body,html{min-height:100%;display:flex;flex-direction:column}body>:not(footer){flex:1}.footer{margin-top:4rem;border-top:1px solid var(--border-color);background-color:var(--surface-color);padding:2.5rem 0;transition:background-color .3s ease,border-color .3s ease}.footer .container{text-align:center}.footer p{margin:0;color:var(--muted-color);font-size:.9rem;font-weight:500}.tutorial-error-container{text-align:center;padding:2rem;color:#d9534f}.tutorial-header{margin-bottom:2rem;border-bottom:1px solid #eaeaea;padding-bottom:1rem;display:flex;justify-content:space-between;align-items:center}.tutorial-meta{display:flex;gap:1rem;font-size:.9rem;color:#666}.btn-back{display:inline-block;margin-bottom:1rem;color:#0070f3;text-decoration:none;font-weight:700;transition:color .3s}.btn-back:hover{color:#0056b3;text-decoration:underline}