:root {
  --bg: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-tertiary: #1a1a25;
  --text: #e0e0e8;
  --text-secondary: #8888a0;
  --border: #2a2a3a;
  --accent: #6c5ce7;
  --accent-hover: #7d6ff0;
  --sent-bg: #2d1f6e;
  --received-bg: #1e1e2e;
  --danger: #e74c3c;
  --success: #2ecc71;

  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 14px;
  color: var(--text);
  background: var(--bg);
}

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

body {
  margin: 0;
  overflow: hidden;
}

#root {
  width: 100vw;
  height: 100vh;
}

/* Auth Page */
.auth-page {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background: var(--bg);
}

.auth-form {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 40px;
  width: 100%;
  max-width: 400px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.auth-form h2 {
  text-align: center;
  color: var(--text);
  font-size: 24px;
  margin-bottom: 8px;
}

.auth-form input {
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}

.auth-form input:focus {
  border-color: var(--accent);
}

.auth-form button {
  padding: 12px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.auth-form button:hover:not(:disabled) {
  background: var(--accent-hover);
}

.auth-form button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.auth-form .link-btn {
  background: none;
  color: var(--accent);
  padding: 0;
  font-weight: 400;
  cursor: pointer;
}

.auth-form .link-btn:hover {
  background: none;
  text-decoration: underline;
}

.auth-form p {
  text-align: center;
  color: var(--text-secondary);
  font-size: 13px;
}

.error {
  background: rgba(231, 76, 60, 0.15);
  color: var(--danger);
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 13px;
}

/* Chat App Layout */
.chat-app {
  display: flex;
  height: 100vh;
}

/* Sidebar */
.sidebar {
  width: 320px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h3 {
  color: var(--text);
  font-size: 18px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text-secondary);
}

.logout-btn {
  padding: 4px 10px;
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
}

.logout-btn:hover {
  color: var(--danger);
  border-color: var(--danger);
}

.new-chat-form,
.group-form {
  display: flex;
  padding: 12px 16px;
  gap: 8px;
}

.new-chat-form input,
.group-form input {
  flex: 1;
  padding: 8px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-size: 13px;
  outline: none;
}

.new-chat-form input:focus,
.group-form input:focus {
  border-color: var(--accent);
}

.new-chat-form button,
.group-form button {
  padding: 8px 14px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
}

.group-form {
  flex-direction: column;
}

.toggle-group-btn {
  margin: 0 16px;
  padding: 6px 12px;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  text-align: center;
}

.toggle-group-btn:hover {
  color: var(--text);
  border-color: var(--accent);
}

.conversation-list {
  flex: 1;
  overflow-y: auto;
}

.conversation-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  cursor: pointer;
  transition: background 0.15s;
  border-bottom: 1px solid var(--border);
}

.conversation-item:hover {
  background: var(--bg-tertiary);
}

.conversation-item.active {
  background: var(--accent);
}

.conversation-item.active .conv-name,
.conversation-item.active .conv-type {
  color: white;
}

.conv-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 600;
  color: var(--accent);
  flex-shrink: 0;
}

.conversation-item.active .conv-icon {
  background: rgba(255, 255, 255, 0.2);
  color: white;
}

.conv-info {
  min-width: 0;
}

.conv-name {
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conv-type {
  font-size: 12px;
  color: var(--text-secondary);
}

.empty-state {
  padding: 20px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 13px;
}

/* Chat Window */
.chat-window {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--bg);
}

.chat-window.empty {
  align-items: center;
  justify-content: center;
}

.no-chat-selected {
  text-align: center;
  color: var(--text-secondary);
}

.no-chat-selected h2 {
  font-size: 20px;
  margin-bottom: 8px;
  color: var(--text);
}

.chat-header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-secondary);
}

.chat-header h3 {
  font-size: 16px;
}

.encryption-badge {
  font-size: 11px;
  padding: 4px 10px;
  background: rgba(108, 92, 231, 0.15);
  color: var(--accent);
  border-radius: 20px;
  font-weight: 500;
}

.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.message {
  max-width: 70%;
  padding: 10px 14px;
  border-radius: 12px;
  position: relative;
}

.message.sent {
  align-self: flex-end;
  background: var(--sent-bg);
  border-bottom-right-radius: 4px;
}

.message.received {
  align-self: flex-start;
  background: var(--received-bg);
  border-bottom-left-radius: 4px;
}

.message-sender {
  font-size: 11px;
  color: var(--accent);
  margin-bottom: 4px;
  font-weight: 500;
}

.message-content {
  word-break: break-word;
  line-height: 1.5;
}

.message-time {
  font-size: 10px;
  color: var(--text-secondary);
  margin-top: 4px;
  text-align: right;
}

.message-input-form {
  display: flex;
  padding: 16px 24px;
  gap: 10px;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
}

.message-input-form input {
  flex: 1;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 14px;
  outline: none;
}

.message-input-form input:focus {
  border-color: var(--accent);
}

.message-input-form button {
  padding: 12px 24px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
}

.message-input-form button:hover:not(:disabled) {
  background: var(--accent-hover);
}

.message-input-form button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}