:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --card-hover: rgba(255, 255, 255, 0.08);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #10b981;
    --glass-blur: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

header {
    padding: 2rem;
    text-align: center;
    border-bottom: 1px solid var(--card-border);
    backdrop-filter: blur(var(--glass-blur));
    position: sticky;
    top: 0;
    z-index: 100;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    background: linear-gradient(to right, #818cf8, #34d399);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

main {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    width: 100%;
}

.tool-display {
    margin-top: 1rem;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 1.5rem;
    padding: 3rem;
    backdrop-filter: blur(var(--glass-blur));
}

#viewport-info {
    text-align: center;
}

.pixel-value {
    font-size: 4rem;
    font-weight: 800;
    color: var(--accent-color);
    margin: 1rem 0;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 2rem;
}

.info-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.info-item.full-width {
    grid-column: 1 / -1;
    margin-top: 1.5rem;
}

.info-item .label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.info-item .value {
    font-size: 1.25rem;
    font-weight: 600;
}

.ua-container {
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: 0.5rem;
    word-break: break-all;
    font-family: monospace;
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-align: left;
    margin-top: 0.5rem;
}

.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    text-decoration: none;
    display: inline-block;
}

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

footer {
    padding: 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.75rem;
    }

    main {
        padding: 1rem;
    }

    .tool-display {
        padding: 1.5rem;
    }

    .pixel-value {
        font-size: 2.5rem;
    }

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