.mult-expression {
    font-size: 2.2rem;
    font-weight: 700;
    text-align: center;
    margin: 1.5rem 0;
    letter-spacing: .05em;
}

.mult-prompt {
    font-size: 1.15rem;
    font-weight: 700;
    text-align: center;
    margin: 0 0 .75rem;
}

.mult-hint {
    font-size: 1.15rem;
    font-weight: 700;
    text-align: center;
    margin: 0 0 .75rem;
}

.mult-options {
    display: flex;
    flex-wrap: wrap;
    gap: .6rem;
    justify-content: center;
    margin: 1rem 0;
}

.mult-option {
    padding: .6rem 1.1rem;
    font-size: 1.15rem;
    font-weight: 700;
    border: 2px solid #cbd5e1;
    border-radius: 12px;
    background: #ffffff;
    color: #1a1a2e;
    cursor: pointer;
    transition: transform .15s, border-color .15s, background-color .15s;
    min-width: 3.5rem;
}

.mult-option:hover {
    border-color: #4a90d9;
    transform: scale(1.05);
}

.mult-input {
    width: 5ch;
    text-align: center;
    font-size: 2rem;
    padding: .3rem;
    border: 2px solid #bbb;
    border-radius: 8px;
    margin: 1rem auto;
    display: block;
}

.mult-input:focus {
    border-color: #4a90d9;
    outline: none;
}

.mult-groups {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin: 1.25rem 0;
}

.mult-group {
    display: flex;
    flex-wrap: wrap;
    gap: .25rem;
    padding: .5rem .7rem;
    background: rgba(79, 134, 247, 0.08);
    border-radius: 12px;
    border: 2px solid rgba(79, 134, 247, 0.2);
}

.mult-item {
    font-size: 1.2rem;
    color: #4a90d9;
}

@media (max-width: 380px) {
    .mult-expression {
        font-size: 1.8rem;
    }

    .mult-option {
        font-size: 1rem;
        padding: .5rem .8rem;
    }
}