/* Core UI */
body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; margin: 0; background-color: #f8f9fa; }
header { background: #343a40; color: white; padding: 1rem 2rem; display: flex; justify-content: space-between; align-items: center; }
nav input { padding: 0.5rem; width: 300px; border-radius: 4px; border: none; }
nav button { padding: 0.5rem 1rem; background: #007bff; color: white; border: none; border-radius: 4px; cursor: pointer; }
main { padding: 2rem; }
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 1rem; margin-top: 1rem; }
.product-card { background: white; padding: 1rem; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); text-align: center; }
#ai-chat { position: fixed; bottom: 20px; right: 20px; width: 300px; background: white; border-radius: 8px; box-shadow: 0 4px 12px rgba(0,0,0,0.15); display: flex; flex-direction: column; }
#ai-chat h3 { margin: 0; padding: 1rem; background: #28a745; color: white; border-radius: 8px 8px 0 0; }
#chat-messages { height: 200px; padding: 1rem; overflow-y: auto; border-bottom: 1px solid #ddd; }
#chatInput { border: none; padding: 1rem; border-radius: 0 0 8px 8px; outline: none; width: 100%; box-sizing: border-box; }