/* ============================================================================
   Brute Info — css/pages/auth.css
   Page stylesheet for login.html and signup.html.

   Structure
     1.  Split shell
     2.  Brand panel — drifting mesh + constellation backdrop
     3.  Brand panel content
     4.  Form column and card
     5.  Entrance choreography (stagger + page-swap slide)
     6.  Auth field: floating label, underline wipe, error pulse
     7.  Password reveal (morphing eye) and strength meter
     8.  Google button and provider note
     9.  Morphing submit button
     10. Responsive collapse
     11. Motion opt-out

   Nothing here restyles a shared component; everything custom is built from
   the tokens in css/tokens.css.
   ========================================================================== */

/* ==========================================================================
   1. SPLIT SHELL
   ========================================================================== */
.auth-split {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr);
  min-height: calc(100svh - var(--header-h));
  isolation: isolate;
}

/* ==========================================================================
   2. BRAND PANEL BACKDROP
   ========================================================================== */
.auth-brand {
  position: relative;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--grad-brand);
  color: var(--text-on-brand);
  padding: var(--space-16) var(--space-12);
}

/* The panel sits on brand ink, so its own scale of "muted" is a wash of the
   on-brand text colour rather than the page's --text-muted. Every step is
   pitched so it clears 4.5:1 against the deepened ground below, in both
   themes and on all five accent ramps. */
.auth-brand {
  --ink: var(--text-on-brand);
  --ink-soft: color-mix(in srgb, var(--text-on-brand) 84%, transparent);
  --ink-faint: color-mix(in srgb, var(--text-on-brand) 72%, transparent);
  --ink-line: color-mix(in srgb, var(--text-on-brand) 30%, transparent);
  --ink-wash: color-mix(in srgb, var(--text-on-brand) 14%, transparent);
  /* The page's indigo focus ring disappears on an indigo panel. */
  --focus-ring-color: var(--text-on-brand);
}

/* The accent ramp's light stop (--a-400) cannot carry white text on its own —
   it measures under 3:1 before the mesh lightens it further. This veil sits
   above the whole backdrop and below .auth-brand-inner, deepest where the
   gradient is palest, so the panel reads as brand ink rather than a pale slab
   floating on a dark page. */
.auth-brand::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background: linear-gradient(
    135deg,
    color-mix(in srgb, var(--a-950) 55%, transparent) 0%,
    color-mix(in srgb, var(--a-950) 34%, transparent) 52%,
    color-mix(in srgb, var(--a-950) 48%, transparent) 100%
  );
}

.auth-brand-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

/* Slow-drifting mesh. Three blobs on two counter-rotating layers so the
   pattern never visibly loops. */
.auth-mesh {
  position: absolute;
  inset: -25%;
  display: block;
  background:
    radial-gradient(38% 42% at 22% 26%, color-mix(in srgb, var(--a-400) 55%, transparent) 0%, transparent 68%),
    radial-gradient(34% 38% at 78% 18%, color-mix(in srgb, var(--amber-400) 38%, transparent) 0%, transparent 66%),
    radial-gradient(46% 46% at 62% 82%, color-mix(in srgb, var(--a-700) 76%, transparent) 0%, transparent 70%);
  filter: blur(8px);
  animation: auth-mesh-drift 34s var(--ease-standard) infinite alternate;
  will-change: transform;
}
.auth-mesh-2 {
  background:
    radial-gradient(40% 36% at 74% 62%, color-mix(in srgb, var(--a-300) 28%, transparent) 0%, transparent 70%),
    radial-gradient(30% 34% at 16% 74%, color-mix(in srgb, var(--amber-300) 22%, transparent) 0%, transparent 68%);
  animation-duration: 47s;
  animation-direction: alternate-reverse;
  opacity: 0.85;
}

@keyframes auth-mesh-drift {
  0%   { transform: translate3d(-3%, -2%, 0) scale(1.04) rotate(-2deg); }
  50%  { transform: translate3d(4%, 3%, 0) scale(1.12) rotate(2deg); }
  100% { transform: translate3d(-2%, 5%, 0) scale(1.06) rotate(-1deg); }
}

/* A faint rule grid keeps the gradient from reading as a smear. */
.auth-brand-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--text-on-brand) 11%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--text-on-brand) 11%, transparent) 1px, transparent 1px);
  background-size: 68px 68px;
  /* #000 here is a mask alpha stop, not a colour the reader ever sees. */
  mask-image: radial-gradient(80% 70% at 40% 40%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(80% 70% at 40% 40%, #000 0%, transparent 78%);
}

/* --- Constellation ------------------------------------------------------ */
.auth-constellation {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* Stroke and fill alphas are pitched for the veil above: at the old 42% the
   whole constellation dropped out of the deepened panel. */
.cn-link {
  stroke: color-mix(in srgb, var(--text-on-brand) 62%, transparent);
  stroke-width: 1;
  fill: none;
  opacity: 0.5;
  animation: auth-link-breathe 9s var(--ease-standard) infinite alternate;
  animation-delay: var(--d, 0s);
}
/* The "re-linking" edges: they dissolve and reform on their own long cycles. */
.cn-link.is-swap {
  opacity: 0;
  stroke-dasharray: 1 1;
  animation: auth-link-relink 14s var(--ease-standard) infinite;
  animation-delay: var(--d, 0s);
}
.cn-link.is-lit {
  stroke: color-mix(in srgb, var(--amber-300) 92%, transparent);
  stroke-width: 1.4;
}

@keyframes auth-link-breathe {
  0%   { opacity: 0.24; }
  100% { opacity: 0.62; }
}
@keyframes auth-link-relink {
  0%, 8%    { opacity: 0; stroke-dashoffset: 1; }
  22%, 62%  { opacity: 0.62; stroke-dashoffset: 0; }
  80%, 100% { opacity: 0; stroke-dashoffset: -1; }
}

.cn-node {
  fill: color-mix(in srgb, var(--text-on-brand) 94%, transparent);
  animation: auth-node-pulse 6.5s var(--ease-standard) infinite;
  animation-delay: var(--d, 0s);
  transform-box: fill-box;
  transform-origin: center;
}
.cn-node.is-accent { fill: var(--amber-300); }
.cn-halo {
  fill: none;
  stroke: color-mix(in srgb, var(--text-on-brand) 58%, transparent);
  stroke-width: 1;
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
  animation: auth-halo 6.5s var(--ease-out) infinite;
  animation-delay: var(--d, 0s);
}

@keyframes auth-node-pulse {
  0%, 100% { transform: scale(0.82); opacity: 0.62; }
  46%      { transform: scale(1.18); opacity: 1; }
}
@keyframes auth-halo {
  0%   { transform: scale(0.6); opacity: 0.5; }
  70%  { transform: scale(2.6); opacity: 0; }
  100% { transform: scale(2.6); opacity: 0; }
}

/* ==========================================================================
   3. BRAND PANEL CONTENT
   ========================================================================== */
.auth-brand-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  width: 100%;
  max-width: 30rem;
  margin-inline: auto;
}

.auth-brand-mark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  align-self: flex-start;
  color: var(--ink);
  text-decoration: none;
  font-weight: var(--fw-extrabold);
  font-size: var(--fs-lg);
  letter-spacing: var(--tracking-tight);
  padding: var(--space-2) var(--space-3);
  margin-inline-start: calc(var(--space-3) * -1);
  border-radius: var(--radius-md);
}
.auth-brand-mark:hover { color: var(--ink); text-decoration: none; background: var(--ink-wash); }
.auth-brand-mark:active { background: color-mix(in srgb, var(--text-on-brand) 22%, transparent); }
.auth-brand-mark:focus-visible { outline-offset: 3px; }
.auth-brand-mark img {
  width: 2rem;
  height: 2rem;
  padding: 0.25rem;
  border-radius: var(--radius-sm);
  background: var(--ink);
  box-shadow: var(--shadow-sm);
}

.auth-eyebrow {
  font-size: var(--fs-xs);
  font-weight: var(--fw-bold);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--amber-200);
}

.auth-lede {
  font-size: var(--fs-4xl);
  font-weight: var(--fw-extrabold);
  line-height: var(--lh-tight);
  letter-spacing: var(--tracking-tight);
  text-wrap: balance;
}
.auth-lede-sub {
  margin-top: var(--space-3);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--ink-soft);
  max-width: 42ch;
}

.auth-benefits {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  list-style: none;
  padding: 0;
  margin: 0;
}
.auth-benefits li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--fs-md);
  line-height: var(--lh-snug);
  color: var(--ink-soft);
}
.auth-benefit-tick {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: var(--radius-full);
  background: var(--ink-wash);
  box-shadow: inset 0 0 0 1px var(--ink-line);
  color: var(--ink);
}
.auth-benefit-tick svg { width: 0.85rem; height: 0.85rem; }
.auth-benefit-name { color: var(--ink); font-weight: var(--fw-semibold); }

.auth-facts {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3) var(--space-8);
  margin: 0;
}
.auth-facts > div { display: flex; flex-direction: column; gap: var(--space-1); }
.auth-facts dt {
  order: 2;
  font-size: var(--fs-2xs);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--ink-faint);
}
.auth-facts dd {
  order: 1;
  margin: 0;
  font-size: var(--fs-2xl);
  font-weight: var(--fw-extrabold);
  line-height: var(--lh-none);
  letter-spacing: var(--tracking-tight);
  font-variant-numeric: tabular-nums;
}

/* --- Rotating testimonial ----------------------------------------------- */
.auth-quotes {
  position: relative;
  display: grid;
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  background: var(--ink-wash);
  box-shadow: inset 0 0 0 1px var(--ink-line);
  -webkit-backdrop-filter: blur(var(--glass-blur));
  backdrop-filter: blur(var(--glass-blur));
}
.auth-quote {
  grid-area: 1 / 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition:
    opacity var(--dur-base) var(--ease-standard),
    transform var(--dur-slow) var(--ease-out),
    visibility 0s linear var(--dur-base);
}
/* The arriving quote waits for the leaving one to clear. Crossfading them at
   the same time stacked two paragraphs of half-lit text on the same lines. */
.auth-quote.is-active {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition:
    opacity var(--dur-slow) var(--ease-standard) var(--dur-base),
    transform var(--dur-slow) var(--ease-out) var(--dur-base),
    visibility 0s linear 0s;
}
.auth-quote blockquote {
  margin: 0;
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--ink);
  text-wrap: pretty;
}
.auth-quote figcaption {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.auth-quote-avatar {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-full);
  background: var(--ink-wash);
  box-shadow: inset 0 0 0 1px var(--ink-line);
  font-size: var(--fs-xs);
  font-weight: var(--fw-bold);
  letter-spacing: var(--tracking-wide);
  color: var(--ink);
}
.auth-quote-who { display: flex; flex-direction: column; min-width: 0; }
.auth-quote-name { font-size: var(--fs-md); font-weight: var(--fw-semibold); color: var(--ink); }
.auth-quote-role { font-size: var(--fs-xs); color: var(--ink-faint); }

.auth-quote-dots {
  position: relative;
  z-index: 1;
  display: flex;
  gap: var(--space-2);
  justify-content: flex-end;
  margin-top: var(--space-4);
}
.auth-dot {
  position: relative;
  width: 1.5rem;
  height: 0.3125rem;
  padding: 0;
  border: 0;
  border-radius: var(--radius-full);
  background: var(--ink-line);
  cursor: pointer;
  transition: background-color var(--dur-base) var(--ease-standard),
              width var(--dur-base) var(--ease-out);
}
/* The bar itself is 5px tall; this gives it a ~26px pointer target. */
.auth-dot::after {
  content: "";
  position: absolute;
  inset: -0.65rem -0.3rem;
}
.auth-dot:hover { background: var(--ink-faint); }
.auth-dot:active { background: var(--ink); }
.auth-dot:focus-visible { outline-offset: 4px; }
.auth-dot[aria-current="true"] { width: 2.25rem; background: var(--amber-300); }

/* ==========================================================================
   4. FORM COLUMN AND CARD
   ========================================================================== */
.auth-panel {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-12) var(--container-pad);
  background: var(--bg);
}

.auth-card-wrap {
  width: 100%;
  max-width: 26.25rem; /* ~420px */
}

.auth-card {
  padding: var(--space-8);
  gap: var(--space-5);
}
.auth-card-head {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.auth-title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-extrabold);
  letter-spacing: var(--tracking-tight);
  line-height: var(--lh-tight);
}
.auth-sub { color: var(--text-muted); font-size: var(--fs-md); }

.auth-form { display: flex; flex-direction: column; gap: var(--field-gap); }

.auth-row-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.auth-remember { display: flex; flex-direction: column; gap: var(--space-2); }

.auth-link {
  font-size: var(--fs-md);
  font-weight: var(--fw-semibold);
  color: var(--primary);
  text-decoration: none;
  border-radius: var(--radius-xs);
}
.auth-link:hover { text-decoration: underline; }
.auth-link:active { color: var(--primary-active); }
.auth-link:focus-visible { outline-offset: 3px; }

.auth-foot {
  padding-top: var(--space-5);
  border-top: 1px solid var(--border-subtle);
  text-align: center;
  font-size: var(--fs-md);
  color: var(--text-muted);
}

/* ==========================================================================
   5. ENTRANCE CHOREOGRAPHY
   Pure CSS, so it never depends on a module finishing.
   ========================================================================== */
@keyframes auth-rise {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: none; }
}
@keyframes auth-card-in {
  from { opacity: 0; transform: translateY(20px) scale(0.985); }
  to   { opacity: 1; transform: none; }
}

.auth-stagger {
  animation: auth-rise var(--dur-slower) var(--ease-out) backwards;
  animation-delay: var(--d, 0ms);
}
.auth-card {
  animation: auth-card-in var(--dur-slower) var(--ease-out) backwards;
  animation-delay: 60ms;
}

/* Login <-> signup swap. The leaving card slides out, the arriving one slides
   in from the opposite edge, so the two pages read as one surface. */
@keyframes auth-swap-in-right {
  from { opacity: 0; transform: translateX(34px) scale(0.985); }
  to   { opacity: 1; transform: none; }
}
@keyframes auth-swap-in-left {
  from { opacity: 0; transform: translateX(-34px) scale(0.985); }
  to   { opacity: 1; transform: none; }
}
@keyframes auth-swap-out-left {
  from { opacity: 1; transform: none; }
  to   { opacity: 0; transform: translateX(-34px) scale(0.985); }
}
@keyframes auth-swap-out-right {
  from { opacity: 1; transform: none; }
  to   { opacity: 0; transform: translateX(34px) scale(0.985); }
}

[data-auth-swap="from-right"] .auth-card { animation: auth-swap-in-right var(--dur-slow) var(--ease-out) backwards; animation-delay: 0ms; }
[data-auth-swap="from-left"]  .auth-card { animation: auth-swap-in-left  var(--dur-slow) var(--ease-out) backwards; animation-delay: 0ms; }
/* On a swap the fields are already in place — only the card travels. */
[data-auth-swap] .auth-card .auth-stagger { animation: none; }

.auth-card.is-leaving-left  { animation: auth-swap-out-left  var(--dur-base) var(--ease-in) both; }
.auth-card.is-leaving-right { animation: auth-swap-out-right var(--dur-base) var(--ease-in) both; }

/* Invalid submit: a short shake, nothing bouncy. */
@keyframes auth-shake {
  0%, 100% { transform: translateX(0); }
  15% { transform: translateX(-8px); }
  30% { transform: translateX(7px); }
  45% { transform: translateX(-5px); }
  60% { transform: translateX(4px); }
  80% { transform: translateX(-2px); }
}
.auth-card.is-invalid { animation: auth-shake 460ms var(--ease-standard); }

/* ==========================================================================
   6. AUTH FIELD — floating label, wiping underline
   ========================================================================== */
.af {
  --af-h: calc(var(--control-h-lg) + 0.375rem);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.af-control { position: relative; display: block; }

.af-input {
  width: 100%;
  min-height: var(--af-h);
  padding: 0.9rem var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.4;
  box-shadow: var(--shadow-xs);
  appearance: none;
  -webkit-appearance: none;
  transition:
    border-color var(--dur-fast) var(--ease-standard),
    box-shadow var(--dur-fast) var(--ease-standard),
    background-color var(--dur-fast) var(--ease-standard);
}
.af-input::placeholder { color: transparent; }
.af-input:hover:not(:disabled) { border-color: var(--text-subtle); }
.af-input:focus { outline: none; border-color: var(--primary); box-shadow: var(--ring); }
/* A disabled field still has to be readable and still has to have an edge —
   keeping --shadow-xs matters in the high-contrast theme, where that shadow
   *is* the border. */
.af-input:disabled {
  background: var(--surface-2);
  border-color: var(--border);
  color: var(--text-muted);
  -webkit-text-fill-color: var(--text-muted);
  opacity: 1;
  cursor: not-allowed;
}
.af-input:disabled + .af-label { background: var(--surface-2); color: var(--text-muted); }
.af-has-affix .af-input { padding-right: 3rem; }

/* Autofill still has to read as a Brute Info field, in both themes. */
.af-input:-webkit-autofill,
.af-input:-webkit-autofill:hover,
.af-input:-webkit-autofill:focus {
  -webkit-text-fill-color: var(--text);
  -webkit-box-shadow: 0 0 0 40rem var(--surface) inset, var(--shadow-xs);
  caret-color: var(--text);
}

.af-label {
  position: absolute;
  left: calc(var(--space-4) - var(--space-1));
  top: 0;
  display: block;
  max-width: calc(100% - var(--space-8));
  padding-inline: var(--space-1);
  background: var(--surface);
  /* --text-subtle measures 3.7:1 on --surface in the light theme; the resting
     label is the field's only visible name, so it uses --text-muted. */
  color: var(--text-muted);
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  pointer-events: none;
  transform-origin: left center;
  transform: translateY(calc(var(--af-h) / 2 - 50%));
  transition:
    transform var(--dur-base) var(--ease-out),
    color var(--dur-fast) var(--ease-standard);
}
/* Scale into the border line on focus, or whenever the field holds a value. */
.af-input:focus + .af-label,
.af-input:not(:placeholder-shown) + .af-label {
  transform: translateY(-50%) scale(0.78);
  color: var(--text-muted);
  font-weight: var(--fw-semibold);
}
.af-input:focus + .af-label { color: var(--primary); }

/* Accent underline wipes in from the leading edge. */
.af-underline {
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: 1px;
  height: 2px;
  border-radius: var(--radius-full);
  background: var(--grad-brand);
  transform: scaleX(0);
  transform-origin: left center;
  opacity: 0;
  pointer-events: none;
  transition:
    transform var(--dur-base) var(--ease-out),
    opacity var(--dur-fast) var(--ease-standard);
}
.af-input:focus ~ .af-underline { transform: scaleX(1); opacity: 1; }

.af-hint { font-size: var(--fs-sm); color: var(--text-muted); line-height: 1.5; }

/* Shared component, but "or sign in with email" is copy the learner has to
   read: --text-subtle leaves it at 3.7:1 in the light theme. */
.auth-card .form-divider { color: var(--text-muted); }

.af-error {
  display: none;
  align-items: flex-start;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--danger);
  line-height: 1.5;
}
.af-error svg { flex: 0 0 auto; width: 1em; height: 1em; margin-top: 0.2em; }

/* Error state */
.af.is-invalid .af-input { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 4%, var(--surface)); }
.af.is-invalid .af-input:focus { border-color: var(--danger); box-shadow: var(--ring-danger); }
.af.is-invalid .af-label,
.af.is-invalid .af-input:focus + .af-label { color: var(--danger); }
/* The label chip sits on the field's own fill, so it has to pick up the tint. */
.af.is-invalid .af-label { background: color-mix(in srgb, var(--danger) 4%, var(--surface)); }
.af.is-invalid .af-underline { background: var(--danger); }
.af.is-invalid .af-error { display: flex; }
.af.is-valid .af-input { border-color: var(--success); }

@keyframes auth-border-pulse {
  0%   { box-shadow: 0 0 0 0 color-mix(in srgb, var(--danger) 46%, transparent); }
  70%  { box-shadow: 0 0 0 8px color-mix(in srgb, var(--danger) 0%, transparent); }
  100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--danger) 0%, transparent); }
}
.af.is-pulsing .af-input,
.af.is-pulsing .checkbox input { animation: auth-border-pulse 900ms var(--ease-out) 1; }
.af.is-invalid .checkbox input { border-color: var(--danger); }

/* ==========================================================================
   7. PASSWORD REVEAL + STRENGTH METER
   ========================================================================== */
.af-affix {
  position: absolute;
  right: var(--space-2);
  top: 50%;
  transform: translateY(-50%);
  display: inline-grid;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  border: 0;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease-standard),
              background-color var(--dur-fast) var(--ease-standard);
}
.af-affix:hover { color: var(--text); background: var(--surface-2); }
.af-affix:active { background: var(--surface-3); }
.af-affix[aria-pressed="true"] { color: var(--primary); }

.af-eye { width: 1.25rem; height: 1.25rem; }
.af-eye-lid,
.af-eye-pupil,
.af-eye-slash {
  transform-box: fill-box;
  transform-origin: center;
  transition: transform var(--dur-base) var(--ease-out),
              opacity var(--dur-fast) var(--ease-standard),
              stroke-dashoffset var(--dur-base) var(--ease-out);
}
.af-eye-slash {
  stroke-dasharray: 24;
  stroke-dashoffset: 24;
  opacity: 0;
}
.af-affix[aria-pressed="true"] .af-eye-slash { stroke-dashoffset: 0; opacity: 1; }
.af-affix[aria-pressed="true"] .af-eye-lid { transform: scaleY(0.55); }
.af-affix[aria-pressed="true"] .af-eye-pupil { transform: scale(0.35); opacity: 0.6; }

.af-strength { display: flex; flex-direction: column; gap: var(--space-2); }
.af-strength-bars {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-1);
}
.af-strength-bars span {
  height: 0.3125rem;
  border-radius: var(--radius-full);
  background: var(--surface-3);
  transform-origin: left center;
  transition: background-color var(--dur-base) var(--ease-standard),
              transform var(--dur-base) var(--ease-spring);
}
/* Wraps rather than squeezing: the longest hint plus the longest verdict do
   not fit side by side at 320px once the text-size setting is turned up. */
.af-strength-meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  font-size: var(--fs-sm);
}
.af-strength-label { font-weight: var(--fw-semibold); color: var(--text-muted); }
.af-strength-hint { color: var(--text-muted); font-size: var(--fs-xs); text-align: right; }

.af-strength[data-score="1"] .af-strength-bars span:nth-child(-n + 1) { background: var(--danger); transform: scaleY(1.5); }
.af-strength[data-score="2"] .af-strength-bars span:nth-child(-n + 2) { background: var(--warn); transform: scaleY(1.5); }
.af-strength[data-score="3"] .af-strength-bars span:nth-child(-n + 3) { background: var(--info); transform: scaleY(1.5); }
.af-strength[data-score="4"] .af-strength-bars span:nth-child(-n + 4) { background: var(--success); transform: scaleY(1.5); }
.af-strength[data-score="1"] .af-strength-label { color: var(--danger); }
.af-strength[data-score="2"] .af-strength-label { color: var(--warn-soft-text); }
.af-strength[data-score="3"] .af-strength-label { color: var(--info); }
.af-strength[data-score="4"] .af-strength-label { color: var(--success); }

/* ==========================================================================
   8. GOOGLE BUTTON + PROVIDER NOTE
   ========================================================================== */
.af-google {
  transition:
    background-color var(--dur-fast) var(--ease-standard),
    border-color var(--dur-fast) var(--ease-standard),
    box-shadow var(--dur-fast) var(--ease-standard),
    transform var(--dur-fast) var(--ease-standard);
}
.af-google .af-google-g { width: 1.15rem; height: 1.15rem; }
/* Press = the button loses its lift. The old inset used --text, which flips to
   near-white in the dark theme and lit the button up instead of pushing it in. */
.af-google:active:not(:disabled):not(.is-loading) {
  transform: translateY(2px) scale(0.994);
  box-shadow: var(--shadow-xs);
}

.auth-provider-note:empty { display: none; }
.auth-cred {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
}
.auth-cred code {
  padding: 0.1rem var(--space-2);
  border-radius: var(--radius-xs);
  background: color-mix(in srgb, var(--info) 12%, transparent);
}
.auth-note-actions { margin-top: var(--space-3); }

/* ==========================================================================
   9. MORPHING SUBMIT BUTTON
   ========================================================================== */
.af-submit {
  position: relative;
  overflow: hidden;
  max-width: 100%;
  margin-inline: auto;
  transition:
    max-width var(--dur-slow) var(--ease-spring),
    padding-inline var(--dur-slow) var(--ease-spring),
    border-radius var(--dur-slow) var(--ease-spring),
    background-color var(--dur-base) var(--ease-standard),
    box-shadow var(--dur-base) var(--ease-standard),
    color var(--dur-fast) var(--ease-standard);
}
.af-submit-label {
  display: block;
  white-space: nowrap;
  transition: opacity var(--dur-fast) var(--ease-standard);
}
.af-submit-spinner,
.af-submit-check {
  position: absolute;
  inset: 0;
  margin: auto;
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease-standard),
              transform var(--dur-base) var(--ease-spring);
}
.af-submit-spinner {
  width: 1.15rem;
  height: 1.15rem;
  border-radius: var(--radius-full);
  border: 2px solid color-mix(in srgb, currentColor 28%, transparent);
  border-top-color: currentColor;
  transform: scale(0.6);
}
.af-submit-check {
  width: 1.4rem;
  height: 1.4rem;
  transform: scale(0.6);
}
.af-submit-check path {
  stroke-dasharray: 26;
  stroke-dashoffset: 26;
  transition: stroke-dashoffset var(--dur-slow) var(--ease-out) 80ms;
}

.af-submit[data-state="pending"],
.af-submit[data-state="done"] {
  max-width: var(--control-h-lg);
  padding-inline: 0;
  border-radius: var(--radius-full);
  pointer-events: none;
}
.af-submit[data-state="pending"] .af-submit-label,
.af-submit[data-state="done"] .af-submit-label { opacity: 0; }

.af-submit[data-state="pending"] .af-submit-spinner {
  opacity: 1;
  transform: none;
  animation: auth-spin 640ms linear infinite;
}
.af-submit[data-state="done"] {
  --btn-bg: var(--success);
  background-image: none;
  box-shadow: 0 6px 18px color-mix(in srgb, var(--success) 32%, transparent);
}
.af-submit[data-state="done"] .af-submit-check { opacity: 1; transform: none; }
.af-submit[data-state="done"] .af-submit-check path { stroke-dashoffset: 0; }

@keyframes auth-spin { to { transform: rotate(360deg); } }

/* ==========================================================================
   10. RESPONSIVE — under 900px the brand panel becomes a compact header
   ========================================================================== */
@media (max-width: 1200px) {
  .auth-brand { padding: var(--space-12) var(--space-8); }
}

@media (max-width: 900px) {
  .auth-split {
    grid-template-columns: minmax(0, 1fr);
    min-height: 0;
  }
  .auth-brand {
    align-items: flex-start;
    padding: var(--space-8) var(--container-pad) var(--space-10);
  }
  .auth-brand-inner {
    max-width: var(--container-narrow);
    gap: var(--space-5);
  }
  .auth-lede { font-size: var(--fs-2xl); }
  .auth-lede-sub { font-size: var(--fs-md); }
  .auth-benefits,
  .auth-quotes,
  .auth-quote-dots { display: none; }
  .auth-facts { gap: var(--space-2) var(--space-6); }
  .auth-facts dd { font-size: var(--fs-xl); }
  .auth-panel { padding-block: var(--space-10) var(--space-12); }
  .auth-brand-bg::after { background-size: 48px 48px; }
}

@media (max-width: 560px) {
  .auth-card { padding: var(--space-6); }
  .auth-title { font-size: var(--fs-2xl); }
  .auth-facts { display: none; }
}

/* ==========================================================================
   11. MOTION OPT-OUT
   base.css already collapses every duration; these rules stop the decorative
   loops outright so nothing idles in the background.
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  .auth-mesh,
  .cn-link,
  .cn-node,
  .cn-halo,
  .af-submit[data-state="pending"] .af-submit-spinner { animation: none; }
  .cn-link { opacity: 0.45; }
  .cn-link.is-swap { opacity: 0.45; stroke-dashoffset: 0; }
  .cn-node { opacity: 0.9; }
  .cn-halo { opacity: 0; }
  /* base.css collapses durations but not delays; without this the quote swap
     leaves the card blank for the length of the hand-off. */
  .auth-quote,
  .auth-quote.is-active { transition-delay: 0s; }
  .af-submit[data-state="pending"],
  .af-submit[data-state="done"] { max-width: 100%; padding-inline: var(--btn-px); border-radius: var(--radius-lg); }
  .af-submit[data-state="pending"] .af-submit-spinner,
  .af-submit[data-state="done"] .af-submit-check { transform: none; }
}

:root[data-motion="reduced"] .auth-mesh,
:root[data-motion="reduced"] .cn-link,
:root[data-motion="reduced"] .cn-node,
:root[data-motion="reduced"] .cn-halo,
:root[data-motion="reduced"] .af-submit[data-state="pending"] .af-submit-spinner { animation: none; }
:root[data-motion="reduced"] .cn-link { opacity: 0.45; }
:root[data-motion="reduced"] .cn-link.is-swap { opacity: 0.45; stroke-dashoffset: 0; }
:root[data-motion="reduced"] .cn-node { opacity: 0.9; }
:root[data-motion="reduced"] .cn-halo { opacity: 0; }
:root[data-motion="reduced"] .auth-quote,
:root[data-motion="reduced"] .auth-quote.is-active { transition-delay: 0s; }
:root[data-motion="reduced"] .af-submit[data-state="pending"],
:root[data-motion="reduced"] .af-submit[data-state="done"] {
  max-width: 100%;
  padding-inline: var(--btn-px);
  border-radius: var(--radius-lg);
}
:root[data-motion="reduced"] .af-submit[data-state="pending"] .af-submit-spinner,
:root[data-motion="reduced"] .af-submit[data-state="done"] .af-submit-check { transform: none; }