/* CSS Reset & Base Styles - Optimized for PageSpeed 100/100 */
:root {
    /* Color Palette - Dutch Design inspired */
    --primary: #2C3E50;
    --secondary: #3498DB;
    --success: #2ECC71;
    --danger: #E74C3C;
    --warning: #F39C12;
    --light: #ECF0F1;
    --dark: #34495E;
    --white: #FFFFFF;
    --gray: #7F8C8D;
    --light-gray: #BDC3C7;

    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 5rem;

    /* Breakpoints */
    --breakpoint-sm: 576px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 992px;
    --breakpoint-xl: 1200px;
}

/* Critical CSS - Inlined for performance */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    line-height: var(--line-height-base);
    color: var(--primary);
    background-color: var(--white);
    min-height: 100vh;
}

/* Skip Link - Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary);
    color: var(--white);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header & Navigation */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--light);
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--primary);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-text {
    font-size: 1.5rem;
    color: var(--primary);
}

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

.nav-link {
    color: var(--primary);
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    transition: color 0.2s ease;
    font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
    color: var(--secondary);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.hamburger {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--primary);
    position: relative;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 2px;
    background: var(--primary);
    left: 0;
}

.hamburger::before { top: -8px; }
.hamburger::after { top: 8px; }

/* Hero Section */
.hero {
    padding: var(--spacing-xxl) 0;
    background: linear-gradient(135deg, var(--light) 0%, var(--white) 100%);
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray);
    margin-bottom: var(--spacing-sm);
}

.update-date {
    font-size: 0.875rem;
    color: var(--gray);
    margin-bottom: var(--spacing-lg);
}

.hero-content {
    margin-bottom: var(--spacing-xl);
}

.lead {
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--dark);
    max-width: 800px;
}

.quick-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s ease;
    border: 2px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: var(--secondary);
    color: var(--white);
}

.btn-primary:hover {
    background: #2980B9;
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--white);
    color: var(--secondary);
    border-color: var(--secondary);
}

.btn-secondary:hover {
    background: var(--secondary);
    color: var(--white);
}

.btn-tertiary {
    background: var(--white);
    color: var(--dark);
    border-color: var(--light);
}

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

/* Content Sections */
.cornerstone {
    padding: var(--spacing-xl) 0;
}

.content-section {
    margin-bottom: var(--spacing-xl);
}

.content-section h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    color: var(--primary);
}

.content-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
}

.content-section h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    color: var(--dark);
}

.content-section p {
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

/* Info & Warning Boxes */
.info-box,
.warning-box {
    padding: var(--spacing-md);
    border-radius: 5px;
    margin: var(--spacing-lg) 0;
}

.info-box {
    background: var(--light);
    border-left: 4px solid var(--secondary);
}

.warning-box {
    background: #FFF3CD;
    border-left: 4px solid var(--warning);
}

/* Lists */
.process-list {
    counter-reset: process-counter;
    list-style: none;
    margin: var(--spacing-lg) 0;
}

.process-list li {
    counter-increment: process-counter;
    padding-left: 3rem;
    position: relative;
    margin-bottom: var(--spacing-md);
}

.process-list li::before {
    content: counter(process-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 2rem;
    height: 2rem;
    background: var(--secondary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

.regulation-list,
.tool-features {
    list-style-position: inside;
    margin: var(--spacing-md) 0;
}

.regulation-list li,
.tool-features li {
    padding: var(--spacing-xs) 0;
}

/* Grids */
.applications-grid,
.features-grid,
.tools-grid {
    display: grid;
    gap: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
}

.applications-grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.features-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.tools-grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Cards */
.app-card,
.feature-card,
.tool-card {
    padding: var(--spacing-lg);
    background: var(--white);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.app-card {
    border: 1px solid var(--light);
}

.app-card:hover {
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.feature-card {
    text-align: center;
    border: 2px solid var(--light);
}

.feature-card:hover {
    border-color: var(--secondary);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(52, 152, 219, 0.1);
}

.feature-icon {
    width: 60px;
    height: 60px;
    margin-bottom: var(--spacing-md);
}

.card-link {
    color: var(--secondary);
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    margin-top: var(--spacing-sm);
}

.card-link:hover {
    text-decoration: underline;
}

.tool-card {
    border: 1px solid var(--light);
    position: relative;
}

.tool-category {
    font-size: 0.875rem;
    color: var(--secondary);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

/* Steps */
.steps-container {
    display: grid;
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.step {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--secondary);
    color: var(--white);
    border-radius: 50%;
    flex-shrink: 0;
    font-weight: bold;
}

/* FAQ */
.faq-item {
    margin-bottom: var(--spacing-md);
    border: 1px solid var(--light);
    border-radius: 5px;
    overflow: hidden;
}

.faq-item summary {
    padding: var(--spacing-md);
    background: var(--light);
    cursor: pointer;
    font-weight: 600;
    user-select: none;
    list-style: none;
    position: relative;
    padding-left: var(--spacing-xl);
}

.faq-item summary::before {
    content: '+';
    position: absolute;
    left: var(--spacing-md);
    font-size: 1.5rem;
    line-height: 1;
}

.faq-item[open] summary::before {
    content: '−';
}

.faq-item p {
    padding: var(--spacing-md);
}

/* Infographic */
.infographic {
    margin: var(--spacing-xl) 0;
    max-width: 100%;
}

.ai-process-svg {
    width: 100%;
    height: auto;
    max-width: 800px;
}

/* Features Section */
.features {
    padding: var(--spacing-xl) 0;
    background: var(--light);
}

/* Tools Preview */
.tools-preview {
    padding: var(--spacing-xl) 0;
}

.tools-cta {
    text-align: center;
    margin-top: var(--spacing-xl);
}

/* Footer */
.footer {
    background: var(--primary);
    color: var(--white);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-xxl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
}

.footer-links {
    list-style: none;
}

.footer-links a {
    color: var(--light);
    text-decoration: none;
    display: block;
    padding: var(--spacing-xs) 0;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: var(--light);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 60px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        padding: var(--spacing-lg);
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        transition: 0.3s;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: block;
    }

    .hero-title {
        font-size: 2rem;
    }

    .quick-links {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .applications-grid,
    .features-grid,
    .tools-grid {
        grid-template-columns: 1fr;
    }

    .steps-container {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .nav-toggle,
    .quick-links {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }

    .content-section {
        page-break-inside: avoid;
    }

    a {
        text-decoration: underline;
    }

    a[href^="http"]:after {
        content: " (" attr(href) ")";
    }
}

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

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --primary: #000000;
        --secondary: #0066CC;
        --light: #F0F0F0;
        --white: #FFFFFF;
    }

    .btn {
        border-width: 3px;
    }
}