:root { color-scheme: light dark; --fg: #1b1b1b; --bg: #ffffff; --muted: #5c5c5c; --accent: #0b5cad; --error: #b3261e; }
@media (prefers-color-scheme: dark) {
  :root { --fg: #ececec; --bg: #161616; --muted: #a8a8a8; --accent: #6aa8ff; --error: #ff8a80; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 17px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; }
main { max-width: 40rem; margin: 0 auto; padding: 1.5rem 1rem 3rem; }
h1 { font-size: 1.5rem; margin: 0 0 0.5rem; }
textarea { width: 100%; font: 0.85rem/1.4 ui-monospace, Menlo, Consolas, monospace; padding: 0.75rem; border: 1px solid var(--muted);
  border-radius: 6px; background: transparent; color: var(--fg); resize: vertical; word-break: break-all; }
button { display: block; width: 100%; margin: 1rem 0; padding: 1.1rem; font-size: 1.3rem; font-weight: 600; color: #fff;
  background: var(--accent); border: 0; border-radius: 10px; cursor: pointer; }
button:active { opacity: 0.85; }
.error { color: var(--error); font-weight: 600; }
.small { color: var(--muted); font-size: 0.85rem; margin-top: 2rem; }
#status { min-height: 1.5em; }