/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Apple-inspired colour palette */
    --primary-blue: #007AFF;
    --primary-blue-hover: #0056CC;
    --secondary-grey: #8E8E93;
    --background-white: #FFFFFF;
    --background-grey: #F2F2F7;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --border-light: #D1D1D6;
    --success-green: #34C759;
    --warning-orange: #FF9500;
    --error-red: #FF3B30;
    
    /* Typography */
    --font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Navigation Header */
.nav-header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.nav-brand h1 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.nav-subtitle {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: 400;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-xl);
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 400;
    font-size: var(--font-size-base);
    transition: color 0.3s ease;
    padding: var(--spacing-sm) 0;
    border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-blue);
    border-bottom-color: var(--primary-blue);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--background-grey) 0%, var(--background-white) 100%);
    padding: var(--spacing-3xl) var(--spacing-xl);
    text-align: center;
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.2;
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-lg);
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    min-width: 140px;
}

.btn-primary {
    background-color: var(--primary-blue);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background-color: var(--primary-blue-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-secondary:hover {
    background-color: var(--primary-blue);
    color: white;
    transform: translateY(-2px);
}

/* Search Section */
.search-section {
    background-color: var(--background-white);
    padding: var(--spacing-2xl) var(--spacing-xl);
    border-bottom: 1px solid var(--border-light);
}

.search-container {
    max-width: 1200px;
    margin: 0 auto;
}

.search-bar {
    display: flex;
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.search-input {
    flex: 1;
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg) 0 0 var(--radius-lg);
    font-size: var(--font-size-base);
    outline: none;
    transition: border-color 0.3s ease;
}

.search-input:focus {
    border-color: var(--primary-blue);
}

.search-btn {
    background-color: var(--primary-blue);
    border: none;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.search-btn:hover {
    background-color: var(--primary-blue-hover);
}

.search-icon {
    font-size: var(--font-size-lg);
}

/* Filter Tabs */
.filter-tabs {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.filter-tab {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    background-color: var(--background-grey);
    color: var(--text-secondary);
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all 0.3s ease;
}

.filter-tab:hover {
    background-color: var(--border-light);
}

.filter-tab.active {
    background-color: var(--primary-blue);
    color: white;
}

/* Proficiency Filter */
.proficiency-filter {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.proficiency-filter label {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-secondary);
}

.proficiency-select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    background-color: white;
    font-size: var(--font-size-sm);
    cursor: pointer;
    outline: none;
}

.proficiency-select:focus {
    border-color: var(--primary-blue);
}

/* Skills Section */
.skills-section {
    padding: var(--spacing-3xl) var(--spacing-xl);
    background-color: var(--background-grey);
}

.skills-container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 600;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--text-primary);
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.skill-card {
    background-color: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    cursor: pointer;
    border: 1px solid var(--border-light);
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.skill-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.skill-category-badge {
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.skill-category-badge.technical {
    background-color: rgba(52, 199, 89, 0.1);
    color: var(--success-green);
}

.skill-category-badge.strategic {
    background-color: rgba(255, 149, 0, 0.1);
    color: var(--warning-orange);
}

.skill-category-badge.human {
    background-color: rgba(0, 122, 255, 0.1);
    color: var(--primary-blue);
}

.skill-description {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.5;
}

.skill-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
}

.skill-proficiency {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.proficiency-dots {
    display: flex;
    gap: 2px;
}

.proficiency-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--border-light);
}

.proficiency-dot.filled {
    background-color: var(--primary-blue);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.modal-overlay.active {
    display: flex;
}

.modal-content {
    background-color: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.modal-title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: var(--font-size-2xl);
    cursor: pointer;
    color: var(--text-secondary);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: background-color 0.3s ease;
}

.modal-close:hover {
    background-color: var(--background-grey);
}

.modal-body > div {
    margin-bottom: var(--spacing-lg);
}

.modal-body h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.modal-body p,
.modal-body ul {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    line-height: 1.6;
}

.modal-body ul {
    padding-left: var(--spacing-lg);
}

.modal-body li {
    margin-bottom: var(--spacing-xs);
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: var(--spacing-2xl) var(--spacing-xl) var(--spacing-xl);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: white;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

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

.footer-bottom p {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.7);
}

/* Proficiency Guide Styles for How to Use Modal */
.proficiency-guide {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.proficiency-level {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm);
    background-color: var(--background-grey);
    border-radius: var(--radius-md);
}

.proficiency-level span {
    font-size: var(--font-size-sm);
    line-height: 1.5;
}

/* About Section */
.about-section {
    padding: var(--spacing-3xl) var(--spacing-xl);
    background-color: var(--background-white);
}

.about-container {
    max-width: 1200px;
    margin: 0 auto;
}

.about-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-2xl);
    margin-top: var(--spacing-2xl);
}

.about-card {
    background-color: var(--background-grey);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    text-align: left;
}

.about-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.about-card p {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    line-height: 1.6;
}

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

/* Contact Section */
.contact-section {
    padding: var(--spacing-3xl) var(--spacing-xl);
    background-color: var(--background-grey);
}

.contact-container {
    max-width: 800px;
    margin: 0 auto;
}

.contact-content {
    display: flex;
    justify-content: center;
    margin-top: var(--spacing-2xl);
}

.contact-card {
    background-color: white;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    max-width: 500px;
    width: 100%;
}

.contact-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.contact-info h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.contact-info p {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.linkedin-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background-color: var(--primary-blue);
    color: white;
    text-decoration: none;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

.linkedin-link:hover {
    background-color: var(--primary-blue-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.linkedin-icon {
    font-size: var(--font-size-lg);
}

.rse-link {
    color: var(--primary-blue);
    text-decoration: none;
    transition: color 0.3s ease;
}

.rse-link:hover {
    color: var(--primary-blue-hover);
    text-decoration: underline;
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .nav-menu {
        gap: var(--spacing-lg);
    }
    
    .hero-title {
        font-size: var(--font-size-3xl);
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .filter-tabs {
        flex-direction: column;
        align-items: center;
    }
    
    .proficiency-filter {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-sm);
    }
    
    .modal-content {
        margin: var(--spacing-md);
        width: calc(100% - 2rem);
    }
}

@media (max-width: 480px) {
    .hero {
        padding: var(--spacing-2xl) var(--spacing-md);
    }
    
    .search-section,
    .skills-section {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .hero-title {
        font-size: var(--font-size-2xl);
    }
    
    .search-bar {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .search-input,
    .search-btn {
        border-radius: var(--radius-lg);
    }
    
    /* Modal responsive improvements */
    .modal-content {
        padding: var(--spacing-lg);
    }
    
    .industry-tags {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .proficiency-level {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
        text-align: left;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .about-card,
    .contact-card {
        padding: var(--spacing-lg);
    }
}