html {
  font-size: 14px;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

.btn:focus,
.btn:active:focus,
.btn-link.nav-link:focus,
.form-control:focus,
.form-check-input:focus {
  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
}

html {
  position: relative;
  min-height: 100%;
}

body {
  color: #1f2937;
}

.site-shell {
  background:
    radial-gradient(circle at top, rgba(13, 110, 253, 0.08), transparent 28%),
    linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
}

.site-brand {
  letter-spacing: 0.02em;
}

@media (max-width: 991.98px) {
  .site-brand {
    width: 100%;
  }
}

.site-footer {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 9999px;
  background: #2563eb;
  color: #fff;
  font-size: 24px;
  line-height: 1;
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease, background-color 0.2s ease;
}

.back-to-top:hover {
  background: #1d4ed8;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:focus-visible {
  outline: 3px solid rgba(147, 197, 253, 0.9);
  outline-offset: 3px;
}