/* Reference-derived layered scene. All elements share one coordinate space. */
.machine-journey{height:360svh;position:relative;background:#eef2f4}
.journey-sticky{position:sticky;top:0;height:100svh;padding:85px 3vw 20px;display:flex;flex-direction:column;gap:14px;overflow:hidden}
.journey-copy{display:flex;align-items:center;justify-content:space-between;gap:24px}
.journey-copy .eyebrow{font-size:9px;color:#697179;letter-spacing:.2em;margin:0}
.journey-copy h2{font-size:clamp(24px,2.4vw,38px);margin:0;letter-spacing:-.04em;white-space:nowrap}
.journey-copy>p:not(.eyebrow){display:none}
.journey-steps{display:flex;gap:20px;margin:0}
.journey-step{display:flex;align-items:center;gap:6px;opacity:.35;border-bottom:2px solid transparent;padding:8px 0;transition:opacity .2s}
.journey-step.active{opacity:1;border-color:#b31320}.journey-step span{font-size:9px;color:#a10f19}.journey-step h3{font-size:10px;margin:0}.journey-step p{display:none}
#machineStage{position:relative;inset:auto;width:100%;height:auto;flex:1;min-height:0;overflow:hidden;border-radius:18px;background:#e8edef;isolation:isolate;opacity:1}
#engineAssembly{position:absolute;left:50%;top:50%;width:1672px;height:941px;transform-origin:center;perspective:2200px}
.engine-background{position:absolute;inset:0;width:100%;height:100%;z-index:0;object-fit:cover}
.engine-part,#engineTechnician{position:absolute;left:0;top:0;height:auto;max-width:none;pointer-events:none;user-select:none;will-change:transform;filter:drop-shadow(0 14px 10px #18272f24);backface-visibility:hidden}
#engineTechnician{z-index:50;filter:drop-shadow(0 7px 5px #14232c35)}
.part-callout{position:absolute;z-index:60;padding:14px 18px;width:212px;background:#fffffff0;border:1px solid white;border-radius:10px;box-shadow:0 6px 20px #42556512;opacity:0}
.part-callout b{display:block;color:#b10b19;font-size:16px;margin-bottom:6px}.part-callout small{display:block;font-size:13px;line-height:1.3;color:#596773}
.part-callout:after{content:'';position:absolute;top:40%;width:40px;height:1px;background:#e43743}
.callout-turbo{left:420px;top:62px}.callout-turbo:after{right:100%}
.callout-head{left:1130px;top:60px}.callout-head:after{right:100%}
.callout-piston{left:1380px;top:220px}.callout-piston:after{right:100%}
.callout-crank{left:325px;top:640px}.callout-crank:after{left:100%}
.callout-transmission{left:1350px;top:698px}.callout-transmission:after{right:100%}
.depth-meter{position:absolute;left:18px;top:18px;z-index:70;padding:9px 12px;background:#ffffffcf;border-radius:6px;display:flex;align-items:center;gap:12px}.depth-meter span{font-size:8px;letter-spacing:.15em}.depth-meter b{font-size:14px;color:#a8111d;font-variant-numeric:tabular-nums}
.scene-progress{position:absolute;left:18px;right:18px;bottom:12px;height:3px;background:#ffffff85;z-index:70}.scene-progress i{display:block;width:100%;height:100%;background:#c31522;transform-origin:left;transform:scaleX(0)}
.scroll-hint{position:absolute;right:18px;bottom:24px;padding:8px 10px;background:#ffffffe0;border-radius:5px;z-index:70}.scroll-hint small{font-size:8px;letter-spacing:.1em}
@media(max-width:1050px){.journey-copy{flex-wrap:wrap;gap:6px 18px}.journey-copy .eyebrow{display:none}.journey-steps{gap:12px}.journey-step h3{font-size:9px}}
@media(max-width:650px){.machine-journey{height:300svh}.journey-sticky{padding:80px 10px 16px;gap:10px}.journey-copy{display:block}.journey-copy h2{font-size:28px}.journey-steps{justify-content:space-between;gap:6px}.journey-step{max-width:25%;align-items:start}.journey-step span{display:none}.journey-step h3{font-size:9px;line-height:1.3}.scroll-hint{display:none}#machineStage{border-radius:12px}.depth-meter{left:10px;top:10px}.part-callout{padding:12px;width:240px}.part-callout b{font-size:22px}.part-callout small{display:none}}
@media(max-height:550px) and (min-width:651px){.journey-sticky{padding-top:70px}.journey-copy h2{font-size:23px}.journey-copy .eyebrow{display:none}}
@media(prefers-reduced-motion:reduce){.machine-journey{height:auto}.journey-sticky{position:relative;height:850px;max-height:none}.engine-part,#engineTechnician{will-change:auto}.scroll-hint{display:none}}

#machineStage{background:#e8edef url('../img/engine-reference/background.webp') center/cover no-repeat}.portrait-scene .engine-background{display:none}

/* Contained split layout matching the supplied section reference. */
.machine-journey{height:340svh;background:linear-gradient(180deg,#f8fafb,#eef2f4,#fff)}
.journey-sticky{display:grid;grid-template-columns:minmax(270px,.68fr) minmax(0,1.32fr);align-items:center;gap:4vw;max-width:1600px;margin:0 auto;padding:96px 4vw 36px;height:100svh}
.journey-copy{display:block;max-width:440px}
.journey-copy .eyebrow{display:block;margin:0 0 24px;font-size:10px}
.journey-copy h2{font-size:clamp(30px,3.2vw,50px);white-space:normal;line-height:1.1;margin:0 0 24px;font-weight:750}
.journey-copy>p:not(.eyebrow){display:block;font-size:12px;line-height:1.75;margin:0 0 24px}
.journey-steps{display:block;margin:0}
.journey-step{display:flex;max-width:none;align-items:flex-start;gap:14px;border-bottom:0;border-left:1px solid #dbe0e3;padding:11px 0 11px 16px;margin:6px 0;opacity:.3}
.journey-step.active{border-color:#b31320;opacity:1}
.journey-step span{display:block;font-size:10px;padding-top:2px}
.journey-step h3{font-size:13px;line-height:1.3;margin:0 0 5px}
.journey-step p{display:block;font-size:10px;line-height:1.6;color:#687179;margin:0}
#machineStage{flex:none;width:100%;height:auto;aspect-ratio:5/4;max-height:calc(100svh - 140px);border-radius:26px;border:1px solid #dce3e7;box-shadow:0 24px 65px #25384416;align-self:center}
@media(max-width:980px){
 .journey-sticky{grid-template-columns:1fr;grid-template-rows:auto minmax(0,1fr);gap:14px;padding:86px 24px 26px;max-width:780px}
 .journey-copy{max-width:none}.journey-copy .eyebrow{margin:0 0 8px;font-size:9px}.journey-copy h2{font-size:30px;margin:0 0 10px}.journey-copy>p:not(.eyebrow){display:none}
 .journey-steps{display:flex;gap:12px}.journey-step{flex:1;padding:6px 0 6px 8px;margin:0;gap:5px}.journey-step h3{font-size:10px;margin:0}.journey-step p{display:none}.journey-step span{font-size:8px}
 #machineStage{height:100%;max-height:540px;aspect-ratio:auto;border-radius:20px}
}
@media(max-width:550px){
 .machine-journey{height:300svh}.journey-sticky{padding:82px 18px 26px;gap:14px}.journey-copy h2{font-size:27px}.journey-step span{display:none}.journey-step h3{font-size:9px}.journey-steps{gap:6px}#machineStage{max-height:480px;border-radius:18px}
}
@media(max-height:620px) and (min-width:700px){
 .journey-sticky{grid-template-columns:.68fr 1.32fr;grid-template-rows:1fr;padding:78px 3vw 20px;max-width:1600px}.journey-copy h2{font-size:27px;margin-bottom:15px}.journey-copy .eyebrow{margin-bottom:12px}.journey-copy>p:not(.eyebrow),.journey-step p{display:none}.journey-steps{display:block}.journey-step{padding:7px 0 7px 12px;margin:3px 0}.journey-step h3{font-size:11px}#machineStage{height:100%;max-height:calc(100svh - 100px)}
}
@media(prefers-reduced-motion:reduce){.machine-journey{height:auto}.journey-sticky{position:relative;height:auto;min-height:650px;padding-top:60px;padding-bottom:60px}#machineStage{height:540px;max-height:none}@media(max-width:980px){.journey-sticky{min-height:0;grid-template-rows:auto auto}#machineStage{height:480px}}}
/* A single background avoids duplicated platform edges in the taller card. */
#machineStage .engine-background{display:none}