:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --border: #d0d7de;
  --text: #1f2328;
  --muted: #57606a;
  --accent: #0969da;
  --accent-hover: #0550ae;
  --danger: #b42318;
  --radius: 10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  background: linear-gradient(180deg, #f8fafc 0%, #edf2f7 100%);
  color: var(--text);
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 16px 40px rgba(15, 23, 42, 0.08);
  padding: 22px;
}

.auth-title {
  margin: 0 0 6px;
  font-size: 24px;
  font-weight: 700;
}

.auth-subtitle {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 14px;
}

.auth-row {
  display: grid;
  gap: 6px;
  margin-bottom: 12px;
}

.auth-row label {
  font-size: 13px;
  color: var(--muted);
}

.auth-row input {
  width: 100%;
  padding: 10px 12px;
  font-size: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  outline: none;
}

.auth-row input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(9, 105, 218, 0.12);
}

.auth-btn {
  width: 100%;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.auth-btn:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.auth-btn:disabled {
  opacity: 0.7;
  cursor: wait;
}

.auth-error {
  min-height: 18px;
  margin: 10px 0 0;
  color: var(--danger);
  font-size: 13px;
}

.auth-footer {
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
}

.auth-footer a {
  color: var(--accent);
  text-decoration: none;
}

.auth-footer a:hover {
  text-decoration: underline;
}