*{box-sizing:border-box;}
body{
  margin:0;
  background:#0b1020;
  color:#eef2ff;
  font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,Helvetica,sans-serif;
}
.wrap{
  max-width:960px;
  margin:0 auto;
  padding:16px;
}
header{
  margin-bottom:12px;
}
h1{
  margin:0 0 6px;
  font-size:24px;
  font-weight:750;
}
.sub{
  opacity:.9;
  margin:0 0 14px;
  font-size:14px;
  line-height:1.5;
}
.panel{
  background:#121a35;
  border:1px solid #223059;
  border-radius:16px;
  padding:16px;
  box-shadow:0 10px 30px rgba(0,0,0,.25);
}

/* Controls: mobile-first - stacked */
.controls{
  display:flex;
  flex-direction:column;
  align-items:stretch;
  gap:10px;
  margin-bottom:12px;
}
.controls label{
  font-size:13px;
  display:flex;
  flex-direction:column;
  gap:4px;
}
.controls select,
.controls button{
  padding:10px 12px;
  border-radius:999px;
  border:1px solid #2a3a62;
  background:#0e1731;
  color:#e7ebff;
  font-size:14px;
}
.controls button{
  cursor:pointer;
  text-align:center;
}
.controls button:hover{
  background:#182446;
}
.controls .small{
  font-size:12px;
  opacity:.95;
  flex-direction:row;
  align-items:center;
  gap:6px;
}

/* IO area */
.io{
  display:grid;
  grid-template-columns:1fr;
  gap:10px;
}
textarea{
  min-height:220px;
  width:100%;
  padding:10px 12px;
  border-radius:12px;
  border:1px solid #223059;
  background:#090f21;
  color:#f4f6ff;
  resize:vertical;
  font-size:15px;
  line-height:1.5;
}
textarea::placeholder{
  color:#7f8bb8;
}
.note{
  margin-top:10px;
  color:#c9d5ff;
  font-size:13px;
}

/* Medium screens: space controls horizontally, bit bigger text */
@media (min-width:600px){
  .wrap{padding:20px;}
  h1{font-size:26px;}
  .sub{font-size:15px;}
  .controls{
    flex-direction:row;
    flex-wrap:wrap;
    align-items:center;
  }
  .controls label{
    width:auto;
    min-width:200px;
  }
  .controls button{
    padding:10px 18px;
  }
}

/* Desktop: side-by-side textareas */
@media (min-width:900px){
  .wrap{padding:24px;}
  .io{
    grid-template-columns:1fr 1fr;
  }
  textarea{
    min-height:260px;
  }
}