/* V92 · eigenständige 1x1-Übungen */
:root{--navy:#102d45;--blue:#2e719f;--ink:#173047;--muted:#698091;--line:#dae5ed;--good:#e5f6ed;--bad:#ffebe7;--bg:#f3f7f9}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}body{margin:0;background:linear-gradient(#eaf2f7,#f7fafb 34%,#f1f6f9);color:var(--ink);font-family:Inter,system-ui,-apple-system,"Segoe UI",Arial,sans-serif}button,input{font:inherit}button{cursor:pointer}button:disabled{opacity:.48;cursor:not-allowed}[hidden]{display:none!important}
.topbar{background:var(--navy);color:white}.topbar>div{max-width:1120px;margin:auto;display:flex;align-items:center;gap:9px;flex-wrap:wrap;padding:12px 18px;font-size:.88rem}.topbar a{color:#fff;text-decoration:none;font-weight:750}.topbar span{opacity:.5}.page{max-width:1100px;margin:auto;padding:20px 18px 60px}.hero,.levels-card,.work-card,.plan,.finish-card,.game-card{background:white;border:1px solid var(--line);border-radius:19px;box-shadow:0 9px 26px #0c304510}.hero{padding:25px;display:flex;gap:12px;justify-content:space-between;align-items:center}.eyebrow{color:#a94d2e;font-size:.74rem;letter-spacing:.09em;text-transform:uppercase;font-weight:950}.hero h1{margin:7px 0 10px;color:var(--navy);font-size:clamp(2rem,4.5vw,3.25rem);line-height:1.05}.hero p{margin:0;color:var(--muted);max-width:800px;line-height:1.55}.hero-badge{min-width:115px;background:#edf5fa;padding:13px;border-radius:17px;text-align:center}.hero-badge strong{font-size:2.3rem;display:block}.hero-badge span{font-size:.76rem;font-weight:850}.levels-card{margin-top:14px;padding:16px}.levels-card h2{font-size:.77rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 10px}.levels{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.level{border:1px solid var(--line);background:white;border-radius:13px;padding:12px;text-align:left;color:var(--ink)}.level b{display:block;font-size:1rem}.level small{display:block;margin-top:3px;line-height:1.35;color:var(--muted)}.level.active{background:#eaf3fa;border-color:#6ea4cb;box-shadow:inset 0 0 0 1px #6ea4cb}.level-note{margin:10px 0 0;background:#f6f9fa;border-radius:10px;color:var(--muted);font-size:.87rem;padding:10px}.work-card{margin-top:14px;padding:22px;min-height:475px}.task-head{display:flex;align-items:center;justify-content:space-between;gap:10px;color:var(--muted);font-size:.82rem}.pill{background:#eaf3fa;border-radius:99px;padding:6px 11px;color:#275e86;font-weight:900}.counter{font-weight:850}.progress{height:9px;background:#eaf0f5;border-radius:99px;margin-top:12px;overflow:hidden}.progress>span{display:block;background:#3e83b4;width:0;height:100%;transition:width .2s}.question{font-size:clamp(1.55rem,3.8vw,2.18rem);text-align:center;font-weight:950;color:var(--navy);margin:32px auto 12px;line-height:1.2}.sub{text-align:center;max-width:800px;margin:0 auto 18px;color:var(--muted);line-height:1.45}.problem-grid{display:grid;gap:12px;max-width:930px;margin:20px auto}.problem-grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.problem-grid.four{grid-template-columns:repeat(2,minmax(0,1fr))}.problem{display:grid;grid-template-columns:32px minmax(0,1fr) minmax(115px,160px);align-items:center;gap:10px;padding:12px;background:#f8fafb;border:1px solid var(--line);border-radius:13px;min-width:0}.problem.wide{grid-template-columns:32px minmax(0,1fr) minmax(115px,170px)}.letter{width:32px;height:32px;display:grid;place-items:center;border-radius:50%;background:#e9f2f8;color:#285d80;font-weight:950}.expr{font-size:clamp(1.25rem,2.8vw,1.75rem);font-weight:950;line-height:1.35;white-space:normal;overflow-wrap:break-word;color:var(--navy)}.problem input,.wall input{min-width:0;width:100%;border:2px solid #b9cbd8;border-radius:10px;text-align:center;padding:9px 5px;min-height:48px;font-size:1.25rem;font-weight:900;outline:none;background:white}.problem input:focus,.wall input:focus{border-color:#498fc0;box-shadow:0 0 0 3px #4a90bf26}.problem input.correct,.wall input.correct{background:var(--good);border-color:#69ae80}.problem input.wrong,.wall input.wrong{background:var(--bad);border-color:#c77d73}.answer-row{display:flex;justify-content:center;margin:15px 0;gap:8px}.btn{border:0;border-radius:11px;padding:11px 16px;font-weight:900;min-height:45px}.primary{background:var(--blue);color:#fff}.secondary{color:var(--navy);background:white;border:1px solid var(--line)}.feedback{display:none;max-width:850px;margin:15px auto;border-radius:12px;padding:13px 16px;text-align:center;font-weight:850}.feedback.show{display:block}.feedback.good{background:var(--good);color:#1c603a}.feedback.bad{background:var(--bad);color:#974539}.hint{background:#fff4d5;border:1px solid #edd895;color:#73591b;padding:10px 14px;margin-top:9px;border-radius:10px;font-weight:650;font-size:.89rem}.actions{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;padding-top:20px}.actions>*{min-width:140px}.wall-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:18px auto;max-width:1000px}.wall{background:#f8fafb;border:1px solid var(--line);border-radius:14px;padding:12px 6px;text-align:center}.wall b{display:block;font-size:.85rem;margin-bottom:7px;color:#4a6676}.wall-row{display:flex;justify-content:center;gap:7px;margin:6px 0}.stone{width:clamp(60px,11vw,91px);height:58px;display:grid;place-items:center;border:2px solid #b8cad7;background:white;border-radius:9px;font-size:1.35rem;font-weight:950}.stone input{height:100%;border:0}.wall-guide{font-size:.82rem;color:var(--muted);text-align:center;line-height:1.45}.summary{margin:18px auto;background:#f8fafb;border:1px solid var(--line);padding:18px;border-radius:13px;text-align:center;max-width:730px}.summary strong{display:block;font-size:2.1rem;color:var(--navy)}.plan{margin-top:14px;padding:17px}.plan h2{font-size:1.05rem;margin:0 0 10px}.plan-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.plan-grid div{background:#f7fafb;border:1px solid var(--line);border-radius:11px;padding:10px}.plan-grid b{display:block;font-size:1.5rem;color:var(--blue)}.plan-grid span{font-size:.81rem;color:var(--muted)}.finish-card,.game-card{margin-top:15px;text-align:center;padding:22px}.finish-card h2,.game-card h2{margin:5px 0 8px}.finish-card p,.game-card p{color:var(--muted)}.game-card{border:2px solid #aad2b2;background:#fbfffb}.snake-wrap{width:min(100%,500px);margin:15px auto}.snake-wrap canvas{display:block;width:min(100%,400px);height:auto;margin:auto;border:2px solid #b9d5c3;border-radius:13px;background:#f5fbf6}.snake-controls{display:grid;grid-template-areas:'. up .' 'left down right';justify-content:center}.snake-up{grid-area:up}.snake-left{grid-area:left}.snake-down{grid-area:down}.snake-right{grid-area:right}.snake-control{background:white;border:1px solid #bbd6c4;color:#246444}.snake-message{font-size:.87rem;color:#557662;margin-top:10px}.snake-stats{font-size:1rem;margin:10px}.snake-stats strong{font-size:1.5rem;color:#276943}.cross-links{display:flex;flex-wrap:wrap;gap:10px;margin-top:14px}.cross-links a{background:#edf4fa;color:#245d87;text-decoration:none;font-weight:850;border-radius:11px;padding:9px 12px}.minihelp{max-width:780px;margin:0 auto;color:var(--muted);text-align:center;font-size:.88rem}
@media(max-width:760px){.page{padding:10px 10px 35px}.hero,.work-card{padding:16px}.hero-badge{display:none}.levels{grid-template-columns:1fr}.problem-grid.two,.problem-grid.four,.wall-grid{grid-template-columns:1fr}.plan-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:430px){.problem{grid-template-columns:25px minmax(0,1fr) minmax(86px,120px);gap:6px;padding:9px}.letter{width:25px;height:25px}.expr{font-size:1.13rem}.problem input{font-size:1.1rem}.stone{width:64px}.actions>*{flex:1}.plan-grid{grid-template-columns:1fr}}