:root{--bg:#f7f5f0;--card:#fff;--ink:#1f2a2e;--muted:#5d6b6f;--accent:#2f6f62;--accent-soft:#e3efeb;--line:#e4e0d6;--warn:#fff6e0;--warn-line:#e9d39a;--r:16px;--max:1080px}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--ink);line-height:1.6;font-size:17px}
a{color:var(--accent)}img{max-width:100%}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}
header.site{position:sticky;top:0;z-index:10;background:rgba(247,245,240,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:60px;flex-wrap:wrap}
.brand{font-weight:700;letter-spacing:.2px;text-decoration:none;color:var(--ink);display:flex;align-items:center;gap:10px}
.brand .dot{width:28px;height:28px;border-radius:50%;background:radial-gradient(circle at 35% 35%,#6fb3a2,var(--accent));display:inline-block}
nav.main{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;padding:6px 0;width:100%}
nav.main a{white-space:nowrap;text-decoration:none;color:var(--muted);padding:6px 12px;border-radius:999px;font-size:15px}
nav.main a[aria-current=page],nav.main a:hover{background:var(--accent-soft);color:var(--accent)}
@media(min-width:760px){nav.main{width:auto}}
.preview-bar{background:var(--ink);color:#fff;font-size:13px;text-align:center;padding:6px 12px}
main{padding:28px 0 56px}
h1{font-size:clamp(30px,7vw,48px);line-height:1.12;margin:.2em 0 .4em;letter-spacing:-.5px}
h2{font-size:clamp(22px,4.5vw,30px);line-height:1.2;margin:1.6em 0 .5em}
h3{font-size:19px;margin:0 0 .3em}
.lede{font-size:clamp(18px,3.6vw,21px);color:var(--muted);max-width:40em}
.hero{padding:24px 0 8px;display:grid;gap:28px;align-items:center}
@media(min-width:860px){.hero{grid-template-columns:1.2fr .8fr}}
.quote{font-size:clamp(20px,4.4vw,26px);font-weight:600;border-left:4px solid var(--accent);padding:4px 0 4px 16px;margin:20px 0}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;padding:12px 22px;border-radius:999px;font-weight:600;margin:6px 8px 6px 0}
.btn.ghost{background:transparent;color:var(--accent);border:1.5px solid var(--accent)}
.cards{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));margin-top:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px}
.card p{margin:.3em 0 0;color:var(--muted)}
.placeholder{background:var(--warn);border:1px dashed var(--warn-line);border-radius:10px;padding:2px 8px;font-size:.92em}
.ph-block{background:var(--warn);border:1px dashed var(--warn-line);border-radius:var(--r);padding:16px 18px;margin:16px 0}
.ph-tag{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.8px;text-transform:uppercase;background:#e9d39a;color:#5a4710;border-radius:6px;padding:1px 6px;margin-right:6px;vertical-align:middle}
/* vertical video */
.video{position:relative;width:100%;max-width:360px;aspect-ratio:9/16;border-radius:18px;overflow:hidden;background:#1f2a2e;margin:0 auto;box-shadow:0 10px 30px rgba(31,42,46,.18)}
.video iframe,.video video{position:absolute;inset:0;width:100%;height:100%;border:0}
.video .empty{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;color:#cfdad7;padding:18px;gap:8px;background:linear-gradient(160deg,#27373b,#1a2427)}
.video .empty .play{width:58px;height:58px;border-radius:50%;border:2px solid #cfdad7;display:flex;align-items:center;justify-content:center;font-size:22px;padding-left:4px}
.video .empty small{font-family:ui-monospace,Menlo,monospace;font-size:12px;opacity:.8}
.lesson{margin-top:34px}
.lesson-head{display:flex;align-items:baseline;justify-content:space-between;gap:10px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:6px}
.parts{display:grid;gap:22px;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));margin-top:16px}
.part{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:12px}
.part .video{max-width:none;border-radius:12px;box-shadow:none}
.part h3{font-size:16px;margin:10px 4px 2px}
.part .meta{font-size:13px;color:var(--muted);margin:0 4px 4px}
@media(max-width:520px){.parts{grid-template-columns:1fr}.part .video{max-width:340px;margin:0 auto}}
footer.site{border-top:1px solid var(--line);background:#efece4;padding:26px 0 40px;font-size:14px;color:var(--muted)}
footer.site .disc{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-bottom:14px;color:var(--ink)}
footer.site a{color:var(--muted)}
.narrow{max-width:720px}
/* articles */
.part .articles{border-top:1px solid var(--line);margin:8px 4px 2px;padding-top:8px}
.part .articles h4{font-size:12px;letter-spacing:.8px;text-transform:uppercase;color:var(--muted);margin:0 0 4px}
.part .articles ul{list-style:none;margin:0;padding:0}
.part .articles li{font-size:14px;line-height:1.4;margin:6px 0}
.part .articles a{text-decoration:none}.part .articles a:hover{text-decoration:underline}
.articles-none{font-size:13px;color:var(--muted);opacity:.75;margin:8px 4px 2px}
.narrow .articles{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:14px 18px;margin:16px 0}
.narrow .articles h4{margin:0 0 4px}.narrow .articles ul{margin:0;padding-left:18px}
.part{scroll-margin-top:80px}
.article .crumb{margin:0;font-size:14px}.article .crumb a{text-decoration:none}
.article-body h2{font-size:22px;margin:1.4em 0 .4em}.article-body h3{margin-top:1.2em}
.article-body li{margin:4px 0}
.article-disc{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:12px;padding:14px 18px;margin:32px 0 20px;font-size:15px;color:var(--muted)}
.article-disc p{margin:.5em 0}.article-disc strong{color:var(--ink)}
/* home: walk score next to the Stability Gap video */
.hero-solo{grid-template-columns:1fr!important}
.ws-home{display:grid;gap:24px;align-items:start;margin:18px 0 8px}
@media(min-width:860px){.ws-home{grid-template-columns:1.2fr .8fr}}
.ws-card{background:var(--card);border:2px solid var(--accent);border-radius:var(--r);padding:26px 24px;box-shadow:0 10px 30px rgba(31,42,46,.10)}
.ws-card h2{margin:.1em 0 .35em}
.ws-card p{margin:.4em 0}
.ws-card .eyebrow{margin:0;color:var(--accent);font-weight:700;font-size:14px;letter-spacing:.6px;text-transform:uppercase}
.btn.big{font-size:19px;padding:15px 28px;margin-top:12px}
.ws-video{margin:0}
.ws-video figcaption{max-width:360px;margin:12px auto 0;font-size:15px;color:var(--muted);text-align:center}
.ws-video figcaption strong{color:var(--ink)}
.intro-home{margin-top:24px}