/* Dark by default, light when the system asks for it (below). */
:root {
  color-scheme: dark;
  --bg: #0d1117;
  --panel: #161b22;
  --border: #30363d;
  --fg: #e6edf3;
  --muted: #8b949e;
  --accent: #7ee787;
  --err: #ff7b72;
  --info: #79c0ff;
  --run-bg: rgba(126, 231, 135, 0.04);
  --run-err-bg: rgba(255, 123, 114, 0.06);
  --mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --bg: #ffffff;
    --panel: #f6f8fa;
    --border: #d0d7de;
    --fg: #1f2328;
    --muted: #59636e;
    --accent: #1a7f37;
    --err: #cf222e;
    --info: #0969da;
    --run-bg: rgba(26, 127, 55, 0.05);
    --run-err-bg: rgba(207, 34, 46, 0.05);
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  display: flex;
  flex-direction: column;
  height: 100vh;
}

header { padding: 18px 24px 10px; }
header h1 { margin: 0; font-size: 22px; font-weight: 700; letter-spacing: -0.01em; }
header h1 span { color: var(--accent); font-weight: 500; }
header p { margin: 6px 0 0; color: var(--muted); font-size: 14px; line-height: 1.5; max-width: 74ch; }

main {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  min-height: 0;
  margin: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.pane {
  background: var(--panel);
  display: flex;
  flex-direction: column;
  min-height: 0;
  /* Without this a grid item defaults to min-width:auto, so a pane with long
     unwrapped lines (the compiled Python) grows past its 1fr track and breaks
     the 50/50 split. min-width:0 keeps the columns equal; long lines scroll
     inside their own pane instead. */
  min-width: 0;
}

.pane-label {
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 6px 10px 6px 14px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 34px;
}

#run {
  font: inherit;
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: none;
  color: var(--bg);
  background: var(--accent);
  border: 0;
  border-radius: 6px;
  padding: 4px 12px;
  cursor: pointer;
  font-weight: 600;
}
#run:hover:not(:disabled) { filter: brightness(1.1); }
#run:disabled { background: var(--border); color: var(--muted); cursor: default; }

.pane-tools { display: flex; align-items: center; gap: 10px; }

#copy-link {
  font: inherit;
  font-size: 12px;
  letter-spacing: normal;
  text-transform: none;
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 10px;
  cursor: pointer;
}
#copy-link:hover { border-color: var(--muted); }

.example-pick {
  display: flex;
  align-items: center;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
#examples {
  font: inherit;
  font-size: 12px;
  letter-spacing: normal;
  text-transform: none;
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 8px;
  cursor: pointer;
}
#examples:hover { border-color: var(--muted); }
#examples:focus { outline: 1px solid var(--info); outline-offset: 0; }

#run-output {
  border-top: 1px solid var(--border);
  padding: 10px 14px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  white-space: pre-wrap;
  overflow: auto;
  max-height: 45%;
  color: var(--fg);
  background: var(--run-bg);
}
#run-output.run-error { color: var(--err); background: var(--run-err-bg); }
#run-output::before {
  content: "output";
  display: block;
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}

#editor {
  flex: 1;
  resize: none;
  border: 0;
  outline: 0;
  padding: 14px;
  background: transparent;
  color: var(--fg);
  font-family: var(--mono);
  font-size: 15px;
  line-height: 1.6;
  tab-size: 2;
  white-space: pre;
  overflow: auto;
}

#output {
  flex: 1;
  margin: 0;
  padding: 14px;
  overflow: auto;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  color: var(--fg);
  white-space: pre;
}
#output.output-empty { color: var(--muted); }

#diagnostics { max-height: 45%; overflow: auto; }
#diagnostics.has-diags { border-top: 1px solid var(--border); }
.diag { font-family: var(--mono); font-size: 13px; line-height: 1.5; padding: 6px 14px; }
.diag-error { color: var(--err); }
.diag-info { color: var(--info); }

footer { padding: 10px 24px 14px; color: var(--muted); font-size: 12px; }
footer a { color: var(--info); text-decoration: none; }
footer a:hover { text-decoration: underline; }
footer code { color: var(--accent); }

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