*{margin:0;padding:0;box-sizing:border-box}html,body,#root{height:100%;width:100%;overflow:hidden}html{height:-webkit-fill-available}.app-container{display:flex;flex-direction:column;height:100dvh;max-width:768px;margin:0 auto;overflow:hidden}.app-header{display:flex;align-items:center;justify-content:space-between;padding:8px 16px;border-bottom:1px solid #e0e0e0;flex-shrink:0}.app-header h1{font-size:1.1rem;font-weight:600;color:#3e7f4c}.chat-area{flex:1;overflow-y:auto;padding:8px;-webkit-overflow-scrolling:touch}.input-area{flex-shrink:0;border-top:1px solid #e0e0e0;padding-bottom:env(safe-area-inset-bottom,0px)}@media(max-width:480px){.app-header{padding:6px 12px}.chat-area{padding:4px}}