:root {
  color-scheme: dark;
  --bg: #0b0f14;
  --surface: #121821;
  --surface-elevated: #1a2230;
  --border: #2a3444;
  --text: #e6edf5;
  --text-muted: #8b9cb3;
  --accent: #3d6df0;
  --accent-hover: #4f7ef5;
  --success: #7ee787;
  --error: #ff8f87;
  --radius: 12px;
  --shadow: 0 16px 48px rgba(0, 0, 0, 0.45);
  --font: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--text);
  background: radial-gradient(circle at top, #141c28 0%, var(--bg) 60%);
  display: grid;
  place-items: center;
  padding: 24px;
}

.auth-shell {
  width: min(420px, 100%);
}

.auth-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.logo {
  width: 44px;
  height: 44px;
  border-radius: 11px;
  background: linear-gradient(135deg, #3d6df0, #6b8cff);
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.02em;
  box-shadow: var(--shadow);
}

.auth-header h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.auth-header p {
  margin: 4px 0 0;
  font-size: 14px;
  color: var(--text-muted);
}

.auth-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}

.auth-card h2 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
}

.auth-card .lead {
  margin: 0 0 24px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-muted);
}

.steps {
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.steps li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.45;
}

.step-num {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  font-size: 11px;
  font-weight: 700;
  color: var(--text);
}

.btn-github {
  width: 100%;
  padding: 13px 16px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--surface-elevated);
  color: var(--text);
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}

.btn-github:hover:not(:disabled) {
  background: #202a38;
  border-color: #3a4658;
}

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

.btn-github:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.github-mark {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.status {
  min-height: 20px;
  margin-top: 18px;
  font-size: 13px;
  text-align: center;
  line-height: 1.45;
}

.status[data-state='loading'] {
  color: var(--text-muted);
}

.status[data-state='success'] {
  color: var(--success);
}

.status[data-state='error'] {
  color: var(--error);
}

.footer-note {
  margin-top: 18px;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
}