:root{font-family:-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Noto Sans JP",sans-serif;color:#233f3b;background:#f4f7f4;font-size:15px;line-height:1.65;--green:#206f61;--border:#d6e3dc}*{box-sizing:border-box}body{margin:0}[hidden]{display:none!important}a{color:var(--green);text-underline-offset:4px}header{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:18px max(24px,calc((100vw - 1260px)/2));background:#fcfdfb;border-bottom:1px solid var(--border)}.brand{display:flex;align-items:center;gap:12px;font-size:22px;font-weight:750;text-decoration:none;color:inherit}.brand img{width:42px;height:42px;border-radius:12px}.brand small{display:block;font-size:10px;letter-spacing:.13em}nav{display:flex;gap:18px;align-items:center}.teacher-main{max-width:1310px;margin:auto;padding:30px 25px 60px}.hero{max-width:920px;margin:15px 0 26px}.hero h1{font-size:32px;line-height:1.5;margin:10px 0}.hero 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0}.bubble{background:#eef4ec;border:1px solid #dce8d8;border-radius:18px 18px 18px 4px;padding:18px 20px;max-width:90%;align-self:flex-start;min-width:120px}.bubble.student{background:#e0eee8;border-color:#cee0d4;align-self:flex-end;border-radius:18px 18px 4px 18px}.bubble .speaker{font-size:11px;letter-spacing:.05em;color:#69846d}.bubble p{white-space:pre-wrap;margin:8px 0 12px}.bubble button{font-size:12px;min-height:36px;padding:5px 12px}.share{margin-top:24px;background:#f9fbef}.share input{margin:5px 0 12px;font-size:12px}footer{color:#708277;font-size:12px;text-align:center;margin:30px 0 5px}dialog{border:1px solid var(--border);border-radius:22px;padding:28px;max-width:700px;width:90%;max-height:90vh;overflow:auto}dialog::backdrop{background:#19382f70}.learner{background:#faf8f0}.learner header{background:#fffdf8}.hint-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:15px;background:#f3e7ba;color:#9a6d23}.learn-main{max-width:790px;padding:12px 24px 40px;margin:auto}.problem-card{padding:26px 30px;background:#fffdf7;border:1px solid #e7e3d3;border-radius:22px;margin:12px 0 20px}.problem-card h1{font-size:23px;margin:8px 0 15px}.problem-card p{font-size:18px;line-height:1.9}.learning-tools{display:flex;flex-wrap:wrap;align-items:center;gap:12px;font-size:12px}.learning-tools label{display:flex;align-items:center;gap:8px;margin:0;font-size:12px}.learning-tools select{width:auto;max-width:190px;font-size:12px;margin:0}.learning-tools .check{align-items:center}.learning-tools button{min-height:36px;font-size:12px;padding:5px 10px}.learner .bubble{background:#fff;border-color:#e2e6d8;font-size:17px}.learner .bubble.student{background:#e8efe2;font-size:15px}.composer{padding:22px}.composer-bottom{display:flex;align-items:center;justify-content:space-between;gap:10px}.difficulty{display:flex;flex-wrap:wrap;gap:8px;padding:8px 0 12px}.difficulty button{font-size:12px;background:#f9f4e6}.voice-focus 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@media(max-width:760px){header{padding:13px 16px;gap:10px;align-items:flex-start}.brand{font-size:18px}.brand small{font-size:8px}nav{font-size:11px;gap:10px;flex-wrap:wrap;justify-content:flex-end}header>button{font-size:11px;max-width:130px}.teacher-main{padding:18px 14px 35px}.hero h1{font-size:25px}.columns{grid-template-columns:1fr}.columns>aside{max-height:320px;overflow:auto}.card{padding:19px;border-radius:16px}.tabs button{font-size:13px}.learn-main{padding:8px 13px 25px}.problem-card{padding:21px}.problem-card h1{font-size:20px}.problem-card p{font-size:17px}.bubble{max-width:95%;padding:16px}.learning-tools{gap:9px}.hint-row{grid-template-columns:52px 1fr}.section-heading{align-items:flex-start}.position{grid-template-columns:1fr}.composer-bottom small{font-size:11px}.actions button{flex-grow:1}dialog{padding:20px}.learner .messages{gap:12px}}
.learner #learn-messages{max-height:55vh;min-height:140px;overflow:auto;padding-right:4px}