.exercise-guide{border-bottom:1px solid var(--line)}
.exercise-guide:first-child{border-top:1px solid var(--line)}
.exercise-guide summary{list-style:none;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 2px;cursor:pointer}
.exercise-guide summary::-webkit-details-marker{display:none}
.exercise-guide summary:hover .exercise-title{color:var(--mint)}
.exercise-guide summary:focus-visible{outline:2px solid var(--mint);outline-offset:3px;border-radius:6px}
.exercise-title{font-weight:700;line-height:1.35}
.exercise-title small{display:block;margin-top:3px;color:var(--muted);font-size:11px;font-weight:500}
.exercise-right{display:flex;align-items:center;gap:14px;color:var(--muted);font-size:12px;white-space:nowrap}
.exercise-toggle{display:grid;place-items:center;width:24px;height:24px;border:1px solid var(--line);border-radius:7px;color:var(--mint);font-size:17px;font-weight:400;line-height:1;transition:transform .18s ease}
.exercise-guide[open] .exercise-toggle{transform:rotate(45deg)}
.exercise-explainer{margin:0 0 14px;padding:14px 16px;border:1px solid #344b50;border-radius:10px;background:linear-gradient(130deg,rgba(179,242,154,.08),rgba(139,223,229,.04))}
.exercise-explainer p{margin:0 0 10px;color:var(--text);font-size:12px;line-height:1.7}
.exercise-explainer p:last-child{margin-bottom:0}
.exercise-explainer strong{display:inline-block;margin-right:10px;color:var(--mint);font-size:11px;letter-spacing:.06em}
.exercise-reference{margin:12px 0 0;color:var(--muted);font-size:11px;line-height:1.6}
.exercise-reference a{color:var(--cyan);text-underline-offset:2px}
@media(prefers-reduced-motion:reduce){.exercise-toggle{transition:none}}