:root{--primary-color:#4a90e2;--bg-color:#f5f7fb;--chat-bg:#fff;--text-main:#333;--text-muted:#666;--bot-msg-bg:#f0f2f5;--user-msg-bg:#4a90e2;--border-color:#e1e4e8;--shadow:0 10px 25px #0000000d}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-main);justify-content:center;align-items:center;height:100vh;font-family:Pretendard,-apple-system,BlinkMacSystemFont,system-ui,Roboto,sans-serif;display:flex}#root{justify-content:center;align-items:center;width:100%;height:100%;display:flex}.app-container{background-color:var(--chat-bg);width:100%;max-width:800px;height:90vh;box-shadow:var(--shadow);border-radius:20px;flex-direction:column;margin:20px;display:flex;overflow:hidden}.chat-header{background-color:var(--chat-bg);border-bottom:1px solid var(--border-color);align-items:center;gap:15px;padding:24px;display:flex}.chat-header h1{color:var(--primary-color);font-size:1.5rem;font-weight:700}.chat-header p{color:var(--text-muted);font-size:.9rem}.messages-container{background-color:#fafbfc;flex-direction:column;flex:1;gap:16px;padding:24px;display:flex;overflow-y:auto}.message-wrapper{flex-direction:column;max-width:75%;display:flex}.message-wrapper.bot{align-self:flex-start}.message-wrapper.user{align-self:flex-end}.message-bubble{border-radius:18px;padding:14px 18px;font-size:1rem;line-height:1.5;position:relative}.bot .message-bubble{background-color:var(--bot-msg-bg);color:var(--text-main);border-top-left-radius:4px}.user .message-bubble{background-color:var(--user-msg-bg);color:#fff;border-top-right-radius:4px}.message-time{color:var(--text-muted);margin-top:5px;padding:0 5px;font-size:.75rem}.user .message-time{text-align:right}.input-area{background-color:var(--chat-bg);border-top:1px solid var(--border-color);padding:24px}.input-form{border:1px solid var(--border-color);background-color:#f8f9fa;border-radius:30px;gap:12px;padding:8px;transition:border-color .2s,box-shadow .2s;display:flex}.input-form:focus-within{border-color:var(--primary-color);box-shadow:0 0 0 3px #4a90e21a}.input-form input{background:0 0;border:none;outline:none;flex:1;padding:10px 15px;font-size:1rem}.send-button{background-color:var(--primary-color);color:#fff;cursor:pointer;border:none;border-radius:50%;justify-content:center;align-items:center;width:44px;height:44px;transition:transform .2s,background-color .2s;display:flex}.send-button:hover{background-color:#357abd;transform:scale(1.05)}.send-button:disabled{cursor:not-allowed;background-color:#ccc}.typing-indicator{color:var(--text-muted);margin-bottom:10px;padding:0 5px;font-size:.85rem;font-style:italic}@media (width<=600px){.app-container{border-radius:0;height:100vh;margin:0}}