/* DAS Lab field notes: original diagrams, with a readable linear fallback. */
.twin-main { position: relative; z-index: 1; }
.twin-main [id] { scroll-margin-top: 96px; }
.twin-main h1, .twin-main h2, .twin-main h3 { text-wrap: balance; }
.twin-main p { word-break: keep-all; overflow-wrap: anywhere; }
.twin-main a:focus-visible, .twin-main button:focus-visible { outline: 2px solid var(--cyan); outline-offset: 5px; }
.twin-main button { font-family: inherit; }
.twin-main [hidden] { display: none !important; }
.twin-section { padding: 100px 3rem; border-bottom: 1px solid var(--border); }
.twin-section-alt { background: rgba(8, 15, 27, .88); }
.twin-section-heading { margin-bottom: 42px; }
.twin-main .section-label { font-size: .72rem; }
.twin-main .section-title { line-height: 1.4; font-size: clamp(1.8rem, 3vw, 2.75rem); letter-spacing: -.04em; }
.twin-lead { max-width: 770px; color: var(--text-dim); font-size: 1rem; line-height: 1.95; }
.twin-kicker { display: block; color: var(--cyan); font: .7rem/1.5 var(--mono); letter-spacing: .09em; margin-bottom: 16px; }
.twin-cite { margin-left: .35em; font: .7rem/1.3 var(--mono); white-space: nowrap; vertical-align: super; }
.twin-cite a { color: var(--cyan); text-decoration: none; }
.twin-cite a:hover { text-decoration: underline; }
.twin-footnote { margin-top: 22px; color: var(--text-dim); font-size: .81rem; line-height: 1.85; max-width: 1000px; }
.twin-hero { padding: 68px 3rem 76px; }
.twin-hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 64px; align-items: center; }
.twin-eyebrow { font: .8rem/1.4 var(--mono); letter-spacing: .28em; color: var(--text-dim); margin-bottom: 25px; }
.twin-hero h1 { color: #f1f6fa; font-size: clamp(2.35rem, 4.25vw, 3.85rem); letter-spacing: -.06em; line-height: 1.32; margin-bottom: 26px; }
.twin-hero h1 em { color: var(--cyan); font-style: normal; }
.twin-hero .twin-lead { max-width: 490px; font-size: .95rem; }
.twin-hero .hero-actions { margin-top: 32px; align-items: center; gap: 20px; }
.twin-hero .btn-primary { font-family: inherit; font-size: .83rem; letter-spacing: 0; padding: 13px 22px; }
.twin-text-link { display: inline-block; font-size: .85rem; color: #c4dbe8; text-decoration: none; border-bottom: 1px solid #466378; padding: 5px 0; }
.twin-text-link:hover { color: var(--cyan); border-color: var(--cyan); }
.twin-hero-visual { min-width: 0; background: radial-gradient(ellipse at center, #0c243588, transparent 72%); border: 1px solid #254051; }
.twin-visual-topline { display: flex; justify-content: space-between; gap: 10px; padding: 16px 18px; border-bottom: 1px solid #254051; color: var(--text-dim); font: .58rem/1.5 var(--mono); letter-spacing: .06em; }
.twin-status-dot { color: #83c4b0; }
.twin-status-dot::before { content: ''; display: inline-block; width: 5px; height: 5px; border-radius: 50%; background: var(--green); margin: 0 7px 1px 0; }
.twin-hero-visual svg { display: block; width: 100%; height: auto; }
.twin-hero-visual figcaption { margin: 0 22px; padding: 18px 0; border-top: 1px solid #254051; font-size: .8rem; color: #c3d6e2; }
.twin-visual-note { display: block; font-size: .65rem; color: var(--text-dim); margin-top: 4px; }
.twin-toc { display: grid; grid-template-columns: repeat(5, 1fr); border: 1px solid #254051; background: #0a1220; }
.twin-toc > a { display: flex; align-items: center; gap: 12px; min-height: 65px; padding: 15px 20px; color: var(--cyan); text-decoration: none; font: .72rem/1.6 var(--mono); }
.twin-toc > a + a { border-left: 1px solid #254051; }
.twin-toc > a > span { color: #b8cad8; font-family: var(--sans); font-size: .8rem; }
.twin-toc > a:hover { background: #122333; }
.twin-editorial { display: grid; grid-template-columns: 1fr 1fr; gap: 52px; margin-bottom: 38px; }
.twin-editorial p { color: var(--text-dim); line-height: 1.95; font-size: .96rem; }
.twin-editorial strong { color: #e0edf7; font-weight: 600; }
.twin-maturity { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: #254051; border: 1px solid #254051; }
.twin-maturity article { min-width: 0; padding: 28px; background: #0b1421; }
.twin-maturity .is-connected { background: #0a212b; }
.twin-maturity h3, .twin-distinction h3 { color: #e0edf7; font-size: 1.15rem; margin-bottom: 10px; }
.twin-maturity p, .twin-distinction p { font-size: .88rem; line-height: 1.9; color: var(--text-dim); }
.twin-mini-flow { font: .78rem/1.6 var(--mono); color: var(--text-dim); margin: 23px 0 26px; display: flex; align-items: center; justify-content: space-between; gap: 6px; }
.twin-mini-flow span { color: var(--cyan); font-size: 1.7rem; }
.twin-distinction { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; border-top: 1px solid #254051; margin-top: 44px; padding-top: 32px; }
.twin-distinction .twin-kicker { color: #a0b6c7; }
.twin-layer-details { scroll-margin-top: 90px; border-top: 1px solid #254051; background: #0c1827; }
.twin-layer-detail { display: grid; grid-template-columns: 1.35fr 1fr; gap: 48px; padding: 30px; }
.twin-layer-detail + .twin-layer-detail { border-top: 1px solid #254051; }
.twin-layer-details[data-enhanced] .twin-layer-detail { border-top: 0; min-height: 267px; }
.twin-layer-detail .twin-kicker { margin-bottom: 10px; }
.twin-layer-detail h3 { color: #e7f3fc; font-size: 1.16rem; margin-bottom: 12px; }
.twin-layer-detail p:not(.twin-kicker) { color: var(--text-dim); font-size: .89rem; line-height: 1.9; }
.twin-layer-stack { border-left: 1px solid #294658; padding-left: 30px; }
.twin-layer-detail .twin-layer-note { margin-top: 18px; font-size: .8rem !important; color: #91adbf !important; }
.twin-outcome-strip { display: flex; align-items: center; flex-wrap: wrap; gap: 16px 26px; padding-top: 30px; margin-top: 32px; border-top: 1px solid #294658; }
.twin-outcome-strip > span { color: var(--text-dim); font-size: .8rem; }
.twin-outcome-strip strong { font-size: .89rem; font-weight: 500; color: #cbede7; }
.twin-outcome-strip strong::before { content: '+'; margin-right: 9px; color: var(--green); }
.twin-stack-table { border: 1px solid #294658; }
.twin-stack-header, .twin-stack-row { display: grid; grid-template-columns: 1fr 1.4fr 1.6fr; gap: 30px; padding: 24px 26px; }
.twin-stack-header { font: .64rem/1.5 var(--mono); letter-spacing: .1em; color: #8dabbf; padding-top: 14px; padding-bottom: 14px; background: #101d2c; }
.twin-stack-row { border-top: 1px solid #294658; align-items: center; background: #0b1421; }
.twin-stack-row h3 { font-size: .92rem; color: #d7e6f0; display: flex; gap: 14px; align-items: baseline; }
.twin-stack-number { font: .72rem var(--mono); color: var(--cyan); flex-shrink: 0; }
.twin-stack-tools { font: .77rem/1.9 var(--mono); color: #b7dcec; }
.twin-stack-purpose { color: var(--text-dim); font-size: .84rem; line-height: 1.85; }
.twin-platforms { display: grid; grid-template-columns: 1fr 1fr; gap: 38px; margin-top: 38px; }
.twin-platforms article { border-top: 2px solid #275165; padding-top: 24px; }
.twin-platforms h3 { font-size: 1.1rem; color: #d6e9f4; margin-bottom: 13px; }
.twin-platforms p:not(.twin-kicker) { color: var(--text-dim); font-size: .87rem; line-height: 1.9; }
.twin-gap-intro { display: grid; grid-template-columns: 1fr 1.5fr 1fr; align-items: center; gap: 16px; margin: 10px 0 38px; padding: 26px; border: 1px solid #294658; background: #0b1421; }
.twin-gap-end > span { font: .67rem/1.6 var(--mono); letter-spacing: .12em; color: var(--cyan); }
.twin-gap-end strong { display: block; color: #dceaf3; font-weight: 500; font-size: 1.1rem; margin-top: 9px; }
.twin-gap-end:last-child { text-align: right; }
.twin-gap-bridge { text-align: center; color: #7ba7be; }
.twin-gap-bridge > span { font: .58rem/1.6 var(--mono); letter-spacing: .08em; }
.twin-gap-bridge > div { font: 1.2rem/1.5 var(--mono); white-space: nowrap; color: var(--cyan); margin-top: 9px; }
.twin-gap-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.twin-gap-grid article { border: 1px solid #294658; padding: 28px; background: #0b1421; }
.twin-gap-grid h3 { font-size: 1.14rem; color: #dfedf6; margin-bottom: 13px; }
.twin-gap-grid p { color: var(--text-dim); font-size: .9rem; line-height: 1.9; }
.twin-loop-visual { display: grid; grid-template-columns: 1fr minmax(160px, .7fr) 1fr; align-items: center; gap: 14px; margin: 0 0 34px; }
.twin-loop-node { position: relative; margin: 0; border: 1px solid #294658; background: #070d16; }
.twin-loop-art { display: block; aspect-ratio: 3 / 2; background: url('../images/digital-twin/architecture-scenes.webp') no-repeat; background-size: 200% 200%; }
.art-real { background-position: 0 0; }
.art-sim { background-position: 100% 0; }
.twin-loop-node figcaption { display: flex; gap: 10px; align-items: baseline; padding: 12px 16px; border-top: 1px solid #294658; color: #b9cfdc; font-size: .82rem; }
.twin-loop-node figcaption b { font: 600 .68rem var(--mono); letter-spacing: .14em; color: var(--cyan); }
.twin-loop-badge { position: absolute; top: 12px; right: 12px; padding: 5px 10px; border: 1px solid var(--cyan); background: #061019d9; color: var(--cyan); font: .62rem var(--mono); letter-spacing: .1em; }
.twin-loop-mobile { display: none; margin: 0; padding: 0; list-style: none; }
.twin-loop-mobile li { flex: 1; text-align: center; padding: 8px 4px; border: 1px solid #294658; font: .6rem/1.4 var(--mono); letter-spacing: .04em; color: var(--cyan); }
.twin-loop-mobile .lm-d { border-style: dashed; }
.twin-loop-mobile .lm-g { color: var(--green); border-color: #1f5a46; }
.twin-loop-arrows { width: 100%; height: auto; overflow: visible; }
.twin-loop-arrows text { font: 9px var(--mono); letter-spacing: .08em; fill: #8fd8f0; }
.lp-flow { stroke-dasharray: 6 5; animation: lp-flow 1.6s linear infinite; }
.lp-dash { stroke-dasharray: 3 6; }
@keyframes lp-flow { to { stroke-dashoffset: -22; } }
.twin-loop { position: relative; display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; margin: 6px 0 34px; padding: 0; list-style: none; }
.twin-loop li { position: relative; border: 1px solid #294658; border-top: 2px solid var(--cyan); padding: 24px 22px; background: #0b1421; }
.twin-loop li:last-child { border-top-color: var(--green); }
.twin-loop li + li::before { content: '→'; position: absolute; left: -22px; top: 50%; transform: translateY(-50%); color: var(--cyan); font: 1rem var(--mono); }
.twin-loop-tag { display: block; font: .64rem/1.6 var(--mono); letter-spacing: .1em; color: var(--cyan); margin-bottom: 12px; }
.twin-loop h3 { font-size: 1.12rem; color: #e3f0f8; margin-bottom: 10px; }
.twin-loop p { color: var(--text-dim); font-size: .86rem; line-height: 1.85; }
.twin-loop-compare { overflow-x: auto; margin-bottom: 30px; }
.twin-loop-compare table { width: 100%; border-collapse: collapse; font-size: .88rem; }
.twin-loop-compare caption { text-align: left; font: .66rem/1.6 var(--mono); letter-spacing: .1em; color: var(--cyan); padding-bottom: 12px; }
.twin-loop-compare th, .twin-loop-compare td { border-bottom: 1px solid #22394a; padding: 14px 16px; text-align: left; vertical-align: top; line-height: 1.7; }
.twin-loop-compare thead th { color: #9fc3d6; font-weight: 500; font-size: .8rem; border-bottom-color: #2f6f86; }
.twin-loop-compare tbody th { color: #e3f0f8; font-weight: 600; white-space: nowrap; }
.twin-loop-compare td { color: var(--text-dim); }
.twin-loop-details { border: 1px solid #294658; background: #0b1421; margin-bottom: 26px; }
.twin-loop-details summary { cursor: pointer; padding: 18px 24px; color: #dceaf3; font-size: .95rem; }
.twin-loop-details summary::marker { color: var(--cyan); }
.twin-loop-details[open] summary { border-bottom: 1px solid #294658; }
.twin-loop-details .twin-gap-grid { padding: 24px; }
.twin-ax-note { padding: 28px 32px; border-left: 2px solid var(--green); margin-top: 30px; background: #0b2024; }
.twin-ax-note .twin-kicker { color: var(--green); }
.twin-ax-note h3 { color: #d7f1e8; font-size: 1.1rem; margin-bottom: 13px; }
.twin-ax-note p:not(.twin-kicker) { color: #a0bdc4; font-size: .9rem; line-height: 1.9; }
.twin-demo-card { display: grid; grid-template-columns: 1.1fr .9fr; border: 1px solid #2d4b5d; background: #0b1421; }
.twin-arm-visual { margin: 0; display: flex; flex-direction: column; justify-content: center; border-right: 1px solid #2d4b5d; background: #060b13; }
.twin-arm-frame { position: relative; aspect-ratio: 3 / 2; }
.twin-arm-photo { position: absolute; inset: 0; background: url('../images/digital-twin/architecture-scenes.webp') no-repeat 0 0 / 200% 200%; }
.twin-arm-frame svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.arm-path { stroke-dasharray: 10 6; animation: lp-flow 1.2s linear infinite; filter: drop-shadow(0 0 4px #00c8ff99); }
.arm-label path { stroke: #9fc3d6; stroke-width: 1; }
.arm-label text, .arm-note, .arm-axes text, .arm-readout text { font: 13px var(--mono); letter-spacing: .08em; fill: #dceaf3; paint-order: stroke; stroke: #060b13; stroke-width: 5px; stroke-linejoin: round; }
.arm-note { fill: #8fd8f0; font-size: 11px; }
.arm-axes path { stroke-width: 2.5; }
.arm-readout text { font-size: 11px; fill: #9fc3d6; }
.twin-arm-visual figcaption { margin-top: auto; padding: 12px 18px; color: #96afc1; font-size: .72rem; border-top: 1px solid #2d4b5d; }
.twin-arm-sketch { display: flex; flex-direction: column; justify-content: center; align-items: center; padding: 38px 26px; background: radial-gradient(ellipse at center, #12304380, transparent 70%); border-right: 1px solid #2d4b5d; }
.twin-arm-sketch svg { width: 100%; max-width: 420px; height: auto; }
.twin-arm-sketch p { color: #96afc1; font-size: .72rem; }
.twin-demo-copy { padding: 38px; }
.twin-coming-soon { display: inline-block; font-size: .7rem; padding: 4px 9px; color: #c6bea2; border: 1px solid #685e41; background: #24251e; margin-bottom: 18px; }
.twin-demo-copy h3 { font: 600 1.8rem/1.3 var(--sans); color: #e7f1f8; margin-bottom: 20px; }
.twin-demo-subtitle { color: #bdcedb; line-height: 1.8; font-size: 1.03rem; margin-bottom: 23px; }
.twin-demo-stages { padding: 0; list-style: none; counter-reset: demo-step; }
.twin-demo-stages li { position: relative; padding-left: 31px; counter-increment: demo-step; color: #a1b8ca; font-size: .83rem; margin-bottom: 13px; line-height: 1.8; }
.twin-demo-stages li::before { content: '0' counter(demo-step); position: absolute; left: 0; top: 2px; color: var(--cyan); font: .72rem/1.8 var(--mono); }
.twin-demo-note { border-top: 1px solid #294658; padding-top: 20px; margin-top: 25px; color: #96aabd; font-size: .78rem; line-height: 1.9; }
.twin-demo-disabled { display: block; width: 100%; padding: 14px; margin: 24px 0 18px; border: 1px solid #3c4e5a; background: #16212b; color: #a2b0bb; font-size: .86rem; cursor: not-allowed; }
.twin-references { padding-top: 70px; background: #08101b; }
.twin-references .section-title { font-size: 1.8rem; }
.twin-reference-list { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 28px 42px; }
.twin-reference-list li { display: flex; gap: 14px; border-top: 1px solid #294658; padding-top: 20px; min-width: 0; }
.twin-reference-list li:target { background: #102837; outline: 10px solid #102837; }
.twin-reference-number { color: var(--cyan); font: .72rem/1.7 var(--mono); flex-shrink: 0; }
.twin-reference-author { font: .65rem/1.7 var(--mono); color: #89a4b8; margin-bottom: 7px; }
.twin-reference-list a { color: #c2dce9; text-decoration: none; font-size: .84rem; line-height: 1.7; }
.twin-reference-list a:hover { color: var(--cyan); text-decoration: underline; }
.twin-reference-venue { color: #7e9cb0; font: .64rem/1.8 var(--mono); margin-top: 7px; }
.twin-reference-use { font-size: .74rem; color: #91adbf; margin-top: 5px; }
@media (max-width: 1180px) {
 .twin-hero-grid { gap: 30px; }
 .twin-layer-detail { gap: 30px; }
 .twin-toc { margin-left: 3rem; margin-right: 3rem; }
 .twin-toc > a { padding: 14px; gap: 8px; }
}
@media (max-width: 900px) {
 .twin-section { padding: 68px 1.5rem; }
 .twin-hero { padding: 45px 1.5rem 48px; }
 .twin-hero-grid { grid-template-columns: 1fr; gap: 36px; }
 .twin-hero h1 { font-size: clamp(2.4rem, 6vw, 3.8rem); }
 .twin-hero .twin-lead { max-width: 650px; }
 .twin-hero-visual { max-width: 590px; width: 100%; justify-self: center; }
 .twin-toc { margin-left: 1.5rem; margin-right: 1.5rem; }
 .twin-toc > a { flex-direction: column; align-items: flex-start; gap: 4px; min-width: 0; }
 .twin-toc > a > span { font-size: .73rem; }
 .twin-editorial { gap: 28px; }
 .twin-maturity article { padding: 24px 19px; }
 .twin-maturity h3 { font-size: 1.05rem; }
 .twin-distinction { gap: 30px; }
 .twin-layer-detail { padding: 25px; grid-template-columns: 1fr; gap: 24px; }
 .twin-layer-stack { padding: 22px 0 0; border-left: 0; border-top: 1px solid #294658; }
 .twin-layer-details[data-enhanced] .twin-layer-detail { min-height: 0; }
 .twin-stack-header, .twin-stack-row { grid-template-columns: 1fr 1.4fr; gap: 14px 25px; }
 .twin-stack-header > span:last-child { display: none; }
 .twin-stack-purpose { grid-column: 2; }
 .twin-gap-intro { grid-template-columns: 1fr 1.2fr 1fr; padding: 24px 18px; }
 .twin-gap-bridge > div { font-size: .9rem; }
 .twin-gap-end strong { font-size: .95rem; }
 .twin-demo-card { grid-template-columns: 1fr 1.25fr; }
 .twin-demo-copy { padding: 28px; }
 .twin-demo-copy h3 { font-size: 1.5rem; }
 .twin-reference-list { gap: 24px; }
}
@media (max-width: 600px) {
 .twin-section { padding: 55px 1.25rem; }
 .twin-section-heading { margin-bottom: 28px; }
 .twin-main .section-title { font-size: 1.8rem; }
 .twin-lead { font-size: .9rem; }
 .twin-hero { padding: 34px 1.25rem 38px; }
 .twin-hero h1 { font-size: 2.4rem; }
 .twin-hero .hero-actions { gap: 18px; }
 .twin-hero .btn-primary { width: 100%; text-align: center; }
 .twin-visual-topline { font-size: .5rem; padding: 12px; }
 .twin-hero-visual figcaption { font-size: .73rem; margin: 0 16px; padding: 14px 0; }
 .twin-toc { margin: 0 1.25rem; grid-template-columns: repeat(3, 1fr); }
 .twin-toc > a { padding: 13px 12px; }
 .twin-toc > a:nth-child(4) { border-left: 0; }
 .twin-toc > a:nth-child(n+4) { border-top: 1px solid #254051; }
 .twin-loop { grid-template-columns: 1fr 1fr; }
 .twin-loop li:nth-child(3)::before { display: none; }
 .twin-editorial, .twin-maturity, .twin-distinction, .twin-platforms, .twin-gap-grid, .twin-demo-card, .twin-reference-list { grid-template-columns: 1fr; }
 .twin-editorial { gap: 20px; }
 .twin-editorial p { font-size: .9rem; }
 .twin-maturity article { padding: 24px; }
 .twin-mini-flow { max-width: 250px; margin: 17px 0 20px; }
 .twin-distinction { gap: 28px; margin-top: 30px; }
 .twin-layer-detail { padding: 23px 20px; }
 .twin-layer-detail h3 { font-size: 1.08rem; }
 .twin-layer-detail p:not(.twin-kicker) { font-size: .84rem; }
 .twin-outcome-strip { flex-direction: column; align-items: flex-start; gap: 13px; }
 .twin-stack-header { display: none; }
 .twin-stack-row { grid-template-columns: 1fr; padding: 23px; gap: 14px; }
 .twin-stack-row:first-of-type { border-top: 0; }
 .twin-stack-purpose { grid-column: auto; }
 .twin-stack-tools { font-size: .74rem; }
 .twin-platforms { gap: 28px; }
 .twin-platforms h3 { font-size: 1.05rem; }
 .twin-loop { grid-template-columns: 1fr; gap: 26px; padding-bottom: 0; }
 .twin-loop-visual { grid-template-columns: 1fr; }
 .twin-loop-arrows { display: none; }
 .twin-loop-mobile { display: flex; justify-content: space-between; gap: 6px; }
 .twin-arm-visual { border-right: 0; border-bottom: 1px solid #2d4b5d; }
 .twin-loop::after { display: none; }
 .twin-loop li + li::before { content: '↓'; left: 50%; top: -22px; transform: translateX(-50%); }
 .twin-loop li:nth-child(3)::before { display: block; }
 .twin-gap-intro { grid-template-columns: 1fr 1fr; padding: 20px; gap: 22px 10px; }
 .twin-gap-bridge { grid-row: 2; grid-column: 1 / -1; }
 .twin-gap-end:last-child { grid-column: 2; grid-row: 1; }
 .twin-gap-grid { gap: 16px; }
 .twin-gap-grid article { padding: 24px; }
 .twin-ax-note { padding: 24px; }
 .twin-arm-sketch { padding: 24px; border-right: 0; border-bottom: 1px solid #2d4b5d; }
 .twin-arm-sketch svg { max-width: 300px; }
 .twin-demo-copy { padding: 25px; }
 .twin-demo-copy h3 { font-size: 1.48rem; }
 .twin-demo-disabled { font-size: .77rem; }
 .twin-references .section-title { font-size: 1.6rem; }
}
@media (prefers-reduced-motion: reduce) {
 .lp-flow, .arm-path { animation: none; }
 .twin-main *, .twin-main *::before, .twin-main *::after { animation: none !important; transition: none !important; }
}