.lesson-menu-btn{display:none}.lesson-menu-btn__bar{transition:transform .2s,opacity .2s}.lesson-shell--nav-open .lesson-menu-btn__bar:first-child{transform:translateY(7px)rotate(45deg)}.lesson-shell--nav-open .lesson-menu-btn__bar:nth-child(2){opacity:0}.lesson-shell--nav-open .lesson-menu-btn__bar:nth-child(3){transform:translateY(-7px)rotate(-45deg)}.lesson-topbar__nav{scrollbar-width:thin}.lesson-drawer-backdrop{display:none}.lesson-sidebar{position:sticky;top:80px}.lesson-sidebar__details summary{list-style:none}.lesson-sidebar__details summary::-webkit-details-marker{display:none}.lesson-sidebar__summary:after{content:"";border-bottom:2px solid #64748b;border-right:2px solid #64748b;width:8px;height:8px;transition:transform .2s;transform:rotate(45deg)translateY(-2px)}.lesson-sidebar__details[open] .lesson-sidebar__summary:after{transform:rotate(225deg)translateY(-2px)}@media (max-width:800px){.lesson-menu-btn{display:inline-flex}.lesson-topbar__nav{flex-wrap:nowrap;justify-content:flex-start;overflow-x:auto}.lesson-drawer-backdrop{z-index:110;opacity:0;pointer-events:none;transition:opacity .2s;display:block;position:fixed;inset:0}.lesson-shell--nav-open .lesson-drawer-backdrop{opacity:1;pointer-events:auto}.lesson-sidebar{z-index:120;width:min(300px,88vw);height:100dvh;max-height:100dvh;padding-top:max(20px, env(safe-area-inset-top,0px));padding-bottom:max(20px, env(safe-area-inset-bottom,0px));border-top:none;border-bottom:none;border-left:none;border-radius:0;margin:0;transition:transform .28s;position:fixed;top:0;left:0;transform:translate(-100%)}.lesson-shell--nav-open .lesson-sidebar{transform:translate(0)}}@media (min-width:801px){.lesson-drawer-backdrop,.lesson-sidebar__close{display:none!important}}