:root {
  --navy: #0F172A;
  --blue: #1877F2;
  --blue-soft: #2DA8FF;
  --text: #334155;
  --muted: #64748B;
  --danger: #DC2626;
  --ok: #059669;
  --card: rgba(255, 255, 255, 0.92);
  --line: rgba(15, 23, 42, 0.08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(45, 168, 255, 0.35), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(24, 119, 242, 0.28), transparent 50%),
    linear-gradient(165deg, #e8f3ff 0%, #f8fafc 45%, #eef2ff 100%);
}

.shell {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 20px 28px;
  gap: 20px;
}

.brand {
  text-align: center;
}

.logo {
  height: 44px;
  width: auto;
  display: block;
}

.panel {
  width: min(420px, 100%);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 28px 24px 24px;
  box-shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
  backdrop-filter: blur(10px);
  text-align: center;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.45rem;
  line-height: 1.25;
  color: var(--navy);
  font-weight: 700;
}

.lead {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.45;
}

.error {
  margin: 0 0 14px;
  padding: 10px 12px;
  border-radius: 10px;
  background: #FEF2F2;
  color: var(--danger);
  font-size: 0.9rem;
}

.status {
  margin: 0 0 14px;
  padding: 10px 12px;
  border-radius: 10px;
  background: #ECFDF5;
  color: var(--ok);
  font-size: 0.9rem;
}

.btn {
  appearance: none;
  border: 0;
  width: 100%;
  padding: 14px 18px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--blue) 0%, var(--blue-soft) 100%);
  color: #fff;
  font-size: 1.05rem;
  font-weight: 650;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, opacity 0.15s ease;
  box-shadow: 0 10px 24px rgba(24, 119, 242, 0.28);
}

.btn:hover:not(:disabled) {
  transform: translateY(-1px);
}

.btn:active:not(:disabled) {
  transform: translateY(0);
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  box-shadow: none;
}

.btn.busy {
  opacity: 0.8;
  pointer-events: none;
}

.hint {
  margin: 16px 0 0;
  color: #94A3B8;
  font-size: 0.82rem;
  line-height: 1.4;
}

.foot {
  color: #94A3B8;
  font-size: 0.78rem;
}

@media (max-width: 420px) {
  .panel { padding: 24px 18px 20px; }
  h1 { font-size: 1.3rem; }
}