:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body { font-family: system-ui, -apple-system, Segoe UI, Roboto, "PingFang SC", "Microsoft Yahei", sans-serif; margin: 0; }
.app { max-width: 720px; margin: 48px auto; padding: 0 16px; }
h1 { font-size: 22px; margin: 0 0 24px; }
.controls { display: flex; gap: 8px; margin-bottom: 12px; }
input { flex: 1; padding: 10px 12px; border: 1px solid #ccc; border-radius: 8px; font-size: 16px; }
button { padding: 10px 16px; border: none; border-radius: 8px; background: #2f6fed; color: #fff; font-size: 16px; cursor: pointer; }
button:hover { filter: brightness(1.05); }
.loading { margin: 12px 0; }
.card { border: 1px solid #e5e7eb; border-radius: 12px; padding: 16px; }
.row { display: flex; gap: 8px; margin: 6px 0; }
.key { width: 110px; color: #6b7280; }
.val { flex: 1; }
.error { color: #b91c1c; }