:root {
            --bg: #f4f6fb;
            --text: #222;
            --card: #fff;
            --accent: #4f5bff;
            --border: #dcdfff;

            --footer-bg: #222;
            --footer-text: #aaa;
        }

        @media (prefers-color-scheme: dark) {
            :root {
                --bg: #0f1115;
                --text: #eaeaea;
                --card: #232730;
                --border: #3a3f8f;
                --accent: #6c7bff;

                --footer-bg: #000;
                --footer-text: rgba(255, 255, 255, 0.7);
            }
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: Arial;
        }

        body {
            background: var(--bg);
            color: var(--text);
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        /* center page */
        .page {
            flex: 1;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .container {
            background: var(--card);
            padding: 25px;
            border-radius: 12px;
            width: 100%;
            max-width: 420px;
            text-align: center;
        }

        @media(min-width:768px) {
            .container {
                max-width: 900px;
            }
        }

        h2 {
            margin-bottom: 10px;
        }

        input {
            width: 100%;
            padding: 12px;
            border: 1px solid var(--border);
            border-radius: 8px;
            margin-bottom: 15px;
            background: transparent;
            color: var(--text);
        }

        .upload-box {
            border: 2px dashed var(--border);
            border-radius: 10px;
            padding: 20px;
            margin-bottom: 10px;
            cursor: pointer;
            transition: .3s;
        }

        .upload-box:hover {
            border-color: var(--accent);
        }

        #fileName {
            font-size: 13px;
            margin-bottom: 10px;
            color: green;
            display: none;
        }

        #logoInput {
            display: none;
        }

        button {
            width: 100%;
            padding: 12px;
            background: var(--accent);
            color: #fff;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            margin-bottom: 10px;
            font-weight: bold;
        }

        canvas {
            width: 220px;
            height: 220px;
            margin-top: 10px;
        }

        #downloadBtn {
            display: none;
            margin-top: 15px;
        }

        /* ===== NAVBAR ===== */
        .navbar {
            position: sticky;
            top: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(0, 0, 0, 0.2);
            backdrop-filter: blur(8px);
        }

        @media (prefers-color-scheme: dark) {
            .navbar {
                background: rgba(0, 0, 0, 0.4);
            }
        }

        .nav-container {
            max-width: 1100px;
            margin: auto;
            padding: 14px 18px;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .logo {
            color: #fff;
            font-size: 18px;
            font-weight: bold;
            text-decoration: none;
        }

        .menu-btn {
            width: 28px;
            height: 22px;
            position: relative;
            cursor: pointer;
        }

        .menu-btn span {
            position: absolute;
            height: 3px;
            width: 100%;
            background: #fff;
            border-radius: 2px;
            transition: 0.3s;
        }

        .menu-btn span:nth-child(1) {
            top: 0;
        }

        .menu-btn span:nth-child(2) {
            top: 9px;
        }

        .menu-btn span:nth-child(3) {
            top: 18px;
        }

        .menu-btn.active span:nth-child(1) {
            transform: rotate(45deg);
            top: 9px;
        }

        .menu-btn.active span:nth-child(2) {
            opacity: 0;
        }

        .menu-btn.active span:nth-child(3) {
            transform: rotate(-45deg);
            top: 9px;
        }

        .nav-menu {
            display: none;
            flex-direction: column;
            background: rgba(0, 0, 0, 0.9);
        }

        .nav-menu a {
            padding: 14px 20px;
            color: #fff;
            text-decoration: none;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .nav-menu a:hover {
            background: rgba(255, 255, 255, 0.1);
        }

        @media(min-width:768px) {
            .menu-btn {
                display: none
            }

            .nav-menu {
                display: flex !important;
                flex-direction: row;
                background: none;
                justify-content: center;
                padding-bottom: 10px;
            }

            .nav-menu a {
                border: none;
                padding: 0 14px;
            }
        }

        /* ===== SEO TEXT ===== */
        .seo-text {
            margin-top: 30px;
            background: var(--card);
            color: var(--text);
            padding: 20px;
            border-radius: 10px;
            border: 1px solid var(--border);
            font-size: 15px;
            line-height: 1.7;
            text-align: center;
        }

        .seo-text p {
            margin-bottom: 12px;
        }

        .seo-text ul {
            padding-left: 20px;
            text-align: left;
            display: inline-block;
        }

        .seo-text li {
            margin-bottom: 8px;
        }

        /* ===== SECTION ===== */
        .section {
            margin-top: 30px;
            background: var(--card);
            color: var(--text);
            padding: 20px;
            border-radius: 10px;
            border: 1px solid var(--border);
            text-align: center;
        }

        .section h2 {
            margin-bottom: 15px;
        }

        .section p {
            margin-bottom: 12px;
            font-size: 15px;
            line-height: 1.7;
        }

        .section ol {
            padding-left: 20px;
            line-height: 1.8;
            text-align: left;
            display: inline-block;
        }

        .section li {
            margin-bottom: 8px;
        }

        /* ===== FOOTER ===== */
        footer {
            background: var(--footer-bg);
            color: var(--footer-text);
            text-align: center;
            padding: 15px;
            margin-top: 18px;
            font-size: 16px;
        }

        footer a {
            color: var(--footer-text);
            text-decoration: none;
            margin: 0 6px;
        }

        footer a:hover {
            text-decoration: underline;
        }