:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #57606a;
  --border: #d0d7de;
  --accent: #0969da;
  --warn: #bf8700;
  --error: #cf222e;
  --good: #1a7f37;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font: 14px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
}

header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  background: #f6f8fa;
}

h1 {
  margin: 0 0 12px;
  font-size: 20px;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

.controls label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 12px;
  color: var(--muted);
}

.controls input,
.controls select,
.controls button {
  font: inherit;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: white;
  min-width: 200px;
}

.controls button {
  cursor: pointer;
  min-width: auto;
}

.controls button:hover {
  background: var(--accent);
  color: white;
}

.status {
  font-size: 12px;
  color: var(--muted);
}

.status.ok { color: var(--good); }
.status.err { color: var(--error); }

main {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 0;
  height: calc(100vh - 200px);
}

.editor-pane,
.diagnostics-pane {
  padding: 16px 24px;
  overflow: auto;
}

.editor-pane {
  border-right: 1px solid var(--border);
}

#editor {
  width: 100%;
  height: 100%;
  resize: none;
  font: 14px/1.6 "SF Mono", Monaco, Menlo, Consolas, monospace;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
}

.diagnostics-pane h2 {
  font-size: 14px;
  margin: 0 0 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.badge {
  background: var(--error);
  color: white;
  border-radius: 12px;
  padding: 0 8px;
  font-size: 12px;
}

.badge.zero { background: var(--good); }

#diagnostics {
  list-style: none;
  padding: 0;
  margin: 0;
}

#diagnostics li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

#diagnostics button.word {
  background: transparent;
  border: 0;
  color: var(--error);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  padding: 0;
}

#diagnostics .suggestions {
  margin-left: 8px;
  color: var(--muted);
}

#diagnostics .suggestions button {
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  border-radius: 4px;
  padding: 2px 6px;
  margin: 0 4px;
  cursor: pointer;
  font: inherit;
}

#diagnostics .suggestions button:hover {
  background: var(--accent);
  color: white;
}

.empty {
  color: var(--good);
  font-style: italic;
}

footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  background: #f6f8fa;
  color: var(--muted);
  font-size: 12px;
}

footer a { color: var(--accent); }