body { font-family: sans-serif; background: #f4f7f6; display: flex; justify-content: center; align-items: center; height: 100vh; margin: 0; }
.chat-container { width: 350px; height: 500px; background: #fff; border-radius: 8px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); display: flex; flex-direction: column; overflow: hidden; }
.login-mode { height: auto; padding: 20px; }
.chat-header { background: #007bff; color: #fff; padding: 15px; display: flex; justify-content: space-between; align-items: center; }
.close-btn { background: transparent; border: 1px solid #fff; color: #fff; border-radius: 4px; cursor: pointer; font-size: 12px; }
.chat-messages { flex: 1; padding: 15px; overflow-y: auto; background: #f9f9f9; display: flex; flex-direction: column; gap: 10px; }
.message { max-width: 80%; padding: 8px 12px; border-radius: 15px; font-size: 14px; line-height: 1.4; position: relative; }
.message.sent { align-self: flex-end; background: #007bff; color: #fff; border-bottom-right-radius: 2px; }
.message.received { align-self: flex-start; background: #e9ecef; color: #333; border-bottom-left-radius: 2px; }
.chat-input-area { padding: 15px; border-top: 1px solid #eee; display: flex; gap: 10px; }
textarea { flex: 1; resize: none; border: 1px solid #ddd; border-radius: 4px; padding: 8px; height: 40px; }
button { background: #007bff; color: white; border: none; padding: 0 15px; border-radius: 4px; cursor: pointer; }
input { width: 100%; padding: 10px; margin-bottom: 10px; box-sizing: border-box; }
.status-tick { font-size: 10px; margin-left: 5px; opacity: 0.7; }