/* ===================================
   CSS Reset & Base Styles
   =================================== */

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

:root {
    /* Color Palette - Professional Blues & Grays */
    --color-primary: #2563eb;
    --color-primary-dark: #1e40af;
    --color-secondary: #64748b;
    --color-text: #1e293b;
    --color-text-light: #64748b;
    --color-background: #ffffff;
    --color-background-alt: #f8fafc;
    --color-border: #e2e8f0;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Layout */
    --container-max-width: 1200px;
    --border-radius: 8px;
    
    /* Transitions */
    --transition-base: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   Accessibility
   =================================== */

/* Skip to main content link */
.skip-link {
    position: absolute;
    top: -100%;
    left: 0;
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    font-weight: 600;
    z-index: 10000;
    border-radius: 0 0 var(--border-radius) 0;
    transform: translateY(-100%);
}

.skip-link:focus {
    top: 0;
    transform: translateY(0);
    outline: 3px solid var(--color-primary-dark);
    outline-offset: 2px;
}

/* Focus styles for all interactive elements */
a:focus,
button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: 2px;
}

/* Focus-visible for modern browsers (removes focus ring on mouse click) */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
    outline: none;
}

/* Ensure text remains visible during font loading */
@font-face {
    font-display: swap;
}

/* Reduced motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .fade-in {
        opacity: 1;
        transform: none;
    }
}

/* ===================================
   Container & Layout
   =================================== */

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-content {
    max-width: 100%;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-xl);
    text-align: center;
    letter-spacing: -0.02em;
}

/* ===================================
   Navigation
   =================================== */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-links a {
    text-decoration: none;
    color: var(--color-text-light);
    font-weight: 500;
    transition: var(--transition-base);
    font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a:focus {
    color: var(--color-primary);
}

.nav-links a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 4px;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    padding: var(--spacing-3xl) 0;
    margin-top: 80px;
    min-height: 60vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    line-height: 1.8;
    font-weight: 400;
}

/* ===================================
   About Section
   =================================== */

.about {
    background-color: var(--color-background);
}

.about-grid {
    max-width: 800px;
    margin: 0 auto;
}

.about-text {
    text-align: left;
}

.lead-text {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    line-height: 1.7;
}

.about-text p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
    font-size: 1.05rem;
}

.about-text p:last-child {
    margin-bottom: 0;
}

/* ===================================
   Approach Section
   =================================== */

.approach {
    background-color: var(--color-background-alt);
}

.approach-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.approach-card {
    background-color: var(--color-background);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    transition: var(--transition-base);
}

.approach-card:hover,
.approach-card:focus-within {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.08);
    border-color: var(--color-primary);
}

/* Ensure cards are keyboard accessible if they become interactive later */
.approach-card:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.approach-icon {
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.approach-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.approach-description {
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===================================
   Footer
   =================================== */

.footer {
    background-color: var(--color-background);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
}

.footer-content {
    text-align: center;
}

.footer-text {
    color: var(--color-text-light);
    font-size: 0.9rem;
}

/* ===================================
   Animation Utilities
   =================================== */

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .nav-links {
        gap: var(--spacing-md);
    }
    
    .hero {
        margin-top: 70px;
        min-height: 50vh;
        padding: var(--spacing-2xl) 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .section {
        padding: var(--spacing-2xl) 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .approach-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .logo-text {
        font-size: 1rem;
    }
    
    .nav-links {
        font-size: 0.85rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .lead-text {
        font-size: 1.1rem;
    }
}

/* ===================================
   Print Styles
   =================================== */

@media print {
    .nav {
        position: static;
    }
    
    .approach-card {
        break-inside: avoid;
    }
}