:root{--paper:#f7f8f4;--ink:#202e2a;--muted:#69756f;--green:#285846;--lime:#e3edbb;--border:#dfe4da;--mono:Menlo,Monaco,Consolas,monospace}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:14px;line-height:1.6}button,a,textarea,summary{ -webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}button:disabled{cursor:not-allowed}button:focus-visible,a:focus-visible,summary:focus-visible,textarea:focus-visible{outline:3px solid #b38c34;outline-offset:3px}button{border:0}button:hover{filter:brightness(.96)}[hidden]{display:none!important}.sidebar{position:fixed;inset:0 auto 0 0;width:246px;padding:27px 20px 18px;border-right:1px solid var(--border);background:#eef1e8;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--ink);font-weight:760;font-size:18px;line-height:1.2}.brandmark{display:grid;place-items:center;width:40px;height:42px;background:var(--green);color:var(--lime);border-radius:12px;font:700 18px var(--mono)}.brandlight{display:block;font-size:12px;font-weight:500;margin-top:4px;letter-spacing:.3px}.course-label{font-size:10px;letter-spacing:1.7px;color:var(--muted);margin:34px 0 13px}.progress-label{display:flex;justify-content:space-between;font-size:11px}.progress-label strong{font-weight:600}.progress-label>span{color:var(--muted)}progress{appearance:none;width:100%;height:5px;margin:10px 0 17px;border:0;border-radius:8px;background:#dce2d5}progress::-webkit-progress-bar{background:#dce2d5;border-radius:8px}progress::-webkit-progress-value{background:var(--green);border-radius:8px}progress::-moz-progress-bar{background:var(--green);border-radius:8px}nav{overflow:auto;min-height:0;flex:1;margin:0 -9px;padding:0 9px}.nav-group{font-size:10px;font-weight:700;letter-spacing:1.2px;text-transform:uppercase;color:var(--muted);margin:15px 0 7px 8px}.nav-item{display:flex;align-items:center;gap:9px;width:100%;padding:8px 9px;margin:2px 0;text-align:left;background:transparent;border-radius:8px;color:#45534c;font-size:11px;line-height:1.3;min-height:35px}.nav-item.current{background:var(--green);color:white}.nav-item:disabled{color:#929b91}.nav-number{font:10px var(--mono);display:grid;place-items:center;flex:0 0 22px;height:22px;border:1px solid #d4dccd;border-radius:50%}.current .nav-number{border-color:#779681;color:var(--lime)}.done .nav-number{background:#dce7c9;color:var(--green)}.sidebar-bottom{padding:16px 4px 0;font-size:10px;color:#657361}.sidebar-bottom small{display:block;margin-top:4px;font-size:10px}.dot,.live-dot{display:inline-block;width:6px;height:6px;background:#51805b;border-radius:50%;margin-right:5px}.sidebar-bottom .text-button{margin-top:8px;font-size:10px}main{margin-left:246px;max-width:1600px;padding:0 38px 22px}.topbar{height:63px;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;font-size:10px;letter-spacing:1px;color:var(--muted)}.separator{margin:0 12px;color:#adb4aa}.offline{font-size:11px;letter-spacing:0}.lesson-heading{display:flex;justify-content:space-between;align-items:center;margin:28px 0 23px}.eyebrow,.step{font-size:10px;font-weight:700;letter-spacing:1.7px;color:var(--green)}h1{font-size:32px;line-height:1.2;letter-spacing:-1px;margin:9px 0}h2{font-size:20px;line-height:1.3;letter-spacing:-.4px;margin:7px 0 12px}.source{font-size:11px;color:var(--muted);margin:0}.lesson-icon{background:var(--lime);width:57px;height:57px;border-radius:18px;display:grid;place-items:center;font:21px var(--mono);color:var(--green)}.learning-card{display:grid;grid-template-columns:1.05fr 1fr;border:1px solid var(--border);background:white;border-radius:14px;overflow:hidden}.explanation{padding:24px}.explanation p{margin:0;font-size:13px;line-height:1.85;color:#536159}.example{background:#f0f3eb;padding:21px 24px;border-left:1px solid var(--border);min-width:0}.code-caption{display:flex;justify-content:space-between;font-size:9px;letter-spacing:1.4px;color:#6e7e6e;margin-bottom:12px}.example pre{font:12px/1.7 var(--mono);margin:0;overflow:auto;max-height:225px;color:#284f42;white-space:pre-wrap;overflow-wrap:anywhere}.practice{margin-top:29px}.section-head{display:flex;justify-content:space-between;align-items:center}.section-head h2{margin-bottom:0}.practice>p{color:#526057;line-height:1.7;margin:12px 0;font-size:13px}.subtle{background:white;border:1px solid var(--border);border-radius:7px;padding:8px 12px;font-size:11px;color:#43584b}.hint{background:#f0ebd6;padding:13px 17px;border-radius:8px;color:#66562b!important}.text-button{background:none;color:var(--muted);padding:0;font-size:10px;text-decoration:underline;text-underline-offset:3px}details{font-size:12px}summary{cursor:pointer;color:#536257}#requirements{margin:14px 0}#requirements summary{font-size:11px}#ruleCount{color:#8a9489;margin-left:7px}#checklist{list-style:none;padding:8px 0;margin:0;display:grid;grid-template-columns:1fr 1fr;gap:7px 22px}#checklist li{font-size:11px;color:#68756b;display:flex;gap:8px}#checklist li::before{content:'○';color:#8b9788}#checklist li.passed{color:#285846}#checklist li.passed::before{content:'✓';font-weight:bold}.workspace{display:grid;grid-template-columns:1fr 1fr;border:1px solid #d5ddd1;border-radius:12px;overflow:hidden;background:white}.editor-pane,.preview-pane{min-width:0}.editor-pane{background:#202e29;color:#dce6de}.pane-head{height:40px;padding:0 14px;display:flex;align-items:center;justify-content:space-between;font-size:10px;gap:10px;border-bottom:1px solid #ffffff15}.editor-pane .text-button{color:#bccdbd;font-size:10px}.file-dot{display:inline-block;background:#c2d889;width:6px;height:6px;border-radius:2px;margin-right:7px}.preview-pane .pane-head{background:#fff;border-bottom:1px solid #e8ebe4;color:#5e6b61}.preview-pane{border-left:1px solid var(--border)}#previewTitle{max-width:50%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#889385;font-size:9px}.editor-wrap{height:280px;display:flex;padding:16px 0 10px}.editor-wrap pre{font:12px/1.8 var(--mono);margin:0;padding:0 12px 0 15px;min-width:40px;text-align:right;color:#718577;overflow:hidden;user-select:none}textarea#editor{resize:none;min-width:0;flex:1;background:transparent;border:0;outline-offset:-3px;color:#e0eddb;font:12px/1.8 var(--mono);tab-size:2;padding:0 15px 0 0;white-space:pre;overflow:auto}iframe{display:block;width:100%;height:280px;border:0;background:white}.editor-footer,.preview-footer{height:31px;font-size:8px;padding:8px 12px;color:#91a494;border-top:1px solid #ffffff12;display:flex;justify-content:space-between;gap:10px}.preview-footer{color:#8b9588;border-color:#edf0e9;font-size:9px}.actions{display:flex;justify-content:space-between;align-items:center;margin-top:17px;gap:15px}.actions>span{font-size:11px;color:var(--muted)}.primary{border-radius:8px;background:var(--green);color:white;padding:12px 20px;font-size:12px;font-weight:600}.primary span{margin-left:16px;color:var(--lime)}#feedback{margin-top:16px;border:1px solid #e4cc9d;border-radius:9px;background:#fbf4e6;padding:14px 18px;color:#795729;font-size:12px}#feedback.success{background:#edf4e5;border-color:#c5dab5;color:#315633}#feedback ul{margin:8px 0 0;padding-left:19px}#completion{background:var(--lime);padding:30px;border-radius:14px;margin-top:25px}#completion p{max-width:620px}footer{margin:35px 0 0;padding-top:16px;border-top:1px solid var(--border);display:flex;justify-content:space-between;gap:20px;color:#88917f;font-size:10px}footer details{font-size:10px;max-width:550px}footer details[open]{flex:1}dialog{border:1px solid var(--border);border-radius:16px;padding:28px;max-width:460px;color:var(--ink)}dialog::backdrop{background:#14251d66}.dialog-actions{display:flex;gap:10px;justify-content:flex-end;margin-top:24px}.skip{position:fixed;top:-100px;z-index:10;background:white;padding:10px}.skip:focus{top:8px;left:260px}@media(min-width:1500px){main{padding-left:60px;padding-right:60px}.editor-wrap,iframe{height:330px}}@media(max-width:1100px){.sidebar{width:220px;padding-left:15px;padding-right:15px}main{margin-left:220px;padding:0 24px 20px}h1{font-size:28px}.explanation,.example{padding:20px}.editor-footer span:last-child{display:none}}@media(max-width:760px){.sidebar{position:relative;width:auto;padding:18px}.brandlight{display:inline;margin-left:8px}.course-label,.sidebar-bottom{display:none}.progress-label{margin-top:18px}nav{display:flex;gap:5px;max-height:80px;overflow:auto}.nav-group{display:none}.nav-item{min-width:175px}.sidebar progress{margin-bottom:12px}main{margin:0;padding:0 18px 20px}.topbar{height:47px}.offline{display:none}.learning-card,.workspace{grid-template-columns:1fr}.example{border-left:0;border-top:1px solid var(--border)}.preview-pane{border:0;border-top:1px solid var(--border)}#checklist{grid-template-columns:1fr}.actions{align-items:flex-start}.actions>span{max-width:40%}.lesson-icon{display:none}h1{font-size:26px}.source{font-size:10px}footer{flex-direction:column}.skip:focus{left:10px}}

/* Gut sichtbare Schreibmarke auf dem dunklen Editorhintergrund. */
textarea#editor{caret-color:#e3edbb;cursor:text;color-scheme:dark}

/* Klar gegliederte Arbeitsfläche, Touch-Bedienung und sichtbare Schreibmarke. */
button:focus-visible,a:focus-visible,summary:focus-visible,textarea:focus-visible{outline-color:#7b9b82}
#navToggle{display:none}
.learning-card{grid-template-columns:1fr 1fr}.explanation p,.practice>p{font-size:14px}
.hint{background:#eaf0e4;color:#355543!important;border-left:3px solid #88a379}
#feedback{background:#f0f3eb;border-color:#b7c8af;color:#354c3c}
.workspace{gap:18px;border:0;background:transparent;overflow:visible;align-items:start}
.editor-pane,.preview-pane{border:1px solid #d5ddd1;border-radius:12px;overflow:hidden}
.preview-pane{background:white}.pane-head{height:54px}.editor-wrap{position:relative;height:340px;overflow:hidden;padding-top:18px}
textarea#editor{font-size:16px;line-height:1.7;caret-color:#e3edbb;-webkit-text-fill-color:#e0eddb;cursor:text}
.editor-wrap pre{font-size:16px;line-height:1.7}
#writingCaret{position:absolute;width:2px;background:#e3edbb;pointer-events:none;z-index:2;border-radius:1px;animation:caretBlink 1.1s step-end infinite}
@keyframes caretBlink{0%,55%{opacity:1}56%,100%{opacity:0}}
.editor-pane:focus-within{box-shadow:0 0 0 3px #b8cda3;border-color:#658361}
textarea#editor:focus-visible{outline:none}
.preview-tabs{display:flex;gap:4px}.preview-tabs button{background:transparent;color:#61705f;font-size:11px;min-height:38px;padding:8px 10px;border-radius:7px}
.preview-tabs button[aria-pressed="true"]{background:#e5edda;color:#274c37;font-weight:650}
iframe{height:340px}.editor-footer{height:auto;min-height:34px;flex-wrap:wrap}.editor-footer span:last-child{font-size:9px}
.preview-footer{height:auto;min-height:34px}.actions{margin-bottom:25px}.primary,.subtle{min-height:44px}
#previewTitle{display:none}summary{min-height:36px;padding:6px 0}.nav-item{min-height:40px}
@media(max-width:1199px){.sidebar{width:210px}main{margin-left:210px;padding-left:24px;padding-right:24px}.workspace{grid-template-columns:1fr}.editor-wrap{height:320px}iframe{height:260px}.learning-card{grid-template-columns:1fr 1fr}.editor-footer span:last-child{display:block}.preview-pane .pane-head{height:52px}}
@media(max-width:900px){.sidebar{position:relative;width:100%;padding:18px 24px;display:grid;grid-template-columns:1fr auto;gap:8px 20px}.brand{grid-column:1}.brandlight{display:block;margin-left:0}#navToggle{display:block;grid-column:2;grid-row:1;align-self:center}.course-label{display:none}.progress-label{grid-column:1/-1;margin-top:6px}progress{grid-column:1/-1;margin:0;height:5px}nav{display:none;grid-column:1/-1;max-height:320px;margin:0;overflow:auto}.sidebar.nav-open nav{display:block}.sidebar-bottom{display:none;grid-column:1/-1}.sidebar.nav-open .sidebar-bottom{display:block}.nav-item{width:100%;font-size:13px;min-height:44px}.nav-group{display:block}.sidebar-bottom .text-button{min-height:44px}.sidebar-bottom small{font-size:12px}main{margin:0;padding:0 24px 24px}.topbar{height:48px}.lesson-heading{margin-top:23px}.workspace{grid-template-columns:1fr 1fr;gap:14px}.editor-wrap,iframe{height:330px}.editor-footer span:last-child{display:none}.pane-head{padding:0 10px}.learning-card{grid-template-columns:1fr 1fr}h1{font-size:29px}.lesson-icon{display:grid}.offline{display:none}.skip:focus{left:12px}}
@media(max-width:699px){.sidebar{padding:16px}.brand{font-size:17px}.brandlight{font-size:11px}.workspace,.learning-card{grid-template-columns:1fr}.example{border-left:0;border-top:1px solid var(--border)}main{padding:0 16px 20px}.lesson-icon{display:none}h1{font-size:27px}.explanation,.example{padding:19px}.practice{margin-top:24px}.section-head{gap:12px}.section-head h2{font-size:21px}.section-head .subtle{white-space:nowrap}.editor-wrap{height:300px}iframe{height:240px}.preview-tabs button{font-size:12px}.actions{flex-direction:column;align-items:stretch;gap:12px}.actions>span{max-width:none}.actions>div,.actions .primary{width:100%}.editor-pane .text-button{min-height:44px}#checklist{grid-template-columns:1fr}#checklist li{font-size:13px}.practice>p{font-size:15px}.source{font-size:11px}.preview-footer{font-size:10px}dialog{max-width:calc(100% - 28px)}.dialog-actions{flex-wrap:wrap}}
@media(prefers-reduced-motion:reduce){#writingCaret{animation:none}*{scroll-behavior:auto!important}}

/* Anfängerübungen: unveränderlicher Code und klar benannte Lücken. */
.easy-steps{padding-left:24px;font-size:16px;line-height:1.9}.easy-steps strong{color:#285846}.locked-note{color:#47624b;font-size:13px}.guided-code{background:#202e29;color:#dfe9dc;padding:22px;border-radius:12px;font:15px/2.3 var(--mono);white-space:pre-wrap;overflow-wrap:anywhere;max-height:470px;overflow:auto;margin-bottom:18px}.guided-code input{font:16px var(--mono);color:#183c28;background:#f1f7e9;border:2px solid #a6bf8a;border-radius:5px;padding:6px 8px;min-height:40px;max-width:100%;caret-color:#173c26}.guided-code input:focus{outline:3px solid #d3e6b7;outline-offset:2px}.guided-code input.wrong{border-color:#537357}.workspace{grid-template-columns:1fr!important}.editor-pane{display:none}.preview-pane iframe{height:220px}.example pre{font-size:14px}.explanation p{font-size:16px;line-height:1.8}.source{display:none}.learning-card{grid-template-columns:1fr!important}.example{border-left:0;border-top:1px solid var(--border)}@media(max-width:699px){.guided-code{padding:14px;font-size:13px}.easy-steps{font-size:15px}}

.skip:not(:focus){clip-path:inset(50%);width:1px;height:1px;overflow:hidden}

.guided-code{padding:18px 12px;white-space:normal}.guided-row{display:grid;grid-template-columns:36px minmax(0,1fr);gap:10px;align-items:start}.guided-number{font:13px/28px var(--mono);color:#9aaa9d;white-space:pre;text-align:right;user-select:none;padding-top:5px}.guided-content{white-space:pre-wrap;overflow-wrap:anywhere;min-height:38px;line-height:28px}.guided-content textarea{display:block;width:100%;resize:vertical;min-height:66px;max-height:350px;font:16px/28px var(--mono);padding:4px 8px;background:#f1f7e9;color:#173b28;border:2px solid #a6bf8a;border-radius:6px;caret-color:#173b28;tab-size:2}.guided-content textarea:focus{outline:3px solid #c8dda9;outline-offset:1px}.hint{white-space:pre-wrap;font-family:var(--mono)}@media(max-width:699px){.guided-row{grid-template-columns:25px minmax(0,1fr);gap:6px}.guided-code{padding:14px 7px}}