#startBtn {   display:block;   color:#fff;   border:none;   border-radius:5px;   cursor:pointer;   margin-top:20px; } #preview { max-width:400px; margin:2em auto; background:#fff; border-radius:8px; box-shadow:0 2px 12px rgba(0,0,0,0.07); padding:1.5em 2em 2em 2em; display:flex; flex-direction:column; align-items:center; gap:1.2em; } #video { width:100%; max-width:350px; border-radius:6px; background:#222; box-shadow:0 1px 6px rgba(0,0,0,0.09); } #mic-level { width:100%; max-width:350px; height:18px; background:#e3e7ef; border-radius:9px; overflow:hidden; margin-top:0.8em; box-shadow:0 1px 4px rgba(0,0,0,0.04); } #mic-bar { height:100%; width:0%; background:linear-gradient(90deg, #2a7ae2 60%, #4fd1c5 100%); border-radius:9px 0 0 9px; transition:width 0.1s; } .not-available { color:#fff; background:#e24a4a; padding:0.5em 1em; border-radius:5px; margin:1em 0; font-weight:bold; text-align:center; } .device-select-row {gap:1em;width:100%;justify-content:center;margin-bottom:1em;align-items:center;margin-top:30px;} .device-select-row label { font-weight:500; margin-right:0.5em; } select { padding:0.4em 0.7em; border-radius:4px; border:1px solid #bbb; font-size:1em; } .cameraDiv, .micDiv {   width:100%; }