/* System appearance by default; an explicit selection overrides it. */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) { color-scheme: dark; --page: #101722; --surface: #172130; --soft: #1b293d; --ink: #eef3fc; --muted: #abb9cc; --blue: #72a8ff; --blue-strong: #96beff; --blue-pale: #1a2b46; --line: #2b3a4e; --shadow: 0 24px 70px #060b1626; }
}
:root[data-theme='dark'] { color-scheme: dark; --page: #101722; --surface: #172130; --soft: #1b293d; --ink: #eef3fc; --muted: #abb9cc; --blue: #72a8ff; --blue-strong: #96beff; --blue-pale: #1a2b46; --line: #2b3a4e; --shadow: 0 24px 70px #060b1626; }
/* Primary CTA contrast remains stable in both palettes. */
.btn-primary { background: #1769ee; color: #fff; }
@media (hover: hover) and (pointer: fine) { .btn-primary:hover { background: #1255c6; } }