:root {
  --brand-blue: #143980;
  --brand-blue-dark: #0f2d66;
  --brand-blue-light: #2f6fe8;
  --ink: #10264f;
  --muted: #6b7890;
  --border: #dfe8f6;
  --surface: rgba(255, 255, 255, 0.96);
}

* {
  box-sizing: border-box;
}

body {
  align-items: center;
  background:
    radial-gradient(circle at 18% 18%, rgba(255, 255, 255, 0.18), transparent 28%),
    radial-gradient(circle at 82% 12%, rgba(47, 111, 232, 0.38), transparent 30%),
    linear-gradient(135deg, var(--brand-blue-dark) 0%, var(--brand-blue) 48%, #2460c9 100%);
  color: var(--ink);
  display: flex;
  font-family: "museo-sans-rounded", Arial, Helvetica, sans-serif;
  font-weight: 300;
  justify-content: center;
  margin: 0;
  min-height: 100vh;
  padding: 24px;
}

.error-card {
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 28px;
  box-shadow: 0 26px 75px rgba(5, 18, 49, 0.30);
  max-width: 720px;
  overflow: hidden;
  width: 100%;
}

.error-topbar {
  align-items: center;
  background: linear-gradient(90deg, var(--brand-blue) 0%, var(--brand-blue-light) 100%);
  color: #ffffff;
  display: flex;
  justify-content: space-between;
  padding: 18px 22px;
}

.brand {
  align-items: center;
  display: flex;
  gap: 12px;
  font-weight: 800;
}

.brand-mark {
  align-items: center;
  background: rgba(255, 255, 255, 0.16);
  border-radius: 14px;
  display: inline-flex;
  height: 40px;
  justify-content: center;
  width: 40px;
}

.error-badge {
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  padding: 8px 12px;
  text-transform: uppercase;
}

.error-content {
  padding: clamp(28px, 5vw, 48px);
  text-align: center;
}

.error-icon {
  align-items: center;
  background: #eef4ff;
  border-radius: 22px;
  color: var(--brand-blue);
  display: inline-flex;
  font-size: 2rem;
  height: 72px;
  justify-content: center;
  margin-bottom: 22px;
  width: 72px;
}

.error-code {
  color: var(--brand-blue);
  font-size: clamp(4.25rem, 14vw, 7.5rem);
  font-weight: 900;
  letter-spacing: -0.07em;
  line-height: 0.9;
  margin-bottom: 14px;
}

.error-title {
  color: var(--ink);
  font-size: clamp(1.8rem, 4vw, 2.55rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}

.error-description {
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.65;
  margin: 0 auto 26px;
  max-width: 560px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin: 28px 0;
}

.btn-error-primary,
.btn-error-secondary {
  align-items: center;
  border-radius: 999px;
  display: inline-flex;
  font-weight: 800;
  gap: 8px;
  justify-content: center;
  min-height: 46px;
  padding: 11px 22px;
  text-decoration: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.btn-error-primary {
  background: var(--brand-blue);
  border: 1px solid var(--brand-blue);
  color: #ffffff;
}

.btn-error-primary:hover {
  background: var(--brand-blue-dark);
  color: #ffffff;
  box-shadow: 0 12px 28px rgba(20, 57, 128, 0.22);
  transform: translateY(-1px);
}

.btn-error-secondary {
  background: #ffffff;
  border: 1px solid var(--border);
  color: var(--brand-blue);
}

.btn-error-secondary:hover {
  background: #f4f7fb;
  color: var(--brand-blue-dark);
  transform: translateY(-1px);
}

.help-panel {
  background: #f7f9fd;
  border: 1px solid var(--border);
  border-radius: 18px;
  margin-top: 24px;
  padding: 18px;
  text-align: left;
}

.help-panel h2 {
  color: var(--ink);
  font-size: 1rem;
  font-weight: 900;
  margin-bottom: 12px;
}

.help-list {
  color: var(--muted);
  list-style: none;
  margin: 0;
  padding: 0;
}

.help-list li {
  align-items: flex-start;
  display: flex;
  gap: 10px;
  line-height: 1.5;
  margin-bottom: 9px;
}

.help-list li:last-child {
  margin-bottom: 0;
}

.help-list i {
  color: var(--brand-blue);
  margin-top: 4px;
}

.reference {
  color: rgba(16, 38, 79, 0.55);
  font-size: 0.82rem;
  margin-top: 22px;
}

@media (max-width: 575.98px) {
  body {
    padding: 14px;
  }

  .error-card {
    border-radius: 20px;
  }

  .error-topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .error-actions {
    flex-direction: column;
  }

  .btn-error-primary,
  .btn-error-secondary {
    width: 100%;
  }
}