button {
    padding: 2vw;
    margin-right: 1vw;
    margin-bottom: 1vw;
}

.flex {
    display: flex;
    justify-content: center;
}

.remain-card-number::before {
    content: ':';
    margin: 0 4px;
}

.remain-card-number::after {
    content: ':';
    margin: 0 4px;
}

.card {
    border: solid 1px black;
}

.card-button {
    width: 31%;
}

.act-count {
    width: 100%;
    text-align: center;
}

.act-result {
    width: 25%;
    display: none;
}

.rate::before {
    content: ':';
    margin: 0 4px;
    color: black;
}

.act-button {
    width: 25%;
}

#game {
    display: flex;
    flex-direction: column;
}

#card-count-area {
    width: 50%;
}

#estimate-area {
    width: 50%;
}

.ml-1char {
    margin-left: 0.6rem;
}

.text-center {
    text-align: center;
}

.half-width {
    width: 50%;
}

.center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.red {
    background-color: red;
}

.green {
    background-color: lightgreen;
}