:root {
  --page: #f4f4f5; --card: #fff; --ink: #0a0a0a; --muted: #8a8a8f; --muted-text: #6b6b70;
  --line: #e4e4e7; --danger: #b42318;
  --radius-card: 20px; --radius: 12px;
  font-family: -apple-system, "Segoe UI", Arial, sans-serif;
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body { background: var(--page); color: var(--ink); display: grid; place-items: center; padding: 16px; }
#backdrop { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 0; pointer-events: none; }
.card {
  position: relative; z-index: 1; width: 100%; max-width: 340px; padding: 32px 28px 28px;
  background: var(--card); border-radius: var(--radius-card); box-shadow: 0 20px 60px rgba(0,0,0,.08);
  text-align: center;
}
.wordmark { margin: 0; font-size: 22px; font-weight: 400; letter-spacing: -.01em; }
.wordmark b { font-weight: 700; }
.caption { margin: 6px 0 20px; font-size: 11px; letter-spacing: .18em; text-transform: uppercase; color: var(--muted-text); }
.segments { display: grid; grid-template-columns: 1fr 1fr; padding: 4px; margin-bottom: 8px; background: var(--page); border-radius: 999px; }
.seg { padding: 10px 0; min-height: 44px; display: grid; place-items: center; font-size: 14px; border-radius: 999px; }
.seg-active { background: var(--card); font-weight: 600; box-shadow: 0 1px 3px rgba(0,0,0,.08); }
.seg-disabled { color: var(--muted); cursor: not-allowed; }
.soon { margin: 0 0 16px; font-size: 12px; color: var(--muted-text); }
form { display: grid; gap: 10px; }
input[type="email"], input[type="password"] {
  width: 100%; min-height: 48px; padding: 0 16px; font: inherit; font-size: 15px; color: var(--ink);
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); text-align: center;
}
/* The labels are sr-only, so a placeholder is the one visible name of its field: readable text at
   5.3:1, not decoration. --muted (3.4:1) is left to the inactive Partner segment alone. */
input::placeholder { color: var(--muted-text); letter-spacing: .08em; }
button {
  min-height: 48px; margin-top: 6px; font: inherit; font-size: 15px; font-weight: 700; color: #fff;
  background: var(--ink); border: 0; border-radius: var(--radius); cursor: pointer;
}
button[disabled] { opacity: .6; cursor: progress; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.error { min-height: 18px; margin: 0; font-size: 13px; color: var(--danger); }
.hint, .muted { margin: 0; font-size: 13px; color: var(--muted-text); }
.identity { margin: 0 0 8px; font-size: 16px; font-weight: 600; }
a { color: var(--ink); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }