:root{--ink:#29463f;--muted:#687d73;--green:#4b8176;--line:#d2e1d7;--paper:#fffefa;--bg:#f4f6f1;color-scheme:light;font-family:"Yu Gothic","Hiragino Kaku Gothic ProN","Noto Sans JP",system-ui,sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at 12% 0,#fff9ed,transparent 33%),var(--bg);color:var(--ink)}a{color:inherit;text-decoration:none}button,input,textarea{font:inherit}button,a,input,textarea{touch-action:manipulation}button{cursor:pointer;color:inherit}button:disabled{opacity:.5;cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid 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auto;max-width:650px}.head-links{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin-top:17px}.head-links a{font-size:14px;padding:8px 14px;border-radius:999px;border:1px solid var(--line);background:#fffefa}.route{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border:1px solid var(--line);border-radius:16px;background:#f9fcf5;padding:17px;margin:0 0 30px;gap:16px}.route div{display:flex;align-items:center;gap:10px;font-size:14px;line-height:1.7;color:#57725e}.route b{display:flex;align-items:center;justify-content:center;flex-shrink:0;width:28px;height:28px;background:#e5f0e0;border-radius:50%;font-weight:500}.lesson-group{margin:0 0 30px;scroll-margin-top:18px}.group-title{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:500;margin:0 0 14px}.group-title>span{font-size:12px;color:#6c8a72;border:1px solid var(--line);padding:5px 8px;border-radius:7px}.lesson-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}.lesson-card{display:flex;align-items:center;gap:17px;min-width:0;border:1px solid var(--line);border-radius:17px;background:var(--paper);padding:17px;box-shadow:0 6px 19px #36513e06;transition:transform .16s,border-color .16s}.lesson-card:hover{transform:translateY(-2px);border-color:#87af96}.lesson-art{display:flex;align-items:center;justify-content:center;width:155px;flex:0 0 155px;min-height:100px;background:#f3f8ee;border:1px solid #e1eada;border-radius:11px;overflow:hidden}.lesson-art svg{display:block;width:100%;height:auto}.lesson-text{min-width:0;flex:1}.lesson-meta{display:flex;gap:7px;flex-wrap:wrap;align-items:center;font-size:12px;color:#6b806d;margin-bottom:7px}.lesson-meta b{font-size:13px;color:#497860;font-weight:500}.lesson-text h3{font-size:17px;font-weight:500;line-height:1.6;margin:0 0 6px}.lesson-text p{font-size:13px;line-height:1.8;color:#6c7d6f;margin:0}.lesson-card .go{font-size:24px;color:#82a18b;flex-shrink:0}.lesson-card.challenge{border-color:#d4c390;background:linear-gradient(115deg,#fffbed,#fffefa);grid-column:1/-1}.challenge .lesson-art{background:#f9f4e4;border-color:#e8dab4}.print-entry{border:1px solid #c9dbc4;background:#fffefa;border-radius:20px;padding:27px;margin-top:32px}.print-entry h2{font-size:23px;font-weight:500;margin:0 0 10px}.print-entry p{font-size:15px;line-height:1.9;color:var(--muted);margin:0 0 16px}.actions{display:flex;gap:10px;flex-wrap:wrap}.button,.primary{display:inline-flex;align-items:center;justify-content:center;gap:7px;min-height:44px;padding:10px 16px;border:1px solid #a9c6b7;border-radius:11px;background:#f3f8f1;color:#466d57;font-size:14px;font-weight:500;line-height:1.7}.primary{background:var(--green);color:white;border-color:var(--green)}.button:hover{background:#e7f2e8}.primary:hover{background:#326c60}.print-note{font-size:13px!important;margin:13px 0 0!important;color:#748571!important}.footer{text-align:center;color:#7b8b7b;font-size:12px;line-height:1.8;margin:27px 0 0}.practice-header{margin-bottom:20px}.practice-header .head-links{margin-top:12px}.practice-nav{display:flex;gap:6px;flex-wrap:wrap;margin:0 0 18px}.question-tab{border:1px solid #c5d7bd;border-radius:8px;background:#fffefa;min-width:46px;min-height:44px;padding:8px;font-size:14px;color:#60775b}.question-tab[aria-current=page]{background:#4b8176;border-color:#4b8176;color:#fff}.question-tab.correct{box-shadow:inset 0 -4px #9cc199}.practice-layout{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:17px;align-items:start}.card{border:1px solid var(--line);border-radius:19px;background:var(--paper);padding:23px;min-width:0}.question-header{display:flex;gap:12px;justify-content:space-between;align-items:center;margin-bottom:12px}.question-header h2{font-size:21px;line-height:1.6;font-weight:500;margin:0}.badge{padding:4px 8px;border:1px solid #dfd2af;border-radius:7px;font-size:12px;color:#8e743a;background:#fbf6e9;white-space:nowrap}.question-intro,.question-ask,.relation{font-size:16px;line-height:1.9;margin:0 0 13px}.relation{font-size:15px;background:#fff6e3;border-left:3px solid #c5a155;padding:10px 12px;border-radius:0 10px 10px 0;color:#786440}.purchase{border:1px solid #dbe7d5;background:#f8fbf4;border-radius:12px;margin:0 0 10px;padding:12px}.purchase-head{display:flex;justify-content:space-between;align-items:center;gap:8px;margin-bottom:8px;font-size:14px;color:#687f64}.purchase-letter{display:inline-flex;align-items:center;justify-content:center;width:24px;height:24px;border-radius:7px;background:#e5efe0;color:#597754}.purchase-head strong{font-size:23px;font-weight:500;color:#3d7274;white-space:nowrap}.purchase-head small{font-size:13px}.purchase-items{display:flex;gap:7px;align-items:stretch}.purchase-kind{flex:1;min-width:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:5px;font-size:13px;border-radius:9px;background:#fffefa;border:1px solid #dce6d9;padding:9px 4px}.purchase-icons{display:flex;align-items:center;justify-content:center;gap:3px;flex-wrap:wrap;max-width:100%}.purchase-icons .icon{width:24px;height:27px}.question-ask{background:#f0f7ed;border-left:3px solid #669473;border-radius:0 10px 10px 0;padding:11px 13px;margin-top:14px;font-size:15px}.card h3{font-size:15px;font-weight:500;margin:0 0 10px;color:#547553}.writing{display:block;font-size:14px;line-height:1.7;margin-bottom:13px;color:#5c755e}.writing textarea{display:block;resize:vertical;min-height:64px;width:100%;border:1px solid #b9d0bd;border-radius:10px;margin-top:5px;padding:9px 11px;font-size:16px;line-height:1.8;background:repeating-linear-gradient(#fffefa 0,#fffefa 28px,#e2e9de 29px,#fffefa 30px);color:var(--ink)}.answer-fields{display:grid;gap:9px;margin:17px 0 13px}.answer-field{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:10px 12px;border:1px solid #d3dfca;border-radius:10px;background:#f5f9ef;font-size:14px}.answer-field>span:first-child{display:flex;align-items:center;gap:6px}.answer-field input{width:91px;height:43px;border:1px solid #a8c6b0;background:#fffefa;border-radius:9px;font-size:22px;text-align:center;color:var(--ink)}.answer-field .input-wrap{display:flex;align-items:center;gap:6px}.answer-field input[aria-invalid=true]{border-color:#c2994c;background:#fff7e9}.answer-field input.valid{border-color:#659672;background:#eff9e9}.check-button{width:100%;margin-top:0}.feedback{margin:12px 0 0;padding:11px 13px;background:#fff5df;color:#7f622e;border-radius:10px;font-size:14px;line-height:1.8}.feedback.success{background:#eaf5e8;color:#427148}.hint{margin-top:10px;padding:12px;border:1px solid #e1d3ac;background:#fffaf0;border-radius:10px;font-size:14px;line-height:1.9}.support-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:13px}.support-actions .button{font-size:13px}.solution{margin-top:14px;padding:14px;background:#f3f8ed;border:1px solid #c7d9bf;border-radius:12px;font-size:14px;line-height:1.9}.solution ol{padding-left:22px;margin:0}.solution li{margin:7px 0}.solution strong{font-weight:500;color:#416b4e}.solution small{display:block;font-size:13px;color:#6d7e65}.solution .mini-answer{margin-top:12px;padding-top:10px;border-top:1px solid #d0dfc6}.reward{display:flex;align-items:center;gap:14px;border:1px solid #d5bd76;border-radius:13px;background:linear-gradient(115deg,#fff4ca,#fffdfa);padding:13px 16px;margin-top:13px;color:#83622a}.reward svg{width:55px;height:65px;flex-shrink:0}.reward strong{display:block;font-size:20px;font-weight:500;margin-bottom:5px}.reward span{font-size:13px}.progress-strip{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 0 13px;font-size:14px;color:#60795c;flex-wrap:wrap}.question-navigation{display:flex;justify-content:space-between;gap:10px;margin-top:17px}.practice-tip{font-size:13px;line-height:1.8;color:#72836b;margin-top:9px}.practice-footer{margin-top:20px;text-align:center;font-size:14px;color:#71836c}
@media(max-width:850px){.lesson-art{width:120px;flex-basis:120px}.lesson-card{padding:13px;gap:11px}.lesson-text h3{font-size:16px}.lesson-text p{font-size:13px}.practice-layout{grid-template-columns:1fr}.route{gap:10px}.route div{font-size:13px}.card{padding:21px}}
@media(max-width:700px){.lesson-grid{grid-template-columns:1fr}.lesson-card.challenge{grid-column:auto}.lesson-art{width:143px;flex-basis:143px}.head{margin-bottom:23px}.group-title{font-size:18px}.route{grid-template-columns:1fr;gap:10px;padding:15px}.route div{font-size:14px}.route b{width:25px;height:25px}.print-entry{padding:21px}.print-entry h2{font-size:21px}.actions>a{flex:1;min-width:170px}.lesson-text h3{font-size:17px}.global-nav{margin-top:12px}.question-header h2{font-size:19px}.question-header{align-items:flex-start;flex-wrap:wrap}}
@media(max-width:400px){.shell{width:calc(100% - 22px)}.lesson-card{padding:12px;gap:10px}.lesson-art{width:96px;flex-basis:96px;min-height:85px}.lesson-text h3{font-size:15px}.lesson-text p{font-size:12px}.lesson-meta{font-size:12px;gap:3px}.lesson-card .go{display:none}.head h1{font-size:30px}.lead{font-size:14px}.group-title{font-size:17px}.card{padding:16px}.purchase{padding:10px}.purchase-kind{font-size:12px}.purchase-icons .icon{width:21px;height:24px}.purchase-items{gap:4px}.purchase-icons{gap:1px}.answer-field{padding:9px}.answer-field input{width:76px}.question-tab{min-width:43px}.question-intro,.relation{font-size:14px}.question-ask{font-size:14px}.global-nav a{font-size:13px;padding:9px 12px}.print-entry{padding:18px}.print-entry h2{font-size:19px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
@media print{.global-nav,.head-links,.practice-nav,.support-actions,.question-navigation,.actions{display:none}.shell{width:100%}.practice-layout{display:block}.card{break-inside:avoid;box-shadow:none;margin-bottom:12px}.reward{display:none}}