:root {
  --bg: #0b1020;
  --card: #121a33;
  --text: #e7ecff;
  --muted: #aab4e6;
  --accent: #7c5cff;
  --accent2: #22c55e;
  --border: rgba(255,255,255,0.08);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background: radial-gradient(1200px 800px at 15% 10%, rgba(124,92,255,0.25), transparent),
              radial-gradient(1000px 700px at 85% 25%, rgba(34,197,94,0.14), transparent),
              var(--bg);
  color: var(--text);
}
#app { max-width: 1100px; margin: 0 auto; padding: 28px 18px 40px; }
header { margin-bottom: 18px; }
.brand { font-weight: 800; letter-spacing: 0.3px; font-size: 24px; }
.sub { color: var(--muted); margin-top: 6px; }
main { display: grid; grid-template-columns: 1fr; gap: 16px; }
.card {
  background: rgba(18, 26, 51, 0.85);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  backdrop-filter: blur(8px);
}
h2 { margin: 0 0 10px; font-size: 16px; }
textarea {
  width: 100%;
  min-height: 140px;
  padding: 12px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.25);
  color: var(--text);
  resize: vertical;
  outline: none;
}
textarea:focus { border-color: rgba(124,92,255,0.65); }
.row { display: flex; gap: 10px; margin-top: 10px; }
button {
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid rgba(124,92,255,0.55);
  background: rgba(124,92,255,0.25);
  color: var(--text);
  cursor: pointer;
  font-weight: 700;
}
button.secondary { border-color: var(--border); background: rgba(255,255,255,0.04); }
button:disabled { opacity: 0.5; cursor: not-allowed; }
pre {
  margin: 0;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.28);
  overflow: auto;
  white-space: pre-wrap;
  line-height: 1.35;
  min-height: 160px;
}
.hint { margin-top: 10px; color: var(--muted); font-size: 13px; }
.sandbox { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.sandbox__pane {
  border: 1px dashed rgba(255,255,255,0.16);
  border-radius: 12px;
  padding: 12px;
  min-height: 140px;
  background: rgba(0,0,0,0.16);
}
.sandbox__title { font-weight: 800; font-size: 13px; margin-bottom: 8px; color: var(--muted); }
.muted { color: var(--muted); font-size: 13px; }
footer { margin-top: 14px; display: flex; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: 13px; }
code { color: var(--text); }
@media (max-width: 900px) {
  .sandbox { grid-template-columns: 1fr; }
}