/* General Styles & System Font Stack */
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
            background-color: #f3f4f6;
            color: #1f2937;
            display: flex;
            flex-direction: column; /* Stack header, main, footer */
            min-height: 100vh;
            margin: 0;
            box-sizing: border-box;
        }

        /* Header Styles */
        .site-header {
            width: 100%;
            background-color: #ffffff;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            padding: 1rem 2rem;
            box-sizing: border-box;
        }
        .header-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            max-width: 1200px;
            margin: 0 auto;
        }
        .site-title {
            font-weight: 700;
            font-size: 1.5rem;
            color: #111827;
        }
        .site-nav a {
            margin-left: 1.5rem;
            text-decoration: none;
            color: #4b5563;
            font-weight: 500;
            transition: color 0.2s;
        }
        .site-nav a:hover {
            color: #2563eb;
        }

        /* Main Content Area */
        main {
            flex: 1; /* Allows main content to grow and fill space */
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1rem;
            width: 100%;
            box-sizing: border-box;
        }

        /* Main Container */
        .container {
            width: 100%;
            max-width: 48rem; /* 768px */
            background-color: #ffffff;
            border-radius: 1rem; /* 16px */
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
            padding: 2rem;
            animation: fadeIn 0.5s ease-in-out;
            margin: 2rem 0; /* Add margin for spacing */
        }

        /* Header inside container */
        .tool-header {
            text-align: center;
            margin-bottom: 1.5rem; /* 24px */
        }
        .tool-header h1 {
            font-size: 2.25rem; /* 36px */
            font-weight: 700;
            color: #111827;
            margin: 0;
        }
        .tool-header p {
            margin-top: 0.5rem; /* 8px */
            color: #6b7280;
        }

        /* Editable Section */
        .editable-section {
            padding: 1rem 0;
            margin-bottom: 1.5rem;
            min-height: 20px;
            color: #4b5563;
            line-height: 1.6;
        }
        .editable-section:focus {
            outline: none; /* No visual effect on focus */
        }


        /* Instructions Box */
        .instructions {
            background-color: #eff6ff;
            border-left: 4px solid #3b82f6;
            color: #1d4ed8;
            padding: 1rem; /* 16px */
            border-radius: 0.5rem; /* 8px */
            margin-bottom: 1.5rem; /* 24px */
        }
        .instructions h2 {
            font-weight: 500;
            margin: 0 0 0.25rem 0;
            font-size: 1em;
        }
        .instructions ul {
            list-style-position: inside;
            margin: 0;
            padding: 0;
            font-size: 0.875rem; /* 14px */
        }

        /* Form Elements */
        .form-group {
            margin-bottom: 1rem; /* 16px */
        }
        .form-group label {
            display: block;
            font-size: 0.875rem; /* 14px */
            font-weight: 500;
            color: #374151;
            margin-bottom: 0.5rem; /* 8px */
        }
        textarea {
            width: 100%;
            padding: 0.75rem; /* 12px */
            background-color: #f9fafb;
            border: 1px solid #d1d5db;
            border-radius: 0.5rem; /* 8px */
            transition: border-color 0.2s, box-shadow 0.2s;
            box-sizing: border-box; /* Ensures padding doesn't affect width */
            resize: vertical;
        }
        textarea:focus {
            outline: none;
            border-color: #3b82f6;
            box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.4);
        }
        textarea#outputText {
            background-color: #f3f4f6;
            font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
        }
        
        /* Button Styles */
        .btn-container {
            text-align: center;
            margin-bottom: 1.5rem;
            display: flex;
            gap: 1rem;
            justify-content: center;
        }
        .btn {
            background-color: #2563eb;
            color: white;
            font-weight: 700;
            padding: 0.75rem 2rem;
            border: none;
            border-radius: 0.5rem; /* 8px */
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            cursor: pointer;
            transition: background-color 0.2s, transform 0.2s, box-shadow 0.2s;
        }
        .btn:hover {
            background-color: #1d4ed8;
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
        }
        .btn.btn-secondary {
             background-color: #6b7280;
        }
        .btn.btn-secondary:hover {
            background-color: #4b5563;
        }

        /* Output Area */
        .output-actions {
            margin-top: 0.75rem;
            text-align: center;
        }
        #copyBtn {
            background-color: #e5e7eb;
            color: #374151;
            font-weight: 500;
            padding: 0.5rem 1rem;
            border: 1px solid #d1d5db;
            border-radius: 0.5rem;
            cursor: pointer;
            transition: background-color 0.2s;
        }
        #copyBtn:hover {
            background-color: #d1d5db;
        }
        #copy-feedback {
            font-size: 0.875rem; /* 14px */
            margin-top: 0.5rem; /* 8px */
            text-align: center;
            height: 1rem; /* 16px */
        }
        
        /* Footer Styles */
        .site-footer {
            width: 100%;
            background-color: #1f2937;
            color: #d1d5db;
            padding: 2rem;
            text-align: center;
            box-sizing: border-box;
        }
        .site-footer a {
            color: #9ca3af;
            text-decoration: none;
        }
        .site-footer a:hover {
            text-decoration: underline;
        }

        /* Animation */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(-10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        /* Responsive Design */
        @media (max-width: 768px) {
            .header-container {
                flex-direction: column;
            }
            .site-title {
                margin-bottom: 1rem;
            }
            .site-nav {
                display: flex;
                flex-wrap: wrap;
                justify-content: center;
            }
            .site-nav a {
                margin: 0.5rem;
            }
            .container {
                padding: 1.5rem;
                margin: 1rem 0;
            }
            .tool-header h1 {
                font-size: 1.875rem; /* 30px */
            }
            .btn-container {
                flex-direction: column;
            }
        }