:root {
            --bg-color: #f5f5f5;
            --container-bg: white;
            --text-color: #333;
            --border-color: #ddd;
            --label-color: #555;
            --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            --primary-btn: #2196F3;
            --primary-btn-hover: #0b7dda;
            --copy-btn: #4CAF50;
            --copy-btn-hover: #45a049;
        }

        .dark-mode {
            --bg-color: #121212;
            --container-bg: #1e1e1e;
            --text-color: #f5f5f5;
            --border-color: #444;
            --label-color: #bbb;
            --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
            transition: background-color 0.3s, color 0.3s, border-color 0.3s;
        }
        
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background-color: var(--bg-color);
            color: var(--text-color);
            padding: 1rem;
            line-height: 1.5;
        }
        
        .container {
            width: 100%;
            max-width: 500px;
            background-color: var(--container-bg);
            padding: 1.5rem;
            border-radius: 0.5rem;
            box-shadow: var(--shadow);
        }
        
        h1 {
            text-align: center;
            margin-bottom: 1.25rem;
            font-size: clamp(1.25rem, 4vw, 1.5rem);
        }
        
        .password-display {
            display: flex;
            margin-bottom: 1.25rem;
            gap: 0.25rem;
        }
        
        #password {
            flex-grow: 1;
            padding: 0.75rem;
            border: 1px solid var(--border-color);
            border-radius: 0.25rem 0 0 0.25rem;
            font-size: 1rem;
            background-color: var(--container-bg);
            color: var(--text-color);
            min-width: 0; /* Permite que o input encolha */
        }
        
        #copy-btn {
            padding: 0 1rem;
            background-color: var(--copy-btn);
            color: white;
            border: none;
            border-radius: 0 0.25rem 0.25rem 0;
            cursor: pointer;
            white-space: nowrap;
            font-size: 0.875rem;
        }
        
        #copy-btn:hover {
            background-color: var(--copy-btn-hover);
        }
        
        .controls {
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }
        
        .control-group {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }
        
        label {
            font-size: 0.875rem;
            color: var(--label-color);
        }
        
        input[type="range"] {
            width: 100%;
            margin: 0.5rem 0;
        }
        
        .length-display {
            text-align: center;
            font-size: 1rem;
            font-weight: bold;
        }
        
        .checkbox-group {
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
        }
        
        .checkbox-item {
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        
        #generate-btn {
            padding: 0.75rem;
            background-color: var(--primary-btn);
            color: white;
            border: none;
            border-radius: 0.25rem;
            font-size: 1rem;
            cursor: pointer;
            margin-top: 0.5rem;
            width: 100%;
        }
        
        #generate-btn:hover {
            background-color: var(--primary-btn-hover);
        }
        
        .theme-toggle {
            position: fixed;
            top: 1rem;
            right: 1rem;
            background: none;
            border: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: var(--text-color);
            z-index: 100;
            padding: 0.5rem;
            border-radius: 50%;
            background-color: rgba(0,0,0,0.1);
        }
        
        .dark-mode .theme-toggle {
            background-color: rgba(255,255,255,0.1);
        }
        
        /* Melhorias para telas muito pequenas */
        @media (max-width: 350px) {
            .container {
                padding: 1rem;
            }
            
            .password-display {
                flex-direction: column;
            }
            
            #password {
                border-radius: 0.25rem;
                width: 100%;
            }
            
            #copy-btn {
                border-radius: 0.25rem;
                padding: 0.5rem;
            }
            
            .theme-toggle {
                font-size: 1.25rem;
                top: 0.5rem;
                right: 0.5rem;
            }
        }
        
        /* Melhorias para inputs e checkboxes */
        input[type="checkbox"] {
            width: 1.1em;
            height: 1.1em;
            accent-color: var(--primary-btn);
        }
        
        input[type="range"] {
            height: 0.5rem;
            background: var(--border-color);
            border-radius: 0.25rem;
        }
        
        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 1.25rem;
            height: 1.25rem;
            background: var(--primary-btn);
            border-radius: 50%;
            cursor: pointer;
        }