*{box-sizing:border-box}
body{
  margin:0;
  min-height:100vh;
  padding-bottom:40px;
  background:radial-gradient(circle at top,#27303a,#0d0f13 60%);
  color:#fff;
  font-family:Arial,Helvetica,sans-serif;
}
header{
  display:flex;
  justify-content:space-between;
  padding:18px 5%;
  background:#11141a;
  border-bottom:1px solid #303641;
}
header a{
  color:#f2c94c;
  text-decoration:none;
  font-weight:bold;
}
.painel{
  width:min(900px,92%);
  margin:28px auto;
  padding:28px;
  background:#1b1e24;
  border-radius:20px;
}
h1{
  margin:0;
  text-align:center;
  color:#f2c94c;
  font-size:clamp(32px,6vw,52px);
}
.painel>p{
  text-align:center;
  color:#aeb5c0;
}
.card{
  margin-top:16px;
  padding:18px;
  background:#12151a;
  border:1px solid #303641;
  border-radius:14px;
}
h2{
  color:#f2c94c;
  margin-top:0;
}
label{
  display:block;
  margin:12px 0 6px;
}
button,select{
  width:100%;
  min-height:44px;
  padding:10px;
  color:#fff;
  background:#272c34;
  border:1px solid #464d58;
  border-radius:8px;
}
button{
  cursor:pointer;
  font-weight:bold;
}
.destaque{
  background:#f2c94c;
  color:#111;
}
.botoes{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:10px;
  margin-top:12px;
}
.grade{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:18px;
}
input[type=range]{
  width:100%;
  accent-color:#f2c94c;
}
.afinador{
  transition:
    border-color .15s ease,
    box-shadow .15s ease,
    background .15s ease;
}
.afinador.afinado{
  border-color:#33e676;
  background:linear-gradient(145deg,#10251a,#111a15);
  box-shadow:
    0 0 12px rgba(51,230,118,.7),
    0 0 36px rgba(51,230,118,.35),
    inset 0 0 28px rgba(51,230,118,.10);
}
.nota{
  margin:8px 0;
  text-align:center;
  font-size:clamp(74px,14vw,120px);
  font-weight:900;
  color:#f2c94c;
}
.afinado .nota{
  color:#61ff99;
  text-shadow:0 0 22px rgba(97,255,153,.65);
}
.freq{
  text-align:center;
  font-size:26px;
  color:#d9dde4;
}
.luzes{
  display:grid;
  grid-template-columns:1fr 100px 1fr;
  gap:15px;
  align-items:center;
  margin:24px 0 18px;
}
.luz{
  min-height:54px;
  display:flex;
  justify-content:center;
  align-items:center;
  border-radius:12px;
  background:#252a31;
  border:1px solid #3c424c;
  color:#6f7783;
  font-weight:bold;
}
.luz.ativa-grave,
.luz.ativa-agudo{
  background:#4a2419;
  color:#ff956f;
  border-color:#e05e36;
  box-shadow:0 0 18px rgba(224,94,54,.35);
}
.luz.centro{
  font-size:48px;
  color:#28342d;
}
.luz.centro.acesa{
  background:#12331f;
  color:#48ff87;
  border-color:#48ff87;
  box-shadow:
    0 0 12px #33e676,
    0 0 30px rgba(51,230,118,.9),
    0 0 58px rgba(51,230,118,.55);
  animation:pulsoVerde .9s ease-in-out infinite;
}
@keyframes pulsoVerde{
  0%,100%{transform:scale(1);filter:brightness(1)}
  50%{transform:scale(1.04);filter:brightness(1.25)}
}
.meter{
  position:relative;
  height:28px;
  overflow:hidden;
  background:#2b313a;
  border-radius:20px;
}
.center{
  position:absolute;
  left:50%;
  top:0;
  bottom:0;
  width:4px;
  background:#55d187;
  transform:translateX(-50%);
}
.needle{
  position:absolute;
  top:0;
  bottom:0;
  left:50%;
  width:8px;
  background:#f2c94c;
  transform:translateX(-50%);
  transition:left .22s ease-out;
}
.afinado .needle{
  background:#55ff8f;
  box-shadow:0 0 14px #55ff8f;
}
.guia{
  display:flex;
  justify-content:space-between;
  margin-top:7px;
  color:#9aa2ad;
  font-size:13px;
}
.cents{
  margin-top:12px;
  text-align:center;
  font-size:25px;
  font-weight:bold;
}
.mensagem-afinacao{
  margin-top:8px;
  text-align:center;
  font-size:22px;
  font-weight:900;
  color:#aeb5c0;
}
.mensagem-afinacao.ok{
  color:#55ff8f;
  text-shadow:0 0 15px rgba(85,255,143,.55);
}
.mensagem-afinacao.grave,
.mensagem-afinacao.agudo{
  color:#ff956f;
}
#status{
  margin-top:16px;
  padding:13px;
  background:#111318;
  border-left:5px solid #ff5c5c;
  border-radius:8px;
}
#status.ok{
  border-left-color:#55d187;
}
@media(max-width:700px){
  .grade,.botoes{
    grid-template-columns:1fr;
  }
  .luzes{
    grid-template-columns:1fr 70px 1fr;
  }
}