/* --- THEME DEFINITIONS --- */
        :root {
            --font-main: 'Inter', sans-serif;
            --font-mono: 'Fira Code', monospace;
            --shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
        }

        .theme-dark {
            --bg-color: #1a1d24;
            --window-bg: rgba(20, 22, 27, 0.7);
            --window-border: rgba(255, 255, 255, 0.1);
            --header-bg: rgba(40, 44, 52, 0.8);
            --text-color: #e0e0e0;
            --text-muted: #888;
            --primary-color: #9f54ff;
            --secondary-color: #54c6ff;
            --accent-green: #2ecc71;
            --accent-red: #e74c3c;
            --accent-yellow: #f1c40f;
            --terminal-prompt: #54c6ff;
            --terminal-output: #2ecc71;
        }

        .theme-light {
            --bg-color: #f0f2f5;
            --window-bg: rgba(255, 255, 255, 0.7);
            --window-border: rgba(0, 0, 0, 0.1);
            --header-bg: rgba(230, 232, 235, 0.8);
            --text-color: #2c3e50;
            --text-muted: #7f8c8d;
            --primary-color: #8e44ad;
            --secondary-color: #2980b9;
            --accent-green: #27ae60;
            --accent-red: #c0392b;
            --accent-yellow: #f39c12;
            --terminal-prompt: #2980b9;
            --terminal-output: #2c3e50;
        }

        .theme-matrix {
            --bg-color: #000000;
            --window-bg: rgba(0, 10, 0, 0.7);
            --window-border: rgba(0, 255, 0, 0.3);
            --header-bg: rgba(0, 20, 0, 0.8);
            --text-color: #00ff00;
            --text-muted: #008000;
            --primary-color: #00ff00;
            --secondary-color: #00ff00;
            --accent-green: #00ff00;
            --accent-red: #00ff00;
            --accent-yellow: #00ff00;
            --font-main: 'Fira Code', monospace;
            --font-mono: 'Fira Code', monospace;
            --terminal-prompt: #00ff00;
            --terminal-output: #00ff00;
        }

        /* --- BASE STYLES --- */
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

        html, body {
            width: 100%;
            height: 100%;
            overflow: hidden;
            font-family: var(--font-main);
            color: var(--text-color);
            background-color: var(--bg-color);
            transition: background-color 0.3s ease;
        }

        #desktop {
            width: 100%;
            height: 100%;
            position: relative;
        }

        /* --- TASKBAR --- */
        #taskbar {
            position: absolute;
            bottom: 10px;
            left: 50%;
            transform: translateX(-50%);
            width: max-content;
            height: 60px;
            background: var(--window-bg);
            backdrop-filter: blur(20px);
            border: 1px solid var(--window-border);
            border-radius: 15px;
            display: flex;
            align-items: center;
            padding: 0 1rem;
            gap: 0.5rem;
            box-shadow: var(--shadow);
            z-index: 20000;
        }

        .dock-icon {
            width: 48px;
            height: 48px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: transform 0.2s, background-color 0.2s;
            border-radius: 8px;
            position: relative;
            color: var(--text-color);
        }
        .dock-icon:hover {
            transform: translateY(-5px);
            background: rgba(255, 255, 255, 0.1);
        }
        .dock-icon.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            width: 6px;
            height: 6px;
            background: var(--secondary-color);
            border-radius: 50%;
        }

        #clock {
            position: absolute;
            top: 20px;
            right: 20px;
            font-family: var(--font-mono);
            font-size: 1.2rem;
            text-shadow: 0 0 10px rgba(0,0,0,0.5);
            z-index: 1;
        }

        /* --- WINDOW STYLES --- */
        .window {
            position: absolute;
            background: var(--window-bg);
            backdrop-filter: blur(15px);
            border: 1px solid var(--window-border);
            border-radius: 10px;
            box-shadow: var(--shadow);
            min-width: 350px;
            min-height: 200px;
            display: flex;
            flex-direction: column;
            resize: both;
            overflow: auto; /* Changed from hidden to allow resize handle to always be accessible */
        }

        .window-header {
            height: 35px;
            background: var(--header-bg);
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 10px;
            cursor: move;
            flex-shrink: 0;
        }
        .window-title { font-weight: 500; }
        .window-controls { display: flex; gap: 8px; }
        .control-btn { width: 14px; height: 14px; border-radius: 50%; cursor: pointer; }
        .close-btn { background: var(--accent-red); }
        .minimize-btn { background: var(--accent-yellow); }
        .maximize-btn { background: var(--accent-green); }

        .window-body {
            flex-grow: 1;
            padding: 1rem;
            overflow-y: auto;
            font-size: 1rem;
        }

        /* --- TERMINAL APP --- */
        .terminal-body {
            background: rgba(0,0,0,0.5);
            font-family: var(--font-mono);
            padding: 0.5rem;
            height: 100%;
            overflow-y: auto;
            line-height: 1.5;
            white-space: pre-wrap;
        }
        .terminal-line { display: flex; }
        .terminal-input-line { display: flex; }
        .prompt { color: var(--terminal-prompt); margin-right: 0.5rem; }
        .terminal-input {
            flex-grow: 1;
            background: transparent;
            border: none;
            outline: none;
            color: var(--text-color);
            font-family: var(--font-mono);
        }
        .output { color: var(--terminal-output); }
        .output.error { color: var(--accent-red); }
        .output a { color: var(--secondary-color); text-decoration: underline; }
        
        /* --- GENERIC APP STYLES --- */
        .app-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
            gap: 1.5rem;
            align-content: start;
        }
        .app-icon {
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
            cursor: pointer;
            color: var(--text-color);
            text-decoration: none;
        }
        .app-icon i { font-size: 3rem; margin-bottom: 0.5rem; width: 60px; height: 60px; display:flex; align-items:center; justify-content:center; background: rgba(0,0,0,0.2); border-radius: 10px;}
        .app-icon span { font-size: 0.9rem; }

        /* --- CHAT APP STYLES --- */
        .chat-body-wrapper {
            display: flex;
            flex-direction: column;
            padding: 0;
            height: 100%;
        }
        .message-area {
            flex-grow: 1;
            padding: 1rem;
            overflow-y: auto;
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }
        .message {
            padding: 0.75rem 1rem;
            border-radius: 15px;
            max-width: 80%;
            line-height: 1.4;
        }
        .message.user {
            background: var(--primary-color);
            align-self: flex-end;
            border-bottom-right-radius: 5px;
            color: #fff;
        }
        .message.bot {
            background: #3a3f4b;
            align-self: flex-start;
            border-bottom-left-radius: 5px;
        }
        .chat-input-area {
            display: flex;
            padding: 1rem;
            border-top: 1px solid var(--window-border);
            flex-shrink: 0;
        }
        .chat-input {
            flex-grow: 1;
            background: rgba(0,0,0,0.3);
            border: 1px solid var(--window-border);
            border-radius: 20px;
            padding: 0.5rem 1rem;
            color: var(--text-color);
            outline: none;
        }
        .send-btn {
            background: none;
            border: none;
            color: var(--secondary-color);
            font-size: 1.5rem;
            margin-left: 1rem;
            cursor: pointer;
        }

        /* --- MINDMAP APP STYLES --- */
        .mindmap-body {
            position: relative;
            overflow: hidden;
            height: 100%;
            padding: 0;
        }
        .mindmap-canvas {
            position: absolute;
            top: 0; left: 0;
            width: 100%; height: 100%;
        }

        /* --- RESPONSIVENESS IMPROVEMENTS --- */
        @media (max-width: 768px) {
            #taskbar {
                width: 95%;
                height: 55px;
                padding: 0 0.5rem;
                gap: 0.25rem;
                border-radius: 12px;
            }
            .dock-icon {
                width: 44px;
                height: 44px;
                font-size: 1.3rem;
            }
            #clock {
                font-size: 1rem;
                top: 15px;
                right: 15px;
            }
            .window {
                /* On mobile, windows are non-resizable and take up most of the screen */
                resize: none;
                min-width: 0;
                min-height: 0;
                border-radius: 5px;
            }
            .app-grid {
                gap: 1rem;
                grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
            }
            .app-icon i {
                font-size: 2.5rem;
                width: 50px;
                height: 50px;
            }
            .app-icon span {
                font-size: 0.8rem;
            }
        }