.theme-toggle{display:inline-flex;align-items:center;justify-content:center;flex:none;width:44px;height:44px;padding:10px;border:1px solid var(--color-line);border-radius:var(--radius-control);background:transparent;color:var(--color-ink);cursor:pointer}
.theme-toggle[hidden]{display:none}
.theme-toggle:hover{background:var(--color-surface)}
.theme-toggle svg{display:block;width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.theme-toggle[data-next-theme="dark"] .theme-sun,.theme-toggle[data-next-theme="light"] .theme-moon{display:none}

/* Music Theory gold, adjusted for contrast on each page theme. */
:root{--color-brand:#8f5c06}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]){--color-brand:#f4bf3b}}
:root[data-theme="dark"]{--color-brand:#f4bf3b}
.brand-mark,.brand strong{color:var(--color-brand)}