.youtube {
    width: 100%;
    aspect-ratio: 16 / 9;
}
.youtube iframe {
    width: 100%;
    height: 100%;
}

.hatena-button {
    margin-left: 4px;
    width: 20px;
    height: 20px;
    line-height: 10px;
    vertical-align: middle;
    cursor: pointer;
}
.v-middle {
    vertical-align: middle;
}

.error-message,
.success-message {
    padding: 8px 16px;
    border-radius: 8px;
    font-weight: bold;
}
.error-message {
    background-color: rgb(239, 172, 172);
}
.success-message {
    background-color: rgb(107, 246, 199);
}

.user-icon {
    display: inline-block;
    width: 20px;
    height: 20px;
    vertical-align: middle;
}
.user-icon-big {
    width: 80px;
    height: 80px;
}
.user-name {
    vertical-align: middle;
    text-decoration: underline;
}
.user-used-count-info {
    font-size: 12px;
    color: #666;
}
.user-bio {
    margin-top: 15px;
    margin-bottom: 10px;
}