body, html { margin: 0; padding: 0; font-family: 'Segoe UI', sans-serif; background: #181824; color: #f3f3f3; }
.login-page { display: flex; align-items: center; justify-content: center; height: 100vh; }
.login-container { background: #23233a; padding: 32px 40px; border-radius: 12px; box-shadow: 0 2px 16px #0004; }
.login-container h2 { margin-bottom: 24px; color: #f3f3f3; }
.login-container form { display: flex; flex-direction: column; gap: 12px; }
.login-container input { padding: 10px; border: 1px solid #33364a; border-radius: 6px; background: #23233a; color: #f3f3f3; }
.login-container button { background: #3b82f6; color: #fff; border: none; padding: 10px; border-radius: 6px; cursor: pointer; transition: background 0.2s; }
.login-container button:hover { background: #2563eb; }
.register-link { margin-top: 16px; text-align: center; color: #b3b3b3; }
.register-link a { color: #60a5fa; text-decoration: underline; }
.main-layout { display: flex; height: 100vh; }
.sidebar { width: 260px; background: #23233a; color: #f3f3f3; display: flex; flex-direction: column; padding: 0 0 16px 0; transition: width 0.2s; border-right: 1px solid #23233a; }
.sidebar-header { padding: 16px; }
#toggleSidebar { background: none; border: none; color: #f3f3f3; font-size: 22px; cursor: pointer; }
.new-chat-btn { margin: 0 16px 16px 16px; padding: 10px; background: #3b82f6; border: none; border-radius: 6px; color: #fff; cursor: pointer; transition: background 0.2s; }
.new-chat-btn:hover { background: #2563eb; }
.chat-list { list-style: none; padding: 0 16px; margin: 0; }
.chat-list li { margin-bottom: 10px; }
.chat-list a { color: #f3f3f3; text-decoration: none; transition: color 0.2s; }
.chat-list a:hover { color: #60a5fa; }
.chat-section { flex: 1; display: flex; flex-direction: column; background: #181824; }
.chat-header { display: flex; justify-content: flex-end; align-items: center; padding: 16px; background: #23233a; border-bottom: 1px solid #23233a; }
.user-menu { position: relative; }
.user-menu img { width: 40px; height: 40px; border-radius: 50%; cursor: pointer; border: 2px solid #3b82f6; background: #23233a; }
.dropdown-menu { display: none; position: absolute; right: 0; top: 48px; background: #23233a; color: #f3f3f3; border-radius: 8px; box-shadow: 0 2px 8px #0006; min-width: 120px; border: 1px solid #33364a; z-index: 10; }
.dropdown-menu a { display: block; padding: 10px 16px; color: #f3f3f3; text-decoration: none; transition: background 0.2s; }
.dropdown-menu a:hover { background: #31314a; }
.chat-messages { flex: 1; padding: 24px; overflow-y: auto; display: flex; flex-direction: column; gap: 18px; }
.message { display: flex; align-items: flex-end; gap: 10px; }
.message.user { flex-direction: row-reverse; }
.message.ai { flex-direction: row; }
.message img { width: 32px; height: 32px; border-radius: 50%; background: #23233a; border: 2px solid #3b82f6; }
.message-content { background: #23233a; padding: 12px 18px; border-radius: 16px; max-width: 60%; color: #f3f3f3; border: 1px solid #33364a; }
.message.user .message-content { background: #3b82f6; color: #fff; border: none; }
.chat-input { display: flex; padding: 16px; background: #23233a; border-top: 1px solid #23233a; }
#messageInput { flex: 1; padding: 10px; border: 1px solid #33364a; border-radius: 6px; background: #181824; color: #f3f3f3; }
.chat-input button { margin-left: 10px; background: #3b82f6; color: #fff; border: none; padding: 10px 18px; border-radius: 6px; cursor: pointer; transition: background 0.2s; }
.chat-input button:hover { background: #2563eb; }
.sidebar.collapsed { width: 60px; }
.sidebar.collapsed .chat-list, .sidebar.collapsed .new-chat-btn { display: none; } 
.messageInput { flex: 1; padding: 10px; border: 1px solid #33364a; border-radius: 6px; background: #181824; color: #f3f3f3; }