/* A quieter layer over the original guide. Without JS, the original guide remains readable. */
:root{--ink:#292621;--soft:#706b63;--line:#e8e2d9;--paper:#fffefa;--accent:#b65d42;--ease-out:cubic-bezier(.23,1,.32,1);--ease-in-out:cubic-bezier(.77,0,.175,1)}
body.course-ready{background:#f8f6f1;color:var(--ink);line-height:1.75}
.course-ready .wrap{max-width:1080px;padding-inline:clamp(20px,4vw,48px)}
.course-ready header.hero{padding:96px 0 64px;text-align:right}
.course-ready header.hero .wrap{max-width:1080px}
.course-ready header.hero::after{content:"";display:block;height:1px;background:var(--line);margin-top:60px}
.course-ready .pill{margin-bottom:22px;background:#f7eae3;color:#93472f;font-size:13px}
.course-ready h1{font-family:'Heebo',sans-serif;font-weight:800;font-size:clamp(38px,6vw,76px);max-width:790px;line-height:1.12;letter-spacing:-.02em;margin-bottom:18px}
.course-ready h1 .l2{font-size:clamp(17px,2.5vw,25px);font-weight:600;margin-top:20px;line-height:1.45;letter-spacing:0}
.course-ready .hero p.sub{margin:0;max-width:640px;font-size:clamp(16px,2vw,19px);color:#625d56;line-height:1.8}
.course-ready .hero-stats,.course-ready .hero-badges,.course-ready .scroll-hint{display:none}
.course-ready nav.toc{display:none}
.course-ready .course-bar{position:sticky;top:0;z-index:60;background:rgba(248,246,241,.96);backdrop-filter:blur(16px);border-bottom:1px solid var(--line)}
.course-ready .course-bar .wrap{display:flex;align-items:center;justify-content:space-between;gap:18px;min-height:68px}
.course-ready .course-brand{color:#382e29;font-weight:700;white-space:nowrap;font-size:16px}
.course-ready .course-brand:hover{text-decoration:none;color:var(--accent)}
.course-ready .course-bar-meta{font-size:13px;color:var(--soft);white-space:nowrap}
.course-ready .course-bar .back-link{font-size:14px;color:var(--accent);font-weight:600}
.course-ready .course-home-intro{padding:28px 32px;border:1px solid var(--line);border-radius:16px;background:#fffefa;max-width:760px;margin:0 0 76px;color:#5c574f;font-size:15px;line-height:1.8}
.course-ready .course-home-intro b{color:#3c362f}
.course-ready .curriculum{margin-bottom:100px}
.course-ready .curriculum-head{margin-bottom:38px}
.course-ready .curriculum-head h2{font-weight:800;font-size:clamp(26px,4vw,38px);line-height:1.3;letter-spacing:-.015em}
.course-ready .curriculum-head p{color:var(--soft);font-size:16px;margin-top:8px}
.course-ready .course-part{margin:0 0 62px;scroll-margin-top:95px}
.course-ready .course-part-head{display:flex;align-items:baseline;gap:15px;border-bottom:1px solid #ded8cd;padding-bottom:16px;margin-bottom:18px}
.course-ready .course-part-label{font-family:'JetBrains Mono',monospace;color:var(--accent);font-size:12.5px;font-weight:600;letter-spacing:.05em;white-space:nowrap}
.course-ready .course-part-head h3{font-size:clamp(20px,3vw,28px);line-height:1.35;font-weight:700;letter-spacing:-.01em}
.course-ready .lesson-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
.course-ready .lesson-card{display:flex;align-items:flex-start;gap:16px;padding:20px;background:var(--paper);border:1px solid var(--line);border-radius:16px;color:var(--ink);min-height:96px;transition:transform .18s var(--ease-out),border-color .18s ease,box-shadow .18s ease}
.course-ready .lesson-card:focus-visible{transform:translateY(-2px);border-color:#cfaa98;box-shadow:0 10px 28px rgba(58,43,31,.07);text-decoration:none}
.course-ready .lesson-number{font-family:'JetBrains Mono',monospace;color:var(--accent);font-weight:600;font-size:14px;min-width:28px;padding-inline-start:9px;border-inline-start:2px solid #ecc9b8}
.course-ready .lesson-card strong{font-size:17px;line-height:1.45;font-weight:600;display:block}
.course-ready .lesson-card small{font-size:13px;color:var(--soft);display:block;margin-top:8px}
.course-ready .lesson-card .arrow{margin-inline-start:auto;color:var(--accent);font-size:20px;transition:transform .18s var(--ease-out)}
.course-ready.home .part,.course-ready.home article.chapter{display:none}
.course-ready.lesson header.hero,.course-ready.lesson .course-home-intro,.course-ready.lesson .curriculum,.course-ready.lesson section.part{display:none}
.course-ready.lesson article.chapter{display:none}
.course-ready.lesson article.chapter.current{display:block}
.course-ready.lesson article.chapter.current{max-width:760px;margin:28px auto 20px;padding:clamp(24px,4.5vw,52px);border-radius:22px;border:1px solid var(--line);background:var(--paper);box-shadow:0 12px 50px rgba(57,41,28,.035);scroll-margin-top:90px}
.course-ready.lesson .lesson-top{max-width:760px;margin:60px auto 0}
.course-ready .eyebrow{font-size:13px;font-weight:700;color:var(--accent);letter-spacing:.02em;margin-bottom:12px}
.course-ready .lesson-top h2{font-weight:800;font-size:clamp(28px,4vw,42px);line-height:1.28;max-width:760px;letter-spacing:-.02em}
.course-ready .lesson-top p{color:#8a8378;font-size:14px;margin-top:6px}
.course-ready .chapter .ch-head{display:none}
.course-ready .chapter .lesson-step{display:none;animation:fade-step .22s var(--ease-out) both}
.course-ready .chapter .lesson-step.active{display:block}
@keyframes fade-step{from{opacity:.4;transform:translateY(5px)}to{opacity:1;transform:none}}
.course-ready .chapter .lesson-step h4{margin:0 0 20px;font-size:clamp(21px,3vw,26px);line-height:1.35;color:#332d27;font-weight:700;letter-spacing:-.01em;position:relative;padding-inline-start:16px}
.course-ready .chapter .lesson-step h4::before{content:"";position:absolute;inset-inline-start:0;top:.42em;width:8px;height:8px;border-radius:2px;background:var(--accent)}
.course-ready .chapter .lesson-step p{font-size:17px;line-height:1.85;margin:0 0 16px;color:#3a3732}
.course-ready .chapter .lesson-step>:last-child{margin-bottom:0}
.course-ready .chapter ul,.course-ready .chapter ol{margin:18px 24px 26px 0;color:#3a3732}
.course-ready .chapter li{margin:0 0 14px;padding-inline-start:5px;line-height:1.75}
.course-ready .chapter .callout{margin:26px 0;padding:6px 18px;background:transparent;border:none;border-inline-start:3px solid #e3cf9e;color:#4e4638}
.course-ready .chapter .callout.warn{border-inline-start-color:#dfa48e;color:#754630}
.course-ready .chapter .video-box{margin:22px 0 8px}
.course-ready .chapter .video-cap{font-family:'Heebo',sans-serif;line-height:1.6}
.course-ready .chapter .srcs{margin-top:28px;line-height:1.8}
.course-ready .chapter code{max-width:100%;overflow-wrap:anywhere;white-space:normal;vertical-align:baseline}
.course-ready .chapter .codeblock{max-width:100%;white-space:pre;overflow-x:auto}
.course-ready .chapter .tbl-scroll{max-width:100%;overflow-x:auto}
.course-ready .step-shell{max-width:760px;margin:0 auto 56px}
.course-ready .step-progress{display:flex;align-items:center;gap:12px;margin:0 0 14px;color:#8a8378;font-size:13px}
.course-ready .progress-track{height:3px;flex:1;background:#eae4d9;border-radius:3px;overflow:hidden}
.course-ready .progress-fill{height:100%;width:100%;background:var(--coral);border-radius:5px;transform:scaleX(0);transform-origin:right center;transition:transform .3s var(--ease-out)}
.course-ready .step-picker{display:flex;flex-wrap:nowrap;overflow-x:auto;gap:2px;margin:0 0 18px;border-bottom:1px solid var(--line);scrollbar-width:none;-webkit-mask-image:linear-gradient(to left,transparent,#000 28px);mask-image:linear-gradient(to left,transparent,#000 28px)}
.course-ready .step-picker::-webkit-scrollbar{display:none}
.course-ready .step-picker button{border:none;background:transparent;color:#7a736a;padding:9px 10px 11px;border-radius:0;font:500 13px 'Heebo',sans-serif;cursor:pointer;text-align:right;white-space:nowrap;flex:none;position:relative;transition:color .15s ease}
.course-ready .step-picker button::after{content:"";position:absolute;inset-inline:8px;bottom:-1px;height:2px;border-radius:2px;background:transparent;transition:background .15s ease}
.course-ready .step-picker button:hover{color:#332d27}
.course-ready .step-picker .chip-num{font-family:'JetBrains Mono',monospace;font-size:11px;color:#b8afa2;margin-inline-end:6px}
.course-ready .step-picker button[aria-current="step"]{color:#8f422d;font-weight:600}
.course-ready .step-picker button[aria-current="step"]::after{background:var(--coral)}
.course-ready .step-picker button[aria-current="step"] .chip-num{color:var(--accent)}
.course-ready .step-actions{display:flex;justify-content:space-between;gap:14px;padding-top:20px;border-top:1px solid var(--line)}
.course-ready .step-actions button,.course-ready .step-actions a{border:1px solid #d7cfc3;border-radius:12px;padding:12px 22px;background:#fffefa;color:#4b3c34;font:600 15px 'Heebo',sans-serif;cursor:pointer;text-decoration:none;text-align:center;transition:transform .15s var(--ease-out),box-shadow .15s ease,border-color .15s ease}
.course-ready .step-actions .next{background:#aa563c;color:white;border-color:#aa563c;box-shadow:0 8px 20px rgba(170,86,60,.20)}
@media(hover:hover){.course-ready .step-actions .next:hover{transform:translateY(-1px);box-shadow:0 12px 26px rgba(170,86,60,.26)}.course-ready .step-actions button:not(.next):hover,.course-ready .step-actions a:not(.next):hover{border-color:#b8afa2}}
.course-ready .step-actions button:disabled{opacity:.45;cursor:default}
.course-ready footer{border-top:1px solid var(--line);padding-top:26px;max-width:760px;margin:56px auto 42px;line-height:1.8}
.course-ready .rv{opacity:1;transform:none;transition:none}
@media(max-width:640px){
 .course-ready .wrap{padding-inline:20px}
 .course-ready header.hero{padding:52px 0 40px}
 .course-ready h1{font-size:clamp(34px,9vw,44px)}
 .course-ready .hero p.sub{font-size:16px}
 .course-ready .course-home-intro{padding:20px;margin-bottom:56px}
 .course-ready .lesson-grid{grid-template-columns:1fr}
 .course-ready .lesson-card{min-height:95px;padding:19px}
 .course-ready .course-part{margin-bottom:50px}
 .course-ready .course-bar .wrap{min-height:58px}
 .course-ready .course-brand{font-size:14px}
 .course-ready.lesson .lesson-top{margin-top:36px}
 .course-ready.lesson article.chapter.current{padding:22px 18px;margin:18px -4px 20px;border-radius:17px}
 .course-ready .chapter .lesson-step p{font-size:16px}
 .course-ready .chapter .callout{padding:16px}
 .course-ready .step-actions button,.course-ready .step-actions a{flex:1;padding:12px 8px}
 .course-ready .chapter table.cmp{min-width:600px}
}
@media(prefers-reduced-motion:reduce){.course-ready .chapter .lesson-step{animation:none}.course-ready .lesson-card,.course-ready .step-picker button,.course-ready .step-actions button,.course-ready .step-actions a,.course-ready .progress-fill{transition:none}.course-ready .lesson-card:active,.course-ready .step-picker button:active,.course-ready .step-actions button:active,.course-ready .step-actions a:active{transform:none}}

.course-ready .intro-more{max-width:650px;margin-top:14px;color:var(--soft);font-size:14px}
.course-ready .course-home-intro{padding:16px 24px;margin-bottom:58px}
.course-ready .intro-more summary,.course-ready .course-home-intro summary{cursor:pointer;color:#8c4935;font-size:14px;font-weight:600;list-style:none}
.course-ready .intro-more summary::after,.course-ready .course-home-intro summary::after{content:" +";font-size:19px;vertical-align:middle}
.course-ready .intro-more[open] summary::after,.course-ready .course-home-intro details[open] summary::after{content:" −"}
.course-ready .intro-more p{margin-top:12px}
.course-ready .course-home-intro details{font-size:14px}
.course-ready .course-home-intro details:not([open]){line-height:1.4}
.course-ready .course-home-intro details[open] summary{margin-bottom:12px}
.course-ready .lesson-top{scroll-margin-top:95px}
@media(max-width:640px){
 .course-ready .course-bar .wrap{gap:10px}
 .course-ready .course-brand{overflow:hidden;text-overflow:ellipsis;min-width:0;flex:1}
 .course-ready .course-bar-meta{display:none}
 .course-ready .course-bar .back-link{white-space:nowrap;flex:none}
}

/* Motion + touch polish pass - principles adapted from emilkowalski/skills (MIT) */
html{-webkit-tap-highlight-color:transparent}
.course-ready a,.course-ready button{touch-action:manipulation}
.course-ready .lesson-card,.course-ready .step-picker button,.course-ready .step-actions button,.course-ready .step-actions a{user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}
.course-ready .step-picker button,.course-ready .step-actions button,.course-ready .step-actions a{transition:transform .14s var(--ease-out),background .18s ease,border-color .18s ease,color .18s ease}
@media (hover:hover) and (pointer:fine){
 .course-ready .lesson-card:hover{transform:translateY(-2px);border-color:#cfaa98;box-shadow:0 10px 28px rgba(58,43,31,.07);text-decoration:none}
 .course-ready .lesson-card:hover .arrow{transform:translateX(-3px)}
 .course-ready .step-picker button:hover{border-color:#ba745c;color:#8f422d}
 .course-ready .step-actions .next:hover{background:#8e412b}
}
.course-ready .step-picker button:active,.course-ready .step-actions button:active,.course-ready .step-actions a:active{transform:scale(.97)}
.course-ready .lesson-card:active{transform:scale(.985)}
.course-ready .chapter .video-box video{display:block;max-width:100%;border-radius:14px;border:1px solid var(--line)}

/* ===== v3 learning-experience redesign: sidebar index, flat editorial content, bar progress, video-led steps ===== */
.course-ready.home .lesson-layout{display:none}
.course-ready.lesson .lesson-layout{margin:0 auto}
.course-ready.lesson .lesson-top{margin-top:44px;max-width:760px}
.course-ready .step-rail{display:block;margin:0 0 6px}
.course-ready .step-shell{max-width:none;margin:0}
.course-ready .step-progress{display:flex;align-items:baseline;gap:10px;margin:0 0 22px;font-size:14px}
.course-ready .step-count{font-family:'JetBrains Mono',monospace;font-size:12px;font-weight:600;color:var(--accent);letter-spacing:.04em;white-space:nowrap}
.course-ready .step-name{color:#8a8378;font-size:13.5px}
.course-ready .bar-progress{position:absolute;bottom:-1px;inset-inline:0;height:3px;overflow:hidden}
.course-ready .bar-progress-fill{display:block;height:100%;background:var(--coral);transform:scaleX(0);transform-origin:right center;transition:transform .3s var(--ease-out)}
.course-ready.home .bar-progress{visibility:hidden}
/* flat editorial content: the card is gone */
.course-ready.lesson article.chapter.current{max-width:760px;margin:0;padding:0;border:none;border-radius:0;background:transparent;box-shadow:none;scroll-margin-top:110px}
.course-ready .chapter .lesson-step h4{font-size:clamp(24px,3.4vw,30px);margin:0 0 26px}
.course-ready .chapter .lesson-step p{font-size:18px;line-height:1.8;margin:0 0 20px}
.course-ready .chapter li{margin:0 0 16px}
.course-ready .chapter .video-box{margin:34px 0 14px}
.course-ready .chapter .video-box video{border:none;border-radius:16px;box-shadow:0 18px 44px rgba(57,41,28,.12)}
.course-ready .chapter .video-cap{font-size:14px;color:#7d766c;margin-top:12px}
/* actions: roomier, labeled direction */
.course-ready .step-actions{margin-top:44px;padding-top:26px}
.course-ready .step-actions button,.course-ready .step-actions a{display:inline-flex;align-items:center;justify-content:center;gap:9px;padding:14px 24px;border-radius:14px}
.course-ready .step-actions .act-dir{font-weight:700}
.course-ready .step-actions .next .act-label{max-width:340px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.course-ready .chip-check{display:none}
@media(max-width:1023px){
 .course-ready.lesson .step-actions{position:sticky;bottom:0;z-index:40;background:rgba(248,246,241,.95);backdrop-filter:blur(14px);padding:14px 0;border-top:1px solid var(--line)}
 .course-ready .step-actions .next .act-label{max-width:200px}
}
/* desktop: sidebar step index, wider breathing room */
@media(min-width:1024px){
 .course-ready.lesson .lesson-layout{display:grid;grid-template-columns:264px minmax(0,1fr);gap:64px;align-items:start}
 .course-ready .step-rail{position:sticky;top:108px;margin:0}
 .course-ready .step-picker{flex-direction:column;gap:2px;border-bottom:none;overflow:visible;-webkit-mask-image:none;mask-image:none}
 .course-ready .step-picker button{display:flex;align-items:baseline;gap:11px;width:100%;padding:11px 14px;border-radius:11px;font-size:14px;color:#6d675e;white-space:normal;text-align:right;transition:background .15s ease,color .15s ease}
 .course-ready .step-picker button::after{display:none}
 .course-ready .step-picker button:hover{background:#f2ede4;color:#332d27}
 .course-ready .step-picker button[aria-current="step"]{background:#f7ece4;color:#8f422d;font-weight:600}
 .course-ready .step-picker .chip-num{font-size:11.5px}
 .course-ready .step-picker .chip-label{flex:1;line-height:1.45}
 .course-ready .step-picker button.done .chip-check{display:inline;color:#b65d42;font-size:13px;flex:none}
 .course-ready .step-picker button.done{color:#96907f}
 .course-ready .step-picker button.done .chip-num{color:#c3bbae}
 /* text measures narrower than media: video leads */
 .course-ready.lesson .chapter .lesson-step>p,.course-ready.lesson .chapter .lesson-step>ul,.course-ready.lesson .chapter .lesson-step>ol,.course-ready.lesson .chapter .lesson-step>.callout{max-width:600px}
 .course-ready.lesson .chapter .lesson-step>h4{max-width:680px}
}
@media(max-width:640px){
 .course-ready.lesson article.chapter.current{margin:0;padding:0}
 .course-ready.lesson .lesson-top{margin-top:30px}
 .course-ready .chapter .lesson-step p{font-size:16.5px}
 .course-ready .step-rail{margin:0 0 4px;padding:0}
 .course-ready .step-actions .next .act-label{max-width:150px}
}
/* v3 alignment: lesson header lives inside the content column */
.course-ready.lesson .lesson-top{margin:0 0 34px;max-width:none}
.course-ready.lesson .lesson-top h2{max-width:680px}
@media(max-width:1023px){.course-ready.lesson .lesson-top{margin-top:26px}}

/* review questions (doctrine: scibly-dev/skills assessment-design) */
.course-ready .quiz{display:flex;flex-direction:column;gap:22px;margin-top:14px}
.course-ready .q{border:1px solid var(--line);border-radius:16px;padding:18px 20px;background:#fffefa}
.course-ready .q-stem{font-weight:600;margin:0 0 12px;line-height:1.7}
.course-ready .q.solved .q-stem::before{content:"✓";color:#1a9e54;margin-inline-end:8px}
.course-ready .q-opt{display:block;width:100%;text-align:start;font-family:inherit;font-size:14.5px;line-height:1.6;padding:11px 14px;margin-top:8px;border:1px solid var(--line);border-radius:12px;background:var(--paper);cursor:pointer;color:var(--ink);transition:border-color .15s ease}
.course-ready .q-opt:hover{border-color:var(--accent)}
.course-ready .q-opt.ok{border-color:#1a9e54;background:#eefaf2}
.course-ready .q-opt.no{border-color:#cf5b4e;background:#fdf0ee}
.course-ready .q-fb{display:block;margin-top:8px;font-size:13px;line-height:1.6;color:var(--soft)}
.course-ready .q-fb[hidden]{display:none}

/* intro overlay */
body.intro-lock{overflow:hidden}
#intro-overlay{position:fixed;inset:0;z-index:2000;background:#f8f6f1;display:flex;align-items:center;justify-content:center;opacity:1;transition:opacity .8s var(--ease-out)}
#intro-overlay.intro-out{opacity:0;pointer-events:none}
#intro-overlay video{width:100%;height:100%;object-fit:contain;background:#f8f6f1}
#intro-skip{position:absolute;bottom:calc(20px + env(safe-area-inset-bottom));inset-inline-start:20px;z-index:2001;background:rgba(255,254,250,.92);border:1px solid var(--line);color:var(--soft);border-radius:999px;padding:10px 22px;font-family:inherit;font-size:15px;cursor:pointer}
#intro-skip:hover{color:var(--ink);border-color:var(--accent)}

/* mobile footer compression + slim sticky step bar */
@media(max-width:640px){
 .course-ready footer{margin:34px 0 22px;font-size:11.5px;line-height:1.7;padding-inline:30px}
 .course-ready.lesson .step-actions{padding:8px 0;gap:8px}
 .course-ready.lesson .step-actions button,.course-ready.lesson .step-actions a{padding:8px 10px;font-size:13.5px;border-radius:10px}
}

/* intro: full-bleed cover on portrait screens, contain on landscape */
#intro-overlay video{object-fit:cover}
@media(min-aspect-ratio:4/3){#intro-overlay video{object-fit:contain}}
/* rail edge fade: clipped step chips fade instead of hard-cut (mobile/tablet) */
@media(max-width:1023px){
 .course-ready .step-rail{-webkit-mask-image:linear-gradient(to right,transparent 0,#000 26px calc(100% - 26px),transparent 100%);mask-image:linear-gradient(to right,transparent 0,#000 26px calc(100% - 26px),transparent 100%)}
}
/* lesson page side insets on mobile/tablet; rail keeps edge-to-edge fade with zero page overflow
   (rail negative inline margins exactly cancel its parent's new padding: rail spans 100% of viewport, no sideways scroll range) */
@media(max-width:1023px){
 .course-ready.lesson .lesson-layout{padding-inline:20px}
 .course-ready.lesson .step-rail{margin-inline:-20px;padding-inline:20px}
}