* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  border-radius: 20px;
}

body {
  font-family: 'Poppins', sans-serif;
  background-color: #0d1117;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #c9d1d9;
  transition: background 0.3s ease, color 0.3s ease;
}

body.light-theme {
  background-color: #aaaaaa;
  color: #222;
}

body.light-theme .join-screen,
body.light-theme .chat-screen,
body.light-theme .input-box {
  background-color: #ffffff;
  color: #222;
}

body.light-theme input,
body.light-theme button {
  background-color: #e0e0e0;
  color: #222;
}

.join-screen {
  display: none;
  width: 100%;
  max-width: 600px;
  height: 50vh;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border-radius: 20px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.1);
  overflow: hidden;
}

.chat-screen {
  display: none;
  width: 100%;
  max-width: 600px;
  height: 90vh;
  flex-direction: column;
  justify-content: center;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border-radius: 20px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.1);
  overflow: hidden;
}

.screen.active {
  display: flex;
}

.form {
  width: 80%;
  max-width: 400px;
  padding: 30px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
  text-align: center;
}

.form h2 {
  font-size: 26px;
  margin-bottom: 20px;
  color: #fff;
}

.form input {
  width: 100%;
  padding: 12px;
  margin-bottom: 20px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  font-size: 14px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.form input::placeholder {
  color: rgba(255, 255, 255, 0.5);
}

.form button {
  width: 100%;
  padding: 12px;
  background: #1f6feb;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.form button:hover {
  background: #164da7;
}

/* Chat Screen Layout */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
  background: rgba(0, 0, 0, 0.8);
  color: #fff;
  font-size: 20px;
  font-weight: bold;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header button {
  background: transparent;
  color: #fff;
  padding: 8px 15px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.3s ease, color 0.3s ease;
}

.header button:hover {
  background: rgba(255, 255, 255, 0.2);
}

.header #back-to-menu-btn {
  background: transparent;
  color: #fff;
  padding: 8px 15px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.3s ease, color 0.3s ease;
  margin-right: 10px; 
}

.header #back-to-menu-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Message Area */
.messages {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.2) transparent;
}

.messages::-webkit-scrollbar {
  width: 8px;
}
.messages::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
}
.messages::-webkit-scrollbar-track {
  background: transparent;
}

/* Message Bubbles */
.message {
  display: flex;
  margin-bottom: 10px;
}

.message.own {
  justify-content: flex-end; 
}

.message.other {
  justify-content: flex-start; 
}

.message .bubble {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  padding: 10px;
  max-width: 60%;
  color: #fff;
  font-size: 15px;
  line-height: 1.4;
  animation: fadeIn 0.3s ease;
}

.message.own .bubble {
  background: #4f46e5; 
  color: #fff;
}

.message.other .bubble {
  background: #3c3c3c; 
  color: #f5f5f5;
}

.message .user {
  font-weight: bold;
  color: #ffcc70;
  margin-right: 5px;
}

.system-message {
  text-align: center;
  font-style: italic;
  color: #888;
  margin: 10px 0;
}

.input-box {
  display: flex;
  align-items: center;
  padding: 10px;
  background: rgba(255, 255, 255, 0.05);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.input-box input {
  flex: 1;
  padding: 10px 15px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 20px;
  font-size: 14px;
  background: rgba(255, 255, 255, 0.1); 
  color: #fff; 
  outline: none;
}

.input-box input::placeholder {
  color: rgba(255, 255, 255, 0.5); 
}

.input-box button {
  margin-left: 10px;
  padding: 10px 20px;
  background: #1f6feb;
  color: #fff;
  border: none;
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.input-box button:hover {
  background: #164da7;
}


.participants {
  padding: 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  margin-bottom: 10px;
  color: #fff;
}

.participants h3 {
  margin-bottom: 10px;
}

.participants ul {
  list-style: none;
  padding: 0;
}

.participants ul li {
  margin-bottom: 5px;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}