:root {
  --bg: #0f1419;
  --panel: #151b23;
  --panel-2: #1b232d;
  --border: #2a333f;
  --text: #c9d4e0;
  --muted: #6b7785;
  --accent: #ff5a36;
  --ok: #57c97a;
  --err: #ff6b6b;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, Segoe UI, sans-serif;
}

body { display: flex; flex-direction: column; }

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 1.1rem;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.brand { display: flex; align-items: center; gap: 0.8rem; }
.logo { color: var(--accent); font-size: 1.6rem; line-height: 1; }
header h1 { margin: 0; font-size: 1.05rem; font-weight: 600; }
header p { margin: 0.1rem 0 0; font-size: 0.78rem; color: var(--muted); }
header code { color: var(--text); font-family: var(--mono); font-size: 0.74rem; }
.repo { color: var(--muted); text-decoration: none; font-size: 0.85rem; }
.repo:hover { color: var(--text); }

main {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  min-height: 0;
}

.pane { display: flex; flex-direction: column; background: var(--panel); min-height: 0; }

.pane-head, .tabs {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  background: var(--panel-2);
  border-bottom: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--muted);
  font-family: var(--mono);
}
.pane-head { justify-content: space-between; }
.status { font-size: 0.72rem; }
.status.ok { color: var(--ok); }
.status.err { color: var(--err); }

.tabs { padding: 0.25rem 0.5rem; }
.tab {
  background: none;
  border: none;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.76rem;
  padding: 0.3rem 0.55rem;
  border-radius: 5px;
  cursor: pointer;
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--text); background: var(--panel); }
.tab.has-error { color: var(--err); }

textarea, .output {
  flex: 1;
  margin: 0;
  padding: 0.9rem 1rem;
  border: none;
  background: var(--panel);
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.55;
  overflow: auto;
  white-space: pre;
  tab-size: 2;
}
textarea { resize: none; outline: none; }
.output { color: #b7c2d0; }
#out-diagnostics { color: var(--err); }
.hidden { display: none; }

@media (max-width: 760px) {
  main { grid-template-columns: 1fr; grid-template-rows: 1fr 1fr; }
}