:root {
  --accent: #2563eb;
  --accent-dark: #1e40af;
  --bg: #111827;
  --bg-soft: #1f2937;
  --card: rgba(255, 255, 255, 0.08);
  --text: #ffffff;
  --muted: rgba(255, 255, 255, 0.72);
  --border: rgba(255, 255, 255, 0.16);
  --shadow: rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

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

body {
  font-family: Arial, Helvetica, sans-serif;
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, 0.20), transparent 34%),
    radial-gradient(circle at bottom right, rgba(148, 163, 184, 0.18), transparent 38%),
    linear-gradient(135deg, var(--bg), #020617);
  color: var(--text);
  display: grid;
  place-items: center;
  padding: 28px;
}

.error-card {
  width: min(720px, 100%);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 42px 34px;
  text-align: center;
  box-shadow: 0 24px 80px var(--shadow);
  backdrop-filter: blur(10px);
}

.error-logo {
  max-width: 180px;
  max-height: 70px;
  margin-bottom: 24px;
}

.error-code {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 92px;
  padding: 8px 14px;
  margin-bottom: 18px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.14);
  border: 1px solid rgba(37, 99, 235, 0.38);
  color: #bfdbfe;
  font-weight: 700;
  letter-spacing: 0.08em;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 5vw, 3.4rem);
  line-height: 1.05;
}

p {
  margin: 0 auto 28px;
  max-width: 560px;
  color: var(--muted);
  font-size: 1.06rem;
  line-height: 1.6;
}

.error-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.error-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 20px;
  border-radius: 999px;
  color: #ffffff;
  text-decoration: none;
  border: 1px solid transparent;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, filter 0.15s ease, border-color 0.15s ease;
}

.error-btn.primary {
  background: var(--accent);
  color: #ffffff;
}

.error-btn.secondary {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.30);
}

.error-btn:hover,
.error-btn:focus {
  transform: translateY(-1px);
  filter: brightness(1.08);
}

.error-note {
  margin-top: 24px;
  font-size: 0.86rem;
  color: rgba(255, 255, 255, 0.48);
}

@media (max-width: 520px) {
  body {
    padding: 18px;
  }

  .error-card {
    padding: 32px 22px;
  }

  .error-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .error-btn {
    width: 100%;
  }
}