.lesson-page{max-width:1000px;padding-bottom:32px}
.lesson-page p,.lesson-page li{font-size:var(--body-size);line-height:1.8;color:var(--muted);max-width:70ch}
.lesson-page .eyebrow{font-size:11px;letter-spacing:1.4px}
.lesson-page h1{font-size:clamp(36px,5vw,54px)}
.lesson-page h3{margin:26px 0 12px}
.lesson-page .intro{padding-bottom:28px}
.lesson-nav{display:flex;flex-wrap:wrap;gap:12px 22px;margin-top:24px}
.lesson-nav a{font-size:15px;color:var(--blue);text-decoration:underline}
.lesson-section{border-top:1px solid var(--line);padding:36px 0}
.lesson-section ul{padding-left:22px;max-width:70ch}
.lesson-section li{margin-bottom:12px}
.lesson-page .formula{max-width:70ch;overflow-wrap:anywhere}
.lesson-page table{min-width:540px;background:white}
.lesson-page caption{text-align:left;font-size:14px;color:var(--muted);padding:8px 0 12px}
.lesson-page th[scope=row]{white-space:nowrap}
.lesson-page .table-scroll{margin:20px 0 28px}
.lesson-page figure{max-width:760px;margin:24px auto}
.lesson-page .lesson-callout{padding:18px 22px;border-left:3px solid var(--blue);background:#edf2fc;border-radius:0 8px 8px 0;color:var(--ink)}
.practice-card{border:1px solid var(--line);border-radius:12px;background:white;padding:26px 28px;margin:24px 0}
.practice-card h3{margin-top:0}
.answer-field{max-width:580px;margin:18px 0}
.answer-controls{display:flex;flex-wrap:wrap;gap:10px}
.answer-controls input{font:inherit;font-size:17px;color:var(--ink);background:white;border:1px solid #9daab7;border-radius:6px;padding:10px 12px;min-width:0;width:180px;max-width:100%;min-height:46px}
.answer-controls input:focus-visible{outline:3px solid var(--blue);outline-offset:3px}
.answer-controls button{background:var(--blue);color:white;border:0;border-radius:6px;padding:10px 18px;font-size:15px;min-height:46px}
.answer-controls button:hover{background:#164dd0}
.practice-card button:disabled{cursor:default}
.lesson-page .answer-feedback{margin:10px 0 0;font-size:15px;min-height:0}
.answer-feedback:empty{display:none}
.lesson-page .answer-feedback[data-status=correct]{color:#21613b}
.lesson-page .answer-feedback[data-status=incorrect],.lesson-page .answer-feedback[data-status=invalid]{color:#a22627}
.practice-solution{padding:16px 0;border-top:1px solid var(--line)}
.practice-solution summary{font-size:16px}
.practice-solution p{padding:12px 0 0}
.reset-practice{background:transparent;color:var(--muted);border:1px solid #a4afba;border-radius:6px;padding:8px 18px;font-size:15px;margin-top:16px;min-height:44px}
@media(max-width:720px){.lesson-page .lesson-nav a{display:inline}.lesson-page .intro{padding-top:26px}.practice-card{padding:22px 18px}.lesson-page .lesson-callout{padding:16px}.answer-controls input{flex:1 1 130px}.lesson-page .formula{font-size:21px}.lesson-page .formula span{white-space:normal}}