.lessons-layout{--header-height:80px;padding-top:var(--header-height)}.lesson-content{max-width:65ch;margin:0 auto;line-height:1.7}.lesson-content h1,.lesson-content h2,.lesson-content h3,.lesson-content h4{font-weight:700;margin-top:2em;margin-bottom:.5em}.lesson-content h1{font-size:2.5rem;line-height:1.2}.lesson-content h2{font-size:2rem;line-height:1.3}.lesson-content h3{font-size:1.5rem;line-height:1.4}.lesson-content p{margin-bottom:1.5em}.lesson-content ol,.lesson-content ul{margin-bottom:1.5em;padding-left:2em}.lesson-content li{margin-bottom:.5em}.course-card{transition:all .3s cubic-bezier(.4,0,.2,1)}.course-card:hover{transform:translateY(-4px)}@keyframes progress-fill{0%{width:0}}.progress-bar{animation:progress-fill 1s ease-out forwards}@keyframes skeleton-shimmer{0%{background-position:-200px 0}to{background-position:calc(200px + 100%) 0}}.skeleton{background-color:#eee;background-image:linear-gradient(90deg,#eee,#f5f5f5,#eee);background-size:200px 100%;background-repeat:no-repeat;animation:skeleton-shimmer 1.2s ease-in-out infinite}@keyframes float{0%,to{transform:translateY(0)}50%{transform:translateY(-20px)}}.animate-float{animation:float 6s ease-in-out infinite}