.course-page{--sidebar:270px}.course-header{max-width:none;padding:0 4%;height:88px;background:var(--paper);position:relative;z-index:3}.course-header-label{font-size:9px;letter-spacing:1.5px;color:var(--muted)}.back-home{margin-left:auto;margin-right:40px;font-size:12px}.course-layout{display:grid;grid-template-columns:var(--sidebar) minmax(0,1fr);max-width:1500px;margin:auto}.course-sidebar{padding:34px 26px;border-right:1px solid var(--line);position:sticky;top:0;height:100dvh;overflow:auto;scrollbar-width:thin}.course-title{font-family:'Libre Caslon Display',Georgia,serif;font-size:34px;letter-spacing:-1px}.sidebar-intro{font-size:11px;line-height:1.7;color:var(--muted);margin:9px 0 24px}.progress-label{display:flex;justify-content:space-between;font-size:10px}progress{appearance:none;width:100%;height:4px;border:0;border-radius:2px;margin:10px 0 0;background:#dfe3d6}progress::-webkit-progress-bar{background:#dfe3d6}progress::-webkit-progress-value{background:#6b804d}progress::-moz-progress-bar{background:#6b804d}.local-note{font-size:9px;color:var(--muted);margin:7px 0 25px}.sidebar-section{font-size:8px;letter-spacing:1.5px;text-transform:uppercase;margin:23px 0 9px;color:var(--muted)}#lesson-nav{display:block}.lesson-nav-link{display:flex;gap:9px;font-size:11px;padding:10px 8px;margin:2px -8px;line-height:1.4;border-radius:3px}.lesson-nav-link:hover{background:#ecefe3}.lesson-nav-link[aria-current=page]{background:#e4e9d8;color:var(--ink);font-weight:600}.nav-num{font-size:9px;color:#78836d;min-width:19px;padding-top:2px}.lesson-nav-link.done .nav-num{color:#52743f}.sidebar-home{display:block;font-size:10px;margin:28px 0 10px;text-decoration:underline;text-underline-offset:4px}.lesson-main{padding:52px clamp(25px,5vw,85px) 60px;min-width:0;outline:none}.lesson-breadcrumb{display:flex;justify-content:space-between;gap:15px;font-size:9px;color:var(--muted);letter-spacing:1px;text-transform:uppercase;margin-bottom:30px}.lesson-main h1{font-size:clamp(48px,5.3vw,78px);line-height:1.02;max-width:850px;margin:17px 0 20px;overflow-wrap:anywhere}.lesson-lead{font-size:16px;line-height:1.85;max-width:690px;color:var(--muted)}.lesson-goal{display:flex;gap:18px;align-items:baseline;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:18px 0;margin:28px 0 34px;font-size:12px;line-height:1.7}.lesson-goal>span{font-size:8px;letter-spacing:1.5px;flex-shrink:0;color:var(--muted)}.reading-block{max-width:760px;margin:30px 0}.reading-block h2{font-size:31px;letter-spacing:-.6px;line-height:1.2;margin-bottom:12px}.reading-block p{font-size:14px;line-height:1.95;color:#586858}.lesson-lab{margin:35px -10px;padding:27px;border:1px solid #d1d9c5;background:#edf0e5;border-radius:5px}.lab-heading{display:flex;justify-content:space-between;align-items:center;gap:15px;margin-bottom:18px}.lab-heading .eyebrow{font-size:9px}.lab-badge{font-size:8px;letter-spacing:1px;color:#6b785d}.lab-caption{font-size:12px;line-height:1.8;color:#5b6d56;margin:15px 0}.notation-frame{background:#fafbf5;border:1px solid #dde3d4;border-radius:4px;padding:5px;overflow-x:auto}.notation-frame svg{width:100%;height:auto;min-width:400px;display:block}.notation-frame.staff-frame svg{min-width:320px}.score-label{font-size:9px;color:#6b785d;margin:10px 0 16px;line-height:1.6}.audio-controls{display:flex;align-items:center;gap:17px;flex-wrap:wrap;margin-top:16px}.audio-controls .button{min-width:145px;padding:13px 18px}.audio-controls label{font-size:10px;display:flex;align-items:center;gap:7px}.tempo-control{display:flex;gap:12px;align-items:center;margin:17px 0 0;font-size:10px;color:#586858}.tempo-control input{accent-color:var(--green);width:140px}.audio-progress{height:3px;background:#d7dfce;overflow:hidden;margin-top:18px;border-radius:2px}.audio-progress>span{height:100%;display:block;background:#6b804d;width:0}.score-event{transition:fill .12s}.score-event.active .notehead,.score-event.active .rest-shape{fill:#ab672a}.score-event.active .stem,.score-event.active .ledger{stroke:#ab672a}.score-highlight{fill:#dce89f;opacity:0}.score-event.active .score-highlight{opacity:.6}.lab-task{padding-top:17px;margin-top:18px;border-top:1px solid #d1d9c5;font-size:12px;line-height:1.85;color:#52664c}.lab-task strong{font-size:9px;letter-spacing:1.2px;display:block;margin-bottom:5px}.takeaway{border-left:3px solid #88995d;padding:10px 20px;margin:34px 0}.takeaway span{font-size:9px;letter-spacing:1.5px;color:var(--muted)}.takeaway p{font-family:'Libre Caslon Display',Georgia,serif;font-size:27px;line-height:1.3;margin-top:8px;max-width:690px}.facts-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:10px;margin:24px 0}.fact{padding:17px;background:#ecefe3;border:1px solid var(--line)}.fact strong{display:block;font-family:'Libre Caslon Display',serif;font-size:24px;font-weight:400;margin-bottom:6px}.fact span{font-size:11px;line-height:1.7;color:var(--muted)}.knowledge-check{padding-top:30px;margin-top:35px;border-top:1px solid var(--line)}.knowledge-check>h2{font-size:38px;margin:13px 0 10px}.quiz-intro{color:var(--muted);font-size:12px;line-height:1.8}.question{border:0;padding:0;margin:30px 0;min-width:0}.question legend{font-size:14px;line-height:1.7;margin-bottom:12px;font-weight:500}.quiz-options{display:grid;gap:8px}.quiz-option{display:flex;gap:10px;align-items:center;border:1px solid var(--line);padding:13px 15px;border-radius:3px;font-size:12px;line-height:1.7;cursor:pointer}.quiz-option:hover{background:#eef0e5}.quiz-option:has(input:checked){background:#e6ebd9;border-color:#7c9259}.quiz-option input{accent-color:var(--green);width:15px;height:15px;flex-shrink:0}.question-feedback{margin-top:12px;font-size:12px;line-height:1.8;padding:12px 16px;border-radius:3px;background:#ece5d5;color:#73512d}.question-feedback.correct{color:#355932;background:#e5ecd8}.quiz-result{font-size:12px;line-height:1.8;margin:15px 0}.complete-row{display:flex;align-items:center;gap:15px;flex-wrap:wrap;margin:30px 0 12px}.complete-row .button:disabled{opacity:.45;cursor:not-allowed;transform:none}.completion-tip{font-size:10px;color:var(--muted);line-height:1.8}.lesson-pagination{display:flex;justify-content:space-between;gap:25px;padding-top:27px;margin-top:25px;border-top:1px solid var(--line)}.lesson-pagination a{font-size:12px;line-height:1.7;max-width:48%}.lesson-pagination a:last-child{text-align:right;margin-left:auto}.lesson-pagination small{display:block;font-size:8px;letter-spacing:1.4px;color:var(--muted);margin-bottom:4px}.overview-hero{padding-bottom:30px;border-bottom:1px solid var(--line)}.overview-stats{display:flex;gap:30px;margin-top:28px;font-size:9px;letter-spacing:1.5px;color:var(--muted)}.overview-start{display:flex;align-items:center;gap:20px;margin-top:28px;flex-wrap:wrap}.overview-start>span{font-size:11px;color:var(--muted)}.overview-art{background:var(--green);color:#e7ead6;border-radius:5px;padding:25px;margin:30px 0}.overview-art .eyebrow{font-size:8px}.overview-art svg{display:block;width:100%;height:auto;margin:10px 0}.overview-art p{font-family:'Libre Caslon Display',serif;font-size:27px;text-align:center}.overview-group{margin-top:35px}.overview-group h2{font-size:30px;margin-bottom:14px}.overview-lesson{display:flex;align-items:center;gap:15px;border-top:1px solid var(--line);padding:17px 0}.overview-lesson:hover .overview-lesson-title{text-decoration:underline;text-underline-offset:4px}.overview-lesson .overview-index{font-size:10px;color:var(--muted);min-width:24px}.overview-lesson-title{font-size:13px;line-height:1.6;flex:1}.overview-time{font-size:9px;color:var(--muted);white-space:nowrap}.overview-arrow{font-size:20px;margin-left:10px}.overview-note{font-size:12px;color:var(--muted);line-height:1.9;border-top:1px solid var(--line);padding-top:25px;margin-top:25px}.mobile-course-nav{display:none}.lab-tabs{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:17px}.lab-tabs button{border:1px solid #bfcbb3;background:transparent;padding:9px 12px;border-radius:3px;color:var(--ink);font-size:11px}.lab-tabs button[aria-pressed=true]{background:var(--green);color:#fff;border-color:var(--green)}.explorer-notes{display:flex;gap:7px;flex-wrap:wrap;margin:15px 0}.explorer-notes button{border:1px solid #bfccb4;background:#fafbf5;padding:10px 12px;border-radius:3px;color:var(--ink);font-size:12px}.explorer-notes button[aria-pressed=true]{background:#dce89f;border-color:#8a9c5c}.selected-note{font-family:'Libre Caslon Display',serif;font-size:29px;margin:15px 0 5px}.selected-detail{font-size:11px;line-height:1.8;color:var(--muted)}.keyboard-controls{display:flex;justify-content:space-between;align-items:center;gap:15px;margin:18px 0 15px;flex-wrap:wrap}.keyboard-controls label{font-size:11px;display:flex;align-items:center;gap:7px}.course-piano{height:170px;max-width:580px;margin:auto}.course-piano .black-key{font-size:9px;padding:7px 1px}.course-piano .key{font-size:11px}.keyboard-challenge{margin-top:24px;border-top:1px solid #d1d9c5;padding-top:18px}.keyboard-challenge>p{font-size:12px;line-height:1.8}.keyboard-challenge button{margin-top:10px}.keyboard-challenge .text-button{text-decoration:underline;font-size:11px}.rest-reference{display:grid;grid-template-columns:repeat(5,1fr);gap:5px;margin-bottom:20px}.rest-reference>div{text-align:center;font-size:9px;color:var(--muted);background:#fafbf5;padding:5px 0 12px;border:1px solid #dce2d3}.rest-reference svg{display:block;width:100%;height:68px}.storage-warning{font-size:11px;background:#eee5d6;padding:12px;line-height:1.7}.skip-link{position:absolute;top:-60px;left:20px;background:var(--green);color:#fff;padding:12px;z-index:8}.skip-link:focus{top:10px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.course-footer{font-size:10px;line-height:1.8;color:var(--muted);margin-top:35px}.course-finish{padding:25px;background:#e4ead7;margin-top:25px}.course-finish h2{font-size:35px;margin:12px 0}.course-finish p{line-height:1.9;font-size:13px}.course-finish .button{margin-top:18px}
@media(min-width:1400px){.lesson-main{padding-right:100px;padding-left:85px}}@media(max-width:1050px){.course-page{--sidebar:230px}.course-sidebar{padding:28px 20px}.lesson-main{padding:38px 30px}.course-title{font-size:30px}.lesson-nav-link{font-size:10px}}@media(max-width:760px){.course-header{height:75px}.course-header-label{display:none}.back-home{margin-right:0;font-size:11px}.course-layout{display:block}.course-sidebar{display:none}.lesson-main{padding:22px 5% 45px}.mobile-course-nav{display:flex;align-items:center;gap:12px;padding:10px 0 20px;margin-bottom:18px;border-bottom:1px solid var(--line)}.mobile-course-nav label{font-size:9px;white-space:nowrap;color:var(--muted)}.mobile-course-nav select{min-width:0;flex:1;border:1px solid #cbd3c1;background:var(--paper);color:var(--ink);padding:10px;font-size:12px;border-radius:3px;max-width:100%}.lesson-main h1{font-size:52px;letter-spacing:-1.5px}.lesson-lead{font-size:14px}.lesson-breadcrumb{font-size:8px;margin-bottom:20px}.lesson-goal{display:block;margin-top:22px}.lesson-goal>span{display:block;margin-bottom:7px}.reading-block h2{font-size:29px}.reading-block p{font-size:13px}.lesson-lab{margin:28px 0;padding:17px}.lab-badge{font-size:7px}.audio-controls{gap:12px}.tempo-control{flex-wrap:wrap;gap:8px}.tempo-control input{width:115px}.takeaway p{font-size:25px}.overview-stats{gap:20px;font-size:8px}.overview-time{font-size:8px}.overview-lesson{gap:10px}.overview-lesson-title{font-size:12px}.course-piano{height:145px}.course-piano .black-key{height:85px;font-size:7px}.rest-reference{gap:3px}.rest-reference>div{font-size:8px}.question legend{font-size:13px}.lesson-pagination a{font-size:11px}.course-header .brand{font-size:32px}.notation-frame svg{min-width:500px}.score-label{font-size:9px}.lab-tabs button{font-size:10px;padding:9px 10px}.explorer-notes{gap:5px}.explorer-notes button{padding:9px 10px}.overview-art{padding:20px}.overview-art p{font-size:24px}}