:root {
  color-scheme: light;
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #1f2933;
  --muted: #5f6c7b;
  --border: #d7dde5;
  --primary: #176b87;
  --primary-dark: #10546a;
  --accent: #b45309;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.5; }
main { width: min(1120px, calc(100% - 32px)); margin: 0 auto; padding: 32px 0 40px; }
header { margin-bottom: 22px; }
h1 { margin: 0 0 8px; font-size: clamp(2rem, 5vw, 3.7rem); line-height: 1.05; letter-spacing: 0; }
.lede { max-width: 780px; margin: 0; color: var(--muted); font-size: 1.05rem; }
.notice { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin: 22px 0; }
.notice span { border: 1px solid var(--border); border-radius: 8px; background: var(--panel); padding: 10px 12px; color: var(--muted); font-size: 0.92rem; }
.workspace { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: stretch; }
.pane { min-width: 0; }
.pane-head { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; margin-bottom: 8px; }
h2 { margin: 0; font-size: 1rem; }
.stats { color: var(--muted); font-size: 0.88rem; white-space: nowrap; }
textarea, .result { width: 100%; min-height: 420px; border: 1px solid var(--border); border-radius: 8px; background: var(--panel); color: var(--text); padding: 16px; font: 1rem/1.6 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace; }
textarea { resize: vertical; }
.result { overflow: auto; white-space: pre-wrap; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 16px 0 22px; }
button { border: 1px solid var(--border); border-radius: 8px; background: var(--panel); color: var(--text); cursor: pointer; font: inherit; min-height: 42px; padding: 9px 14px; }
button:hover { border-color: var(--primary); }
.primary { border-color: var(--primary); background: var(--primary); color: #ffffff; font-weight: 700; }
.primary:hover { background: var(--primary-dark); }
.feedback { min-height: 24px; color: var(--accent); font-weight: 600; }
.notes { border-top: 1px solid var(--border); margin-top: 10px; padding-top: 18px; color: var(--muted); }
.notes h2 { color: var(--text); margin-bottom: 8px; }
.notes ul { margin: 0; padding-left: 20px; }
@media (max-width: 820px) {
  main { width: min(100% - 20px, 680px); padding-top: 22px; }
  .notice, .workspace { grid-template-columns: 1fr; }
  textarea, .result { min-height: 300px; }
}