.onb{background:var(--onb-bg,#fff)}.onb-wrap{margin-inline:auto;max-width:var(--onb-max,1320px);padding:24px 16px}.onb-grid{display:grid;gap:28px;grid-template-columns:2fr 1fr}@media (max-width:1024px){.onb-grid{grid-template-columns:1fr}}.onb-h{color:#0f172a;font-size:clamp(24px,3vw,36px);font-weight:800;margin:0 0 8px}.onb-intro{color:#475569;margin:0 0 18px}.onb-lessons{display:grid;gap:16px;list-style:none;margin:0;padding:0}.onb-lesson{background:#fff;border:1px solid rgba(0,0,0,.06);border-radius:12px;overflow:hidden}.onb-lesson__head{align-items:center;background:var(--onb-card-bg,#f5f7f9);display:flex;gap:12px;justify-content:space-between;padding:14px 16px}.onb-lesson__titles{min-width:0}.onb-lesson__title{color:var(--onb-lesson-head,#0f172a);font-size:18px;margin:2px 0 0}.onb-lesson__subtitle{color:var(--onb-lesson-head,#0f172a);font-size:14px;line-height:1.4;margin-top:2px}.onb-lesson__meta{align-items:center;display:flex;flex:0 0 auto;gap:12px}.onb-lesson__dur{background:#eef2f5;border-radius:999px;color:#334155;font-size:13px;padding:4px 8px}.onb-check{align-items:center;cursor:pointer;display:inline-flex;gap:10px;user-select:none}.onb-check__input{appearance:none;-webkit-appearance:none;background:#fff;border:2px solid #cbd5e1;border-radius:8px;box-sizing:border-box;display:grid;flex:0 0 26px;height:26px;margin:0;outline:none;padding:0;place-items:center;width:26px}.onb-check__input:hover{border-color:#94a3b8}.onb-check__input:focus-visible{box-shadow:0 0 0 3px rgba(15,23,42,.12)}.onb-check__input:before{color:#000;content:"\2713";font-size:16px;font-weight:800;line-height:1;opacity:0;transform:translateY(-1px)}.onb-check__input:checked:before{opacity:1}.onb-check__label{color:var(--onb-lesson-head,#0f172a);font-size:13px;font-weight:600;line-height:1.2}.onb-toggle{align-items:center;background:#fff;border:1px solid rgba(0,0,0,.06);border-radius:8px;color:#0f172a;display:inline-flex;height:36px;justify-content:center;margin-left:4px;padding:0;transition:transform .2s ease,background .2s ease,border-color .2s ease;width:36px}.onb-toggle:hover{background:#f3f4f6}.onb-toggle svg{height:18px;transition:transform .2s ease;width:18px}.onb-lesson__body{background:#eee;height:0;overflow-x:visible;overflow-y:hidden;transition:height .25s ease}.onb-lesson.is-open .onb-toggle svg{transform:rotate(180deg)}.onb-video{border-bottom:5px solid var(--onb-divider,#000);display:block;margin:0}.onb-video iframe,.onb-video video{aspect-ratio:16/9;border:0;display:block;width:100%}.onb-summary{color:#475569;padding:12px 16px}.onb-resources-block{padding:8px 16px 16px}.onb-subh{color:#000);font-size:24px;font-weight:700;margin:0 0 8px}.onb-resources{display:grid;gap:6px;grid-auto-rows:min-content}.onb-resource,.onb-resources{margin:0;padding:0}.onb-link{color:var(--onb-accent,#0ea371);text-decoration:underline}.onb-lesson--pulse{box-shadow:0 0 0 2px var(--onb-accent,#0ea371) inset}.onb-side{height:fit-content;position:sticky;top:24px}.onb-card{background:#fff;border:1px solid rgba(0,0,0,.06);border-radius:12px;padding:16px}.onb-card__h{color:#0f172a;font-size:18px;margin:0 0 8px}.onb-progress{margin:8px 0 12px}.onb-progress__bar{background:#eef2f5;border-radius:999px;height:10px;overflow:hidden;position:relative}.onb-progress__fill{background:var(--onb-accent,#0ea371);inset:0 auto 0 0;position:absolute;transition:width .3s ease;width:0}.onb-progress__label{color:#334155;margin-top:6px}.onb-next{display:grid;gap:8px;margin-top:8px}.onb-next__links{display:flex;flex-wrap:wrap;gap:12px}.onb-help{color:#475569;font-size:14px;margin-top:10px}.onb-btn{align-items:center;background:var(--onb-btn,#0a7f5f);border:2px solid transparent;border-radius:10px;box-shadow:0 1px 0 rgba(0,0,0,.04);color:var(--onb-btn-text,#fff);display:inline-flex;font-size:16px;font-weight:600;gap:8px;justify-content:center;padding:12px 16px;text-decoration:none;transition:transform .06s ease,box-shadow .2s ease,background .2s ease,color .2s ease}.onb-btn:hover{box-shadow:0 4px 10px rgba(0,0,0,.08);transform:translateY(-1px)}.onb .ob-icon{align-items:center;display:inline-flex}.onb .ob-icon svg{display:block;fill:currentColor;height:1.125em;overflow:visible;width:1.125em}.onb-icon{display:inline-block;height:1em;vertical-align:middle;width:1em}.onb-icon--arrow{margin-left:.5em;transition:transform .15s ease}.onb-btn:hover .onb-icon--arrow{transform:translateX(2px)}