.animated-gradient{background:linear-gradient(-45deg,#833ab4,#fd1d1d,#fcb045,#405de6);background-size:400% 400%;animation:gradient 15s ease infinite;text-align:center}@keyframes gradient{0%{background-position:0 50%}50%{background-position:100% 50%}100%{background-position:0 50%}}.feature-card:hover{transform:translateY(-5px);box-shadow:0 20px 25px -5px rgba(0,0,0,0.1),0 10px 10px -5px rgba(0,0,0,0.04)}.nav-link-active{border-bottom-color:#6366f1!important;color:#111827!important}.toc-link-active{color:#fff!important;transform:scale(1.05)}.video-container{position:relative;padding-bottom:56.25%;height:0;overflow:hidden;max-width:100%;background:#000;border-radius:.75rem;box-shadow:0 10px 15px -3px rgba(0,0,0,0.1),0 4px 6px -2px rgba(0,0,0,0.05)}.video-container iframe{position:absolute;top:0;left:0;width:100%;height:100%}