:root {
        color-scheme: light;
        --brand: #fe4a26;
        --brand-deep: #d63c12;
        --brand-chip: #c13710;
        --brand-tint: #ffe9e2;
        --brand-wash: #fff5f1;
        --ink: #201e1b;
        --ink-2: #57534c;
        --ink-3: #6e6960;
        --paper: #ffffff;
        --paper-warm: #faf8f5;
        --term: #f4f0ea;
        --line: #e8e3dc;
        --line-soft: #f0ece6;
        --line-strong: #d9d3ca;
      }
      * {
        box-sizing: border-box;
      }
      html {
        -webkit-text-size-adjust: 100%;
      }
      body {
        margin: 0;
        font-family: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "BIZ UDPGothic",
          "Yu Gothic Medium", "Yu Gothic", "Noto Sans JP", Meiryo, sans-serif;
        font-size: 16px;
        line-height: 1.8;
        background: var(--paper);
        color: var(--ink);
        -webkit-font-smoothing: antialiased;
      }
      body::before {
        content: "";
        display: block;
        height: 4px;
        background: linear-gradient(90deg, var(--brand) 0 64px, var(--ink) 64px);
      }
      p {
        margin: 0;
        overflow-wrap: anywhere;
      }
      a {
        color: var(--brand-deep);
        text-decoration-thickness: 1px;
        text-underline-offset: 3px;
      }
      a:hover {
        text-decoration-thickness: 2px;
      }
      :focus-visible {
        outline: 2px solid var(--brand);
        outline-offset: 2px;
        border-radius: 2px;
      }
      .ui {
        background: var(--term);
        border-radius: 4px;
        padding: 1px 4px;
        font-weight: 600;
        font-size: 0.95em;
      }
      .brand-mark {
        display: inline-grid;
        grid-template-columns: 6px 6px;
        grid-auto-rows: 6px;
        gap: 1.5px;
        flex: none;
      }
      .brand-mark i {
        background: var(--ink);
        border-radius: 1px;
      }
      .brand-mark i:first-child {
        background: var(--brand);
        transform: skewX(-10deg);
      }
      .masthead {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 16px;
        padding: 18px 0 14px;
        border-bottom: 1px solid var(--line);
      }
      .brand {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        min-width: 0;
        color: inherit;
        text-decoration: none;
      }
      .brand-name {
        font-size: 13px;
        font-weight: 800;
        letter-spacing: 0.05em;
        white-space: nowrap;
      }
      .brand-sub {
        font-size: 12px;
        color: var(--ink-3);
        letter-spacing: 0.06em;
        white-space: nowrap;
      }
      main {
        counter-reset: sec;
      }
      main > section {
        margin-top: 48px;
        counter-increment: sec;
      }
      main > section > h2 {
        display: flex;
        align-items: center;
        gap: 12px;
        margin: 0 0 20px;
        font-size: 17px;
        font-weight: 800;
        letter-spacing: 0.03em;
        font-feature-settings: "palt";
        line-height: 1.5;
        scroll-margin-top: 16px;
      }
      main > section > h2::before {
        content: counter(sec, decimal-leading-zero);
        font-size: 12.5px;
        font-weight: 800;
        letter-spacing: 0.1em;
        color: var(--brand-deep);
        font-variant-numeric: tabular-nums;
        transform: translateY(1px);
        flex: none;
      }
      main > section > h2::after {
        content: "";
        flex: 1 1 24px;
        height: 1px;
        background: var(--line);
        min-width: 24px;
      }
      .colophon {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 16px;
        margin-top: 56px;
        padding-top: 16px;
        border-top: 1px solid var(--line);
        font-size: 11.5px;
        color: var(--ink-3);
        letter-spacing: 0.04em;
      }
      .colophon .brand-name {
        font-size: 11.5px;
        color: var(--ink-2);
      }
      .colophon-updated {
        font-variant-numeric: tabular-nums;
        white-space: nowrap;
      }
      .layout {
        display: grid;
        grid-template-columns: 200px minmax(0, 720px);
        gap: 48px;
        justify-content: center;
      }
      .content {
        min-width: 0;
      }
      .layout--single,
      html.embedded .layout {
        display: block;
        max-width: 720px;
        margin: 0 auto;
      }
      html.embedded .side {
        display: none;
      }
      .side {
        min-width: 0;
      }
      .side-inner {
        position: sticky;
        top: 20px;
        max-height: calc(100vh - 40px);
        overflow-y: auto;
        padding: 26px 0 8px;
      }
      .side-label {
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.14em;
        color: var(--ink-3);
        margin: 0 0 10px;
        padding-left: 10px;
      }
      .side-group + .side-group {
        margin-top: 2px;
      }
      .side-cat {
        display: block;
        font-size: 13.5px;
        font-weight: 700;
        color: var(--ink-2);
        text-decoration: none;
        padding: 7px 10px;
        border-radius: 6px;
        transition: background-color 0.15s ease, color 0.15s ease;
      }
      .side-cat:hover {
        color: var(--brand-deep);
        background: var(--paper-warm);
      }
      .side-group.is-current > .side-cat {
        color: var(--ink);
      }
      .side-list {
        list-style: none;
        margin: 2px 0 8px 10px;
        padding: 0 0 0 10px;
        border-left: 1px solid var(--line);
      }
      .side-link {
        display: block;
        font-size: 12.5px;
        font-weight: 500;
        line-height: 1.55;
        color: var(--ink-2);
        text-decoration: none;
        padding: 6px 10px;
        border-radius: 6px;
        position: relative;
        transition: background-color 0.15s ease, color 0.15s ease;
      }
      .side-link:hover {
        color: var(--brand-deep);
        background: var(--paper-warm);
      }
      .side-link.is-active {
        color: var(--brand-deep);
        font-weight: 700;
        background: var(--brand-wash);
      }
      .side-link.is-active::before {
        content: "";
        position: absolute;
        left: -11px;
        top: 6px;
        bottom: 6px;
        width: 2px;
        background: var(--brand);
      }
      @media (max-width: 999px) {
        .side {
          display: none;
        }
        .layout {
          display: block;
          max-width: 720px;
          margin: 0 auto;
        }
      }
      @media (prefers-reduced-motion: reduce) {
        * {
          transition: none !important;
          scroll-behavior: auto !important;
        }
      }


      .page {
        max-width: 1040px;
        margin: 0 auto;
        padding: 0 28px 40px;
      }
      .masthead-search {
        font-size: 12.5px;
        font-weight: 700;
        color: var(--ink-2);
        text-decoration: none;
        border: 1px solid var(--line-strong);
        border-radius: 999px;
        padding: 6px 14px;
        white-space: nowrap;
        transition: border-color 0.15s ease, color 0.15s ease;
      }
      .masthead-search:hover {
        border-color: var(--brand);
        color: var(--brand-deep);
      }
      .crumbs {
        display: flex;
        align-items: center;
        gap: 8px;
        padding: 14px 0 0;
        font-size: 13px;
        color: var(--ink-3);
      }
      .crumbs a {
        color: var(--ink-2);
        text-decoration: none;
      }
      .crumbs a:hover {
        color: var(--brand-deep);
        text-decoration: underline;
      }
      .crumbs .crumbs-sep {
        color: var(--line-strong);
      }
      .article-head {
        padding: 22px 0 28px;
        border-bottom: 2px solid var(--ink);
      }
      .article-labels {
        display: flex;
        flex-wrap: wrap;
        gap: 6px;
        margin: 0 0 16px;
      }
      .chip {
        display: inline-block;
        font-size: 11px;
        font-weight: 700;
        letter-spacing: 0.08em;
        line-height: 1;
        padding: 6px 10px;
        border-radius: 4px;
      }
      .chip--cat {
        background: var(--ink);
        color: #ffffff;
      }
      .chip--tag {
        border: 1px solid var(--line-strong);
        color: var(--ink-2);
        background: var(--paper);
      }
      h1 {
        margin: 0 0 20px;
        font-size: 28px;
        font-weight: 800;
        line-height: 1.5;
        letter-spacing: 0.015em;
        font-feature-settings: "palt";
        text-wrap: balance;
        word-break: auto-phrase;
      }
      .goal {
        display: block;
        margin: 0;
        padding: 2px 0 3px 17px;
        border-left: 3px solid var(--brand);
      }
      .goal-label {
        display: flex;
        align-items: center;
        gap: 7px;
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.14em;
        color: var(--brand-deep);
        margin: 0 0 6px;
      }
      .goal-label::before {
        content: "";
        width: 8px;
        height: 8px;
        background: var(--brand);
        transform: skewX(-10deg);
        border-radius: 1px;
        flex: none;
      }
      .goal-text {
        font-size: 15px;
        line-height: 1.8;
        margin: 0;
        max-width: 40em;
      }
      .prep {
        margin-top: 14px;
        padding: 2px 0 3px 17px;
        border-left: 3px solid var(--ink);
      }
      .prep-label {
        display: flex;
        align-items: center;
        gap: 7px;
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.14em;
        color: var(--ink-2);
        margin: 0 0 2px;
      }
      .prep-label::before {
        content: "";
        width: 8px;
        height: 8px;
        background: var(--ink);
        transform: skewX(-10deg);
        border-radius: 1px;
        flex: none;
      }
      .prep .checklist li {
        padding-top: 7px;
        padding-bottom: 7px;
        font-size: 14px;
      }
      .prep .checklist li::before {
        top: 11px;
      }
      .toc {
        margin-top: 28px;
        border: 1px solid var(--line);
        border-radius: 10px;
        padding: 14px 18px 13px;
        background: var(--paper);
      }
      .toc-label {
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.14em;
        color: var(--ink-3);
        margin: 0 0 6px;
      }
      .toc-list {
        list-style: none;
        margin: 0;
        padding: 0;
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        column-gap: 28px;
        counter-reset: toc;
      }
      .toc-list li {
        counter-increment: toc;
      }
      .toc-list li + li {
        border-top: 1px solid var(--line-soft);
      }
      .toc-list li:nth-child(2) {
        border-top: 0;
      }
      .toc-list a {
        display: flex;
        align-items: flex-start;
        gap: 10px;
        padding: 7px 2px;
        color: var(--ink);
        text-decoration: none;
        font-size: 14px;
        font-weight: 600;
      }
      .toc-list a:hover .toc-title {
        color: var(--brand-deep);
        text-decoration: underline;
        text-underline-offset: 3px;
      }
      .toc-list a::before {
        content: counter(toc);
        width: 18px;
        height: 18px;
        display: grid;
        place-items: center;
        font-size: 11px;
        font-weight: 800;
        color: #ffffff;
        background: var(--ink);
        border-radius: 5px;
        font-variant-numeric: tabular-nums;
        flex: none;
        margin-top: 3px;
        transition: background-color 0.15s ease;
      }
      .toc-list a:hover::before {
        background: var(--brand);
      }
      .toc-sub {
        display: flex;
        flex-wrap: wrap;
        gap: 6px 14px;
        margin: 10px 0 0;
        padding-top: 11px;
        border-top: 1px solid var(--line-soft);
      }
      .toc-sub a {
        display: inline-flex;
        align-items: center;
        gap: 5px;
        font-size: 12.5px;
        font-weight: 600;
        color: var(--ink-2);
        text-decoration: none;
      }
      .toc-sub a:hover {
        color: var(--brand-deep);
        text-decoration: underline;
        text-underline-offset: 3px;
      }
      .toc-count {
        font-size: 11.5px;
        font-weight: 600;
        color: var(--ink-3);
        font-variant-numeric: tabular-nums;
      }
      main > section {
        scroll-margin-top: 16px;
      }
      .section-lead {
        font-size: 15.5px;
        margin: 0 0 12px;
        max-width: 40em;
      }
      .checklist {
        list-style: none;
        margin: 0;
        padding: 0;
      }
      .checklist li {
        position: relative;
        padding: 9px 0 9px 30px;
        font-size: 14.5px;
        line-height: 1.85;
        max-width: 40em;
      }
      .checklist li + li {
        border-top: 1px solid var(--line-soft);
      }
      .checklist li::before {
        content: "✓";
        position: absolute;
        left: 0;
        top: 13px;
        width: 18px;
        height: 18px;
        display: grid;
        place-items: center;
        border: 1.5px solid var(--brand);
        border-radius: 4px;
        color: var(--brand-deep);
        font-size: 11px;
        font-weight: 800;
        line-height: 1;
      }
      .steps {
        list-style: none;
        margin: 0;
        padding: 0;
      }
      .step {
        position: relative;
        display: grid;
        grid-template-columns: 34px minmax(0, 1fr);
        column-gap: 16px;
        padding-bottom: 30px;
      }
      .step:last-child {
        padding-bottom: 0;
      }
      .step::before {
        content: "";
        position: absolute;
        left: 16.5px;
        top: 40px;
        bottom: 6px;
        width: 1px;
        background: var(--line-strong);
      }
      .step:last-child::before {
        display: none;
      }
      .step-number {
        width: 34px;
        height: 34px;
        display: grid;
        place-items: center;
        background: var(--ink);
        color: #ffffff;
        font-size: 14.5px;
        font-weight: 800;
        line-height: 1;
        border-radius: 8px;
        font-variant-numeric: tabular-nums;
      }
      .step-body {
        min-width: 0;
        padding-top: 4px;
      }
      .step-title {
        margin: 0 0 12px;
        font-size: 17px;
        font-weight: 700;
        line-height: 1.6;
        letter-spacing: 0.01em;
        font-feature-settings: "palt";
      }
      .kv-row {
        display: grid;
        grid-template-columns: 44px minmax(0, 1fr);
        column-gap: 12px;
        align-items: start;
      }
      .kv-row + .kv-row {
        margin-top: 10px;
      }
      .kv-row p {
        font-size: 15.5px;
        line-height: 1.85;
        margin: 0;
        max-width: 40em;
      }
      .kv-row--quiet p {
        font-size: 14.5px;
        color: var(--ink-2);
      }
      .kv-tag {
        display: inline-block;
        justify-self: start;
        font-size: 12px;
        font-weight: 800;
        letter-spacing: 0.14em;
        line-height: 1;
        padding: 0 1px 4px;
        border-bottom: 2px solid currentColor;
        margin-top: 5px;
      }
      .kv-tag--do,
      .kv-tag--symptom {
        color: var(--ink);
      }
      .kv-tag--check,
      .kv-tag--fix {
        color: var(--brand-deep);
      }
      .kv-tag--plain {
        color: var(--ink-3);
      }
      .sq-list {
        list-style: none;
        margin: 0;
        padding: 0;
      }
      .sq-list li {
        position: relative;
        padding: 10px 0 10px 22px;
        font-size: 15px;
        line-height: 1.9;
        color: var(--ink-2);
        max-width: 40em;
      }
      .sq-list li + li {
        border-top: 1px solid var(--line-soft);
      }
      .sq-list li::before {
        content: "";
        position: absolute;
        left: 2px;
        top: 21px;
        width: 7px;
        height: 7px;
        background: var(--brand);
        transform: skewX(-10deg);
        border-radius: 1px;
      }
      .sq-list--flat li {
        padding-top: 6px;
        padding-bottom: 6px;
      }
      .sq-list--flat li + li {
        border-top: 0;
      }
      .sq-list--flat li::before {
        top: 17px;
      }
      .tips-more {
        margin-top: 4px;
      }
      .tips-more summary {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        cursor: pointer;
        list-style: none;
        font-size: 13px;
        font-weight: 700;
        color: var(--ink-2);
        border: 1px solid var(--line-strong);
        border-radius: 999px;
        padding: 7px 16px;
        margin: 10px 0 4px;
        transition: border-color 0.15s ease, color 0.15s ease;
      }
      .tips-more summary::-webkit-details-marker {
        display: none;
      }
      .tips-more summary::after {
        content: "+";
        font-size: 15px;
        font-weight: 400;
        line-height: 1;
        color: var(--ink-3);
      }
      .tips-more summary:hover {
        border-color: var(--brand);
        color: var(--brand-deep);
      }
      .tips-more[open] summary {
        display: none;
      }
      .tips-more[open] .sq-list li:first-child {
        border-top: 1px solid var(--line-soft);
      }
      .faq {
        border-top: 1px solid var(--line);
      }
      .faq details {
        border-bottom: 1px solid var(--line);
      }
      .faq summary {
        display: grid;
        grid-template-columns: 24px minmax(0, 1fr) 24px;
        column-gap: 10px;
        align-items: start;
        padding: 15px 2px;
        font-size: 15px;
        font-weight: 700;
        line-height: 1.7;
        cursor: pointer;
        list-style: none;
        transition: background-color 0.15s ease;
      }
      .faq summary::-webkit-details-marker {
        display: none;
      }
      .faq summary:hover {
        background: var(--paper-warm);
      }
      .faq summary::before {
        content: "Q";
        color: var(--brand-deep);
        font-weight: 800;
        font-size: 15px;
        text-align: center;
        transform: translateY(1px);
      }
      .faq summary::after {
        content: "+";
        color: var(--ink-3);
        font-size: 19px;
        font-weight: 400;
        line-height: 1;
        text-align: center;
        transform: translateY(4px);
        transition: transform 0.2s ease;
      }
      .faq details[open] summary::after {
        transform: translateY(4px) rotate(45deg);
      }
      .faq details[open] summary {
        background: var(--paper-warm);
      }
      .faq-answer {
        display: grid;
        grid-template-columns: 24px minmax(0, 1fr);
        column-gap: 10px;
        padding: 0 26px 18px 2px;
      }
      .faq-answer::before {
        content: "A";
        color: var(--ink-3);
        font-weight: 800;
        font-size: 14px;
        text-align: center;
      }
      .faq-answer p {
        font-size: 15px;
        line-height: 1.9;
        color: var(--ink-2);
        max-width: 40em;
      }
      .troubles {
        list-style: none;
        margin: 0;
        padding: 0;
        display: grid;
        gap: 12px;
      }
      .trouble {
        background: var(--paper-warm);
        border: 1px solid var(--line-soft);
        border-radius: 10px;
        padding: 16px 18px;
      }
      .trouble .trouble-symptom {
        font-weight: 700;
        color: var(--ink);
      }
      .video {
        margin: 0;
      }
      .video-frame {
        border: 1px solid var(--line-strong);
        border-radius: 10px;
        overflow: hidden;
      }
      .video-player {
        display: block;
        width: 100%;
        background: #000000;
      }
      .video-caption {
        padding: 12px 4px 0;
      }
      .video-title {
        font-size: 14.5px;
        font-weight: 700;
        margin: 0 0 2px;
      }
      .video-desc {
        font-size: 13.5px;
        color: var(--ink-2);
        margin: 0 0 6px;
      }
      .video-link {
        font-size: 13px;
        margin: 4px 0 0;
      }
      main > section.sec-plain {
        counter-increment: none;
      }
      main > section.sec-plain > h2::before {
        content: "▶";
        border: none;
        background: none;
        padding: 0;
        width: auto;
        color: var(--brand);
        font-size: 10px;
        transform: none;
      }
      .article-nav {
        margin-top: 52px;
        padding-top: 24px;
        border-top: 2px solid var(--ink);
      }
      .pn {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 12px;
      }
      .pn-card {
        display: flex;
        flex-direction: column;
        gap: 4px;
        padding: 14px 16px;
        border: 1px solid var(--line);
        border-radius: 10px;
        text-decoration: none;
        color: var(--ink);
        transition: border-color 0.15s ease, background-color 0.15s ease;
      }
      .pn-card:hover {
        border-color: var(--brand);
        background: var(--brand-wash);
      }
      .pn-card--next {
        text-align: right;
      }
      .pn-dir {
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.1em;
        color: var(--ink-3);
      }
      .pn-card--prev .pn-dir::before {
        content: "← ";
      }
      .pn-card--next .pn-dir::after {
        content: " →";
      }
      .pn-card:hover .pn-dir {
        color: var(--brand-deep);
      }
      .pn-title {
        font-size: 14px;
        font-weight: 700;
        line-height: 1.6;
      }
      .related {
        margin-top: 24px;
      }
      .related-label {
        font-size: 11px;
        font-weight: 800;
        letter-spacing: 0.12em;
        color: var(--ink-3);
        margin: 0 0 4px;
      }
      .related-list {
        list-style: none;
        margin: 0;
        padding: 0;
      }
      .related-list li + li {
        border-top: 1px solid var(--line-soft);
      }
      .related-list a {
        display: flex;
        align-items: center;
        gap: 12px;
        padding: 11px 2px;
        color: var(--ink);
        text-decoration: none;
        font-size: 14.5px;
        font-weight: 600;
      }
      .related-list a:hover .related-title {
        color: var(--brand-deep);
        text-decoration: underline;
        text-underline-offset: 3px;
      }
      .related-arrow {
        margin-left: auto;
        color: var(--line-strong);
        transition: color 0.15s ease, transform 0.15s ease;
      }
      .related-list a:hover .related-arrow {
        color: var(--brand);
        transform: translateX(2px);
      }
      .related-more {
        margin: 10px 0 0;
        font-size: 13px;
      }
      .related-more a {
        font-weight: 700;
      }
      .backlink {
        margin: 28px 0 0;
      }
      .backlink a {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        font-size: 13.5px;
        font-weight: 700;
        color: var(--ink-2);
        text-decoration: none;
        border: 1px solid var(--line-strong);
        border-radius: 8px;
        padding: 10px 18px;
        transition: border-color 0.15s ease, color 0.15s ease, background-color 0.15s ease;
      }
      .backlink a:hover {
        border-color: var(--brand);
        color: var(--brand-deep);
        background: var(--brand-wash);
      }
      @media (max-width: 560px) {
        .page {
          padding: 0 18px 32px;
        }
        h1 {
          font-size: 22px;
        }
        .article-head {
          padding-top: 18px;
        }
        .toc-list {
          grid-template-columns: minmax(0, 1fr);
        }
        .toc-list li:nth-child(2) {
          border-top: 1px solid var(--line-soft);
        }
        .toc-list li:first-child {
          border-top: 0;
        }
        .step {
          grid-template-columns: 30px minmax(0, 1fr);
          column-gap: 12px;
        }
        .step-number {
          width: 30px;
          height: 30px;
          font-size: 13.5px;
          border-radius: 7px;
        }
        .step::before {
          left: 14.5px;
          top: 36px;
        }
        .kv-row {
          display: block;
        }
        .kv-tag {
          margin: 0 0 6px;
        }
        .kv-row + .kv-row {
          margin-top: 14px;
        }
        .pn {
          display: flex;
          flex-direction: column-reverse;
        }
        .pn-card--next {
          text-align: left;
        }
      }
      @media print {
        body::before {
          display: none;
        }
        .video-frame {
          display: none;
        }
        .article-nav,
        .crumbs {
          display: none;
        }
      }