/* ============================================
   CSS Variables & Theme Configuration
   ============================================ */
:root {
    /* Color Palette - Professional with warmth */
    --primary-color: #1a4d7a;
    --primary-dark: #0f3049;
    --primary-light: #2d6a9f;
    --secondary-color: #e85d04;
    --secondary-dark: #c44f03;
    --secondary-light: #ff7b2d;
    
    --accent-color: #f4a261;
    --success-color: #06d6a0;
    --info-color: #118ab2;
    --warning-color: #ffd166;
    
    /* Neutral Colors */
    --background-color: #ffffff;
    --background-light: #f8f9fa;
    --background-dark: #1a1a1a;
    --text-color: #2d3748;
    --text-light: #718096;
    --text-dark: #1a202c;
    --border-color: #e2e8f0;
    
    /* Typography */
    --font-primary: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-secondary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
}

/* ============================================
   Global Styles & Resets
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-secondary);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--background-color);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-dark);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-light);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Skip to main content - Accessibility */
.skip-to-main {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: 10000;
    transition: top var(--transition-fast);
}

.skip-to-main:focus {
    top: 0;
}

/* ============================================
   Navigation Bar
   ============================================ */
.navbar {
    background: rgba(26, 77, 122, 0.95) !important;
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
    transition: all var(--transition-medium);
}

.navbar.scrolled {
    background: rgba(26, 77, 122, 0.98) !important;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.15);
}

.navbar-brand img {
    transition: transform var(--transition-medium);
}

.navbar-brand:hover img {
    transform: scale(1.05);
}

.navbar-nav {
    align-items: center;
}

.navbar-nav .nav-link {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    font-family: var(--font-primary);
    padding: 0.75rem 1.25rem;
    margin: 0 0.25rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    position: relative;
}

.navbar-nav .nav-link::after {
    content: '';
    position: absolute;
    bottom: 0.5rem;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--secondary-color);
    transition: all var(--transition-medium);
    transform: translateX(-50%);
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link:focus {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.1);
}

.navbar-nav .nav-link:hover::after,
.navbar-nav .nav-link:focus::after {
    width: 60%;
}

.navbar-nav .nav-link.active {
    color: var(--secondary-color);
    background: rgba(232, 93, 4, 0.1);
}

.navbar-toggler {
    border: none;
    padding: 0.5rem;
}

.navbar-toggler:focus {
    box-shadow: 0 0 0 0.2rem rgba(255, 255, 255, 0.25);
}

/* ============================================
   Hero Section
   ============================================ */
.hero-background {
    position: relative;
    background: linear-gradient(135deg, #1a4d7a 0%, #0f3049 100%);
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 8rem 0 4rem;
}

.hero-background::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(232, 93, 4, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(244, 162, 97, 0.1) 0%, transparent 50%);
    z-index: 1;
}

.hero-background::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('data:image/svg+xml,<svg width="60" height="60" xmlns="http://www.w3.org/2000/svg"><rect width="1" height="1" fill="rgba(255,255,255,0.05)"/></svg>');
    opacity: 0.3;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    opacity: 0.9;
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    margin-top: var(--spacing-xl);
}

.hero-cta .btn {
    margin: 0.5rem;
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-medium);
}

.hero-cta .btn-primary {
    background: var(--secondary-color);
    border: none;
}

.hero-cta .btn-primary:hover {
    background: var(--secondary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

.hero-cta .btn-outline-light:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    animation: bounce 2s infinite;
}

.scroll-indicator i {
    font-size: 2rem;
    color: rgba(255, 255, 255, 0.7);
}

/* Brand Mark Accent */
.brand-mark {
    color: var(--secondary-color);
    font-weight: 700;
}

/* ============================================
   Section Titles
   ============================================ */
.section-title {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xl);
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    border-radius: 2px;
}

/* ============================================
   About Section
   ============================================ */
.profile-image {
    box-shadow: var(--shadow-xl);
    border: 5px solid white;
    transition: transform var(--transition-medium);
    max-width: 300px;
    margin: 0 auto;
}

.profile-image:hover {
    transform: scale(1.05);
}

.about-content {
    font-size: 1.1rem;
}

.about-content .lead {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 500;
}

.highlights {
    margin-top: var(--spacing-xl);
}

.highlight-card {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-medium);
    box-shadow: var(--shadow-md);
}

.highlight-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.highlight-card i {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    opacity: 0.9;
}

.highlight-card h4 {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin: var(--spacing-sm) 0;
}

.highlight-card p {
    margin: 0;
    opacity: 0.9;
    font-size: 0.95rem;
}

/* ============================================
   Skills Section
   ============================================ */
.skill-category {
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-medium);
    height: 100%;
    border: 1px solid var(--border-color);
}

.skill-category:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.skill-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--info-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
}

.skill-icon i {
    font-size: 2rem;
    color: white;
}

.skill-category h3 {
    font-size: 1.5rem;
    text-align: center;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.skill-list {
    list-style: none;
    padding: 0;
}

.skill-list li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding-left: 1.5rem;
    transition: all var(--transition-fast);
}

.skill-list li:last-child {
    border-bottom: none;
}

.skill-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

.skill-list li:hover {
    padding-left: 2rem;
    color: var(--primary-color);
}

/* ============================================
   Navigation Cards
   ============================================ */
.nav-card {
    border: none;
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-medium);
    box-shadow: var(--shadow-md);
    background: white;
}

.nav-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.nav-card .card-body {
    padding: var(--spacing-xl);
}

.card-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    transition: all var(--transition-medium);
}

.card-icon i {
    font-size: 2.5rem;
    color: white;
}

.card-education .card-icon {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.card-experience .card-icon {
    background: linear-gradient(135deg, #06d6a0 0%, #1b9aaa 100%);
}

.card-certifications .card-icon {
    background: linear-gradient(135deg, #118ab2 0%, #073b4c 100%);
}

.card-volunteer .card-icon {
    background: linear-gradient(135deg, #ffd166 0%, #f77f00 100%);
}

.nav-card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

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

.nav-card .card-text {
    color: var(--text-light);
    margin-bottom: var(--spacing-lg);
}

.btn-card {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.btn-card:hover {
    background: var(--primary-color);
    color: white;
    transform: translateX(5px);
}

/* ============================================
   Section Cards (Content Pages)
   ============================================ */
.section-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-medium);
}

.section-card:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.section-card h5 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

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

.section-card p strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* ============================================
   Testimonials
   ============================================ */
.testimonial-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    height: 100%;
    border: 1px solid var(--border-color);
    transition: all var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.testimonial-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform var(--transition-medium);
}

.testimonial-card:hover::before {
    transform: scaleX(1);
}

.testimonial-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.testimonial-content {
    margin-bottom: var(--spacing-md);
}

.testimonial-content i {
    font-size: 3rem;
    color: var(--secondary-color);
    opacity: 0.2;
    margin-bottom: var(--spacing-sm);
}

.testimonial-content p {
    font-style: italic;
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-color);
}

.testimonial-author {
    display: flex;
    align-items: center;
}

.author-info h5 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.author-info p {
    font-size: 0.9rem;
    color: var(--text-light);
    margin: 0;
}

/* ============================================
   Call to Action Section
   ============================================ */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 80% 20%, rgba(232, 93, 4, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 20% 80%, rgba(244, 162, 97, 0.2) 0%, transparent 50%);
}

.cta-section h2 {
    color: white;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
}

.cta-section .lead {
    font-size: 1.2rem;
    opacity: 0.9;
}

.cta-section .btn-light {
    background: white;
    color: var(--primary-color);
    font-weight: 600;
    padding: 1rem 2.5rem;
    border-radius: var(--radius-lg);
    transition: all var(--transition-medium);
}

.cta-section .btn-light:hover {
    background: var(--secondary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

/* ============================================
   Loading Spinner
   ============================================ */
#loading-spinner {
    padding: var(--spacing-xxl) 0;
}

.spinner-border {
    width: 3rem;
    height: 3rem;
    border-width: 0.3rem;
}

/* Content Loading Animation */
#loaded-content {
    transition: opacity var(--transition-slow);
}

#loaded-content.loading {
    opacity: 0;
}

/* ============================================
   Back to Top Button
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-medium);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
}

.back-to-top:hover {
    background: var(--secondary-color);
    transform: translateY(-5px);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

/* ============================================
   Footer
   ============================================ */
footer {
    background: var(--background-dark) !important;
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

footer h5 {
    color: white;
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
}

footer p,
footer li {
    color: rgba(255, 255, 255, 0.7);
}

.footer-link {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--secondary-color);
}

footer hr {
    opacity: 0.2;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    font-family: var(--font-primary);
    font-weight: 600;
    border-radius: var(--radius-md);
    padding: 0.75rem 1.5rem;
    transition: all var(--transition-fast);
    border: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline-primary {
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

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

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    50% {
        transform: translateX(-50%) translateY(-10px);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 992px) {
    .navbar-nav .nav-link {
        padding: 0.75rem 1rem;
        margin: 0.25rem 0;
    }
    
    .hero-background {
        min-height: 60vh;
        padding: 6rem 0 3rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-xxl: 3rem;
    }
    
    .hero-background {
        min-height: 50vh;
        padding: 5rem 0 2rem;
    }
    
    .hero-cta .btn {
        padding: 0.875rem 2rem;
        font-size: 1rem;
    }
    
    .profile-image {
        max-width: 250px;
    }
    
    .skill-category,
    .section-card,
    .testimonial-card {
        padding: var(--spacing-lg);
    }
    
    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
        font-size: 1.25rem;
    }
}

@media (max-width: 576px) {
    .hero-background {
        padding: 4rem 0 2rem;
    }
    
    .hero-cta .btn {
        display: block;
        width: 100%;
        margin: 0.5rem 0;
    }
    
    .profile-image {
        max-width: 200px;
    }
    
    .highlight-card {
        padding: var(--spacing-md);
    }
    
    .skill-icon,
    .card-icon {
        width: 60px;
        height: 60px;
    }
    
    .skill-icon i,
    .card-icon i {
        font-size: 1.75rem;
    }
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    .navbar,
    .hero-background,
    .back-to-top,
    footer,
    #navigatie-tegels,
    .cta-section {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
        color: #000;
    }
    
    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
        color: #000;
    }
    
    img {
        max-width: 100% !important;
    }
}

/* ============================================
   Accessibility Enhancements
   ============================================ */
:focus-visible {
    outline: 3px solid var(--secondary-color);
    outline-offset: 3px;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Reduce 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;
    }
}