.security-b4 {
    margin-top: 2rem;
    padding: 1.5rem;
    color: var(--ns-text);
    background: var(--ns-surface);
    border: 1px solid var(--ns-border);
    border-radius: var(--ns-radius);
    font-family: var(--ns-font);
}
.security-b4 h2 { margin: 0 0 .75rem; font-size: 1.5rem; line-height: 1.3; }
.security-b4__intro { max-width: 70ch; margin: 0 0 1.25rem; color: var(--ns-text-2); line-height: 1.6; }
.security-b4__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: .75rem; }
.security-b4__topic { min-width: 0; align-self: start; border: 1px solid var(--ns-border); border-radius: 8px; background: var(--ns-card); scroll-margin-top: 6rem; }
.security-b4 summary { padding: 1rem; cursor: pointer; font-weight: 600; line-height: 1.5; }
.security-b4 summary:focus-visible, .security-b4 a:focus-visible { outline: 2px solid var(--ns-gold-light); outline-offset: 3px; }
.security-b4__protection { max-width: 72ch; padding: 0 1rem 1rem; overflow-wrap: anywhere; }
.security-b4 h3 { margin: .5rem 0; font-size: 1rem; line-height: 1.4; }
.security-b4__protection p { margin: 0; color: var(--ns-text-2); line-height: 1.6; }
.security-b4__next { margin: 1.25rem 0 0; }
.security-b4 a { color: var(--ns-gold-light); text-underline-offset: .2em; }
@media (max-width: 700px) {
    .security-b4 { padding: 1rem; }
    .security-b4__grid { grid-template-columns: minmax(0, 1fr); }
}