/* ============================
           THEME & VARIABLES
           ============================ */
        :root {
            --primary-color: #012f5b; 
            --accent-color: #0b4e8c;
            --bg-color: #f4f7fa;
            --white: #ffffff;
            --warn-bg: #fff3cd;
            --warn-text: #856404;
            --border-radius: 8px;
        }
        
        * { box-sizing: border-box; }

        body {
            font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background-color: var(--bg-color);
            color: #333;
            margin: 0;
            padding: 20px;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: flex-start;
        }

        .container {
            background: var(--white);
            width: 100%;
            max-width: 1100px;
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(1, 47, 91, 0.1);
        }

        h2 {
            text-align: center;
            color: var(--primary-color);
            margin-top: 0;
            margin-bottom: 30px;
            text-transform: uppercase;
            font-size: 1.5rem;
            letter-spacing: 1px;
            border-bottom: 2px solid #eee;
            padding-bottom: 15px;
        }

        /* LAYOUT GRID */
        .main-content {
            display: grid;
            grid-template-columns: 1fr;
            gap: 40px;
        }
        @media (min-width: 992px) {
            .main-content {
                grid-template-columns: 350px 1fr;
                align-items: start;
            }
            .left-panel {
                position: sticky;
                top: 20px;
                border-right: 1px solid #eee;
                padding-right: 30px;
            }
        }

        /* INPUTS */
        .form-group { margin-bottom: 20px; }
        
        label.input-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 700;
            color: var(--primary-color);
        }

        input[type="text"] {
            width: 100%;
            padding: 14px;
            font-size: 18px;
            border: 2px solid #dce4ec;
            border-radius: var(--border-radius);
            font-weight: bold;
            color: var(--primary-color);
            transition: 0.3s;
        }
        input[type="text"]:focus {
            border-color: var(--primary-color);
            outline: none;
            box-shadow: 0 0 0 3px rgba(1, 47, 91, 0.1);
        }

        /* VAT SELECTION */
        .vat-group {
            display: flex;
            gap: 20px;
            margin-bottom: 15px;
            background: #eef2f6;
            padding: 10px;
            border-radius: var(--border-radius);
            align-items: center;
        }
        .vat-group span {
            font-weight: 600;
            color: var(--primary-color);
            font-size: 0.9rem;
        }
        .vat-option {
            display: flex;
            align-items: center;
            cursor: pointer;
            font-weight: 500;
        }
        .vat-option input {
            margin-right: 6px;
            width: 18px;
            height: 18px;
            accent-color: var(--primary-color);
            cursor: pointer;
        }
        
        /* CHECKBOX */
        .checkbox-group {
            display: flex;
            align-items: center;
            margin-bottom: 25px;
            font-size: 15px;
            color: #555;
            cursor: pointer;
            user-select: none;
        }
        .checkbox-group input {
            margin-right: 10px;
            width: 18px;
            height: 18px;
            accent-color: var(--primary-color);
            cursor: pointer;
        }
        
        button.btn-submit {
            width: 100%;
            padding: 14px;
            background-color: var(--primary-color);
            color: var(--white);
            border: none;
            border-radius: var(--border-radius);
            font-size: 16px;
            font-weight: 700;
            text-transform: uppercase;
            cursor: pointer;
            transition: background 0.3s, transform 0.1s;
        }
        button.btn-submit:hover { background-color: var(--accent-color); }
        button.btn-submit:active { transform: translateY(1px); }

        /* RESULTS AREA */
        #result-area { display: none; }

        /* Suggestion Box */
        #suggestion-box {
            display: none;
            background-color: var(--warn-bg);
            color: var(--warn-text);
            border: 1px solid #ffeeba;
            padding: 15px;
            border-radius: var(--border-radius);
            margin-bottom: 25px;
            font-size: 0.95rem;
            line-height: 1.6;
        }
        .suggest-highlight { font-weight: bold; font-size: 1.2rem; color: #d35400; }
        .btn-apply {
            margin-top: 10px;
            padding: 8px 16px;
            background-color: #d35400;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            font-weight: 600;
        }
        .btn-apply:hover { background-color: #a04000; }

        /* Table */
        .tax-table {
            width: 100%;
            margin-bottom: 30px;
            border-collapse: separate;
            border-spacing: 0;
            border: 1px solid #e1e8ed;
            border-radius: var(--border-radius);
            overflow: hidden;
        }
        .tax-table tr:nth-child(odd) { background-color: #fcfcfc; }
        .tax-table td { padding: 12px 15px; border-bottom: 1px solid #eee; }
        .tax-table tr:last-child td { border-bottom: none; background-color: #eaf2f8; }
        .tax-table td:first-child { color: #666; width: 40%; }
        .tax-table td:last-child {
            text-align: right; font-weight: bold;
            color: var(--primary-color); font-size: 1.1rem;
            font-family: 'Courier New', Courier, monospace;
        }

        /* Copy Block */
        .copy-grid { display: grid; gap: 15px; }
        .copy-row { position: relative; }
        .copy-row label {
            display: block; font-size: 0.75rem; color: #888;
            margin-bottom: 5px; text-transform: uppercase; font-weight: 700;
        }
        .text-box {
            background: #f8f9fa; padding: 12px; padding-right: 80px;
            border: 1px solid #dde2e5; border-radius: 6px;
            color: #333; font-size: 1rem; min-height: 46px;
            display: flex; align-items: center; word-break: break-word;
        }
        .btn-copy {
            position: absolute; right: 5px; top: 50%; transform: translateY(2px);
            background-color: #fff; border: 1px solid var(--primary-color);
            color: var(--primary-color); padding: 6px 12px;
            border-radius: 4px; cursor: pointer; font-size: 0.75rem;
            font-weight: bold; transition: all 0.2s;
        }
        .btn-copy:hover { background-color: var(--primary-color); color: white; }
        .btn-copy.copied { background-color: #27ae60; border-color: #27ae60; color: white; }

        .error-msg {
            color: #e74c3c; background: #fadbd8; padding: 10px;
            border-radius: 6px; text-align: center; display: none;
            margin-bottom: 20px; font-weight: 600;
        }

        /* Intro Text */
        .intro-text {
            text-align: center;
            color: #666;
            font-size: 0.95rem;
            margin-bottom: 30px;
            line-height: 1.5;
        }