.ec10-page .natural-frequency-input {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(220px, .35fr);
    gap: 10px;
    margin-top: 12px;
}

.ec10-page .natural-frequency-input:has(.natural-frequency-density.is-hidden) .natural-frequency-checkbox {
    grid-column: 1 / -1;
}

.ec10-page .natural-frequency-checkbox {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 13px 14px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface-soft);
    cursor: pointer;
}

.ec10-page .natural-frequency-checkbox input {
    width: 18px;
    height: 18px;
    margin: 2px 0 0;
    accent-color: var(--ec10);
}

.ec10-page .natural-frequency-checkbox span {
    display: grid;
    gap: 3px;
}

.ec10-page .natural-frequency-checkbox strong {
    color: var(--ink);
}

.ec10-page .natural-frequency-checkbox small {
    color: var(--muted);
    line-height: 1.4;
    letter-spacing: normal;
    text-transform: none;
}

.ec10-page .natural-frequency-density {
    display: grid;
    align-content: center;
    gap: 6px;
    padding: 10px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface-soft);
}

.ec10-page .natural-frequency-density > span {
    color: var(--muted-strong);
    font-size: .78rem;
    font-weight: 800;
    text-transform: uppercase;
}

.ec10-page .natural-frequency-density .unit-symbol {
    letter-spacing: 0;
    text-transform: none;
}

.ec10-page .natural-frequency-density .field-control {
    width: 100%;
}

.ec10-page .natural-frequency-card {
    --result-accent: #2f6f73;
    --result-surface: #eef7f6;
    margin-top: 18px;
}

.ec10-page .natural-frequency-card.is-below-threshold {
    --result-accent: #b36b21;
    --result-surface: #fff8ee;
}

.ec10-page .natural-frequency-card.is-not-covered {
    --result-accent: #6f7780;
    --result-surface: #f4f5f6;
}

.ec10-page .natural-frequency-result {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
    padding: 12px 14px 10px;
}

.ec10-page .natural-frequency-headline {
    display: grid;
    grid-template-columns: minmax(180px, .75fr) max-content minmax(280px, 1.25fr);
    gap: 16px;
    align-items: center;
    padding: 10px 12px;
    border: 1px solid color-mix(in srgb, var(--result-accent), transparent 65%);
    border-radius: 8px;
    background: color-mix(in srgb, var(--result-accent), transparent 92%);
}

.ec10-page .natural-frequency-headline > span,
.ec10-page .natural-frequency-values dt {
    color: var(--muted);
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.ec10-page .natural-frequency-card .math-var {
    letter-spacing: 0;
    text-transform: none;
}

.ec10-page .natural-frequency-headline strong {
    margin: 0;
    color: var(--result-accent);
    font-size: clamp(1.45rem, 2.4vw, 2rem);
}

.ec10-page .natural-frequency-headline p,
.ec10-page .natural-frequency-not-covered p {
    margin: 0;
    color: var(--muted-strong);
    line-height: 1.45;
}

.ec10-page .natural-frequency-headline p strong {
    color: inherit;
    font-size: inherit;
}

.ec10-page .natural-frequency-values {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 7px;
    margin: 0;
}

.ec10-page .natural-frequency-values div {
    padding: 7px 9px;
    border: 1px solid var(--line);
    border-radius: 7px;
    background: var(--surface);
}

.ec10-page .natural-frequency-values dd {
    margin: 3px 0 0;
    color: var(--ink);
    font-weight: 700;
}

.ec10-page .natural-frequency-not-covered {
    padding: 18px;
}

.ec10-page .natural-frequency-not-covered strong {
    display: block;
    margin-bottom: 6px;
    color: var(--result-accent);
    font-size: 1.2rem;
}

.ec10-page .natural-frequency-source {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
    padding: 0 14px 7px;
    color: var(--muted);
    font-size: 0.82rem;
}

.ec10-page .natural-frequency-card > .method-note {
    margin: 0 14px 10px;
}

.ec10-page .natural-frequency-comparison {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
    padding: 0 14px 10px;
}

.ec10-page .natural-frequency-scenario {
    padding: 9px 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
}

.ec10-page .natural-frequency-scenario.is-selected {
    border-color: var(--result-accent);
    background: color-mix(in srgb, var(--result-accent), transparent 92%);
}

.ec10-page .natural-frequency-scenario h4 {
    margin: 0 0 6px;
    color: var(--ink);
    font-size: 0.9rem;
}

.ec10-page .natural-frequency-scenario dl {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
}

.ec10-page .natural-frequency-scenario dt { color: var(--muted); font-size: 0.7rem; text-transform: uppercase; }
.ec10-page .natural-frequency-scenario dd { margin: 3px 0 0; color: var(--ink); font-weight: 800; }

.ec10-page .natural-frequency-case-results {
    padding: 0 14px 10px;
}

.ec10-page .natural-frequency-case-table {
    width: 100%;
    border-collapse: collapse;
    table-layout: fixed;
}

.ec10-page .natural-frequency-case-table th,
.ec10-page .natural-frequency-case-table td {
    padding: 8px 9px;
    border-bottom: 1px solid var(--line);
    text-align: left;
    vertical-align: middle;
    white-space: nowrap;
}

.ec10-page .natural-frequency-case-table th {
    background: color-mix(in srgb, var(--result-accent), var(--surface) 92%);
    color: var(--muted-strong);
    font-size: .69rem;
    text-transform: uppercase;
}

.ec10-page .natural-frequency-case-table th:first-child { width: 24%; }
.ec10-page .natural-frequency-case-table th:nth-child(2) { width: 9%; }
.ec10-page .natural-frequency-case-table th:nth-child(3) { width: 14%; }
.ec10-page .natural-frequency-case-table th:nth-child(n+4) { width: 17.666%; }
.ec10-page .natural-frequency-case-table td { color: var(--ink); font-size: .82rem; }
.ec10-page .natural-frequency-case-table td small { display: block; margin-top: 2px; color: var(--result-accent); font-size: .66rem; }
.ec10-page .natural-frequency-case-table tr.is-governing { background: color-mix(in srgb, var(--result-accent), transparent 91%); }

body.theme-dark .ec10-page .natural-frequency-checkbox,
body.theme-dark .ec10-page .natural-frequency-density,
body.theme-dark .ec10-page .natural-frequency-values div {
    background: #211f25;
}

@media (max-width: 760px) {
    .ec10-page .natural-frequency-input {
        grid-template-columns: 1fr;
    }

    .ec10-page .natural-frequency-headline {
        grid-template-columns: 1fr;
        gap: 5px;
    }

    .ec10-page .natural-frequency-values {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .ec10-page .natural-frequency-comparison {
        grid-template-columns: 1fr;
    }

    .ec10-page .natural-frequency-case-table,
    .ec10-page .natural-frequency-case-table tbody,
    .ec10-page .natural-frequency-case-table tr,
    .ec10-page .natural-frequency-case-table td {
        display: block;
        width: 100%;
    }

    .ec10-page .natural-frequency-case-table thead {
        display: none;
    }

    .ec10-page .natural-frequency-case-table tr {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 5px 10px;
        margin-bottom: 8px;
        padding: 8px;
        border: 1px solid var(--line);
        border-radius: 7px;
    }

    .ec10-page .natural-frequency-case-table td {
        padding: 2px 0;
        border: 0;
        white-space: nowrap;
    }

    .ec10-page .natural-frequency-case-table td::before {
        display: block;
        margin-bottom: 2px;
        color: var(--muted);
        content: attr(data-label);
        font-size: .62rem;
        font-weight: 800;
        text-transform: uppercase;
    }

    .ec10-page .natural-frequency-case-table td:first-child,
    .ec10-page .natural-frequency-case-table td:nth-child(n+4) {
        grid-column: 1 / -1;
    }
}

@media print {
    .ec10-page .natural-frequency-card {
        break-inside: avoid;
        page-break-inside: avoid;
        margin-top: 3mm;
    }

    .ec10-page .natural-frequency-result {
        grid-template-columns: 1fr;
        gap: 1.5mm;
        padding: 2.5mm;
    }

    .ec10-page .natural-frequency-headline {
        grid-template-columns: .75fr max-content 1.25fr;
        gap: 2mm;
    }

    .ec10-page .natural-frequency-values {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .ec10-page .natural-frequency-headline,
    .ec10-page .natural-frequency-values div {
        padding: 1.7mm 2mm;
    }

    .ec10-page .natural-frequency-source {
        padding: 0 2.5mm 1.5mm;
    }

    .ec10-page .natural-frequency-card > .method-note {
        margin: 0 2.5mm 2mm;
    }
}