:root{
  --bg:#eef2f7;
  --panel:#fff;
  --ink:#172033;
  --muted:#64748b;
  --line:#dbe3ed;
  --blue:#2563eb;
  --editor:#0f172a;
}

*{box-sizing:border-box}

body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font:15px/1.55 Inter,system-ui,sans-serif;
}

.app{max-width:1600px;margin:auto;padding:20px}

.back{
  display:inline-block;
  margin-bottom:12px;
  color:var(--muted);
  font-size:13px;
  font-weight:650;
  text-decoration:none;
}
.back:hover{color:var(--blue)}

header,.panel{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:17px;
  box-shadow:0 8px 25px #0f172a10;
}

header{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:16px;
  padding:15px 18px;
  margin-bottom:17px;
}
header h1{margin:0;font-size:21px}
header p{margin:1px 0;color:var(--muted);font-size:13px}

nav{display:flex;gap:8px;flex-wrap:wrap}

button,.button{
  border:1px solid var(--line);
  border-radius:10px;
  background:#fff;
  padding:9px 13px;
  font:inherit;
  font-weight:750;
  cursor:pointer;
}
.button input{display:none}
.primary{background:var(--blue);border-color:var(--blue);color:#fff}

.grid{
  display:grid;
  grid-template-columns:minmax(350px,1fr) minmax(500px,1fr);
  gap:17px;
}

.panel{overflow:hidden;display:flex;flex-direction:column}

.panel-head{
  height:55px;
  padding:10px 14px;
  border-bottom:1px solid var(--line);
  display:flex;
  align-items:center;
  justify-content:space-between;
  flex:none;
}
.panel-head.sub{height:44px;border-top:1px solid var(--line)}
.panel-head small{color:var(--muted)}

.options{
  display:flex;
  flex-wrap:wrap;
  gap:18px;
  align-items:center;
  padding:12px 14px;
  border-bottom:1px solid var(--line);
  background:#f8fafc;
  font-size:13px;
  color:var(--muted);
}
.options label{display:flex;align-items:center;gap:6px}
.options select{
  padding:5px 8px;
  border:1px solid var(--line);
  border-radius:8px;
  font:inherit;
  color:var(--ink);
  background:#fff;
}
.options .checkbox{cursor:pointer}
.options .checkbox input{width:15px;height:15px;accent-color:var(--blue)}

textarea{
  display:block;
  width:100%;
  min-height:56vh;
  resize:vertical;
  border:0;
  outline:0;
  padding:19px;
  background:var(--editor);
  color:#e2e8f0;
  font:13px/1.65 ui-monospace,monospace;
  flex:1;
}
textarea.drag-over{box-shadow:inset 0 0 0 2px var(--blue)}

.align-row{
  display:flex;
  flex-wrap:wrap;
  gap:6px;
  padding:10px 14px;
  border-bottom:1px solid var(--line);
  background:#f8fafc;
}
.align-btn{
  border:1px solid var(--line);
  border-radius:999px;
  background:#fff;
  padding:5px 11px;
  font-size:12px;
  font-weight:700;
  cursor:pointer;
  color:var(--muted);
}
.align-btn:hover{border-color:#93c5fd;color:var(--ink)}

.output-code{
  margin:0;
  padding:19px;
  background:var(--editor);
  color:#e2e8f0;
  font:12.5px/1.6 ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace;
  white-space:pre;
  overflow:auto;
  min-height:22vh;
  max-height:32vh;
}

.preview-shell{padding:18px;background:#f8fafc;overflow:auto;flex:1}

#previewTable{
  width:100%;
  border-collapse:collapse;
  font-size:13px;
  background:#fff;
  border-radius:10px;
  overflow:hidden;
  box-shadow:0 1px 0 var(--line);
}
#previewTable th{padding:9px 11px;background:#0f172a;color:#fff;font-weight:700}
#previewTable td{padding:9px 11px;border-bottom:1px solid #e2e8f0}
#previewTable tr:last-child td{border-bottom:0}

@media(max-width:1050px){
  .grid{grid-template-columns:1fr}
  header{align-items:flex-start;flex-direction:column}
}