.learn-controls{align-items:flex-end;gap:14px;display:flex}.learn-controls label{letter-spacing:.05em;text-transform:uppercase;color:var(--ink-3);flex-direction:column;gap:5px;font-size:11px;font-weight:600;display:flex}.learn-controls select{background:var(--panel);color:var(--ink);border:1px solid var(--rule-strong);border-radius:var(--radius);text-transform:capitalize;letter-spacing:0;min-width:170px;padding:7px 10px;font-size:13px;font-weight:400}.seg{border:1px solid var(--rule-strong);border-radius:var(--radius);display:flex;overflow:hidden}.seg button{background:var(--panel);color:var(--ink-2);cursor:pointer;border:0;padding:8px 13px;font-size:13px}.seg button+button{border-left:1px solid var(--rule)}.seg button.on{background:var(--accent);color:#fff}.lesson-list{border-top:1px solid var(--rule);margin:0;padding:0;list-style:none}.lesson-list>li{border-bottom:1px solid var(--rule)}.lesson-list.plain>li{padding:13px 15px}.lesson-head{text-align:left;cursor:pointer;width:100%;color:inherit;font:inherit;background:0 0;border:0;align-items:center;gap:12px;padding:12px 15px;display:flex}.lesson-head:hover{background:var(--panel-2)}.lesson-head.static{cursor:default;padding:0 0 5px}.keyword{letter-spacing:.04em;background:var(--panel-2);color:var(--accent-ink);text-align:center;border-radius:5px;flex:none;min-width:96px;padding:4px 8px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12.5px;font-weight:600}.lesson-title{font-size:14px;font-weight:500}.alt{color:var(--ink-3);font-size:12px}.chev{color:var(--ink-3);margin-left:auto;font-size:16px;line-height:1}.lesson-body{padding:0 15px 15px 123px}.lesson-body p{color:var(--ink-2);max-width:68ch;margin:0 0 9px;font-size:13px}.lesson-summary{color:var(--ink-2);max-width:74ch;margin:0;font-size:13px}.steps{flex-direction:column;gap:6px;margin:0;padding-left:18px;display:flex}.steps li{color:var(--ink-2);font-size:13px}.steps b{color:var(--ink);font-weight:500}.steps .reply{color:var(--ink-3);font-size:12.5px;display:block}.lesson-video{border-radius:var(--radius);border:1px solid var(--rule);width:100%;max-width:520px;margin-top:10px}.sheet-grid{grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:10px;padding:0 15px 15px;display:grid}.sheet-card{border:1px solid var(--rule);border-radius:var(--radius);flex-direction:column;gap:8px;padding:12px;display:flex}.sheet-card b{text-transform:capitalize;font-size:13.5px;font-weight:600}.sheet-links{gap:8px;display:flex}.sheet-links a{text-align:center;border:1px solid var(--rule-strong);color:var(--ink-2);border-radius:6px;flex:1;padding:6px 8px;font-size:12.5px;text-decoration:none}.sheet-links a:hover{border-color:var(--accent);color:var(--accent-ink)}