/* CSS Variables for theming */
:root {
    /* Light mode colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --accent-primary: #1d4ed8;
    --accent-secondary: #1e40af;
    --link-color: #1d4ed8;
    --link-hover: #1e40af;
    --border-color: #e2e8f0;
    --shadow-light: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-medium: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-heavy: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* Dark mode colors */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #0f172a;
        --bg-secondary: #1e293b;
        --bg-tertiary: #334155;
        --text-primary: #f8fafc;
        --text-secondary: #cbd5e1;
        --text-muted: #94a3b8;
        --accent-primary: #3b82f6;
        --accent-secondary: #60a5fa;
        --link-color: #60a5fa;
        --link-hover: #93c5fd;
        --border-color: #334155;
        --shadow-light: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
        --shadow-medium: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
        --shadow-heavy: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    }
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Accessibility improvements */
:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Visually hidden elements for screen readers */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* Ensure all links have proper contrast */
a {
    color: var(--link-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover,
a:focus {
    color: var(--link-hover);
}

/* Override for specific link types */
.logo {
    color: var(--text-primary) !important;
}

.logo:hover {
    color: var(--accent-primary) !important;
}

/* Skip to main content link for screen readers */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--accent-primary);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
}

.skip-link:focus {
    top: 6px;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header and Navigation */
.header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.9);
}

@media (prefers-color-scheme: dark) {
    .header {
        background-color: rgba(15, 23, 42, 0.9);
    }
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.75rem;
    font-weight: 600;
    letter-spacing: -0.025em;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.logo:hover {
    color: var(--accent-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    font-weight: 500;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--link-hover);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link:focus::after {
    width: 100%;
}

/* Hero Section */
.hero {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: var(--shadow-medium);
}

.cta-button:hover,
.cta-button:focus {
    transform: translateY(-2px);
    box-shadow: var(--shadow-heavy);
}

/* Section Titles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-align: center;
    color: var(--text-primary);
}

/* Clients Section */
.clients {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.clients-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-top: 3rem;
    align-items: center;
    justify-content: center;
    max-width: 1500px;
    margin-left: auto;
    margin-right: auto;
}

.client-logo {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem;
    background-color: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    height: 120px;
    width: 120px;
    flex-shrink: 0;
}

.client-logo img {
    max-width: 80px;
    max-height: 80px;
    width: auto;
    height: auto;
    object-fit: contain;
    filter: grayscale(100%);
    transition: filter 0.3s ease;
}

.client-logo:hover img {
    filter: grayscale(0%);
}

/* About Section */
.about {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: start;
    margin-top: 3rem;
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.skills {
    margin-top: 2rem;
}

.skills h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.skills-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.5rem;
    list-style: none;
}

.skills-list li {
    padding: 0.5rem 1rem;
    background-color: var(--bg-tertiary);
    border-radius: 6px;
    color: var(--text-secondary);
    font-weight: 500;
    border-left: 3px solid var(--accent-primary);
}

.about-image {
    display: flex;
    justify-content: center;
}

.about-image img {
    width: 100%;
    max-width: 300px;
    height: auto;
    border-radius: 16px;
    box-shadow: var(--shadow-medium);
    object-fit: cover;
}

/* Contact Section */
.contact {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.contact-text {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.contact-item {
    text-align: center;
    padding: 2rem;
    background-color: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.contact-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.contact-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.contact-item a {
    font-weight: 500;
}

.contact-item a:hover,
.contact-item a:focus {
    text-decoration: underline;
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .clients-grid {
        gap: 1rem;
        max-width: 100%;
    }
    
    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .skills-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .hero {
        padding: 4rem 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        justify-content: center;
    }
}

/* Print styles */
@media print {
    .header,
    .footer {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .hero {
        background: white;
    }
    
    .about,
    .clients,
    .contact {
        background: white;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --text-primary: #000000;
        --text-secondary: #333333;
        --bg-primary: #ffffff;
        --bg-secondary: #f0f0f0;
        --accent-primary: #0066cc;
        --link-color: #0066cc;
        --link-hover: #004499;
        --border-color: #000000;
    }
    
    @media (prefers-color-scheme: dark) {
        :root {
            --text-primary: #ffffff;
            --text-secondary: #cccccc;
            --bg-primary: #000000;
            --bg-secondary: #1a1a1a;
            --accent-primary: #66b3ff;
            --link-color: #66b3ff;
            --link-hover: #99ccff;
            --border-color: #ffffff;
        }
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    html {
        scroll-behavior: auto;
    }
}