/* Header BGM control follows Lucent's circular notification controls. */
.lucent-bgm{position:relative;display:inline-flex;align-items:center;justify-content:center;flex:none;order:0;box-sizing:border-box;width:var(--ctl-h);height:var(--ctl-h);padding:0;border:var(--lucent-border-width,1px) solid var(--glass-border);border-radius:50%;background:var(--glass-bg-strong);color:var(--text);cursor:pointer;transition:color .15s,border-color .15s,background-color .15s,transform .15s}
.lucent-bgm:hover{color:var(--lucent-accent);border-color:var(--lucent-accent);transform:translateY(-1px)}
.lucent-bgm.is-playing{color:var(--lucent-accent);border-color:var(--lucent-accent);background:color-mix(in srgb,var(--lucent-accent) 12%,var(--glass-bg-strong))}
.lucent-bgm:focus-visible{outline:2px solid var(--lucent-accent);outline-offset:3px}
.lucent-bgm-status{position:absolute;width:1px;height:1px;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}
@media(prefers-reduced-motion:reduce){.lucent-bgm{transition:none}.lucent-bgm:hover{transform:none}}