.lesson-guide{margin:24px 0 22px;padding-top:22px;border-top:1px solid var(--line);font-size:calc(1rem * var(--reading-scale,1));line-height:1.85;color:var(--ink);word-break:keep-all;overflow-wrap:anywhere}
.lesson-guide[hidden]{display:none}
.lesson-guide-title{margin:0 0 12px;font-size:1.2em;font-weight:700;line-height:1.55;letter-spacing:-.025em}
.lesson-guide-introduction{margin:10px 0;color:var(--muted)}
.lesson-guide-sections{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin-top:22px}
.lesson-guide-section{min-width:0;padding:20px;border:1px solid var(--line);border-radius:16px;background:var(--surface)}
.lesson-guide-section h4{margin:0 0 12px;font-size:1em;line-height:1.6}
.lesson-guide-formula{margin:0 0 12px;padding:10px 12px;border-radius:9px;background:var(--soft);color:var(--pine);font-size:1.05em;font-weight:650;line-height:1.65}
.lesson-guide-explanation{margin:0;color:var(--muted)}
.lesson-guide-example{margin-top:18px;padding-top:16px;border-top:1px solid var(--line)}
.lesson-guide-example p{margin:0}
.lesson-guide-example-target{font-weight:600;line-height:1.65}
.lesson-guide-example .lesson-guide-example-meaning{margin-top:6px;color:var(--muted)}
.lesson-guide-note{margin-top:18px;padding:16px 18px;border-inline-start:3px solid var(--pine);background:var(--soft);border-radius:0 12px 12px 0}
.lesson-guide-note strong{font-weight:650}
.lesson-guide-note p{margin:5px 0 0;color:var(--muted)}
.lesson-guide-practice{margin:22px 0 0;color:var(--pine);font-weight:600}
@media(max-width:760px){.lesson-guide-sections{grid-template-columns:minmax(0,1fr);gap:12px}.lesson-guide-section{padding:17px}.lesson-guide{margin-top:20px;padding-top:20px}.lesson-guide-title{font-size:1.15em}}