decomposition-tree-exercise:not(:defined){display:none}.dt-wrapper{display:flex;flex-direction:column;gap:1rem}.dt-controls{display:flex;flex-wrap:wrap;align-items:center;gap:.75rem}.dt-select-label{font-size:.9rem;font-weight:600;color:var(--text-secondary);white-space:nowrap}.dt-select{flex:1;min-width:180px;padding:.5rem .75rem;border:2px solid var(--color-gray-100, #eee);border-radius:8px;font-size:.9rem;color:var(--text-primary);background:#fff;cursor:pointer;min-height:44px;transition:border-color .15s ease}.dt-select:focus{outline:2px solid var(--color-teal);outline-offset:2px;border-color:var(--color-teal)}.dt-reset-btn{white-space:nowrap;min-height:44px;padding:.5rem 1rem}.dt-hint{font-size:.9rem;color:var(--text-secondary);background:var(--color-cream, #fff8f0);border:1px solid var(--color-gray-100, #eee);border-radius:8px;padding:.75rem 1rem;margin:0;line-height:1.6}.dt-hint--complete{background:#e8f5e9;border-color:#66bb6a;color:#2e7d32;font-weight:600}.dt-scroll-container{overflow-x:auto;overflow-y:visible;padding:1rem .5rem 1.5rem;border:1px solid var(--color-gray-100, #eee);border-radius:12px;background:#fafafa;min-height:200px}.dt-tree{display:flex;justify-content:center;min-width:max-content}.dt-node-wrapper{display:flex;flex-direction:column;align-items:center;position:relative;padding:0 .5rem}.dt-node-wrapper:has(>.dt-children:not([hidden])):after{content:"";display:block;width:2px;height:1.5rem;background:var(--color-teal, #2B6777);opacity:.6;flex-shrink:0}.dt-children{display:flex;flex-direction:row;justify-content:center;gap:.75rem;position:relative;padding-top:1.5rem}.dt-children[hidden]{display:none}.dt-children:before{content:"";position:absolute;top:0;left:var(--connector-left, 10%);width:var(--connector-width, 80%);height:2px;background:var(--color-teal, #2B6777);opacity:.6}.dt-node-wrapper:before{content:"";position:absolute;top:-1.5rem;left:50%;transform:translate(-50%);width:2px;height:1.5rem;background:var(--color-teal, #2B6777);opacity:.6}.dt-tree>.dt-node-wrapper:before{display:none}.dt-node{display:flex;align-items:center;justify-content:center;gap:.4rem;background:#fff;border:2px solid var(--color-teal, #2B6777);border-radius:8px;padding:.5rem .85rem;min-width:110px;max-width:160px;text-align:center;cursor:pointer;font-size:.82rem;font-weight:500;color:var(--text-primary);user-select:none;-webkit-tap-highlight-color:transparent;transition:background .15s ease,box-shadow .15s ease,border-color .15s ease;min-height:44px;line-height:1.3;position:relative;z-index:1}.dt-node:hover,.dt-node:focus-visible{background:var(--color-cream, #fff8f0);box-shadow:0 2px 8px #2b677726;outline:none}.dt-node:focus-visible{outline:2px solid var(--color-teal);outline-offset:2px}.dt-node--expanded{background:var(--color-teal, #2B6777);color:#fff;border-color:var(--color-teal, #2B6777)}.dt-node--expanded:hover{background:#235a6a;border-color:#235a6a}.dt-node-label{flex:1}.dt-node-indicator{font-size:1rem;font-weight:700;line-height:1;flex-shrink:0;width:1.1em;text-align:center}.dt-add-btn{display:block;margin-top:.5rem;padding:.4rem .75rem;min-height:44px;min-width:110px;background:transparent;border:2px dashed var(--color-teal, #2B6777);border-radius:8px;color:var(--color-teal, #2B6777);font-size:.8rem;font-weight:600;cursor:pointer;transition:background .15s ease,color .15s ease;-webkit-tap-highlight-color:transparent}.dt-add-btn:hover,.dt-add-btn:focus-visible{background:#2b677714;outline:none}.dt-add-btn:focus-visible{outline:2px solid var(--color-teal);outline-offset:2px}.dt-add-input{display:block;margin-top:.5rem;padding:.4rem .6rem;min-height:44px;min-width:110px;max-width:160px;border:2px solid var(--color-teal, #2B6777);border-radius:8px;font-size:.82rem;color:var(--text-primary);background:#fff}.dt-add-input:focus{outline:2px solid var(--color-teal);outline-offset:2px}@media(max-width:500px){.dt-node{min-width:80px;max-width:120px;font-size:.75rem;padding:.4rem .6rem}.dt-add-btn,.dt-add-input{min-width:80px;font-size:.75rem}.dt-controls{flex-direction:column;align-items:stretch}.dt-select{width:100%}}