@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Instrument+Serif:ital@0;1&display=swap');
:root{--paper:#f7f6f2;--ink:#282333;--muted:#797482;--purple:#6b3ee8;--line:#34234c20;font-family:'DM Sans',Arial,sans-serif;background:var(--paper);color:var(--ink);font-synthesis:none}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0}a{color:inherit;text-decoration:none}button,select{font:inherit}a:focus-visible,button:focus-visible,select:focus-visible{outline:3px solid #9768f4;outline-offset:5px}::selection{background:#e1d2fb}.skip{position:fixed;top:-100px;background:white;z-index:30;padding:16px}.skip:focus{top:0}
.header{position:fixed;inset:0 4% auto;height:92px;display:flex;align-items:center;justify-content:space-between;background:var(--paper);z-index:20;border-bottom:1px solid var(--line)}.brand{font-size:29px;font-weight:700;letter-spacing:-1.5px;display:flex;align-items:center}.brand-icon{width:31px;height:31px;background:var(--purple);color:white;display:grid;place-items:center;border-radius:10px 10px 10px 2px;font-size:23px;letter-spacing:0;margin-right:9px}.brand-dot{color:var(--purple)}.header nav{display:flex;gap:27px}.header nav a{font-size:13px;color:var(--muted);padding:15px 0;position:relative}.header nav a[aria-current]{color:var(--purple)}.header nav a[aria-current]:after{content:'';position:absolute;bottom:6px;left:0;right:0;height:2px;background:var(--purple)}.sign-in{border-bottom:1px solid #9b93a3;padding:13px 0;font-size:13px;display:flex;gap:25px}
#journey{position:relative}.chapter{width:34%;margin-left:12%;min-height:112svh;padding:145px 0 100px;display:flex;align-items:center;position:relative;z-index:3;pointer-events:none}.chapter:first-child{min-height:100svh}.copy{pointer-events:auto;width:100%;max-width:490px}.eyebrow{font-size:11px;font-weight:600;letter-spacing:1.7px;color:var(--purple);margin:0 0 24px;display:flex;align-items:center;gap:9px}.eyebrow:before{content:'';width:5px;height:5px;border-radius:50%;background:var(--purple)}h1,h2{font-family:'Instrument Serif',Georgia,serif;font-weight:400;letter-spacing:-1.5px;line-height:1.02;font-size:clamp(51px,5.5vw,88px);margin:0}h2{font-size:clamp(49px,5.25vw,82px)}em{font-weight:400;color:var(--purple)}.intro{font-size:18px;line-height:1.55;margin:26px 0 15px;max-width:340px}.description{font-size:15px;color:var(--muted);line-height:1.85;max-width:340px;margin:0 0 28px}.primary{display:inline-flex;align-items:center;justify-content:space-between;gap:38px;background:var(--purple);color:white;border-radius:4px;padding:18px 22px;font-size:14px;transition:background .2s,transform .2s}.primary:hover{background:#4e27b7;transform:translateY(-2px)}.primary span{font-size:20px}.next-link{display:inline-flex;align-items:center;gap:30px;font-size:14px;border-bottom:1px solid #b3a7c9;padding:12px 0;margin-top:14px}.note{border-left:1px solid #baabd2;padding-left:17px;margin:29px 0;color:var(--muted);font-size:14px;line-height:1.7;max-width:320px}.language-select{display:flex;align-items:center;gap:13px;font-size:12px;color:var(--muted);margin:23px 0 0}.language-select select{max-width:190px;padding:9px 27px 9px 11px;border:1px solid #d8d0e3;background:transparent;color:var(--ink);border-radius:4px;font-size:13px}.language-list{display:flex;flex-wrap:wrap;gap:6px 13px;margin:19px 0 0;max-width:360px;font-size:11px;line-height:1.7;color:var(--muted)}.language-list span.active{color:var(--purple);font-weight:700}.scroll-cue{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);margin-top:28px}.scroll-cue b{display:grid;place-items:center;width:27px;height:36px;border:1px solid #c9c2d1;border-radius:25px;font-size:16px;font-weight:400}
.visual{position:fixed;top:98px;bottom:66px;right:1.5%;width:56%;z-index:2;isolation:isolate}.visual:before,.visual:after{content:'';border:1px solid #76609c0c;position:absolute;width:80%;aspect-ratio:1;border-radius:50%;top:49%;left:50%;transform:translate(-50%,-50%);z-index:-1}.visual:after{width:66%;border-color:#76609c0a}.scene-index{position:absolute;top:20px;left:13%;display:flex;gap:14px;align-items:center;font-size:10px;letter-spacing:1.5px;color:#8a7e9c;z-index:2}.scene-index>span:first-child{font:italic 24px 'Instrument Serif',Georgia,serif;color:var(--purple)}.index-line{width:25px;height:1px;background:#b8a9cc}#world{width:100vw;height:calc(100% - 116px);position:absolute;top:5px;left:0;display:block;touch-action:pan-y;cursor:grab}#world.dragging{cursor:grabbing}#fallback{position:absolute;top:30%;left:15%;right:15%;line-height:1.8}.floating-caption{position:absolute;bottom:81px;right:7%;min-width:210px;max-width:65%;padding:13px 18px;background:#fffefaef;border:1px solid #ddd5e6;box-shadow:5px 6px 0 #ded6e555,0 15px 30px #4537550c;transform:rotate(-3deg);pointer-events:none;transition:transform .7s,border-color .7s;z-index:3}.card-kicker{display:block;font-size:9px;letter-spacing:1.4px;color:#8a7e9c;margin-bottom:9px}.floating-caption #demo-phrase{display:block;font:italic 25px/1.14 'Instrument Serif',Georgia,serif;color:#4d3373}.card-detail{display:block;font-size:11px;margin-top:10px;color:#94859e;line-height:1.5}.visual[data-scene='2'] .floating-caption{transform:rotate(3deg)}.visual[data-scene='3'] .floating-caption{transform:rotate(-2deg)}.scene-controls{position:absolute;bottom:48px;left:0;right:0;display:flex;justify-content:center;align-items:center;gap:8px;font-size:9px;letter-spacing:1.4px;color:#a094af}.scene-controls span{margin-right:9px}.scene-controls button{border:1px solid #d9d1df;width:28px;height:28px;border-radius:50%;background:transparent;color:#8d7c9b;font-size:16px;cursor:pointer}.scene-controls button:hover{color:var(--purple);border-color:var(--purple)}.scene-footer{position:absolute;bottom:10px;left:13%;right:8%;display:flex;align-items:center;justify-content:space-between;gap:15px;border-top:1px solid var(--line);padding-top:9px;font-size:9px;letter-spacing:1.1px;color:#978aa4}.step-dots{display:flex;gap:3px}.step-dots a{width:26px;height:28px;display:grid;place-items:center}.step-dots a:after{content:'';width:5px;height:5px;border-radius:5px;background:#cbc3d6}.step-dots a.active:after{width:17px;background:var(--purple)}
.voice-rail{position:absolute;top:130px;bottom:100px;left:0;width:9%;pointer-events:none;z-index:4}.voice-rail svg{width:100%;height:100%;position:absolute;overflow:visible}#route,#trail{fill:none;stroke:#c6bad5;stroke-width:1;stroke-dasharray:2 8}#trail{stroke:#9777c1;stroke-dasharray:none;stroke-width:1.3}#traveler{position:absolute;width:84px;height:84px;left:0;top:0}.journey-footer{position:fixed;bottom:0;left:4%;right:4%;height:58px;border-top:1px solid var(--line);background:var(--paper);z-index:20;display:flex;align-items:center;justify-content:space-between;color:#948a9b;font-size:11px}.footer-label{font-size:9px;letter-spacing:1.5px}.position{display:flex;align-items:center;gap:13px}.progress-track{height:2px;width:130px;background:#e2dbe9}.progress-track i{height:100%;background:var(--purple);display:block;width:0}#current-step{color:var(--purple)}#motion{border:0;background:none;color:#8f829d;padding:12px 0;font-size:11px;cursor:pointer}#motion:before{content:'Ⅱ';margin-right:8px}
@media(max-width:1000px){.header{height:80px}.header nav{gap:18px}.chapter{width:37%;margin-left:10%;padding-top:120px}h1,h2{font-size:clamp(47px,6.4vw,65px)}.intro{font-size:16px}.description{font-size:14px;line-height:1.7}.visual{width:54%;right:0;top:85px}.floating-caption{max-width:70%;right:8%;bottom:78px;padding:11px 15px;min-width:180px}.floating-caption #demo-phrase{font-size:25px}.scene-index{left:12%;font-size:9px}.language-list{font-size:10px}.voice-rail{width:8%}.scroll-cue{margin-top:20px}}
@media(max-width:700px){.header{height:68px;inset:0 6% auto}.brand{font-size:25px}.header nav{display:none}.sign-in{font-size:12px}.visual{top:70px;left:10%;right:0;width:90%;height:40svh;bottom:auto;z-index:6;background:var(--paper)}#world{height:calc(100% - 64px);top:0}.scene-index{top:4px;left:7%;font-size:8px;gap:9px}.scene-index>span:first-child{font-size:18px}.floating-caption{bottom:39px;right:6%;min-width:145px;max-width:59%;padding:10px 13px}.floating-caption #demo-phrase{font-size:21px}.card-kicker{font-size:7px;letter-spacing:.8px;margin-bottom:5px}.card-detail{display:none}.scene-controls{bottom:18px;font-size:7px;gap:5px}.scene-controls button{width:23px;height:23px;font-size:14px}.scene-footer{bottom:-6px;left:8%;right:7%;padding-top:1px;border-top:0;font-size:7px;letter-spacing:.6px}.step-dots a{height:22px;width:22px}.scene-controls span{display:none}.scene-controls{left:15px;right:auto;bottom:17px}.chapter,.chapter:first-child{margin-left:17%;width:76%;padding:calc(40svh + 105px) 0 88px;min-height:125svh;align-items:flex-start}.eyebrow{font-size:10px;margin-bottom:17px;letter-spacing:1px}h1,h2{font-size:clamp(45px,12.2vw,62px);letter-spacing:-.7px}.intro{font-size:16px;margin-top:22px}.description{font-size:14px;line-height:1.8;margin-bottom:22px}.primary{padding:15px 19px;font-size:13px}.language-list{font-size:10px;gap:4px 9px}.language-select{margin-top:20px;font-size:11px;gap:8px}.language-select select{font-size:12px;max-width:160px}.voice-rail{width:13%;top:108px;z-index:7}#traveler{width:64px;height:64px}.journey-footer{height:51px;left:6%;right:6%}.footer-label{display:none}.progress-track{width:92px}.note{font-size:13px;margin:24px 0}.next-link{font-size:13px}.scroll-cue{font-size:11px}.scene-caption{max-width:75%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important}}html[data-reduced='true']{scroll-behavior:auto}html[data-reduced='true'] *{transition:none!important}

/* Give the reference aircraft a full-resolution foreground pass at the finale. */
#s15{min-height:205svh;padding-bottom:105svh}
#journey .voice-rail.is-flying{z-index:25}
#traveler{pointer-events:none}

@media(max-width:700px){.visual[data-scene='1'] .floating-caption #demo-phrase{font-size:18px}}

/* Dense academic samples need real text and vector strokes at narrow sizes. */
.academic-paper{display:none}
@media(max-width:1000px){
 .academic-paper:not([hidden]){display:block;position:absolute;z-index:5;bottom:75px;left:15%;right:5%;padding:16px 18px;background:#fffbee;border:1px solid #d4c9df;box-shadow:5px 6px 0 #e1dae6,0 12px 26px #34204d14;pointer-events:none;color:#30283d}
 .academic-paper [hidden]{display:none}
 .academic-paper p{margin:0}
 .academic-paper .paper-kicker{font-size:9px;letter-spacing:1px;color:#756486;margin-bottom:9px}
 .academic-paper h3{font:600 18px/1.2 'DM Sans',Arial,sans-serif;margin:0 0 8px;text-transform:none}
 #paper-title{text-transform:capitalize}
 .academic-chart{display:block;width:100%;height:auto;margin:5px 0}
 .academic-paper .paper-source{font-size:10px;line-height:1.4;color:#776b80}
 .academic-paper .paper-response{font:16px/1.45 Georgia,serif;margin-top:12px;min-height:70px;border-top:1px solid #ded4e6;padding-top:10px}
 .academic-paper .paper-passage{font:16px/1.5 'DM Sans',Arial,sans-serif;margin:12px 0 14px}
 .paper-passage mark{background:#d7c5f0;color:inherit;padding:0;box-decoration-break:clone;-webkit-box-decoration-break:clone}
 .visual[data-scene='1'] .floating-caption,.visual[data-scene='2'] .floating-caption{display:none}
}
@media(max-width:700px){
 .academic-paper:not([hidden]){top:118px;bottom:auto;left:5%;right:5%;padding:12px 14px;box-shadow:3px 4px 0 #e1dae6}
 .academic-paper .paper-kicker{font-size:8px;margin-bottom:6px}
 .academic-paper h3{font-size:16px;margin-bottom:5px}
 .academic-paper .paper-response{font-size:14px;line-height:1.4;min-height:62px;margin-top:7px;padding-top:7px}
 .academic-paper .paper-passage{font-size:14px;line-height:1.45;margin:10px 0}
 .academic-paper .paper-source{font-size:9px}
}

@media(max-width:700px){
 .visual[data-scene='1'],.visual[data-scene='2']{height:max(410px,50svh)}
 .chapter[data-step='4'],.chapter[data-step='5'],.chapter[data-step='6'],.chapter[data-step='7'],.chapter[data-step='8'],.chapter[data-step='9'],.chapter[data-step='10'],.chapter[data-step='11']{padding-top:calc(max(410px,50svh) + 105px)}
}