body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 20px;
  background: #f9f9f9;
  color: #222;
}
h1,h2 {
  margin-bottom: 20px;
  text-align: center;
}
button {
  padding: 8px 14px;
  margin: 10px ;
  border: none;
  border-radius: 6px;
  background: #1976d2;
  color: white;
  cursor: pointer;
}
button:hover {
  background: #1565c0;
}
input,
textarea {
  width: 100%;
  padding: 8px;
  margin: 6px 0;
  border: 1px solid #ccc;
  border-radius: 6px;
}
textarea {
  height: 120px;
  resize: vertical;
}
.hidden {
  display: none;
}
.panel {
  background: white;
  padding: 16px;
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  margin-top: 20px;
}
#recvResult {
  margin-top: 10px;
  white-space: pre-wrap;
  padding: 10px;
  background: #f1f1f1;
  border-radius: 6px;
  min-height: 40px;
}
.mode-selection {
  margin: auto;
  width: fit-content;
}
#sendBtn,#recvBtn {
  display: block;
  margin: 20px auto 0 auto;
}
#deleteBtn {
  background: #d32f2f;
  margin-top: 10px;
}