:root{color-scheme:light;--ink:#181e1b;--muted:#59645e;--green:#08785e;--paper:#fff;--canvas:#f7f8f6;--line:#dde3de;--page-max:760px;--text-max:640px}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:24px}
body{margin:0;background:var(--canvas);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Yu Gothic",Meiryo,sans-serif;font-size:17px;line-height:1.85;-webkit-text-size-adjust:100%;overflow-wrap:anywhere}
a{color:inherit;text-underline-offset:5px}
a:focus-visible,summary:focus-visible{outline:3px solid var(--green);outline-offset:5px;border-radius:4px}
.page{width:100%;max-width:var(--page-max);margin-inline:auto;padding:0 30px;background:var(--paper);min-height:100svh}
.skip-link{position:absolute;top:8px;left:8px;z-index:5;transform:translateY(-160%);padding:8px 16px;background:var(--ink);color:#fff}
.skip-link:focus{transform:translateY(0)}
.site-header{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:27px 0 23px;border-bottom:1px solid var(--line)}
.wordmark{font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,sans-serif;font-size:20px;line-height:1.3;font-weight:750;letter-spacing:.16em;text-decoration:none;white-space:nowrap}
.wordmark-dot{color:var(--green)}
.site-label{font-size:11px;letter-spacing:.06em;color:var(--muted)}
.hero{max-width:var(--text-max);margin:0 auto;padding:64px 0 53px}
.eyebrow{display:flex;align-items:center;gap:10px;margin:0 0 24px;font-size:12px;font-weight:600;letter-spacing:.14em;color:var(--green)}
.eyebrow span{width:6px;height:6px;background:var(--green);border-radius:50%;flex-shrink:0}
h1{margin:0;font-size:clamp(40px,7vw,65px);font-weight:800;line-height:1.22;letter-spacing:-.045em}
h1 span{display:block;white-space:nowrap}
.lead{margin:26px 0 0;color:var(--muted);font-size:16px;line-height:1.95}
.equation-section{border-top:1px solid var(--line);padding-top:34px}
.section-heading{max-width:var(--text-max);margin:0 auto 26px}
.section-number{font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,sans-serif;margin:0 0 10px;font-size:11px;font-weight:600;line-height:1.6;letter-spacing:.15em;color:var(--muted)}
h2{margin:0;font-size:clamp(24px,4.6vw,31px);font-weight:750;line-height:1.5;letter-spacing:-.025em}
.section-intro{font-size:14px;margin:9px 0 0;color:var(--muted)}
.equation-figure{margin:0}
.equation-figure a{display:block;border-radius:14px;overflow:hidden;border:1px solid #e6e8ed;background:#f2f3f5}
.equation-figure img{display:block;width:100%;height:auto;max-width:100%}
figcaption{text-align:center;font-size:12px;color:var(--muted);margin-top:16px}
.image-link{display:flex;align-items:center;justify-content:center;gap:13px;width:fit-content;max-width:100%;min-height:46px;margin:19px auto 35px;padding:8px 18px;border:1px solid var(--line);border-radius:5px;font-size:13px;font-weight:600;text-decoration:none;background:#fff}
.image-link:hover{border-color:var(--green);color:var(--green)}
.image-link span[aria-hidden]{font-size:17px;line-height:1}
.transcript{max-width:var(--text-max);margin:0 auto;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
summary{display:flex;align-items:center;justify-content:space-between;gap:14px;list-style:none;min-height:60px;padding:17px 2px;cursor:pointer;font-size:14px;font-weight:600}
summary::-webkit-details-marker{display:none}
summary span{color:var(--green);font-size:20px;line-height:1}
details[open] summary span{transform:rotate(45deg)}
.transcript-body{padding:0 2px 24px;font-size:15px;line-height:1.95}
.transcript-body p{margin:0 0 18px}
h3{margin:26px 0 10px;font-size:18px;line-height:1.6}
.earning{color:#4242b2}.wellbeing{color:var(--green)}
.transcript-body .formula{font-size:17px;font-weight:700;color:var(--ink);line-height:1.9;background:#f6f7f5;padding:12px 15px;border-radius:6px}
sup{font-size:.7em}
.transcript-body .transcript-note{margin:26px 0 0;padding-top:19px;border-top:1px solid var(--line);font-size:13px;color:var(--muted)}
.closing{max-width:var(--text-max);margin:0 auto;padding:57px 0 53px}
.closing h2{font-size:clamp(25px,4.8vw,35px);line-height:1.6}
.closing>p:last-child{max-width:510px;margin:19px 0 0;color:var(--muted);font-size:15px;line-height:1.95}
.site-footer{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:22px 0 25px;border-top:1px solid var(--line);font-size:10px;letter-spacing:.045em;color:var(--muted)}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(max-width:520px){body{font-size:16px}.page{padding:0 18px}.site-header{padding:21px 0 19px;gap:10px}.wordmark{font-size:17px}.site-label{font-size:9px;letter-spacing:0}.hero{padding:42px 0 36px}.eyebrow{font-size:10px;letter-spacing:.09em;margin-bottom:19px}.lead{margin-top:20px;font-size:15px;line-height:1.9}.wide-only{display:none}.equation-section{padding-top:25px}.section-heading{margin-bottom:20px}.section-intro{font-size:12px;line-height:1.85}.equation-figure a{border-radius:10px}figcaption{font-size:11px;margin-top:12px}.image-link{margin:14px auto 27px}.transcript-body{font-size:14px}.closing{padding:40px 0 39px}.closing>p:last-child{font-size:14px}.site-footer{font-size:9px;flex-wrap:wrap;padding:19px 0 21px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.transcript-body .explanation-lead{font-size:17px;font-weight:650;line-height:1.9;margin-top:4px}
.transcript-body h3{margin-top:35px;padding-top:12px;border-top:1px solid var(--line)}
.transcript-body h4{margin:22px 0 8px;font-size:15px;line-height:1.75;font-weight:700}
.action-list{padding-left:1.6em;margin:0 0 22px}
.action-list li{margin-bottom:14px;padding-left:4px}
.research-note{margin-top:30px;padding:16px 18px;background:#f6f7f5;border-radius:7px;font-size:13px;line-height:1.95}
.transcript-body .research-note h4{margin:0 0 8px;font-size:13px}
.transcript-body .research-note p{margin:0}
.transcript-body .transcript-note a,.research-note a{color:var(--green)}
@media(max-width:520px){.transcript-body{font-size:15px}.transcript-body .explanation-lead{font-size:16px}.transcript-body h4{font-size:15px}.research-note{padding:14px}.transcript-body h3{font-size:17px}}

.transcript-body .model-note{padding:12px 15px;border-left:3px solid var(--green);background:#f2f7f4;font-size:13px;line-height:1.95}