:root {
  --paper: #e7ecf0;
  --card: #ffffff;
  --ink: #16202b;
  --muted: #5d6b7a;
  --rule: #d4dce3;
  --deep: #0b4f4a;
  --alert: #96162f;
}

* { box-sizing: border-box; }

/* Author display rules beat the browser's [hidden] { display: none }, and the
   sign in screens are toggled with that attribute. */
[hidden] { display: none !important; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: "Segoe UI", system-ui, Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
  display: grid;
  place-items: center;
  align-content: center;
  padding: 24px 20px 40px;
}

button, input { font: inherit; }
button { cursor: pointer; }
:focus-visible { outline: 3px solid var(--deep); outline-offset: 2px; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------------------------------------------------------------- card */

.auth-card {
  width: min(400px, 100%);
  padding: 26px 30px 30px;
  background: var(--card);
  border-radius: 3px;
  border-top: 5px solid var(--deep);
  box-shadow: 0 12px 34px rgba(22, 32, 43, 0.1);
}

.auth-head { position: relative; margin-bottom: 20px; }
.auth-site {
  margin: 0 0 14px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}
.auth-head h1 { font-size: 22px; font-weight: 620; letter-spacing: -0.015em; margin: 0 0 6px; }
.auth-sub { margin: 0; color: var(--muted); font-size: 14px; }

.auth-back {
  position: absolute;
  top: -2px;
  right: 0;
  width: 34px;
  height: 34px;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: transparent;
  color: var(--muted);
  font-size: 16px;
  line-height: 1;
}
.auth-back:hover { background: var(--paper); color: var(--ink); }

.auth-rail {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 14px;
  font-size: 12.5px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.auth-rail i { display: block; width: 22px; height: 3px; border-radius: 2px; background: var(--rule); }
.auth-rail i.done { background: var(--deep); }
.auth-rail span { margin-left: 5px; }

/* A floor under the body means most steps occupy the same box, so moving between
   them swaps content rather than visibly growing the card. */
.auth-body { min-height: 232px; }

.auth-screen { display: block; }
.auth-screen.entering { animation: screen-in 200ms cubic-bezier(0.2, 0, 0.2, 1); }

@keyframes screen-in {
  from { opacity: 0; transform: translateX(12px); }
  to   { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: reduce) {
  .auth-screen.entering { animation: none; }
}

/* -------------------------------------------------------------- fields */

.auth-screen label { display: block; }
.auth-screen label span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 14px;
}
.auth-screen input {
  width: 100%;
  padding: 11px 12px;
  border: 1px solid var(--rule);
  border-radius: 3px;
  margin-bottom: 16px;
  background: #fff;
  color: var(--ink);
}
.auth-screen button[type="submit"],
.auth-screen > button,
.auth-row button {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--deep);
  border-radius: 3px;
  background: var(--deep);
  color: #fff;
  font-weight: 600;
}
.auth-screen button[disabled] { opacity: 0.6; cursor: progress; }
.auth-screen .hint { margin: -4px 0 16px; font-size: 13.5px; color: var(--muted); }

.auth-row { display: flex; gap: 10px; }
.auth-row .secondary {
  border-color: var(--rule);
  background: transparent;
  color: var(--ink);
  font-weight: 400;
}

#twofa-qr { display: block; margin: 0 auto 14px; border: 1px solid var(--rule); border-radius: 3px; }
#twofa-code {
  letter-spacing: 0.32em;
  text-align: center;
  font-size: 22px;
  font-variant-numeric: tabular-nums;
}

.auth-details { margin: 0 0 18px; font-size: 13.5px; }
.auth-details summary { cursor: pointer; color: var(--muted); }
.auth-details .hint { margin: 10px 0 6px; }
code {
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: 13px;
  background: var(--paper);
  padding: 2px 6px;
  border-radius: 2px;
  word-break: break-all;
}

.recovery {
  list-style: none;
  margin: 0 0 16px;
  padding: 14px;
  border: 1px solid var(--rule);
  border-radius: 3px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px 14px;
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: 14px;
}

.err {
  margin: 18px 0 0;
  padding: 11px 13px;
  border-left: 4px solid var(--alert);
  background: #fbeaed;
  font-size: 14px;
}

.auth-foot {
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-items: center;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 12.5px;
  text-align: center;
}
.auth-foot a { color: var(--muted); text-decoration: underline; text-underline-offset: 3px; }