:root{
  --bg:#0f172a;
  --card:#020617;
  --accent:#38bdf8;
  --danger:#ef4444;
  --text:#e5e7eb;
}
*{box-sizing:border-box}
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:system-ui,sans-serif;
}
header{
  padding:20px;
  text-align:center;
}
header h1{margin:0}
main{
  max-width:1200px;
  margin:auto;
  padding:20px;
}
.card{
  background:var(--card);
  padding:20px;
  border-radius:14px;
  margin-bottom:20px;
  box-shadow:0 0 0 1px #1e293b;
}
input{
  width:100%;
  padding:12px;
  border-radius:8px;
  border:1px solid #1e293b;
  background:#020617;
  color:#fff;
}
button{
  margin-top:12px;
  padding:12px 18px;
  border:none;
  border-radius:8px;
  background:var(--accent);
  color:#000;
  cursor:pointer;
  font-weight:600;
}
.tabs{
  display:flex;
  gap:10px;
  margin-bottom:12px;
}
.tabs button{
  flex:1;
  background:#1e293b;
  color:#fff;
}
.tabs button.active{
  background:var(--accent);
  color:#000;
}
.panel{display:none}
.panel.active{display:block}
iframe{
  width:100%;
  height:500px;
  border-radius:10px;
  border:1px solid #1e293b;
  background:#fff;
}
pre{
  background:#020617;
  padding:15px;
  overflow:auto;
  border-radius:10px;
  max-height:500px;
  font-size:13px;
}
.error{
  color:var(--danger);
  margin-top:10px;
}
ul{padding-left:18px}
footer{
  text-align:center;
  padding:20px;
  opacity:.7;
}

@media (min-width:300px) and (max-width:350) {
    header{
        padding:20px;
        text-align:center;
    }
    header h1{margin:0; font-size: smaller;}
    
}