:root{--navy:#15324a;--blue:#2d6da3;--blue2:#eaf4fb;--brick:#c6542c;--bg:#f2f6f9;--paper:#fff;--text:#172432;--muted:#66798a;--line:#d6e1e8;--good:#e7f6ec;--goodb:#3f8d5b;--bad:#fdecea;--badb:#c45248;--warn:#fff7df;--warnb:#e4c45c;--shadow:0 14px 40px rgba(20,48,70,.08)}
*{box-sizing:border-box}html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}body{margin:0;background:linear-gradient(180deg,#eaf1f6 0,#f8fafb 430px,#f2f6f9 100%);font-family:Inter,system-ui,-apple-system,"Segoe UI",Arial,sans-serif;color:var(--text)}button,input,select,textarea{font:inherit}.topbar{background:var(--navy);color:#fff}.topbar-inner{max-width:1180px;margin:auto;padding:9px 18px;display:flex;justify-content:space-between;gap:12px;align-items:center}.topbar a{color:#fff;text-decoration:none;font-weight:850}.topbar span{font-size:13px;opacity:.88}.hero{padding:24px 18px 0}.hero-inner{max-width:1140px;margin:auto;border:1px solid var(--line);border-radius:26px;background:linear-gradient(135deg,#fff 0,#f5f9fc 100%);box-shadow:var(--shadow);padding:30px}.eyebrow{text-transform:uppercase;letter-spacing:.095em;color:var(--brick);font-size:12px;font-weight:950}.hero h1{font-size:clamp(34px,5vw,54px);line-height:1.03;color:var(--navy);margin:7px 0 10px}.hero p{max-width:920px;margin:0;color:var(--muted);font-size:17px;line-height:1.55}.goal-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin-top:20px}.goal{background:#fff;border:1px solid var(--line);border-radius:14px;padding:12px}.goal b{display:block;color:var(--navy);font-size:14px;margin-bottom:3px}.goal span{font-size:12px;color:var(--muted);line-height:1.35}.page{max-width:1140px;margin:auto;padding:18px 18px 64px}.start-card,.section,.summary,.video-hub{background:#fff;border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);padding:22px;margin-bottom:14px}.start-card{display:grid;grid-template-columns:1.35fr .65fr;gap:18px}.start-card h2,.video-hub h2,.summary h2{color:var(--navy);margin:0 0 8px}.start-card p{color:var(--muted);line-height:1.55}.rules{background:#f7fafc;border:1px solid var(--line);border-radius:14px;padding:14px}.rules b{color:var(--navy)}.rules ul{margin:8px 0 0 20px;padding:0;color:#536a7b;line-height:1.55}.video-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:9px}.video-link{display:block;text-decoration:none;border:1px solid var(--line);border-radius:13px;padding:11px;background:#fbfdfe;color:var(--navy)}.video-link:hover{border-color:#8ab0cb;background:#f2f8fc}.video-link b{display:block;font-size:13px}.video-link span{display:block;margin-top:4px;color:var(--muted);font-size:11px;line-height:1.35}.progressbar-wrap{position:sticky;top:0;z-index:30;margin:0 0 14px;background:rgba(255,255,255,.96);backdrop-filter:blur(12px);border:1px solid var(--line);border-radius:15px;box-shadow:var(--shadow);padding:10px 13px;display:flex;align-items:center;gap:12px}.progress-track{height:10px;background:#e8eef2;border-radius:99px;overflow:hidden;flex:1}.progress-track span{display:block;height:100%;width:0;background:linear-gradient(90deg,#2d6da3,#4d9b72);transition:width .25s}.progress-label{font-size:13px;font-weight:900;color:var(--navy);min-width:130px;text-align:right}.section-head{display:flex;gap:11px;align-items:flex-start;margin-bottom:13px}.section-num{display:grid;place-items:center;min-width:40px;height:40px;border-radius:20px;background:var(--navy);color:#fff;font-weight:950}.section-head h2{margin:0;color:var(--navy);font-size:23px}.section-head p{margin:3px 0 0;color:var(--muted);font-size:13px;line-height:1.4}.subhead{font-size:15px;color:#31566f;margin:16px 0 8px}.task-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.task-grid.three{grid-template-columns:repeat(3,1fr)}.task{border:1px solid var(--line);border-radius:14px;background:#fbfdfe;padding:12px}.task.correct{background:var(--good);border-color:var(--goodb)}.task.wrong{background:var(--bad);border-color:var(--badb)}.task-title{font-weight:850;color:#233f54;line-height:1.4;margin-bottom:7px}.eq{font-family:"Cambria Math",Cambria,Georgia,serif;font-size:20px;font-weight:700;color:#112f47;letter-spacing:.01em}.answer-row{display:flex;align-items:center;gap:7px;flex-wrap:wrap;margin-top:7px}.answer-row label{font-size:13px;font-weight:800;color:#50687a}.answer{width:95px;min-height:42px;border:2px solid #b7c9d6;border-radius:10px;padding:7px 9px;text-align:center;font-size:17px;font-weight:850;background:#fff}.answer.wide{width:min(100%,260px);text-align:left}.answer:focus{outline:3px solid rgba(45,109,163,.13);border-color:#5a90b8}.answer.correct,.value-table input.correct{background:#effaf2;border-color:var(--goodb)}.answer.wrong,.value-table input.wrong{background:#fff4f2;border-color:var(--badb)}.table-wrap{overflow:auto}.value-table{border-collapse:collapse;min-width:480px;width:100%;text-align:center}.value-table th,.value-table td{border:1px solid #cfdbe3;padding:9px}.value-table th{background:#eaf2f7;color:var(--navy)}.value-table td:first-child{font-weight:900;background:#f4f8fa}.value-table input{width:74px;min-height:38px;border:2px solid #b7c9d6;border-radius:8px;text-align:center;font-weight:850;font-size:16px}.choice-row{display:flex;flex-wrap:wrap;gap:7px;margin-top:7px}.choice{border:1px solid #b9cad6;background:#fff;color:#25455d;border-radius:10px;padding:9px 11px;font-weight:800;cursor:pointer}.choice.selected{background:#e8f2f9;border-color:#3d7faf}.choice.correct{background:var(--good);border-color:var(--goodb)}.choice.wrong{background:var(--bad);border-color:var(--badb)}.helper{margin-top:12px}.helper summary{cursor:pointer;font-weight:850;color:#315f80}.helper .help-body{margin-top:8px;padding:11px 12px;background:var(--warn);border:1px solid var(--warnb);border-radius:11px;line-height:1.5;color:#654f15}.helper a{color:#1e5e91;font-weight:800}.section-actions{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:14px;padding-top:13px;border-top:1px solid var(--line)}.btn{border:0;border-radius:11px;padding:10px 14px;font-weight:900;cursor:pointer}.btn.primary{background:var(--blue);color:#fff}.btn.secondary{background:#fff;color:var(--navy);border:1px solid #b9c9d5}.btn.solution{background:#fff7df;color:#6f5610;border:1px solid #e2c55e}.section-result{font-size:13px;font-weight:850;color:#526a7b;margin-left:auto}.section-result.good{color:#2c7247}.section-result.bad{color:#9e4037}.solution-box{display:none;margin-top:11px;background:#fff8e8;border:1px solid #e5ca72;border-radius:12px;padding:11px 13px;line-height:1.5;color:#5c4b1f}.solution-box.show{display:block}.graph-card{border:1px solid var(--line);border-radius:15px;background:#fbfdfe;padding:12px}.graph-card.correct{background:var(--good);border-color:var(--goodb)}.graph-card.wrong{background:var(--bad);border-color:var(--badb)}.graph-shell{max-width:560px;margin:9px auto}.graph-canvas{display:block;width:100%;height:auto;aspect-ratio:1.1/1;background:white;border:1px solid #cad8e1;border-radius:12px;touch-action:none;user-select:none}.graph-tools{display:flex;gap:7px;flex-wrap:wrap;justify-content:center;margin-top:8px}.graph-tools button{border:1px solid #b9cbd7;background:#fff;border-radius:9px;padding:8px 10px;font-weight:800;color:#27475e}.graph-tools button.active{background:#dfeef8;border-color:#4f8bb6}.graph-status{text-align:center;font-size:12px;color:var(--muted);margin-top:6px;min-height:18px}.intersection-grid{display:grid;grid-template-columns:1fr;gap:12px}.normal-inputs{display:flex;gap:8px;flex-wrap:wrap;margin:8px 0}.normal-inputs .answer{width:220px;text-align:left}.mini-note{background:#f3f7fa;border:1px solid var(--line);border-radius:10px;padding:9px 10px;color:#536a7a;font-size:12px;line-height:1.45}.mix-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.summary-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin:13px 0}.summary-box{border:1px solid var(--line);background:#f8fafb;border-radius:13px;padding:12px}.summary-box span{display:block;color:var(--muted);font-size:12px}.summary-box strong{font-size:22px;color:var(--navy)}.reflection{width:100%;min-height:90px;border:2px solid #b9cad6;border-radius:11px;padding:10px;resize:vertical}.summary-actions{display:flex;gap:8px;flex-wrap:wrap}.print-only{display:none}.extra-links{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}.extra-links a{text-decoration:none;border:1px solid #b7cad7;background:#f5f9fc;color:#224b69;border-radius:10px;padding:9px 11px;font-weight:850;font-size:13px}
@media(max-width:900px){.goal-grid{grid-template-columns:repeat(2,1fr)}.start-card{grid-template-columns:1fr}.video-grid{grid-template-columns:repeat(2,1fr)}.task-grid.three{grid-template-columns:1fr 1fr}.summary-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:650px){.hero{padding:12px 10px 0}.hero-inner{padding:22px 18px}.page{padding:12px 10px 48px}.goal-grid,.task-grid,.task-grid.three,.mix-grid,.video-grid{grid-template-columns:1fr}.progressbar-wrap{flex-wrap:wrap}.progress-label{text-align:left;min-width:auto}.section{padding:16px}.section-head h2{font-size:20px}.section-result{width:100%;margin-left:0}.answer.wide,.normal-inputs .answer{width:100%}.summary-grid{grid-template-columns:1fr 1fr}.topbar span{display:none}}
@media print{body{background:#fff}.topbar,.hero,.progressbar-wrap,.video-hub,.section-actions,.graph-tools,.extra-links,.no-print{display:none!important}.page{max-width:none;padding:0}.section,.summary{box-shadow:none;border:1px solid #bbb;break-inside:avoid}.print-only{display:block}.graph-canvas{max-width:440px}.solution-box{display:none!important}}

/* V70: stark geführte Hilfe für schwächere Lerngruppen */
.table-help{line-height:1.6}.help-rule{background:#fff3c8;border:1px solid #e2bd45;border-radius:12px;padding:12px 14px;margin-bottom:12px;color:#5c4500}.help-steps{display:grid;gap:9px;margin:12px 0}.help-step{display:grid;grid-template-columns:34px 1fr;gap:10px;align-items:start;background:#f7fafc;border:1px solid #d8e2e9;border-radius:12px;padding:10px 12px}.help-step>span{display:grid;place-items:center;width:30px;height:30px;border-radius:50%;background:#1e5f91;color:#fff;font-weight:900}.example-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:14px}.help-example{background:#fff;border:1px solid #d8e2e9;border-radius:12px;padding:12px;font-size:.96rem}.help-example b:first-child{display:inline-block;margin-bottom:5px;color:#173e5b}.help-warning{margin-top:12px;background:#fdebea;border-left:5px solid #c6542c;border-radius:10px;padding:10px 12px;color:#7a3028;font-weight:700}@media(max-width:820px){.example-grid{grid-template-columns:1fr}}