:root { color-scheme: light; --ink: #0e141c; --muted: #4a5566; --blue: #2f5fd0; }
body { margin: 0; font: 500 16px/1.6 -apple-system, "Apple SD Gothic Neo", system-ui, sans-serif; color: var(--ink); background: #eef2f7; }
.box { max-width: 460px; margin: 8vh auto; background: #fff; border-radius: 16px; padding: 24px 22px; box-shadow: 0 8px 30px rgba(20, 40, 80, 0.12); }
h1 { font-size: 21px; margin: 0 0 10px; } h2 { font-size: 17px; }
.muted { color: var(--muted); font-size: 14px; word-break: break-all; }
input { width: 100%; box-sizing: border-box; font: inherit; padding: 11px 12px; border: 1px solid #c9d2df; border-radius: 10px; margin: 6px 0 10px; }
button { font: inherit; font-weight: 700; padding: 11px 16px; border: 0; border-radius: 10px; background: var(--blue); color: #fff; cursor: pointer; }
.code { font: 700 30px/1.2 ui-monospace, Menlo, monospace; letter-spacing: 4px; text-align: center; padding: 12px; background: #f3f6fb; border-radius: 12px; }