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

:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
    --background-light: #f8f9fa;
    --background-gradient-start: #ffffff;
    --background-gradient-end: #f0f4f8;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    background: linear-gradient(135deg, var(--background-gradient-start) 0%, var(--background-gradient-end) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    overflow: hidden;
}

main {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100vh;
    position: relative;
}

.zip-code {
    font-size: clamp(4rem, 15vw, 12rem);
    font-weight: 700;
    letter-spacing: 0.05em;
    color: var(--primary-color);
    position: relative;
    animation: fadeIn 1.2s ease-out;
    text-align: center;
    padding: 0 2rem;
}

.zip-code::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 4px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
    border-radius: 2px;
    animation: slideIn 1.5s ease-out 0.3s backwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        width: 0%;
        opacity: 0;
    }
    to {
        width: 60%;
        opacity: 1;
    }
}

/* Subtle background pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(52, 152, 219, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(52, 152, 219, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .zip-code {
        font-size: clamp(3rem, 20vw, 8rem);
        letter-spacing: 0.08em;
    }
    
    .zip-code::after {
        width: 70%;
        height: 3px;
    }
}

@media (max-width: 480px) {
    .zip-code {
        font-size: clamp(2.5rem, 25vw, 6rem);
        padding: 0 1rem;
    }
    
    .zip-code::after {
        width: 80%;
        height: 2px;
        bottom: -0.3rem;
    }
}

/* Tablet landscape */
@media (min-width: 769px) and (max-width: 1024px) {
    .zip-code {
        font-size: clamp(5rem, 12vw, 10rem);
    }
}

/* High resolution displays */
@media (min-width: 1920px) {
    .zip-code {
        font-size: clamp(8rem, 10vw, 14rem);
    }
}

/* Accessibility: Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    .zip-code,
    .zip-code::after {
        animation: none;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #e8eaed;
        --accent-color: #5dade2;
        --background-gradient-start: #1a1a1a;
        --background-gradient-end: #2d3436;
    }
    
    body::before {
        background-image: 
            radial-gradient(circle at 20% 30%, rgba(93, 173, 226, 0.05) 0%, transparent 50%),
            radial-gradient(circle at 80% 70%, rgba(93, 173, 226, 0.05) 0%, transparent 50%);
    }
}