:root {
  --bg: #fafafa;
  --surface: #ffffff;
  --border: #e5e5e5;
  --border-focus: #a0a0a0;
  --text: #171717;
  --text-muted: #737373;
  --accent: #171717;
  --accent-hover: #404040;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  line-height: 1.5;
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px;
}

header {
  margin-bottom: 32px;
}

h1 {
  font-size: 1.5rem;
  font-weight: 600;
  margin: 0 0 6px;
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0;
}

.workspace {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 700px) {
  .workspace {
    grid-template-columns: 1fr;
  }
}

.pane {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

textarea {
  width: 100%;
  height: 420px;
  padding: 16px;
  font-family: "SF Mono", "Fira Code", "Consolas", monospace;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  resize: none;
  transition: border-color 0.15s ease;
  overflow: auto;
}

textarea:focus {
  outline: none;
  border-color: var(--border-focus);
}

textarea::placeholder {
  color: #a0a0a0;
}

.controls {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-top: 4px;
}

button {
  padding: 8px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s ease;
}

button.primary {
  background: var(--accent);
  color: white;
  border: none;
}

button.primary:hover {
  background: var(--accent-hover);
}

button.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

button.secondary:hover {
  background: var(--bg);
}

.status {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
}