@charset "UTF-8";
/* Learn (/learn, learn.html): the lessons' overview and a lesson beside its still. Over style.css (the top bar, the
   buttons, the cards, the sliders and the 2D sketch are the lab's), with the theme's tokens (themes.css). */
body.learn-page{overflow:auto;height:auto;min-height:100dvh}

/* The overview: the lessons in their order, then the questions where new users got stuck. */
.learn{max-width:1080px;width:100%;margin:0 auto;padding:28px 18px 60px;display:flex;flex-direction:column;gap:18px}
.learn h1{font-size:24px;margin:0;letter-spacing:-.01em}
.learn-lead{color:var(--muted);font-size:14px;max-width:70ch}
.learn-path{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px}
.learn-card{display:flex}
.learn-open{display:flex;flex-direction:column;align-items:flex-start;gap:4px;width:100%;min-height:128px;padding:14px 16px;text-align:left;
 border-radius:14px;border:1px solid var(--line);background:var(--surface);color:var(--text)}
button.learn-open:hover{border-color:var(--line-strong);background:var(--surface-2)}
.learn-n{font-size:12px;font-weight:700;color:var(--accent);font-variant-numeric:tabular-nums}
.learn-name{font-size:15px}
.learn-line{font-size:13px;color:var(--muted)}
.learn-meta{margin-top:auto;padding-top:10px;font-size:12px;color:var(--faint)}
.learn-card.next .learn-open{border-color:var(--accent);background:rgba(var(--accent-rgb),.09)}
.learn-card.next .learn-meta{color:var(--accent);font-weight:600}
.learn-card.done .learn-meta{color:var(--good);font-weight:600}
.learn-card.soon .learn-open{opacity:.55;cursor:default}
.learn-stuck{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:16px 18px;display:flex;flex-direction:column;gap:10px}
.learn-stuck h2{font-size:16px}
.learn-stuck .stuck details p{line-height:1.55;max-width:75ch}

/* A lesson: its step beside the still, the step's controls lit and the still's others dimmed. */
.lesson{width:100%;max-width:1400px;margin:0 auto;padding:14px 18px 24px;display:flex;flex-direction:column;gap:14px}
.lesson-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.lesson-bar h1{font-size:18px;margin:0}
.lesson-count{font-size:13px;color:var(--faint);margin-right:auto}
.lesson-body{display:grid;grid-template-columns:minmax(260px,360px) minmax(0,1fr);gap:16px;align-items:start}
.lesson-step{display:flex;flex-direction:column;gap:14px;padding:18px;border-radius:var(--radius);
 border:1px solid rgba(var(--accent-rgb),.45);background:rgba(var(--accent-rgb),.07)}
.lesson-step h2{font-size:17px}
#step-body,.lesson-done,.lesson-replace{display:flex;flex-direction:column;gap:14px}
.step-text,.lesson-replace p,.lesson-done p{font-size:15px;line-height:1.55}
.step-check{display:flex;gap:10px;align-items:flex-start;padding:10px 12px;border-radius:12px;border:1px solid var(--line);background:var(--surface)}
.step-check small{display:block;margin-top:2px;font-size:12px;color:var(--faint)}
.check-mark{flex:none;position:relative;width:18px;height:18px;margin-top:1px;border-radius:50%;border:2px solid var(--faint)}
.step-check.passed{border-color:rgba(var(--good-rgb),.5)}
.step-check.passed .check-mark{border-color:var(--good);background:var(--good)}
.step-check.passed .check-mark:after{content:'';position:absolute;left:4px;top:1px;width:5px;height:9px;border:solid var(--bg);border-width:0 2px 2px 0;transform:rotate(45deg)}
.step-hint{font-size:13.5px;line-height:1.5;color:var(--muted);padding:10px 12px;border-radius:12px;background:var(--surface)}
.step-nav{display:flex;gap:8px;flex-wrap:wrap}
.step-nav #step-next{margin-left:auto}

.lesson-view{display:flex;flex-direction:column;gap:10px;min-width:0}
.lesson-run{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.lesson-stage{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:12px;align-items:start}
.lesson-picture{position:relative;min-height:460px;height:calc(100dvh - 250px);max-height:720px;border-radius:var(--radius);overflow:hidden;border:1px solid var(--line-soft)}
.lesson-picture .sketch{border-radius:inherit}
/* A step that shows the run's Summary in the still's place (learn-lesson.js VIEWS). */
.lesson-summary{position:absolute;inset:0;overflow:auto;padding:16px 18px;background:var(--surface)}
.lesson-controls{display:flex;flex-direction:column;gap:12px;min-width:0}
.lesson-card-controls{display:flex;flex-direction:column;gap:8px}
.lesson-card-controls h3{font-size:14px}
.lesson-control{padding:8px;border-radius:12px}
.lesson-control .control-head{margin-bottom:4px}
.lesson-control .control-head output{font-size:18px}
.lesson-readings{display:grid;grid-template-columns:auto minmax(0,1fr);gap:4px 12px;margin:0;font-size:13.5px}
.lesson-readings dt{color:var(--muted)}
.lesson-readings dd{margin:0;text-align:right;font-variant-numeric:tabular-nums}
.lesson-view .lit{box-shadow:0 0 0 2px var(--accent);border-radius:12px}
.lesson-view .dimmed{opacity:.42}
.lesson-note{font-size:12px;color:var(--faint)}

@media (max-width:900px){
 .lesson-body,.lesson-stage{grid-template-columns:minmax(0,1fr)}
 .lesson-picture{height:auto;min-height:360px}
}