:root {
  --bg: #f6f4ef; --card: #ffffff; --ink: #1f2328; --muted: #5b6168; --line: #d9d4c7;
  --accent: #1f6f43; --accent-ink: #ffffff; --bad: #b42318; --ok: #1f6f43;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16181b; --card: #1f2226; --ink: #ece8df; --muted: #a3a8ae; --line: #3d3a32;
    --accent: #4fae78; --accent-ink: #0d1a12; --bad: #f97066; --ok: #4fae78;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #16181b; --card: #1f2226; --ink: #ece8df; --muted: #a3a8ae; --line: #3d3a32;
  --accent: #4fae78; --accent-ink: #0d1a12; --bad: #f97066; --ok: #4fae78;
  color-scheme: dark;
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 16px;
  background: var(--bg); color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { width: 100%; max-width: 420px; background: var(--card); border: 1px solid var(--line);
       border-radius: 10px; padding: 24px; }
h1 { font-size: 20px; margin: 0 0 8px; }
p { margin: 8px 0; }
.muted { color: var(--muted); font-size: 14px; }
label { display: block; margin: 16px 0 6px; font-weight: 600; }
input[type=text] {
  width: 100%; font: 600 28px/1.2 ui-monospace, "Cascadia Mono", Consolas, monospace; letter-spacing: .35em;
  text-align: center; padding: 10px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--ink);
}
textarea {
  width: 100%; font: 13px/1.4 ui-monospace, "Cascadia Mono", Consolas, monospace; padding: 8px;
  border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink); resize: vertical;
  overflow-wrap: anywhere;
}
a { color: var(--accent); }
input:focus-visible, textarea:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
button {
  margin-top: 16px; width: 100%; padding: 12px; font: 600 16px/1 inherit; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink);
}
button.secondary { background: transparent; color: var(--ink); border-color: var(--line); }
button:disabled { opacity: .55; cursor: default; }
.msg { min-height: 1.5em; margin-top: 12px; }
.msg.bad { color: var(--bad); }
.msg.ok { color: var(--ok); }
[hidden] { display: none !important; }