.about-main {
    width: min(88%, 900px);
}

.about-content {
    color: #202020;
    font-size: clamp(1rem, 2.8vw, 1.12rem);
    line-height: 1.75;
    text-align: justify;
}

.about-content > :first-child {
    margin-top: 0;
}

.about-content > :last-child {
    margin-bottom: 0;
}

.about-content h2 {
    margin: 2rem 0 0.75rem;
    color: var(--riichi-red);
    font-size: clamp(1.35rem, 4vw, 1.8rem);
    font-weight: 700;
    line-height: 1.25;
}

.about-content p,
.about-content ul,
.about-content ol {
    margin-bottom: 1rem;
}

.about-content p:not(.about-message),
.about-content li {
    text-align: justify;
    hyphens: auto;
}

.about-content li + li {
    margin-top: 0.4rem;
}

.about-content code {
    padding: 0.15em 0.35em;
    border-radius: 0.25rem;
    color: #262626;
    background: #f1f1f1;
    font-size: 0.95em;
    overflow-wrap: anywhere;
}

.about-content a {
    color: var(--riichi-red);
    text-underline-offset: 0.15em;
}

.about-message {
    margin: 0;
    padding: 1rem;
    border: 1px solid #b02a37;
    border-radius: 0.375rem;
    color: #842029;
    background: #f8d7da;
    text-align: center;
}

@media (min-width: 576px) {
    .about-main {
        width: min(82%, 900px);
    }
}

.about-content h3 {
    margin: 1.5rem 0 0.75rem;
    color: var(--riichi-red);
    font-size: clamp(1.15rem, 3.2vw, 1.4rem);
    line-height: 1.25;
    font-weight: 700;
    text-align: left;
}

.about-table-wrapper {
    margin: 0 0 1.5rem;
    overflow-x: auto;
    border: 1px solid #d9d9d9;
    border-radius: 4px;
    box-shadow: 0 5px 20px rgb(0 0 0 / 8%);
}

.about-table-wrapper:focus-visible {
    outline: 3px solid var(--riichi-red);
    outline-offset: 3px;
}

.about-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    line-height: 1.4;
    font-variant-numeric: tabular-nums;
    text-align: right;
}

.about-table th, .about-table td {
    padding: 0.7rem 0.75rem;
    white-space: nowrap;
}

.about-table thead th {
    color: #fff;
    background: var(--riichi-red);
}

.about-table th:first-child {
    text-align: left;
}

.about-table tbody tr:nth-child(even) {
    background: #fff8dd;
}

.about-table tbody tr + tr {
    border-top: 1px solid #eee8db;
}

.about-tabs:not([hidden]) {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid #dedede;
}

.about-tabs button {
    flex: 1;
    min-height: 44px;
    padding: 0.6rem 0.8rem;
    border: 1px solid #dedede;
    border-radius: 6px;
    color: #444;
    background: #fff;
    font: inherit;
    font-weight: 700;
    cursor: pointer;
}

.about-tabs button[aria-selected="true"] {
    border-color: var(--riichi-red);
    color: #fff;
    background: var(--riichi-red);
}

.about-tabs button:focus-visible,
.about-panel:focus-visible {
    outline: 3px solid #0d6efd;
    outline-offset: 3px;
}

.about-panel > h2:first-of-type + h2 {
    margin-top: 0;
}

.about-details {
    margin: 1.25rem 0;
    padding: 1rem;
    border: 1px solid #dedede;
    border-radius: 6px;
    background: #fafafa;
}

.about-details summary {
    color: var(--riichi-red);
    font-weight: 700;
    text-align: left;
    cursor: pointer;
}

.about-details[open] summary { margin-bottom: 1rem; }
.about-details > :last-child { margin-bottom: 0; }
.about-details summary:focus-visible {
    outline: 3px solid #0d6efd;
    outline-offset: 3px;
}

.about-chart {
    margin: 1.25rem 0;
    padding: 0.5rem;
    overflow-x: auto;
    border: 1px solid #dedede;
    border-radius: 6px;
    background: #fff;
}

.about-chart img {
    display: block;
    width: 100%;
    min-width: 560px;
    height: auto;
}

.about-chart:focus-visible {
    outline: 3px solid #0d6efd;
    outline-offset: 3px;
}