius:5px}@keyframes bar-animation{0%{height:10%}50%{height:90%}to{height:10%}}.control-panel{width:300px;overflow:hidden;margin:20px auto;padding:15px;background:#ffffff1a;border-radius:10px}.calibration-group{margin:10px 0;display:flex;gap:15px;align-items:center}#noiseSlider{flex:1;margin:0 10px;background:linear-gradient(to right,#4caf50,#ffc107,#f44336)}.calibrate-btn{padding:8px 20px;background:#2196f3;border:none;border-radius:5px;cursor:pointer;transition:opacity .3s}.bars div{transition:height .3s ease-in-out,background-color .3s;background:linear-gradient(to top,#4caf50,#8bc34a)}.bars div.active{background:linear-gradient(to top,#ffc107,#ff9800)}.bars div.overload{background:linear-gradient(to top,#f44336,#e91e63)}.bars div{width:8px;background:#4caf50;border-radius:3px 3px 0 0;animation:bar-animation 1.5s ease-in-out infinite;transform-origin:bottom}