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

        :root {
            --black: #1a1a1a;
            --white: #ffffff;
            --gray-50: #fafafa;
            --gray-100: #f0f0f0;
            --gray-200: #e0e0e0;
            --gray-300: #c0c0c0;
            --gray-400: #888888;
            --neon: #39FF14;
            --neon-dim: #2bcc10;
            --pastel-pink: #FFB3BA;
            --pastel-blue: #BAE1FF;
            --pastel-yellow: #FFF3B0;
            --pastel-green: #BAFFC9;
            --pastel-purple: #E8BAFF;
            --red: #FF4444;
            --orange: #FF9500;
            --border: 3px solid var(--black);
            --shadow: 5px 5px 0px var(--black);
            --shadow-sm: 3px 3px 0px var(--black);
            --shadow-lg: 7px 7px 0px var(--black);
            --font-sans: system-ui, -apple-system, sans-serif;
            --font-mono: 'SF Mono', 'Fira Code', monospace;
        }

        body {
            font-family: var(--font-sans);
            min-height: 100vh;
            background: var(--gray-50);
            color: var(--black);
            overflow-x: hidden;
            position: relative;
        }

        .bg-pattern {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 0;
            pointer-events: none;
            background-image: radial-gradient(circle, var(--gray-200) 1px, transparent 1px);
            background-size: 24px 24px;
            opacity: 0.5;
        }

        .container {
            position: relative;
            z-index: 1;
            max-width: 960px;
            margin: 0 auto;
            padding: 48px 24px 40px;
            min-height: 100vh;
        }

        .header {
            text-align: center;
            margin-bottom: 48px;
        }

        .header-tag {
            display: inline-block;
            font-family: var(--font-mono);
            font-size: 0.75rem;
            font-weight: 600;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            background: var(--neon);
            color: var(--black);
            padding: 6px 16px;
            border: var(--border);
            box-shadow: var(--shadow-sm);
            margin-bottom: 20px;
        }

        h1 {
            font-size: 3rem;
            font-weight: 700;
            letter-spacing: -0.03em;
            line-height: 1.1;
            color: var(--black);
            margin-bottom: 8px;
        }

        .subtitle {
            font-size: 1.1rem;
            color: var(--gray-400);
            font-weight: 500;
        }

        .cards {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            margin-bottom: 40px;
        }

        .ip-card {
            background: var(--white);
            border: var(--border);
            box-shadow: var(--shadow);
            padding: 24px;
            position: relative;
            transition: transform 0.15s ease, box-shadow 0.15s ease;
        }

        .ip-card:hover {
            transform: translate(-2px, -2px);
            box-shadow: var(--shadow-lg);
        }

        .ip-card.v6 {
            background: var(--pastel-blue);
        }

        .ip-card.v4 {
            background: var(--pastel-green);
        }

        .ip-card .card-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 16px;
        }

        .ip-card h2 {
            font-size: 0.8rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.1em;
            color: var(--black);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .version-badge {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 3px 10px;
            font-family: var(--font-mono);
            font-size: 0.7rem;
            font-weight: 700;
            border: 2px solid var(--black);
        }

        .badge-v6 {
            background: var(--pastel-purple);
        }

        .badge-v4 {
            background: var(--pastel-yellow);
        }

        .copy-btn {
            background: var(--white);
            border: 2px solid var(--black);
            box-shadow: var(--shadow-sm);
            padding: 6px 14px;
            font-family: var(--font-sans);
            font-size: 0.75rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            cursor: pointer;
            transition: all 0.1s ease;
            display: flex;
            align-items: center;
            gap: 6px;
            color: var(--black);
            opacity: 0;
            pointer-events: none;
        }

        .copy-btn.visible {
            opacity: 1;
            pointer-events: auto;
        }

        .copy-btn:hover {
            background: var(--neon);
        }

        .copy-btn:active {
            transform: translate(2px, 2px);
            box-shadow: none;
        }

        .copy-btn.copied {
            background: var(--neon);
        }

        .copy-btn svg {
            width: 14px;
            height: 14px;
        }

        .ip-address {
            font-family: var(--font-mono);
            font-size: 1.6rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            word-break: break-all;
            line-height: 1.3;
            color: var(--black);
        }

        .loading {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            font-family: var(--font-mono);
            color: var(--gray-400);
            font-size: 1rem;
            font-weight: 500;
        }

        .loading-dots {
            display: inline-flex;
            gap: 4px;
        }

        .loading-dots span {
            width: 6px;
            height: 6px;
            background: var(--gray-400);
            animation: dotBounce 1.4s ease-in-out infinite;
        }

        .loading-dots span:nth-child(2) { animation-delay: 0.16s; }
        .loading-dots span:nth-child(3) { animation-delay: 0.32s; }

        @keyframes dotBounce {
            0%, 80%, 100% { opacity: 0.3; transform: scale(0.8); }
            40% { opacity: 1; transform: scale(1); }
        }

        .error {
            background: var(--white);
            border: 2px solid var(--red);
            padding: 14px 18px;
            font-size: 0.9rem;
            color: var(--black);
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 600;
        }

        .error svg {
            width: 18px;
            height: 18px;
            flex-shrink: 0;
            fill: var(--red);
        }

        .error > div {
            margin: 0;
            font-size: 0.9rem;
            font-weight: 600;
        }

        .section {
            margin-bottom: 40px;
        }

        .section-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 16px;
        }

        .section-title {
            font-size: 1.2rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.04em;
            color: var(--black);
        }

        .section-header::after {
            content: '';
            flex: 1;
            height: 3px;
            background: var(--black);
        }

        .checks-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 14px;
        }

        .check-card {
            background: var(--white);
            border: var(--border);
            box-shadow: var(--shadow-sm);
            padding: 16px 18px;
            display: flex;
            align-items: flex-start;
            gap: 12px;
            transition: transform 0.15s ease, box-shadow 0.15s ease;
        }

        .check-card:hover {
            transform: translate(-1px, -1px);
            box-shadow: 4px 4px 0px var(--black);
        }

        .check-icon {
            width: 30px;
            height: 30px;
            border: 2px solid var(--black);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .check-icon svg {
            width: 16px;
            height: 16px;
        }

        .check-icon.pass {
            background: var(--pastel-green);
        }

        .check-icon.pass svg { fill: #1a7a1a; }

        .check-icon.warn {
            background: var(--pastel-yellow);
        }

        .check-icon.warn svg { fill: #b37400; }

        .check-icon.fail {
            background: var(--pastel-pink);
        }

        .check-icon.fail svg { fill: var(--red); }

        .check-icon.info {
            background: var(--pastel-blue);
        }

        .check-icon.info svg { fill: #2a6cb5; }

        .check-content {
            flex: 1;
            min-width: 0;
        }

        .check-label {
            font-size: 0.65rem;
            font-weight: 700;
            color: var(--gray-400);
            text-transform: uppercase;
            letter-spacing: 0.1em;
            margin-bottom: 2px;
        }

        .check-value {
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--black);
            word-break: break-word;
        }

        .ua-card {
            grid-column: 1 / -1;
        }

        .ua-info {
            display: flex;
            flex-wrap: wrap;
            gap: 6px 24px;
            margin-top: 4px;
        }

        .ua-row {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .ua-key {
            font-size: 0.65rem;
            font-weight: 700;
            color: var(--gray-400);
            text-transform: uppercase;
            letter-spacing: 0.08em;
        }

        .ua-value {
            font-family: var(--font-mono);
            font-size: 0.82rem;
            font-weight: 600;
            color: var(--black);
        }

        .ua-full {
            width: 100%;
            margin-top: 10px;
            padding-top: 10px;
            border-top: 2px dashed var(--gray-200);
            font-family: var(--font-mono);
            font-size: 0.7rem;
            color: var(--gray-400);
            word-break: break-all;
            line-height: 1.5;
        }

        .accordion {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .accordion-item {
            background: var(--white);
            border: var(--border);
            box-shadow: var(--shadow-sm);
            overflow: hidden;
            transition: transform 0.15s ease, box-shadow 0.15s ease;
        }

        .accordion-item:hover {
            transform: translate(-1px, -1px);
            box-shadow: 4px 4px 0px var(--black);
        }

        .accordion-header {
            padding: 18px 20px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            user-select: none;
        }

        .accordion-header:hover {
            background: var(--gray-100);
        }

        .accordion-title {
            font-size: 0.95rem;
            font-weight: 700;
            color: var(--black);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .accordion-title svg {
            width: 18px;
            height: 18px;
            flex-shrink: 0;
        }

        .accordion-chevron {
            width: 20px;
            height: 20px;
            flex-shrink: 0;
            transition: transform 0.2s ease;
        }

        .accordion-item.open .accordion-chevron {
            transform: rotate(180deg);
        }

        .accordion-body {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease;
        }

        .accordion-item.open .accordion-body {
            max-height: 700px;
        }

        .accordion-content {
            padding: 0 20px 20px;
            font-size: 0.88rem;
            line-height: 1.7;
            color: var(--gray-400);
        }

        .accordion-content p {
            margin-bottom: 12px;
        }

        .accordion-content p:last-child {
            margin-bottom: 0;
        }

        .accordion-content strong {
            color: var(--black);
        }

        .accordion-content code {
            font-family: var(--font-mono);
            font-size: 0.8rem;
            background: var(--gray-100);
            border: 1px solid var(--gray-200);
            padding: 2px 6px;
            color: var(--black);
            font-weight: 600;
        }

        .comparison-table {
            width: 100%;
            border-collapse: collapse;
            margin-top: 12px;
            font-size: 0.82rem;
            border: var(--border);
        }

        .comparison-table th,
        .comparison-table td {
            padding: 10px 14px;
            text-align: left;
            border-bottom: 2px solid var(--gray-200);
            border-right: 2px solid var(--gray-200);
        }

        .comparison-table th:last-child,
        .comparison-table td:last-child {
            border-right: none;
        }

        .comparison-table th {
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            font-size: 0.72rem;
            background: var(--gray-100);
        }

        .comparison-table td:first-child {
            color: var(--gray-400);
            font-weight: 600;
        }

        .comparison-table td:nth-child(2) {
            font-family: var(--font-mono);
            font-weight: 600;
        }

        .comparison-table td:nth-child(3) {
            font-family: var(--font-mono);
            font-weight: 600;
        }

        .footer {
            margin-top: 8px;
        }

        .terminal {
            background: var(--black);
            border: var(--border);
            box-shadow: var(--shadow);
            padding: 0;
            margin-bottom: 20px;
            position: relative;
            overflow: hidden;
            cursor: pointer;
            transition: transform 0.15s ease, box-shadow 0.15s ease;
        }

        .terminal:hover {
            transform: translate(-2px, -2px);
            box-shadow: var(--shadow-lg);
        }

        .terminal:active {
            transform: translate(3px, 3px);
            box-shadow: 2px 2px 0px var(--black);
        }

        .terminal-bar {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 10px 16px;
            background: #2a2a2a;
            border-bottom: 2px solid #444;
        }

        .terminal-dots {
            display: flex;
            gap: 6px;
        }

        .terminal-dot {
            width: 10px;
            height: 10px;
            border: 2px solid rgba(255,255,255,0.15);
        }

        .terminal-dot:nth-child(1) { background: #ff5f57; }
        .terminal-dot:nth-child(2) { background: #ffbd2e; }
        .terminal-dot:nth-child(3) { background: #28c840; }

        .terminal-copy-label {
            font-family: var(--font-mono);
            font-size: 0.65rem;
            color: var(--gray-400);
            text-transform: uppercase;
            letter-spacing: 0.08em;
        }

        .terminal-body {
            padding: 18px 20px;
        }

        .terminal code {
            font-family: var(--font-mono);
            font-size: 0.82rem;
            color: var(--gray-300);
            line-height: 1.6;
            display: block;
            white-space: pre-wrap;
            word-break: break-all;
        }

        .terminal code .prompt { color: var(--neon); }
        .terminal code .flag { color: var(--pastel-blue); }
        .terminal code .url { color: var(--pastel-pink); }

        .tags {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            flex-wrap: wrap;
        }

        .tag {
            font-family: var(--font-mono);
            font-size: 0.72rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.06em;
            padding: 6px 14px;
            border: 2px solid var(--black);
            box-shadow: var(--shadow-sm);
            background: var(--white);
            color: var(--black);
            transition: transform 0.1s ease, box-shadow 0.1s ease;
        }

        .tag:nth-child(1) { background: var(--neon); }
        .tag:nth-child(2) { background: var(--pastel-pink); }
        .tag:nth-child(3) { background: var(--pastel-yellow); }

        .ipv6-warning {
            background: var(--pastel-yellow);
            border: var(--border);
            box-shadow: var(--shadow);
            padding: 24px 28px;
            margin-bottom: 40px;
            display: none;
            position: relative;
            animation: ipReveal 0.4s ease both;
        }

        .ipv6-warning.visible {
            display: block;
        }

        .ipv6-warning-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 14px;
        }

        .ipv6-warning-icon {
            width: 36px;
            height: 36px;
            background: var(--black);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .ipv6-warning-icon svg {
            width: 20px;
            height: 20px;
            fill: var(--pastel-yellow);
        }

        .ipv6-warning-title {
            font-size: 1rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.06em;
            color: var(--black);
        }

        .ipv6-warning-body {
            font-size: 0.88rem;
            line-height: 1.7;
            color: var(--black);
        }

        .ipv6-warning-body p {
            margin-bottom: 10px;
        }

        .ipv6-warning-body p:last-child {
            margin-bottom: 0;
        }

        .ipv6-warning-body strong {
            font-weight: 700;
        }

        .ipv6-warning-body ul {
            margin: 10px 0 10px 4px;
            padding: 0;
            list-style: none;
        }

        .ipv6-warning-body ul li {
            padding-left: 20px;
            position: relative;
            margin-bottom: 6px;
        }

        .ipv6-warning-body ul li::before {
            content: '→';
            position: absolute;
            left: 0;
            font-weight: 700;
            color: var(--black);
        }

        .ipv6-warning-dismiss {
            position: absolute;
            top: 12px;
            right: 12px;
            background: var(--white);
            border: 2px solid var(--black);
            box-shadow: var(--shadow-sm);
            width: 28px;
            height: 28px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            font-family: var(--font-mono);
            font-size: 1rem;
            font-weight: 700;
            line-height: 1;
            color: var(--black);
            transition: all 0.1s ease;
        }

        .ipv6-warning-dismiss:hover {
            background: var(--neon);
        }

        .ipv6-warning-dismiss:active {
            transform: translate(2px, 2px);
            box-shadow: none;
        }

        .ip-reveal {
            animation: ipReveal 0.3s ease both;
        }

        @keyframes ipReveal {
            from {
                opacity: 0;
                transform: translateY(6px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @media (max-width: 900px) {
            .checks-grid {
                grid-template-columns: 1fr 1fr;
            }
        }

        @media (max-width: 640px) {
            .container {
                padding: 32px 16px 28px;
            }

            h1 {
                font-size: 2rem;
            }

            .cards {
                grid-template-columns: 1fr;
            }

            .ip-card {
                padding: 20px;
            }

            .ip-address {
                font-size: 1.3rem;
            }

            .copy-btn {
                opacity: 1;
                pointer-events: auto;
            }

            .checks-grid {
                grid-template-columns: 1fr;
            }

            .ua-info {
                flex-direction: column;
                gap: 6px;
            }

            .tags {
                gap: 8px;
            }

            .ipv6-warning {
                padding: 20px;
            }

            .ipv6-warning-body ul li {
                font-size: 0.82rem;
            }
        }