.brand small,.list-heading>span,.example .eyebrow{font-size:12px}
.english,.nav-title,.nav-label,.nav-num,.category-count,.sidebar-note small,.search-meta,.group-heading>span,.article-category,.eyebrow,.intro-count span{font-size:12px}
.category-link,.top-link,.read-more,.breadcrumb,.source a{font-size:14px}
.term-card p{font-size:16px;line-height:1.85}
.term-visual{margin:34px 0 42px;padding:0;overflow:hidden;border:1px solid var(--line);border-radius:16px;background:#f7f5ff;box-shadow:0 8px 24px #29204508}.term-visual img{display:block;width:100%;height:auto}.term-visual figcaption{padding:12px 18px 15px;font-size:13px;line-height:1.7;color:var(--muted);background:#fff}.key-points{padding:26px 28px;background:#fbfbfe;border:1px solid var(--line);border-radius:10px}.key-points ul{margin:0;padding-left:1.35em;color:#4e5569}.key-points li{padding-left:5px;margin:7px 0}.key-points li::marker{color:var(--accent)}
.history,.key-people,.evolution{padding-top:6px}.history .eyebrow{margin-bottom:12px}.history-era{color:var(--muted)!important}.timeline{list-style:none;margin:22px 0 0;padding:0;border-left:2px solid #d9d4f0}.timeline li{display:grid;grid-template-columns:86px 1fr;gap:16px;padding:0 0 20px 20px;position:relative}.timeline li::before{content:"";position:absolute;width:9px;height:9px;border-radius:50%;background:var(--accent);left:-5px;top:6px}.timeline strong{font-size:14px;color:var(--accent)}.timeline span{color:#4e5569}.key-people,.evolution{border-top:1px solid var(--line)}.evolution p{font-weight:650;color:var(--ink)}.source a{display:block;margin:8px 0}
@media(max-width:760px){.term-visual{margin:27px 0 34px;border-radius:12px}.term-visual figcaption{padding:10px 14px;font-size:12px}.key-points{padding:21px 20px}.key-points li{margin:8px 0}}
@media(max-width:760px){.timeline li{grid-template-columns:70px 1fr;gap:10px;padding-left:16px}.timeline strong,.timeline span{font-size:14px}}
.intro>p{font-size:16px}
@media(max-width:760px){.top-link{font-size:14px}.brand small{font-size:12px;letter-spacing:0}.brand{font-size:16px}.intro>p{font-size:16px}.sidebar nav .category-link{font-size:14px}}
.sidebar-search{margin:0 0 29px}.sidebar-search>label{display:block;font-size:14px;font-weight:700;margin-bottom:10px}.sidebar-search-box{display:flex;align-items:center;background:#fff;border:1px solid #d4d7e3;border-radius:7px;overflow:hidden}.sidebar-search-box:focus-within{border-color:var(--accent);box-shadow:0 0 0 3px #6450c815}.sidebar-search-box input{width:100%;min-width:0;height:46px;border:0;background:transparent;padding:0 4px 0 11px;font-size:14px;color:var(--ink);outline:none}.sidebar-search-box button{flex-shrink:0;width:42px;height:46px;border:0;background:var(--purple-light);color:var(--accent);cursor:pointer}.sidebar-search-box button:hover{background:#e3ddf7}.sidebar-search-box svg{width:20px;height:20px;vertical-align:middle}.sidebar-search>small{display:block;margin:10px 0 0;font-size:12px;line-height:1.75;color:var(--muted)}footer{flex-wrap:wrap}.search-privacy{flex-basis:100%;font-size:12px;line-height:1.9}.search-privacy summary{cursor:pointer;text-decoration:underline;text-underline-offset:3px}.search-privacy p{max-width:760px;margin:8px 0 0}@media(max-width:760px){.sidebar-search{margin-bottom:15px}.sidebar-search>label{margin-bottom:7px}.sidebar-search-box input{font-size:16px}.sidebar-search>small{font-size:12px}.sidebar-search>small br{display:none}}
.keyword-index-link{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:10px 0 25px;padding:10px 12px;border:1px solid #ddd9f4;border-radius:8px;color:var(--accent);background:#faf9ff;font-size:14px;font-weight:700;text-decoration:none}.keyword-index-link span{font-size:12px;color:var(--muted);font-weight:500}.keyword-index-link:hover,.keyword-index-link.active{background:#eeeafd;border-color:#c9c2ee}.keyword-teaser{margin:68px 0 10px;padding-top:36px;border-top:1px solid var(--line)}.keyword-teaser>p{margin:0 0 22px;color:var(--muted)}.keyword-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.keyword-card{display:block;padding:22px 23px;border:1px solid var(--line);border-radius:10px;background:#fff;color:inherit;text-decoration:none;box-shadow:0 6px 18px #29204506;transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease}.keyword-card:hover{transform:translateY(-2px);border-color:#b9b1e8;box-shadow:0 10px 24px #29204512}.keyword-card h3{margin:12px 0 8px;font-size:20px}.keyword-card p{margin:0;min-height:3.4em;color:var(--muted);line-height:1.75}.keyword-intro{margin-bottom:35px}.keyword-index-grid{margin-top:3px}.keyword-article .article-body{margin-top:12px}.keyword-sources>div{display:grid;gap:10px}.keyword-sources a{display:grid;grid-template-columns:minmax(120px,.4fr) 1fr auto;align-items:center;gap:15px;padding:14px 16px;border:1px solid var(--line);border-radius:8px;color:inherit;text-decoration:none}.keyword-sources a:hover{border-color:#b9b1e8;background:#faf9ff}.keyword-sources a strong{color:var(--accent)}.keyword-sources a span:nth-child(2){color:var(--muted);font-size:14px;line-height:1.6}.keyword-sources a span:last-child{color:var(--accent)}
.content-tabs{display:flex;gap:4px;margin:40px 0 0;border-bottom:1px solid var(--line)}.content-tab{appearance:none;border:0;border-bottom:3px solid transparent;background:transparent;color:var(--muted);cursor:pointer;padding:13px 22px 14px;font-size:16px;font-weight:700}.content-tab span{display:block;margin-top:3px;font-size:10px;letter-spacing:.14em;font-weight:500;color:#9a9cad}.content-tab:hover{color:var(--accent);background:#faf9ff}.content-tab.active{color:var(--accent);border-bottom-color:var(--accent);background:#fff}.content-panel>.list-heading{margin-top:28px}.index-intro{margin:0 0 25px;color:var(--muted);font-size:14px;line-height:1.8}.index-columns{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}.index-group{min-width:0}.index-group h3{font-size:16px;margin:0 0 13px;padding-bottom:10px;border-bottom:1px solid var(--line)}.index-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.index-term{position:relative;display:flex;align-items:center;min-height:42px;padding:9px 11px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink);font-size:14px;font-weight:650;line-height:1.5}.index-term:hover,.index-term:focus-visible{border-color:#aaa0d7;background:#faf9ff;color:var(--accent);z-index:3}.index-tooltip{position:absolute;left:10px;right:10px;bottom:calc(100% + 8px);padding:9px 11px;border-radius:6px;background:#24283f;color:#fff;box-shadow:0 7px 18px #24283f2e;font-size:12px;font-weight:400;line-height:1.65;opacity:0;pointer-events:none;transform:translateY(4px);transition:opacity .15s,transform .15s}.index-tooltip::after{content:"";position:absolute;left:16px;top:100%;border:5px solid transparent;border-top-color:#24283f}.index-term:hover .index-tooltip,.index-term:focus-visible .index-tooltip{opacity:1;transform:translateY(0)}
.related-keywords>p{margin:0 0 14px;color:var(--muted);font-size:14px}
@media(max-width:760px){.keyword-grid{grid-template-columns:1fr;gap:12px}.keyword-card{padding:18px}.keyword-card h3{font-size:18px}.keyword-sources a{grid-template-columns:1fr auto;gap:5px 12px}.keyword-sources a span:nth-child(2){grid-column:1/-1}.keyword-teaser{margin-top:48px;padding-top:28px}}
@media(max-width:760px){.content-tabs{margin-top:30px}.content-tab{flex:1;padding:11px 10px 12px;font-size:15px}.index-columns{grid-template-columns:1fr;gap:30px}.index-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}.index-term{font-size:13px;padding:8px 9px}}

/* Implementation guide refinements: compact detail chrome, clear page types, and deeper reading blocks. */
.detail-page .topbar{height:64px}
.detail-page .sidebar{padding-top:25px;padding-bottom:20px}
.detail-page main{padding-top:28px;padding-bottom:52px}
.detail-page .sidebar-search{margin-bottom:17px}
.detail-page .sidebar-search-box input,.detail-page .sidebar-search-box button{height:32px}
.detail-page .nav-title{margin-bottom:14px}
.detail-page .nav-label{margin-top:18px;margin-bottom:7px}
.detail-page .all-link{padding-top:9px;padding-bottom:9px}
.detail-page .category-link{padding-top:9px;padding-bottom:9px}
.detail-page .keyword-index-link{margin-top:6px;margin-bottom:15px;padding-top:7px;padding-bottom:7px}
.detail-page .sidebar-note{padding-top:17px;margin-top:24px}
.detail-page .breadcrumb{margin-bottom:24px}
.detail-page footer{padding-top:18px;padding-bottom:18px}
.term-card,.keyword-card{position:relative}
.term-card{border-top:3px solid #4b86bd}
.term-card:hover{border-color:#4b86bd;box-shadow:0 7px 22px #2c6da018}
.keyword-card{border-top:3px solid #8172a9}
.keyword-card:hover{border-color:#8172a9;box-shadow:0 10px 24px #5d4c8c18}
.term-card h3,.keyword-card h3{margin:0 0 8px;font-size:18px;line-height:1.5}
.term-card .card-top,.keyword-card .card-top{align-items:center;gap:8px;margin-bottom:6px}
.term-card .english,.keyword-card .english{flex:1}
.card-kind{flex:none;font-size:9px;letter-spacing:.09em;font-weight:800;line-height:1;padding:5px 6px;border-radius:4px}
.term-kind{color:#28679c;background:#eaf3fb}
.keyword-kind{color:#69598f;background:#f0edf7}
.keyword-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
.article-category{display:inline-flex;align-items:center;gap:8px}
.page-type-label,.link-type{font-size:9px;letter-spacing:.08em;font-weight:800;line-height:1;color:#28679c}
.article-category{background:#eaf3fb;color:#28679c}
.keyword-page-label{background:#f0edf7;color:#69598f}
.keyword-page-label .page-type-label{color:#69598f}
.key-points{background:#f3f8fc;border-color:#cbddea}
.key-points ul{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;list-style:none;padding:0}
.key-points li{margin:0;padding:15px 16px;background:#fff;border:1px solid #d8e5ef;border-radius:8px;color:#43566a;line-height:1.75}
.key-points li::marker{content:none}
.example{background:#f6f2fb;border-left-color:#8172a9}
.takeaway{padding:23px 26px;background:#eef7ff;border:1px solid #c5ddeb;border-radius:10px;box-shadow:0 6px 16px #2c6da00b}
.takeaway h2{color:#245e8d}
.takeaway p{font-weight:650;color:#294b64}
.takeaway::before{content:"KEY TAKEAWAY";display:block;margin-bottom:9px;color:#3578ab;font-size:10px;letter-spacing:.14em;font-weight:800}
.source{opacity:.88}
.source h2{color:#6e7184;font-weight:650}
.source a{font-size:12px}
.related a{display:flex;align-items:center;gap:8px}
.related .link-type{color:#28679c}
.related-keywords .related-keyword-link .link-type,.related-keywords .related-keyword-link>span:nth-child(2){color:#69598f}
.related a>span:nth-child(2){flex:1}
.keyword-sources>div{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
.keyword-source-card{display:grid!important;grid-template-columns:auto 1fr auto;align-items:center;gap:7px!important;padding:12px 14px!important;border-color:#ddd7eb!important;background:#fbfaff}
.keyword-source-card strong{color:#28679c}
.keyword-source-card span:nth-child(3){grid-column:1/-1;color:var(--muted);font-size:13px;line-height:1.55}
.keyword-source-card .link-type{color:#28679c}
@media(max-width:1180px){.keyword-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){
  .detail-page .topbar{height:62px}
  .detail-page .sidebar{padding:10px 22px}
  .detail-page main{padding:19px 22px 38px}
  .detail-page .sidebar-search-box input,.detail-page .sidebar-search-box button{height:32px}
  .detail-page footer{padding:18px 22px}
  .cards,.keyword-grid{grid-template-columns:1fr}
  .key-points ul{grid-template-columns:1fr;gap:9px}
  .keyword-sources>div{grid-template-columns:1fr}
  .keyword-source-card{grid-template-columns:auto 1fr auto}
}

/* AI history long-read */
.history-index-link{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:-16px 0 25px;padding:10px 12px;border:1px solid #d4ddec;border-radius:8px;color:#315f8d;background:#f6f9fc;font-size:14px;font-weight:700;text-decoration:none}
.history-index-link span{font-size:12px;color:#68778a;font-weight:500}
.history-index-link:hover,.history-index-link.active{background:#eaf3fb;border-color:#9dbbd5}
.detail-page .history-index-link{margin-top:-10px;margin-bottom:15px;padding-top:7px;padding-bottom:7px}
.history-teaser{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:end;gap:34px;margin:68px 0 10px;padding:34px 36px;border:1px solid #ccd9e7;border-radius:12px;background:linear-gradient(135deg,#eef6fc 0%,#f8f6ff 100%);box-shadow:0 8px 24px #2c6da00b}
.history-teaser>div>span,.history-feature-label{display:inline-block;color:#326f9d;font-size:12px;font-weight:800;letter-spacing:.13em}
.history-teaser h2{margin:9px 0 10px;font-size:28px;line-height:1.35}
.history-teaser p{max-width:650px;margin:0;color:var(--muted);line-height:1.85}
.history-teaser>a{display:inline-flex;align-items:center;gap:11px;white-space:nowrap;padding:12px 18px;border-radius:7px;background:#2c6fa4;color:#fff;font-size:14px;font-weight:700;text-decoration:none}
.history-teaser>a:hover{background:#225b88}
.history-feature{max-width:900px}
.history-hero{padding:10px 0 38px;border-bottom:1px solid var(--line)}
.history-feature-label{padding:7px 10px;border:1px solid #bcd1e2;border-radius:4px;background:#eef6fc}
.history-hero .article-english{margin-top:27px}
.history-hero h1{margin-bottom:9px;font-size:clamp(42px,6vw,68px);letter-spacing:-.04em}
.history-subtitle{margin:0 0 15px;color:#315f8d;font-size:clamp(20px,3vw,28px);font-weight:700;line-height:1.5}
.history-byline{display:flex;flex-wrap:wrap;gap:10px 22px;margin:0 0 31px!important;color:var(--muted);font-size:13px!important}
.history-lead{margin:17px 0 0!important;color:#41495d!important;font-size:17px!important;line-height:2!important}
.history-at-a-glance{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;margin:34px 0;background:#dbe2eb;border:1px solid #dbe2eb;border-radius:10px;overflow:hidden}
.history-at-a-glance div{padding:20px;background:#f7f9fc}
.history-at-a-glance strong,.history-at-a-glance span{display:block}
.history-at-a-glance strong{margin-bottom:8px;color:#2d6c9c;font-size:18px}
.history-at-a-glance span{color:#5c6474;font-size:13px;line-height:1.6}
.history-toc{margin:0 0 56px;padding:28px 30px;border:1px solid var(--line);border-radius:10px;background:#fbfbfe}
.history-toc>div{display:flex;align-items:baseline;justify-content:space-between;gap:18px;margin-bottom:20px;padding-bottom:15px;border-bottom:1px solid var(--line)}
.history-toc>div>span{color:#7e8190;font-size:12px;font-weight:800;letter-spacing:.16em}
.history-toc h2{margin:0;font-size:20px}
.history-toc ol{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px 28px;margin:0;padding:0;list-style:none}
.history-toc a{display:flex;gap:12px;padding:9px 0;color:#343a4e;font-size:14px;line-height:1.55;text-decoration:none;border-bottom:1px solid #eceef3}
.history-toc a:hover{color:#2d6c9c}
.history-toc a span{flex:none;color:#7893aa;font-size:12px;font-weight:800}
.history-longread{counter-reset:historychapter}
.history-chapter{position:relative;margin:0;padding:10px 0 74px 42px;border-left:2px solid #d7e1eb;scroll-margin-top:85px}
.history-chapter::before{content:"";position:absolute;left:-7px;top:20px;width:12px;height:12px;border-radius:50%;background:#3978a8;box-shadow:0 0 0 6px #eef5fa}
.history-chapter-heading{display:flex;align-items:flex-start;gap:18px;margin-bottom:27px}
.history-chapter-number{display:grid;place-items:center;flex:none;width:43px;height:43px;border:1px solid #b9cfe0;border-radius:50%;color:#2d6c9c;background:#f5f9fc;font-size:12px;font-weight:800}
.history-chapter-heading p{margin:0 0 5px!important;color:#6e7f91!important;font-size:12px!important;font-weight:800;letter-spacing:.08em;text-transform:uppercase}
.history-chapter-heading h2{margin:0;font-size:27px;line-height:1.55}
.history-chapter>p{margin:0 0 20px;color:#41495d;font-size:16px;line-height:2.08}
.history-milestones{margin:30px 0 20px;padding:22px 24px;border:1px solid #d7e1eb;border-radius:9px;background:#f6f9fc}
.history-milestones h3{margin:0 0 16px;color:#344b61;font-size:15px}
.history-milestones ol{margin:0;padding:0;list-style:none}
.history-milestones li{display:grid;grid-template-columns:92px 1fr;gap:16px;padding:10px 0;border-top:1px solid #e0e7ee}
.history-milestones li:first-child{padding-top:0;border-top:0}
.history-milestones li:last-child{padding-bottom:0}
.history-milestones strong{color:#2d6c9c;font-size:13px}
.history-milestones span{color:#536172;font-size:14px;line-height:1.65}
.history-chapter-sources{display:flex;flex-wrap:wrap;gap:7px;margin-top:17px}
.history-chapter-sources a{display:inline-flex;align-items:center;gap:6px;padding:7px 9px;border:1px solid #e1e4eb;border-radius:5px;background:#fff;color:#666d7d;font-size:11px;line-height:1.45;text-decoration:none}
.history-chapter-sources a:hover{border-color:#b6c9d9;color:#2d6c9c}
.history-chapter-sources a>span:first-child{color:#315f8d;font-weight:750}
.history-reference-section{padding:56px 0 18px;scroll-margin-top:85px}
.history-reference-section>.eyebrow,.history-all-sources>.eyebrow{margin-bottom:11px;color:#3978a8}
.history-reference-section>h2,.history-all-sources>h2{margin:0 0 13px;font-size:30px}
.history-reference-section>p,.history-all-sources>p{max-width:760px;color:#535b6c;line-height:1.9}
.history-table-wrap{margin:25px 0 8px;overflow-x:auto;border:1px solid #dfe3ea;border-radius:9px;background:#fff}
.history-table-wrap table{width:100%;min-width:760px;border-collapse:collapse;text-align:left}
.history-table-wrap caption{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.history-table-wrap th,.history-table-wrap td{padding:14px 16px;border-bottom:1px solid #e7e9ee;font-size:13px;line-height:1.65;vertical-align:top}
.history-table-wrap thead th{color:#536071;background:#f5f7fa;font-size:12px;letter-spacing:.04em}
.history-table-wrap tbody th{min-width:160px;color:#2b5274;background:#fafcfe;font-weight:750}
.history-table-wrap tbody tr:last-child th,.history-table-wrap tbody tr:last-child td{border-bottom:0}
.history-takeaway{margin:64px 0 18px;padding:30px 32px;border:1px solid #bdd5e8;border-radius:11px;background:linear-gradient(135deg,#edf7ff,#f4f1fb);box-shadow:0 7px 20px #2c6da00d}
.history-takeaway>span{color:#2d6c9c;font-size:11px;font-weight:800;letter-spacing:.14em}
.history-takeaway h2{margin:10px 0 13px;color:#284f70;font-size:24px}
.history-takeaway p{margin:0;color:#334c61;font-weight:650;line-height:1.95}
.history-related{padding-top:48px}
.history-all-sources{padding:58px 0 22px;border-top:1px solid var(--line)}
.history-all-sources ol{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin:25px 0 0;padding:0;list-style:none}
.history-all-sources li{display:grid;grid-template-columns:30px 1fr;gap:8px;padding:12px 13px;border:1px solid #e3e5eb;border-radius:7px;background:#fbfbfd}
.history-all-sources li>span{color:#8b8f9d;font-size:11px;font-weight:800}
.history-all-sources a{margin:0!important;color:#353b50;text-decoration:none}
.history-all-sources a strong,.history-all-sources a small{display:block}
.history-all-sources a strong{font-size:12px;line-height:1.55}
.history-all-sources a small{margin-top:4px;color:#747988;font-size:11px;line-height:1.45}
.engineering-index-link{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:-16px 0 25px;padding:10px 12px;border:1px solid #ddd5ec;border-radius:8px;color:#654f82;background:#faf8fc;font-size:14px;font-weight:700;text-decoration:none}
.engineering-index-link span{font-size:12px;color:#7b6f8d;font-weight:500}
.engineering-index-link:hover,.engineering-index-link.active{background:#f0eafb;border-color:#b9a6d5}
.detail-page .engineering-index-link{margin-top:-10px;margin-bottom:15px;padding-top:7px;padding-bottom:7px}
.engineering-teaser{margin-top:18px;border-color:#d9d0e8;background:linear-gradient(135deg,#f5effb 0%,#eef7f8 100%)}
.engineering-teaser>div>span{color:#725394}
.engineering-teaser>a{background:#675082}
.engineering-teaser>a:hover{background:#523f68}
.engineering-hero{background:radial-gradient(circle at 94% 8%,#eee7f8 0,transparent 27%)}
.engineering-hero .history-feature-label{color:#725394;border-color:#cdbbdf;background:#f5effb}
.engineering-hero h1{font-size:clamp(38px,4.3vw,54px);letter-spacing:-.035em}
.engineering-hero .history-subtitle{font-size:clamp(18px,2.2vw,24px)}
.engineering-correction{padding:48px 0 42px}
.engineering-correction>.eyebrow,.engineering-timeline>.eyebrow{margin-bottom:10px;color:#725394}
.engineering-correction>h2,.engineering-timeline>h2{margin:0 0 22px;font-size:30px}
.engineering-correction>div{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.engineering-correction article{position:relative;padding:22px 22px 20px;border:1px solid #ded8e8;border-radius:9px;background:#fcfbfe}
.engineering-correction article>span{color:#9a86b3;font-size:11px;font-weight:800;letter-spacing:.12em}
.engineering-correction h3{margin:8px 0 10px;color:#554368;font-size:17px;line-height:1.6}
.engineering-correction p{margin:0;color:#596071;font-size:14px;line-height:1.85}
.engineering-layer-figure{margin:0 0 54px;padding:28px 30px;border:1px solid #d8dce6;border-radius:11px;background:#f8f9fc}
.engineering-layer-figure figcaption{display:grid;grid-template-columns:auto 1fr;gap:4px 16px;margin-bottom:22px}
.engineering-layer-figure figcaption>span{grid-row:1/3;align-self:center;padding:8px 10px;border-radius:5px;color:#fff;background:#64507d;font-size:11px;font-weight:800;letter-spacing:.12em}
.engineering-layer-figure figcaption>strong{font-size:20px}
.engineering-layer-figure figcaption>small{color:#737987;font-size:12px}
.engineering-layer-map{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:6px;align-items:stretch}
.engineering-layer-map div{position:relative;display:flex;flex-direction:column;min-height:112px;padding:13px 11px;border:1px solid #d9d4e4;border-radius:7px;background:#fff}
.engineering-layer-map div:not(:last-child)::after{content:"→";position:absolute;right:-10px;top:44px;z-index:2;color:#8b769f;font-weight:800}
.engineering-layer-map span{color:#9988aa;font-size:10px;font-weight:800}
.engineering-layer-map strong{margin:15px 0 8px;color:#503f65;font-size:12px;letter-spacing:.06em}
.engineering-layer-map small{color:#6a7080;font-size:11px;line-height:1.5}
.engineering-timeline{margin:0 0 54px;padding:0 0 6px}
.engineering-timeline ol{margin:0;padding:0;list-style:none;border-top:1px solid #dcdfe7}
.engineering-timeline li{display:grid;grid-template-columns:130px 1fr;gap:28px;padding:22px 0;border-bottom:1px solid #e1e3e9}
.engineering-timeline time{color:#725394;font-size:15px;font-weight:800}
.engineering-timeline h3{margin:0 0 7px;font-size:17px}
.engineering-timeline p{margin:0;color:#5c6373;font-size:14px;line-height:1.8}
.engineering-toc{border-color:#ded8e8;background:#fcfafe}
.engineering-toc a:hover{color:#654f82}
.engineering-chapter{position:relative;margin:0;padding:10px 0 74px 42px;border-left:2px solid #ded6e8;scroll-margin-top:85px}
.engineering-chapter::before{content:"";position:absolute;left:-7px;top:20px;width:12px;height:12px;border-radius:50%;background:#75569a;box-shadow:0 0 0 6px #f3eef8}
.engineering-chapter .history-chapter-number{color:#654f82;border-color:#cdbdde;background:#faf7fc}
.engineering-chapter .history-chapter-heading p{color:#7d6b91!important}
.engineering-chapter>p{margin:0 0 20px;color:#41495d;font-size:16px;line-height:2.08}
.engineering-practices{margin:29px 0 18px;padding:22px 24px;border:1px solid #d8e2e3;border-radius:9px;background:#f5fafa}
.engineering-practices h3{margin:0 0 15px;color:#365e61;font-size:15px}
.engineering-practices ul{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin:0;padding:0;list-style:none}
.engineering-practices li{position:relative;padding:9px 10px 9px 29px;border-radius:6px;background:#fff;color:#536063;font-size:13px;line-height:1.6}
.engineering-practices li::before{content:"✓";position:absolute;left:10px;top:9px;color:#48868a;font-weight:800}
.engineering-failure{margin:18px 0;padding:17px 20px;border-left:4px solid #a37e72;background:#fbf6f4}
.engineering-failure span{color:#8a5b4c;font-size:11px;font-weight:800;letter-spacing:.1em}
.engineering-failure p{margin:6px 0 0;color:#665651;font-size:13px;line-height:1.75}
.engineering-comparison{padding-top:44px}
.engineering-comparison>.eyebrow{color:#725394}
.engineering-comparison .history-table-wrap tbody th{color:#5b4770;background:#fcfafe}
.engineering-takeaway{border-color:#d0c1e1;background:linear-gradient(135deg,#f3ecfa,#eef8f7)}
.engineering-takeaway>span{color:#6a4d89}
.engineering-takeaway h2{color:#554068}
@media(max-width:760px){
  .history-index-link{margin:-5px 0 13px}
  .history-teaser{grid-template-columns:1fr;align-items:start;gap:20px;margin-top:48px;padding:26px 22px}
  .history-teaser h2{font-size:24px}
  .history-teaser>a{justify-content:center}
  .history-feature{max-width:none}
  .history-hero{padding-top:5px}
  .history-hero h1{font-size:40px}
  .history-lead{font-size:16px!important;line-height:1.95!important}
  .history-at-a-glance{grid-template-columns:1fr}
  .history-at-a-glance div{padding:17px 19px}
  .history-toc{padding:23px 20px;margin-bottom:43px}
  .history-toc>div{display:block}
  .history-toc>div>span{display:block;margin-bottom:7px}
  .history-toc ol{grid-template-columns:1fr}
  .history-chapter{padding-left:24px;padding-bottom:58px}
  .history-chapter-heading{gap:11px}
  .history-chapter-number{width:36px;height:36px}
  .history-chapter-heading h2{font-size:22px}
  .history-chapter>p{font-size:16px;line-height:2}
  .history-milestones{padding:19px 17px}
  .history-milestones li{grid-template-columns:70px 1fr;gap:10px}
  .history-reference-section{padding-top:45px}
  .history-reference-section>h2,.history-all-sources>h2{font-size:25px}
  .history-table-wrap{margin-right:-22px;border-radius:7px 0 0 7px}
  .history-takeaway{padding:25px 22px}
  .history-all-sources ol{grid-template-columns:1fr}
  .engineering-index-link{margin:-5px 0 13px}
  .engineering-teaser{margin-top:14px}
  .engineering-correction{padding:38px 0 34px}
  .engineering-correction>h2,.engineering-timeline>h2{font-size:25px}
  .engineering-correction>div{grid-template-columns:1fr}
  .engineering-layer-figure{padding:23px 19px;margin-bottom:44px}
  .engineering-layer-figure figcaption{display:block}
  .engineering-layer-figure figcaption>span{display:inline-block;margin-bottom:12px}
  .engineering-layer-figure figcaption>strong,.engineering-layer-figure figcaption>small{display:block}
  .engineering-layer-figure figcaption>small{margin-top:5px;line-height:1.6}
  .engineering-layer-map{grid-template-columns:1fr;gap:7px}
  .engineering-layer-map div{min-height:0;padding:12px 14px}
  .engineering-layer-map div:not(:last-child)::after{content:"↓";right:15px;top:auto;bottom:-12px}
  .engineering-layer-map strong{margin:6px 0 4px}
  .engineering-timeline li{grid-template-columns:1fr;gap:6px;padding:18px 0}
  .engineering-chapter{padding-left:24px;padding-bottom:58px}
  .engineering-chapter>p{font-size:16px;line-height:2}
  .engineering-practices{padding:19px 17px}
  .engineering-practices ul{grid-template-columns:1fr}
}