.activity{padding:clamp(18px,3vw,28px);margin:28px 0;border:1px solid var(--border);border-radius:9px;background:var(--surface)}
.activity h2{margin:0 0 16px!important}.activity>.eyebrow{margin:0 0 9px;font-size:12px}.activity-instruction{font-size:19px;font-weight:650;line-height:1.5;margin:0 0 18px!important}
.activity-context{padding:16px 18px;background:var(--surface-2);border-left:3px solid var(--blue);border-radius:3px;margin:18px 0}.activity-context>span{display:block;font-size:12px;font-weight:700;color:var(--muted);margin-bottom:8px}.activity-context p{white-space:pre-line;font-size:16px;margin:0!important;line-height:1.65}
.activity fieldset{border:0;margin:0;padding:0;min-width:0}.activity legend{font-size:14px;color:var(--muted);padding:0;margin-bottom:14px;line-height:1.5}.activity-fields{display:grid;gap:12px}
.activity-option{display:flex;align-items:flex-start;gap:12px;padding:14px;border:1px solid var(--border);border-radius:5px;cursor:pointer;min-height:48px;font-size:16px;line-height:1.5}.activity-option:has(input:checked){border-color:var(--blue);background:var(--surface-2)}.activity-option input{width:19px;height:19px;flex:0 0 19px;margin-top:3px;accent-color:var(--blue)}.activity-option input:disabled{opacity:1}
.activity-line{display:grid;grid-template-columns:minmax(0,1fr) minmax(135px,45%);gap:12px;align-items:center;padding:13px 0;border-bottom:1px solid var(--border)}.activity-line label{font-size:16px;line-height:1.5}.activity-line select,.activity-number input{width:100%;min-width:0;min-height:46px;padding:10px 12px;border:1px solid var(--border);border-radius:5px;background:var(--bg);color:var(--text);font:inherit;font-size:16px}.activity-line select:disabled,.activity-number input:disabled{opacity:1;color:var(--text)}.activity-number{display:flex;gap:9px;align-items:center;min-width:0}.activity-number input{max-width:145px}.activity-number>span{font-size:14px;color:var(--muted)}
.activity .exercise-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:18px;align-items:center}.activity .quiet-link{border:0;background:none;cursor:pointer;color:var(--text);padding:8px 0}.activity [hidden]{display:none!important}.activity .status:empty,.activity-save:empty,.activity-result:empty{display:none}
.activity-result{scroll-margin-top:100px;outline-offset:5px}.activity-feedback{margin-top:22px;padding-top:20px;border-top:2px solid var(--blue)}.activity-feedback h3{font-size:22px;margin:0 0 10px!important}.activity-feedback>p{font-size:15px;margin:0 0 15px!important}.activity-feedback ul{list-style:none;padding:0!important;margin:0;display:grid;gap:12px}.activity-feedback li{padding:12px 14px;background:var(--surface-2);border-radius:4px}.activity-feedback li>strong{font-size:14px;font-weight:650;line-height:1.5;display:block}.activity-feedback li>strong>span{margin-right:6px}.activity-feedback .is-wrong{border-left:3px solid var(--orange)}.activity-feedback .is-correct{border-left:3px solid var(--success)}.activity-feedback li>p{font-size:14px;line-height:1.6;margin:7px 0 0!important}.activity-note,.activity-save{font-size:13px!important;color:var(--muted);line-height:1.6!important;margin:15px 0 0!important}
.lesson-application{margin:24px 0;padding:18px 20px;border:1px solid var(--border);border-radius:6px;scroll-margin-top:100px}.lesson-application>summary{font-size:18px;font-weight:650;cursor:pointer;min-height:32px;line-height:1.6}.lesson-application p{font-size:15px;line-height:1.7;margin-top:16px!important}.lesson-application pre{white-space:pre-wrap;overflow-wrap:anywhere;padding:16px;background:var(--surface-2);font-size:14px;line-height:1.7}.lesson-application details{margin-top:18px}.lesson-application details>summary{cursor:pointer;min-height:44px;font-size:15px;font-weight:650;line-height:1.6}
.lesson-concept{margin:20px 0;padding:20px;background:var(--surface-2);border-radius:6px}.lesson-concept h2{font-size:26px;margin:0 0 15px!important}.lesson-concept p{font-size:17px;line-height:1.75;margin:0!important}
@media(max-width:680px){.activity-line{grid-template-columns:minmax(0,1fr);gap:9px}.activity{padding:18px 16px}.activity-instruction{font-size:18px}.activity .exercise-actions .btn{width:100%}.activity-line select{max-width:100%}.activity-context{padding:14px}.activity-context p{font-size:15px}.activity-option{padding:13px;font-size:15px}.activity-number input{max-width:170px}.lesson-application{padding:16px}.lesson-concept{padding:18px}.lesson-concept p{font-size:16px}}

.lesson-drawer>[data-close-drawer]{width:100%;margin-bottom:16px;min-height:44px}
.lesson-drawer>ol{list-style:none;padding:0;margin:18px 0}.lesson-drawer li+li{margin-top:4px}.lesson-drawer li>a{display:grid;grid-template-columns:20px minmax(0,1fr) 16px;gap:8px;align-items:start;padding:11px 9px;min-height:44px;border-radius:5px;font-size:15px;line-height:1.5}.lesson-drawer li>a.active{background:var(--surface-2);font-weight:700;box-shadow:inset 3px 0 var(--blue)}
.lock-card[data-lesson-access-message]{background:var(--surface-2);border-color:var(--border);text-align:left;padding:24px}