:root{font-family:"Segoe UI",Arial,sans-serif;color:#172b30;background:#f6f7f9;color-scheme:light}*{box-sizing:border-box}body{margin:0}button{font:inherit;cursor:default}button:focus-visible{outline:3px solid #63b9a5;outline-offset:4px}.sidebar{position:fixed;inset:0 auto 0 0;width:250px;background:#fff;border-right:1px solid #e3e8e7;padding:36px 22px;display:flex;flex-direction:column}.brand{display:flex;gap:12px;align-items:center;padding:0 12px;font-weight:650;font-size:18px;letter-spacing:-.5px}.brand small{display:block;font-size:11px;letter-spacing:1.6px;color:#7c8b8d;font-weight:500;margin-top:4px}.logo{height:40px;width:40px;background:#0f766e;border-radius:13px;color:white;display:grid;place-items:center;font-size:26px}.nav{margin-top:58px;display:grid;gap:9px}.nav button{border:0;background:none;text-align:left;padding:14px 16px;color:#657477;border-radius:10px;font-size:14px;display:flex;align-items:center;gap:13px}.nav .active{background:#eaf3ef;color:#126d61;font-weight:650}.ico{font-size:20px;width:22px;display:inline-block;text-align:center}.sidebar-note{margin-top:auto;padding:20px 12px;color:#82908e;font-size:12px;line-height:1.8}.profile{display:flex;gap:11px;border-top:1px solid #edf0ef;padding:22px 10px 0;align-items:center;font-size:13px}.avatar{display:grid;place-items:center;width:36px;height:36px;border-radius:50%;background:#e9eee8;color:#476253;font-weight:600}.profile small{display:block;color:#84908e;margin-top:4px}main{margin-left:250px;padding:0 56px 36px;max-width:1590px}.topbar{height:88px;border-bottom:1px solid #e1e7e5;display:flex;align-items:center;justify-content:space-between;font-size:12px;color:#7a8887}.preview{border:1px solid #dce4df;padding:6px 11px;border-radius:20px;font-size:11px}.content{max-width:1060px;margin:48px auto 0}.eyebrow{text-transform:uppercase;font-size:11px;letter-spacing:1.7px;color:#628276;font-weight:650}h1{font-size:38px;letter-spacing:-1.5px;font-weight:600;margin:12px 0}.lead{font-size:15px;line-height:1.7;color:#75827f;margin:0}.session{display:flex;justify-content:space-between;align-items:center;margin:32px 0 24px;gap:18px}.mode{background:#e9eeeb;padding:5px;border-radius:10px;display:flex;gap:4px}.mode button{border:0;padding:10px 20px;border-radius:7px;background:transparent;color:#72817b;font-size:13px}.mode .selected{background:#fff;color:#1e6557;box-shadow:0 1px 4px #172b300c;font-weight:600}.sound{font-size:12px;color:#75827f;display:flex;align-items:center;gap:10px}.toggle{width:30px;height:18px;background:#dce3df;border-radius:10px;display:inline-flex;align-items:center;padding:3px}.toggle:before{content:"";width:12px;height:12px;background:white;border-radius:50%}.lesson{display:grid;grid-template-columns:1.15fr 1fr;background:white;border:1px solid #dfe7e2;border-radius:18px;overflow:hidden}.lesson-text{padding:36px}.tag{font-size:11px;color:#38735e;background:#eef5ef;display:inline-block;border-radius:5px;padding:6px 9px}.lesson h2{font-size:29px;letter-spacing:-.8px;font-weight:600;line-height:1.25;margin:20px 0 13px}.lesson p{font-size:14px;line-height:1.8;color:#75827f;margin:0;max-width:340px}.meta{display:flex;gap:16px;color:#82908b;font-size:11px;margin:21px 0 28px}.primary{border:0;border-radius:9px;padding:14px 22px;background:#0f766e;color:white;font-size:13px;font-weight:600;display:inline-flex;gap:36px;align-items:center}.resume{font-size:11px!important;margin-top:13px!important;color:#8a9690!important}.fret-panel{margin:20px;background:#f0f5f1;border-radius:12px;display:flex;flex-direction:column;justify-content:center;padding:27px}.fret-caption{font-size:11px;color:#6d897a;display:flex;justify-content:space-between;margin-bottom:15px}.fret-panel svg{width:100%;height:auto;display:block}.fret-note{font-size:11px;color:#84998c;text-align:center;margin-top:12px}.lower{display:grid;grid-template-columns:1.25fr 1fr;gap:32px;margin-top:36px}.section-title{font-size:15px;font-weight:600;margin:0 0 18px;letter-spacing:-.2px}.path{border-left:1px solid #d8e1db;margin-left:8px;padding-left:24px}.step{position:relative;padding:0 0 23px;font-size:13px}.step:before{content:"";position:absolute;left:-30px;top:2px;width:10px;height:10px;border-radius:50%;background:#e3e9e4;border:2px solid #f6f7f9}.step.current:before{background:#0f766e;box-shadow:0 0 0 3px #d9ebe0}.step small{display:block;color:#8a9790;font-size:11px;margin-top:6px}.step.future{color:#8a9691}.review{background:#fff;border:1px solid #e1e7e2;border-radius:12px;padding:23px}.review-label{font-size:10px;text-transform:uppercase;letter-spacing:1.3px;color:#8b9b8f}.review h3{font-size:17px;font-weight:600;margin:13px 0 9px}.review p{font-size:12px;line-height:1.8;color:#839087;margin:0}.text-button{border:0;background:none;padding:0;margin-top:20px;color:#267060;font-size:12px}.footer{border-top:1px solid #e2e8e3;margin-top:32px;padding-top:19px;display:flex;justify-content:space-between;color:#98a29d;font-size:10px}
@media(min-width:1500px){.content{margin-top:65px}.lesson-text{padding:45px}.lesson h2{font-size:34px}}@media(max-width:1100px){.sidebar{width:210px;padding:30px 14px}main{margin-left:210px;padding:0 28px 28px}.lesson-text{padding:28px}.fret-panel{padding:18px;margin:14px}.brand{font-size:16px}.lesson h2{font-size:25px}}@media(max-width:760px){.sidebar{position:relative;width:100%;padding:20px;border-right:0;border-bottom:1px solid #e1e7e5;display:block}.brand small,.sidebar-note,.profile{display:none}.brand{padding:0}.nav{margin-top:20px;display:flex;gap:7px}.nav button{padding:9px 12px;font-size:12px}.ico{font-size:16px;width:16px}main{margin:0;padding:0 20px 25px}.topbar{height:55px}.content{margin-top:28px}h1{font-size:31px}.lead{font-size:14px}.session{align-items:flex-start;flex-direction:column;gap:14px;margin-top:24px}.lesson{grid-template-columns:1fr}.lesson-text{padding:25px}.lesson h2{font-size:28px}.fret-panel{margin:0 16px 16px;padding:20px}.fret-panel svg{max-height:195px}.lower{grid-template-columns:1fr;gap:14px;margin-top:28px}.footer{font-size:10px;gap:20px;line-height:1.6}.primary{width:100%;justify-content:space-between}.meta{margin-bottom:22px}}

a.primary{text-decoration:none;cursor:pointer}a:focus-visible,summary:focus-visible{outline:3px solid #0f766e;outline-offset:4px}.back{color:#256b60;text-decoration:none;font-size:13px}.lesson-page{max-width:900px}.lesson-page h2{font-size:24px;letter-spacing:-.5px;margin:0 0 16px}.block{background:white;border:1px solid #dfe7e2;border-radius:16px;padding:30px;margin-top:24px}.block p,.block li{font-size:16px;line-height:1.8;color:#4f625b}.block p:last-child{margin-bottom:0}.diagram{width:100%;height:auto;display:block;max-height:440px}.parts{display:grid;grid-template-columns:1fr 1fr;gap:0 28px}.parts dt{font-weight:600;margin-top:18px}.parts dd{margin:5px 0 0;color:#4f625b;line-height:1.7;font-size:15px}.callout{padding:18px 20px;background:#edf5ef;border-radius:10px;color:#365e4e;line-height:1.8;margin-top:22px}.strings{width:100%;border-collapse:collapse;margin-top:20px}.strings th,.strings td{text-align:left;padding:12px;border-bottom:1px solid #e1e7e2;font-size:15px}.strings th{font-size:12px;color:#536a5e}summary{cursor:pointer;color:#1d6554;font-weight:600;padding:12px 0}details{border-top:1px solid #e1e7e2;margin-top:20px}.lesson-end{margin:28px 0}.lesson-page .lead{color:#53675e}.lesson-page .meta{color:#53675e}@media(max-width:760px){.block{padding:22px}.parts{grid-template-columns:1fr}.strings th,.strings td{padding:10px 6px;font-size:13px}.diagram{max-height:none}}[hidden]{display:none!important}.learning-controls{background:#fff;border:1px solid #d9e5dd;border-radius:14px;padding:20px;margin:26px 0;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px}.learning-controls .mode{flex-wrap:wrap}.mode button{cursor:pointer}.mode button[aria-pressed="true"]{background:#0f766e;color:#fff;box-shadow:none}.mode-explanation{flex-basis:100%;font-size:15px;line-height:1.7;color:#365e4e;border-top:1px solid #e1e7e2;padding-top:14px}.sound-setting{display:flex;align-items:center;gap:10px;font-size:12px;color:#53675e}.sound-setting select{font:inherit;padding:9px;border:1px solid #bdcfc3;border-radius:7px;background:#fff;color:#284f40}.save-notice{flex-basis:100%;font-size:12px;line-height:1.7;color:#586d62;margin:0}.save-notice:empty{display:none}.requirement{display:block;font-size:12px;font-weight:650;color:#0c625b;margin-bottom:16px}.exercise{border:2px solid #a4c6b6}.exercise fieldset{border:0;padding:0;margin:22px 0}.exercise legend{font-weight:600;line-height:1.6;margin-bottom:10px}.option{display:flex;align-items:flex-start;gap:10px;padding:12px;border:1px solid #dce5df;border-radius:9px;margin:8px 0;line-height:1.6;cursor:pointer;color:#365447}.option input{margin-top:6px;accent-color:#0f766e;flex-shrink:0}.exercise button{cursor:pointer}.secondary{background:#fff;color:#0f766e;border:1px solid #91b5a5;border-radius:8px;padding:12px 16px;margin:8px 8px 0 0}.feedback{padding:16px;border-radius:9px;background:#edf5ef;margin-top:20px;line-height:1.7}.separate-progress{margin-top:28px;border-top:1px solid #dfe7e2;padding-top:16px}.separate-progress p{margin:8px 0;font-size:14px}.separate-progress small{color:#53675e;line-height:1.7;display:block}a.text-button{display:inline-block}@media(max-width:760px){.learning-controls{padding:16px}.learning-controls .mode{width:100%}.mode button{flex:1;padding:12px 15px}.sound-setting{flex-wrap:wrap}}
/* Sound and profile controls, version 20261102-sql1 */
.learning-controls{gap:16px 24px}.learning-controls>.mode{flex:0 1 auto}.sound-setting{margin-left:auto}.sound-switch{display:inline-flex;align-items:center;gap:10px;background:#fff;border:1px solid #b9cec1;border-radius:9px;padding:9px 12px;color:#284f40;font-size:13px;cursor:pointer;white-space:nowrap}.switch-track{width:36px;height:22px;border-radius:20px;background:#bac6c0;display:inline-flex;align-items:center;padding:3px;flex-shrink:0}.switch-thumb{width:16px;height:16px;border-radius:50%;background:white;display:block}.sound-switch[aria-checked="true"] .switch-track{background:#0f766e}.sound-switch[aria-checked="true"] .switch-thumb{transform:translateX(14px)}.profile-bar{display:flex;justify-content:space-between;align-items:center;gap:16px;font-size:13px;color:#4f625b;margin-top:24px}.profile-bar .text-button{margin:0;cursor:pointer}dialog{border:1px solid #ccdbd2;border-radius:18px;max-width:560px;width:calc(100% - 32px);max-height:90svh;overflow:auto;padding:28px;color:#172b30}dialog::backdrop{background:#172b3080}dialog p{line-height:1.7;font-size:14px;color:#4f625b}dialog h2{margin-top:0}dialog form{display:grid;gap:12px;margin:24px 0 12px}dialog input{font:inherit;padding:12px;border:1px solid #9fb9aa;border-radius:8px;width:100%}.profile-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:10px;max-height:220px;overflow:auto}.profile-choice{font:inherit;word-break:break-word;text-align:left;background:#f0f6f2;border:1px solid #c2d8c9;border-radius:8px;padding:14px;color:#245344;cursor:pointer}.sound-block{background:#fff5df;border:1px solid #d9c6a0;padding:18px;border-radius:10px;color:#624e27;line-height:1.8}button:disabled{opacity:.6;cursor:wait}@media(max-width:760px){.sound-setting{margin-left:0;width:100%;justify-content:space-between}.profile-bar{flex-wrap:wrap}.learning-controls>.mode{flex-basis:100%}.sound-switch{min-height:44px}dialog{padding:22px}}
.nav a.implementation-link{display:flex;align-items:center;padding:14px 16px;color:#49695a;text-decoration:none;border-radius:10px;font-size:13px}.nav a.implementation-link:hover{background:#edf4ef}@media(max-width:760px){.nav{flex-wrap:wrap}.nav a.implementation-link{padding:9px 12px;font-size:12px}}
.silence-badge{margin-left:auto;background:#edf5ef;border:1px solid #c9ddcf;color:#36644d;padding:9px 13px;border-radius:20px;font-size:12px;white-space:nowrap}.lesson-home{position:sticky;top:0;z-index:20;display:flex;justify-content:space-between;align-items:center;gap:16px;padding:14px 0;background:#f6f7f9f5;border-bottom:1px solid #dbe5de;backdrop-filter:blur(8px)}.lesson-home a{font-size:14px;font-weight:650;color:#0f766e;text-decoration:none;padding:8px 0}.lesson-home span{font-size:12px;color:#5d7566}.reflection{border-left:3px solid #79a58b;background:#edf4ef;border-radius:0 14px 14px 0;padding:28px 30px;margin-top:30px}.reflection h2{font-size:23px;font-weight:500;line-height:1.5;letter-spacing:-.5px;margin:13px 0}.reflection h3{font-size:14px;font-weight:650;margin:22px 0 8px}.reflection p{font-size:15px;line-height:1.9;color:#456353;margin:8px 0}.reflection .reflection-note{font-size:12px;color:#5d7566}.board-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:7px;margin-top:12px}.board-grid .option{margin:0;min-height:52px;font-size:12px;padding:8px;align-items:center;line-height:1.5}.board-grid .option:has(input:checked){border-color:#0f766e;background:#e6f4eb}.board-grid input{margin:0}.board-grid .option:has(input:focus-visible){outline:3px solid #0f766e;outline-offset:2px}@media(max-width:760px){.lesson-home{padding:8px 0}.lesson-home a{min-height:44px;display:flex;align-items:center}.reflection{padding:22px}.reflection h2{font-size:21px}.board-grid{gap:5px}.board-grid .option{padding:7px 4px;font-size:10px;gap:4px}.silence-badge{margin-left:0}}