:root {
  --paper: #fff8eb; --ink: #0c1018; --text: #322f3c; --muted: #65626f;
  --amaranth: #e81659; --brain: #f7a8c0; --fold: #17151e;
}
@media (prefers-color-scheme: dark) {
  :root { --paper: #17151e; --ink: #efe7d6; --text: #e7e7e9; --muted: #a09dab; --amaranth: #fa2a62; --brain: #d9799a; --fold: #17151e; }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--paper); color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  display: flex; flex-direction: column; align-items: center;
}
main { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px; padding: 24px 16px; text-align: center; }
.brain { width: 132px; height: auto; }
.brain .body { fill: var(--brain); stroke: var(--ink); stroke-width: 2.2; stroke-linejoin: round; }
.brain .fold { fill: none; stroke: var(--fold); stroke-width: 1.6; stroke-linecap: round; }
h1 { margin: 6px 0 0; font-size: clamp(34px, 7vw, 60px); line-height: 1.05; letter-spacing: -0.02em; color: var(--ink); }
.sub { margin: 0; font-size: clamp(17px, 2.6vw, 21px); color: var(--muted); }
button {
  margin-top: 14px; font: inherit; font-weight: 700; font-size: 20px; padding: 14px 44px; cursor: pointer;
  color: #fff; background: var(--amaranth); border: 0; border-radius: 6px;
  box-shadow: 0 0 0 2px var(--ink), 5px 5px 0 0 var(--ink);
  transition: transform 80ms, box-shadow 80ms;
}
button:hover:not(:disabled) { transform: translate(-1px, -1px); box-shadow: 0 0 0 2px var(--ink), 7px 7px 0 0 var(--ink); }
button:active:not(:disabled) { transform: translate(4px, 4px); box-shadow: 0 0 0 2px var(--ink), 1px 1px 0 0 var(--ink); }
button:disabled { cursor: progress; opacity: 0.75; }
button:focus-visible { outline: 3px solid var(--ink); outline-offset: 4px; }
.note { margin: 4px 0 0; min-height: 1.5em; font-size: 15px; color: var(--muted); }
.note.bad { color: var(--amaranth); font-weight: 600; }
footer { padding: 18px 16px; font-size: 14px; color: var(--muted); }
footer a { color: inherit; }
@media (prefers-reduced-motion: reduce) { button { transition: none; } }