.expandable-wrapper{background:#fff;border:1px solid #ddd;border-radius:6px;margin:1rem 0;box-shadow:0 2px 6px #00000014;overflow:hidden}.expandable-header{display:flex;justify-content:space-between;align-items:center;background:#f2f2f2;padding:1rem;cursor:pointer}.expandable-title{margin:0;font-size:1.2rem;font-weight:600}.expandable-toggle{font-size:1.2rem;-webkit-user-select:none;user-select:none}.expandable-content{padding:1rem;animation:fadeIn .25s ease-in-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,sans-serif;background-color:#f6f6f6;color:#222;line-height:1.5}a{color:#07c;text-decoration:none}a:hover{text-decoration:underline}iframe{border:none;width:100%;aspect-ratio:16 / 9}.app-header{background-color:#111;color:#fff;padding:1rem;text-align:center}.app-header h1{margin-bottom:.5rem}.app-header nav a{margin:0 .5rem;color:#ccc}.app-main{padding:2rem;max-width:960px;margin:auto;background:#fff;box-shadow:0 0 10px #0000001a;border-radius:8px}.app-footer{text-align:center;padding:1rem;color:#888;font-size:.9rem}.mobile-controls{display:flex;flex-direction:column;align-items:center;margin-top:1rem;-webkit-user-select:none;user-select:none}.mobile-controls .row{display:flex;justify-content:center;margin:.25rem 0}.mobile-controls button{font-size:1.5rem;padding:.5rem 1rem;margin:.25rem;border:none;background-color:#444;color:#fff;border-radius:8px;width:3rem;height:3rem;touch-action:manipulation}.mobile-controls button:active{background-color:#222}