* {
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  background: linear-gradient(135deg, #007bff, #6610f2);
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chat-container {
  width: 90%;
  max-width: 400px;
  background: #fff;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0,0,0,0.2);
}

.chat-header {
  background: #007bff;
  color: #fff;
  padding: 15px;
  text-align: center;
  font-weight: 600;
}

#chat-box {
  height: 400px;
  overflow-y: auto;
  padding: 10px;
  background: #f4f4f4;
}

.message {
  padding: 8px 12px;
  margin: 8px;
  border-radius: 12px;
  max-width: 75%;
}

.sent {
  background: #007bff;
  color: #fff;
  margin-left: auto;
  text-align: right;
}

.received {
  background: #e9ecef;
  color: #333;
  margin-right: auto;
  text-align: left;
}

.time {
  font-size: 10px;
  color: #888;
  margin-top: 4px;
}

.chat-input {
  display: flex;
  border-top: 1px solid #ddd;
}

.chat-input input {
  flex: 1;
  padding: 12px;
  border: none;
  outline: none;
  font-size: 15px;
}

.chat-input button {
  background: #007bff;
  border: none;
  color: #fff;
  padding: 0 20px;
  cursor: pointer;
  font-weight: bold;
}

.chat-input button:hover {
  background: #0056b3;
}