.duct-hero{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(320px,.92fr);gap:clamp(38px,6vw,78px);align-items:center;padding:70px 0 72px}.duct-hero h1{font-size:clamp(3rem,6vw,5.8rem)}.duct-hero .lede{margin-bottom:18px}.duct-hero figure{margin:0}.duct-hero img{display:block;width:100%;height:auto;border-radius:var(--radius);box-shadow:var(--shadow)}.duct-hero figcaption{margin-top:9px;color:var(--muted);font-size:.78rem}.duct-thesis,.duct-emphasis{font-size:clamp(1.3rem,2.5vw,2rem);font-weight:850;line-height:1.25;color:var(--ink)!important}.duct-feature{padding:72px 0}.duct-feature>.wrap{display:grid;grid-template-columns:1.15fr .85fr;gap:clamp(28px,5vw,60px);align-items:center}.duct-feature h2{font-size:clamp(2rem,4vw,3.4rem)}.duct-layout{display:grid;grid-template-columns:210px minmax(0,760px);gap:70px;justify-content:center;padding:90px 0 100px}.duct-toc{position:sticky;top:110px;align-self:start;font-size:.82rem}.duct-toc strong,.duct-toc a{display:block}.duct-toc strong{margin-bottom:12px}.duct-toc a{padding:5px 0;color:var(--muted)}.duct-toc a:hover{color:var(--accent)}.duct-article section{padding:0 0 72px;scroll-margin-top:105px}.duct-article section+section{padding-top:72px;border-top:1px solid var(--line)}.duct-article h2{margin-top:0}.duct-article blockquote{margin:30px 0;padding:28px;border-left:4px solid var(--accent);background:var(--surface);font-size:clamp(1.25rem,2.5vw,1.8rem);font-weight:850;line-height:1.3}.field-card{margin:30px 0;padding:24px;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface)}.field-card h3{margin:22px 0 6px}.field-placeholder{display:grid;place-content:center;min-height:260px;padding:24px;border:2px dashed color-mix(in srgb,var(--accent) 45%,var(--line));border-radius:18px;background:linear-gradient(145deg,var(--surface),var(--accent2));color:var(--muted);text-align:center}.field-placeholder span,.field-placeholder strong{display:block}.field-placeholder span{margin-bottom:7px;font-size:.7rem;font-weight:850;letter-spacing:.12em;text-transform:uppercase}.field-placeholder strong{overflow-wrap:anywhere;color:var(--ink)}figure.field-placeholder{margin:0}figure.field-placeholder figcaption{margin-top:18px;color:var(--muted);font-size:.8rem}.field-compare{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:28px 0}.field-compare figure{margin:0}.field-compare figure>span{display:block;margin-bottom:8px;color:var(--accent);font-size:.72rem;font-weight:850;letter-spacing:.1em;text-transform:uppercase}.field-compare .field-placeholder{min-height:220px}.field-rule,.field-miss{margin:28px 0;padding:28px;border-radius:var(--radius)}.field-rule{background:var(--accent2)}.field-miss{border:1px solid var(--line);background:var(--surface)}.field-rule span,.field-miss span{display:block;margin-bottom:8px;color:var(--accent);font-size:.7rem;font-weight:850;letter-spacing:.14em;text-transform:uppercase}.field-rule strong,.field-miss strong{display:block;font-size:clamp(1.25rem,2.5vw,1.75rem);line-height:1.3}.whisperfit-bridge{padding:40px!important;border:0!important;border-radius:var(--radius);background:var(--accent2)}.resource-cards{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:28px 0}.resource-cards article{display:flex;flex-direction:column;padding:24px;border:1px solid var(--line);border-radius:18px;background:var(--surface)}.resource-cards article .button{align-self:flex-start;margin-top:auto}.duct-checklist ul{display:grid;grid-template-columns:1fr 1fr;gap:10px;padding:0;list-style:none}.duct-checklist li{position:relative;padding:13px 14px 13px 42px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}.duct-checklist li:before{content:'✓';position:absolute;left:16px;color:var(--accent);font-weight:900}.duct-guide .video-embed{width:100%}
@media(max-width:900px){.duct-hero,.duct-feature>.wrap{grid-template-columns:1fr}.duct-hero figure{max-width:680px}.duct-layout{grid-template-columns:1fr;padding-top:70px}.duct-toc{display:none}}
@media(max-width:650px){.duct-hero{padding:48px 0 55px}.duct-feature{padding:55px 0}.duct-layout{padding-top:55px}.duct-article section{padding-bottom:55px}.duct-article section+section{padding-top:55px}.field-compare,.resource-cards,.duct-checklist ul{grid-template-columns:1fr}.field-placeholder,.field-compare .field-placeholder{min-height:190px}.whisperfit-bridge{padding:28px 22px!important}.resource-cards .button{width:100%;justify-content:center}.duct-article blockquote{padding:22px}.field-rule,.field-miss{padding:22px}}

/* Authentic field photography */
.field-photo{margin:28px 0}.field-photo img,.field-compare img{display:block;width:100%;height:auto;border-radius:18px;background:var(--surface)}.field-photo figcaption{margin-top:9px;color:var(--muted);font-size:.8rem}.field-photo--featured img{box-shadow:var(--shadow)}.field-photo--portrait{max-width:520px}.field-compare--details{align-items:start}.field-compare--details figure:last-child img{max-height:520px;object-fit:contain;background:var(--surface)}
.route-teaching-group{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:18px;align-items:start;margin:28px 0}.route-teaching-group figure{margin:0}.route-teaching-group figure>span{display:block;margin-bottom:8px;color:var(--accent);font-size:.72rem;font-weight:850;letter-spacing:.1em;text-transform:uppercase}.route-teaching-group img{display:block;width:100%;height:auto;border-radius:18px;background:var(--surface)}.route-gable-stack{display:grid;gap:18px}
.duct-video-stop{display:grid;grid-template-columns:160px minmax(0,1fr) auto;gap:20px;align-items:center;margin:0 auto 24px;padding:18px 20px;border:1px solid var(--line);border-radius:18px;background:var(--surface)}.duct-video-thumb{position:relative;overflow:hidden;aspect-ratio:16/9;border-radius:12px;background:#111}.duct-video-thumb img{display:block;width:100%;height:100%;object-fit:cover}.duct-video-thumb span{position:absolute;inset:0;display:grid;place-items:center;color:#fff;font-size:1.35rem;text-shadow:0 2px 12px #000}.duct-video-copy .eyebrow{margin-bottom:5px}.duct-video-copy h3{margin:0 0 5px;font-size:1.2rem}.duct-video-copy p:last-child{margin:0;color:var(--muted);font-size:.9rem;line-height:1.45}.duct-video-action{display:grid;gap:6px;justify-items:center}.duct-video-action .button{white-space:nowrap}.duct-video-action small{color:var(--muted);font-size:.72rem}.duct-video-action .button:focus-visible{outline:3px solid var(--accent);outline-offset:3px}.duct-video-player{display:none}.duct-video-stop.is-playing .duct-video-player{display:block;grid-column:1/-1;overflow:hidden;width:100%;aspect-ratio:16/9;border-radius:14px;background:#111}.duct-video-player iframe{display:block;width:100%;height:100%;border:0}.seal-teaching-group{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,3fr);gap:18px;align-items:start;margin:28px 0}.seal-teaching-group figure{display:flex;flex-direction:column;margin:0}.seal-teaching-group figure>span{display:block;margin-bottom:8px;color:var(--accent);font-size:.72rem;font-weight:850;letter-spacing:.1em;text-transform:uppercase}.seal-teaching-group img{display:block;width:100%;height:auto;border-radius:18px;background:var(--surface)}.seal-process-stack{display:grid;gap:18px}.seal-process-stack img{height:145px;object-fit:cover;object-position:center}
.duct-video-stop--field{grid-template-columns:140px minmax(0,1fr);margin:28px 0;padding:20px}.duct-video-stop--field .duct-video-action{grid-column:2;justify-items:start}.duct-video-stop--field .duct-video-copy h3{font-size:1.15rem;line-height:1.2}.duct-video-stop--field .duct-video-player{max-width:680px}
.airflow-field-test{display:grid;grid-template-columns:minmax(0,1fr) minmax(260px,44%);gap:24px;align-items:center;margin:28px 0;padding:22px;border:1px solid var(--line);border-radius:18px;background:var(--surface)}.airflow-field-test .eyebrow{margin:0 0 6px}.airflow-field-test h3{margin:0 0 10px}.airflow-field-test p:last-child{margin:0;color:var(--muted)}.airflow-field-test video{display:block;width:100%;height:auto;aspect-ratio:544/306;object-fit:contain;border:1px solid var(--line);border-radius:14px;background:var(--bg)}
@media(max-width:900px){.duct-video-stop{grid-template-columns:140px minmax(0,1fr)}.duct-video-action{grid-column:2;justify-items:start}.seal-teaching-group{grid-template-columns:1fr}.seal-process-stack{display:contents}.seal-process-stack img{height:auto;object-fit:initial}}
@media(max-width:650px){.route-teaching-group{grid-template-columns:1fr}.duct-video-stop{grid-template-columns:96px minmax(0,1fr);gap:12px;margin-bottom:0;padding:14px}.duct-video-copy h3{font-size:1.05rem}.duct-video-copy p:last-child{font-size:.82rem}.duct-video-action{grid-column:1/-1;width:100%}.duct-video-action .button{width:100%;justify-content:center}.duct-video-stop.is-playing .duct-video-player{grid-column:1/-1}.duct-video-thumb span{font-size:1rem}.airflow-field-test{grid-template-columns:1fr;padding:16px;gap:16px}}