.lesson-shell{flex-direction:column;height:100dvh;display:flex}.lesson-header{border-bottom:1px solid var(--divider);flex-wrap:wrap;align-items:center;gap:8px 16px;min-height:64px;padding:8px 24px;display:flex}.lesson-header .brand{font-size:17px}.lesson-breadcrumb{color:var(--muted);min-width:0;font-size:14.5px}.lesson-breadcrumb a{color:var(--muted)}.lesson-breadcrumb a:hover,.lesson-breadcrumb span{color:var(--text)}.lesson-position{color:var(--muted);margin-left:auto;font-size:13.5px}.lesson{flex:1;grid-template-rows:minmax(0,1fr);grid-template-columns:minmax(0,1fr) minmax(0,1fr);min-height:0;display:grid}.lesson-reading{border-right:1px solid var(--divider);min-width:0;padding:28px 32px 40px;overflow-y:auto}.lesson-reading>*{max-width:680px}.lesson-chips{flex-wrap:wrap;gap:8px;margin-bottom:22px;display:flex}.lesson-chips button{border:1px solid var(--border-strong);height:36px;color:var(--text);border-radius:18px;align-items:center;gap:7px;padding:0 14px;font-size:14.5px;font-weight:600;display:flex}.lesson-chips button span{color:var(--muted);font-weight:800}.lesson-chips button[aria-current=step]{background:var(--select);border-color:var(--select);color:var(--select-ink);font-weight:700}.lesson-chips button[aria-current=step] span{color:var(--select-ink)}.lesson-reading h1{margin:0 0 14px;font-size:34px;font-weight:800;line-height:40px}.lesson-prose{color:var(--body);font-size:18px;line-height:28px}.lesson-prose p,.lesson-prose ul,.lesson-prose ol{margin:0 0 16px}.lesson-prose li+li{margin-top:6px}.lesson-prose h2{color:var(--text);margin:24px 0 10px;font-size:20px;line-height:26px}.lesson-prose h3{color:var(--text);margin:20px 0 8px;font-size:17px}.lesson-prose code,.lesson-task code{color:var(--link);font-size:.89em}.lesson-prose .code-block code{color:var(--text);font-size:inherit}.lesson-prose>div>.code-block,.lesson-prose>.code-block{margin:0 0 16px}.example{background:var(--panel);border:1px solid var(--border);border-radius:14px;margin:0 0 16px;overflow:hidden}.example .code-block{background:0 0;border:0;border-radius:0}.example-run{border-top:1px solid var(--border);background:var(--select-bg);width:100%;height:44px;color:var(--link);justify-content:center;align-items:center;gap:8px;font-size:15px;font-weight:650;display:flex}.example-run:hover:not(:disabled){background:#1b3048}.example-output{border-top:1px solid var(--border);flex-direction:column;gap:8px;padding:12px 16px;font-size:15px;display:flex}.lesson-continue{margin-top:8px}.lesson-solution{flex-direction:column;min-width:0;min-height:0;display:flex}.lesson-task{border-bottom:1px solid var(--divider);background:var(--rail);flex-direction:column;gap:6px;padding:16px 20px;display:flex}.lesson-task p{color:var(--body);margin:0;font-size:15.5px;line-height:22px}.lesson-task code{font-size:14.5px}.lesson-blocked{background:var(--warn-bg);border:1px solid var(--warn-border);border-radius:12px;padding:10px 12px;color:var(--body)!important;font-size:14.5px!important}.lesson-editor{flex:1;min-height:280px;position:relative}.plain-editor{position:absolute;inset:0;overflow:hidden}.plain-editor .cm-editor{height:100%;font-size:14.5px}.lesson-results{flex-direction:column;flex:none;gap:10px;max-height:45%;margin:0 20px 14px;display:flex;overflow-y:auto}.lesson-results:empty{display:none}.lesson-hint{background:var(--warn-bg);border:1px solid var(--warn-border);border-radius:14px;padding:12px 14px;font-size:14.5px;line-height:21px}.lesson-hint strong{color:var(--warn);font-size:13.5px}.lesson-hint p{color:var(--body);margin:4px 0 0}.check-card{background:var(--panel);border:1px solid var(--border);border-radius:14px;flex-direction:column;gap:4px;padding:12px 14px;display:flex}.check-card strong{font-size:15.5px;font-weight:700}.check-card>span{color:var(--soft);font-size:13.5px}.check-card small{color:var(--muted);font-size:12.5px}.check-card.ok{background:var(--ok-bg);border-color:var(--ok-border)}.check-card.ok strong{color:var(--ok)}.check-card.fail{background:var(--stop-bg);border-color:var(--stop-border)}.check-card.fail strong{color:var(--stop)}.check-card ul{flex-direction:column;gap:6px;margin:2px 0;padding:0;font-size:14px;list-style:none;display:flex}.check-card li{flex-direction:column;display:flex}.check-message{white-space:pre-wrap;font-family:var(--mono);color:var(--body);font-size:13px}.lesson-output{flex-direction:column;gap:6px;display:flex}.lesson-output .transcript{max-height:220px}.lesson-bar{border-top:1px solid var(--divider);background:var(--rail);flex-wrap:wrap;align-items:center;gap:10px;min-height:72px;padding:12px 20px;display:flex}.lesson-bar .pill-button{border-radius:22px;height:44px;font-size:15px}.lesson-bar .pill-button.hint{color:var(--warn)}.lesson-next{margin-left:auto;font-size:15px;font-weight:650}.lesson-check{background:var(--run);height:46px;color:var(--run-ink);border-radius:23px;align-items:center;gap:7px;padding:0 18px 0 15px;font-size:16px;font-weight:750;display:flex}.lesson-check:hover:not(:disabled){background:#ffdc5c}@media (max-width:900px){.lesson-shell{height:auto;min-height:100dvh}.lesson{grid-template-rows:none;grid-template-columns:1fr}.lesson-reading{overflow:visible}.lesson-results{max-height:none}.lesson-reading{border-right:0;border-bottom:1px solid var(--divider);padding:20px 16px 28px}.lesson-reading h1{font-size:28px;line-height:34px}.lesson-prose{font-size:17px;line-height:26px}.lesson-header{padding:8px 16px}.lesson-position{width:100%;margin-left:0}.lesson-editor{flex:none;height:50vh;min-height:320px}.lesson-task,.lesson-bar{padding-left:16px;padding-right:16px}.lesson-results{margin:0 16px 14px}}