.length_series .meters_lesson {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 22px;
}

.length_series .length_relation {
    margin: 0;
    font-size: clamp(22px, 2.5vw, 30px);
    font-weight: var(--main_bolder_weight);
    line-height: 1.5;
}

.length_series .meters_example {
    margin: 0;
    width: 100%;
}

.length_series .meters_example_sum { width: 100%; }
.length_series .meters_equation { font-variant-numeric: tabular-nums; }
.length_series .length_prefix, .length_series .length_suffix { color: var(--main_text); }
.length_series .length_number { color: var(--blue3); }
.length_series .meters_blank { white-space: nowrap; }

.length_series .meters_feedback { min-height: 110px; }
.length_series .length_feedback_title { min-height: 1.5em; }
.length_series .meters_feedback:not([data-kind="wrong"]) > * { visibility: hidden; }

.length_answer_measure {
    position: absolute;
    visibility: hidden;
    white-space: nowrap;
    pointer-events: none;
}

.length_series .meters_option.btn { padding-left: 6px; padding-right: 6px; }
.length_series[data-kind="compound"] .meters_option.btn { font-size: clamp(20px, 2.5vw, 30px); }

@media (max-width: 600px) {
    .length_series .meters_lesson { gap: 18px; }
    .length_series .meters_example_sum { font-size: 19px; }
    .length_series .meters_option.btn { font-size: 20px; }
    .length_series[data-kind="compound"] .meters_option.btn { font-size: 18px; }
    .length_series .meters_feedback { font-size: 17px; }
}