:root {
  --bg: #f7f7fb; --card: #ffffff; --text: #16161d; --muted: #6b6b7b; --line: #e6e6ef;
  --accent: #4f46e5; --accent-ink: #ffffff; --ok-bg: #e9f8ef; --ok: #16794a;
  --err-bg: #fdecec; --err: #b42318; --warn-bg: #fff6e0; --warn: #8a5a00; --code-bg: #f1f1f7;
  --radius: 12px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f14; --card: #17171f; --text: #ececf3; --muted: #9a9aab; --line: #2a2a36;
    --accent: #7c74ff; --ok-bg: #12301f; --ok: #6fd69c; --err-bg: #3a1616; --err: #ff8a80;
    --warn-bg: #352a10; --warn: #f3c66b; --code-bg: #1f1f2a;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
  font: 15px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--accent); }
.topbar { display: flex; justify-content: space-between; align-items: center; padding: 14px 20px;
  border-bottom: 1px solid var(--line); background: var(--card); }
.brand { font-weight: 800; font-size: 19px; color: var(--text); text-decoration: none; letter-spacing: -.02em; }
.brand span { color: var(--accent); }
.who { display: flex; gap: 12px; align-items: center; }
.who form { margin: 0; }
.container { max-width: 860px; margin: 28px auto; padding: 0 16px; }
.narrow { max-width: 460px; margin: 48px auto; padding: 0 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 24px; margin-bottom: 20px; }
.card-head { display: flex; justify-content: space-between; align-items: center; }
.center { text-align: center; }
h1 { font-size: 22px; margin: 0 0 8px; letter-spacing: -.01em; }
h2 { font-size: 17px; margin: 18px 0 10px; }
.card-head h2, .card > h2:first-child { margin-top: 0; }
.muted { color: var(--muted); }
.small, .fine { font-size: 13px; }
.stack { display: grid; gap: 10px; }
label { font-weight: 600; font-size: 14px; }
input { width: 100%; padding: 10px 12px; border-radius: 8px; border: 1px solid var(--line);
  background: var(--bg); color: var(--text); font: inherit; }
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.btn { display: inline-block; border: 1px solid var(--line); background: var(--card); color: var(--text);
  padding: 10px 16px; border-radius: 8px; font: inherit; font-weight: 600; cursor: pointer;
  text-decoration: none; text-align: center; white-space: nowrap; }
.btn:hover { filter: brightness(.97); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn-google { background: var(--card); }
.btn-ghost { background: transparent; }
.btn-danger { color: var(--err); }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-block { display: block; width: 100%; }
.divider { display: flex; align-items: center; gap: 10px; color: var(--muted); margin: 16px 0; font-size: 13px; }
.divider::before, .divider::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.alert { padding: 10px 14px; border-radius: 8px; margin: 12px 0; }
.alert-ok { background: var(--ok-bg); color: var(--ok); }
.alert-error { background: var(--err-bg); color: var(--err); }
.alert-warn { background: var(--warn-bg); color: var(--warn); }
.rows { list-style: none; margin: 0 0 14px; padding: 0; }
.row { display: flex; justify-content: space-between; align-items: center; gap: 12px;
  padding: 12px 0; border-bottom: 1px solid var(--line); }
.row:last-child { border-bottom: 0; }
.row form { margin: 0; }
.row-title { font-weight: 600; }
.badge { font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 999px; margin-left: 6px; }
.badge-on { background: var(--ok-bg); color: var(--ok); }
.badge-off { background: var(--code-bg); color: var(--muted); }
.inline-form { display: flex; gap: 10px; margin-top: 8px; }
.inline-form input { flex: 1; }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 13px; }
pre.code { background: var(--code-bg); padding: 12px 14px; border-radius: 8px; overflow-x: auto; margin: 8px 0; white-space: pre; }
.copyable { display: flex; gap: 10px; align-items: center; background: var(--code-bg); border-radius: 8px; padding: 10px 12px; }
.copyable code { flex: 1; overflow-wrap: anywhere; font-size: 14px; }
.copyable.block { align-items: flex-start; padding: 0 10px 0 0; }
.copyable.block pre { flex: 1; margin: 0; }
.copyable.block .btn { margin-top: 8px; }
.steps { padding-left: 20px; }
.steps li { margin: 4px 0; }
.left { text-align: left; }
.qr { display: block; margin: 10px auto; width: 264px; height: 264px; border-radius: 8px; background: #fff; }
.code-big { font: 700 26px/1.2 ui-monospace, monospace; letter-spacing: .12em; margin: 4px 0 8px; }
.foot { text-align: center; font-size: 12px; padding: 24px 0; }
@media (max-width: 560px) {
  .inline-form { flex-direction: column; }
  .row { flex-direction: column; align-items: flex-start; }
}