.wrapper { padding: 2rem 1rem; }
        h1 {
            text-align: center;
            margin-top: 0px;
            color: #1a202c;
            font-size: 2.25rem;
            font-weight: bold;
        }
        h2 {
            font-size: 1.5rem;
            font-weight: bold;
            color: #1a202c;
            margin-top: 2rem;
            margin-bottom: 1rem;
        }
        p { margin: 0 0 16px; color: var(--color-gray); line-height: 1.6; }
        .articlecontainer { margin: auto; max-width: 800px; width: 100%; }
        .hidden { display: none; }
        .card {
            background-color: var(--color-white);
            border-radius: 16px;
            border: 1px solid var(--border-color);
            box-shadow: 0 10px 15px -3px var(--secondary-color), 0 4px 6px -2px var(--secondary-color);
            padding: 2rem;
            margin-bottom: 2rem;
        }
        input[type="number"] {
            width: 100%;
            padding: 0.75rem;
            border: 1px solid #cbd5e0;
            border-radius: 0.5rem;
            box-shadow: inset 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            font-size: 1rem;
            transition: border-color 0.2s, box-shadow 0.2s;
        }
        input:focus {
            outline: none;
            border-color: var(--main-color);
            box-shadow: 0 0 0 3px rgba(26, 72, 238, 0.3);
        }
        .instructions {
            background-color: var(--color-white);
            padding: 1.5rem;
            border-radius: 8px;
            box-shadow: 0 4px 6px -1px var(--secondary-color), 0 2px 4px -1px var(--secondary-color);
            margin-bottom: 1.5rem;
        }
        .instructions ul { list-style-position: inside; padding-left:0; margin-left: 1rem; }
        .instructions li { margin-bottom: 0.5rem; }
        .ad-container { width: 100%; margin: 2rem auto; text-align: center; min-height: 90px; }
        
        .visually-hidden {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }

        .tab-navigation {
            display: flex;
            border: 1px solid var(--border-color);
            border-radius: 0.5rem;
            background-color: #f8fafc;
            padding: 0.25rem;
            margin-bottom: 1.5rem;
        }
        .tab-btn {
            flex: 1;
            padding: 0.5rem;
            font-size: 0.875rem;
            font-weight: 600;
            border-radius: 0.375rem;
            color: var(--color-gray);
            background-color: transparent;
            border: none;
            cursor: pointer;
            transition: background-color 0.2s ease-in-out, color 0.2s ease-in-out;
        }
        .tab-btn[aria-selected="true"] {
            background-color: var(--main-color);
            color: var(--color-white);
            box-shadow: 0 1px 3px rgba(0,0,0,0.1);
        }
        .calculator-section > p {
            text-align: center;
            font-weight: 500;
            color: var(--color-gray);
            margin-bottom: 1rem;
        }
        .input-group {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1rem;
        }
        @media (min-width: 640px) { .input-group { flex-direction: row; } }
        .input-group div { flex: 1; width: 100%; }
        .input-group input { text-align: center; width: 100%; }
        .input-group span { color: var(--color-gray); font-weight: 500; }
        .result-box {
            margin-top: 1.5rem;
            text-align: center;
            background-color: #eff6ff;
            padding: 1rem;
            border-radius: 0.5rem;
        }
        .result-box .result-label { display: block; font-size: 0.875rem; color: var(--color-gray); }
        .result-box .result-value { font-size: 2.25rem; font-weight: bold; color: var(--main-color); }
        .result-value.increase { color: var(--color-green-dark); }
        .result-value.decrease { color: var(--color-error-dark); }

        .explanation-box {
            margin-top: 1.5rem;
            padding: 1rem;
            background-color: var(--secondary-background);
            border-radius: 0.5rem;
            font-size: 0.9rem;
            line-height: 1.6;
        }
        .explanation-box h3 {
            font-size: 1.1rem;
            font-weight: 600;
            margin-top: 0;
            margin-bottom: 0.5rem;
            text-align: center;
        }
        .explanation-box p {
            margin-bottom: 0.5rem;
        }
        .explanation-box code {
            font-family: monospace;
            background-color: var(--tertiary-background);
            padding: 0.1rem 0.3rem;
            border-radius: 4px;
        }
         /* Mobile-Friendly Styles */
        @media (max-width: 480px) {
            .wrapper {
                padding: 1rem 0.5rem;
            }
            h1 {
                font-size: 1.75rem;
            }
            .card {
                padding: 1.5rem;
            }
            .tab-navigation {
                flex-direction: column;
                gap: 0.25rem;
            }
            .result-box .result-value {
                font-size: 1.75rem;
            }
        }