.app-container{display:flex;flex-direction:column;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif}.header{display:flex;justify-content:space-between;align-items:center;padding:20px;background-color:#fff;border-bottom:1px solid #dee2e6;position:relative}.header h1{margin:0;color:#333;font-size:24px}.header-right{display:flex;align-items:center;gap:12px}.username-input{padding:8px 12px;border:2px solid #ddd;border-radius:6px;font-size:14px;font-family:inherit;background-color:#fff;color:#333;min-width:150px;text-align:center;cursor:text}.username-input:focus{outline:none;border-color:#4a90e2}.username-input:disabled{background-color:#f5f5f5;cursor:not-allowed}.app-wrapper{display:flex;flex:1}.sidebar-menu{width:250px;background-color:#f8f9fa;border-right:1px solid #dee2e6;padding:20px}.sidebar-menu-right{border-right:none;border-left:1px solid #dee2e6}.sidebar-menu h2{margin:0 0 20px;color:#333;font-size:18px}.sidebar-menu h2:not(:first-child){margin-top:30px}.menu-list{list-style:none;padding:0;margin:0}.menu-item{padding:12px 16px;margin-bottom:8px;border-radius:6px;cursor:pointer;color:#555;transition:background-color .2s}.menu-item:hover{background-color:#e9ecef}.menu-item.online-user,.menu-item.current-room{color:#28a745;text-shadow:0 0 8px rgba(40,167,69,.6),0 0 12px rgba(40,167,69,.4);font-weight:600}.app{flex:1;max-width:600px;margin:50px auto;padding:20px;display:flex;flex-direction:column}.form-container{display:flex;flex-direction:column;gap:20px;flex:1;min-height:0}.input-group{display:flex;flex-direction:column;gap:8px}.input-group-room-chat{flex:1;min-height:0;display:flex;flex-direction:column}.room-chat{flex:0;min-height:0;max-height:500px;padding:12px;border:2px solid #ddd;border-radius:6px;resize:none;font-size:14px;font-family:inherit;background-color:#f5f5f5;overflow-y:auto;white-space:pre-wrap}.room-chat-line{margin-bottom:4px}.room-chat-line-darkgreen{color:#006400}.room-chat-line-orange{color:orange}.room-chat-line-darkred{color:#8b0000}.room-chat-line-black{color:#000}label{font-weight:500;color:#555;font-size:14px}input,textarea{padding:12px;border:2px solid #ddd;border-radius:6px;font-size:14px;font-family:inherit;transition:border-color .2s}input:focus,textarea:focus{outline:none;border-color:#4a90e2}textarea{resize:vertical;min-height:120px}#room-chat{flex:1;min-height:0;height:100%}textarea[readOnly]{background-color:#f5f5f5;cursor:default}textarea[readOnly]:focus{border-color:#ddd}.submit-button{padding:12px 24px;background-color:#4a90e2;color:#fff;border:none;border-radius:6px;font-size:16px;font-weight:500;cursor:pointer;transition:background-color .2s}.submit-button:hover{background-color:#357abd}.submit-button:active{background-color:#2a5f8f}.login-button{padding:10px 20px;background-color:#28a745;color:#fff;border:none;border-radius:6px;font-size:14px;font-weight:500;cursor:pointer;transition:background-color .2s}.login-button:hover{background-color:#218838}.login-button:active{background-color:#1e7e34}*{margin:0;padding:0;box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:#f5f5f5}#root{min-height:100vh}