.bubble.tapped {
    color: rgba(255,255,255,.95);
    background: rgba(96,165,250,.22);
    border-color: rgba(255,255,255,.55);
    box-shadow: 0 0 12px rgba(255,255,255,.25), inset 0 0 18px rgba(255,255,255,.06);
}
.bubble.tapped::after { border-color: rgba(255,255,255,.45); }
.bubble.wrong {
    animation: shake .35s ease-in-out;
    border-color: rgba(248,113,113,.8);
    box-shadow: 0 0 20px rgba(248,113,113,.4);
}
@keyframes shake {
    0%,100%{transform:translateX(0)}
    20%,60%{transform:translateX(-8px)}
    40%,80%{transform:translateX(8px)}
}