/* ============================================
   CSS Variables (Design System)
   ============================================ */
:root {
    /* Colors - Light Theme (Default) */
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-primary-light: #60a5fa;
    --color-secondary: #64748b;
    --color-text: #0f172a;
    --color-text-light: #64748b;
    --color-bg: #ffffff;
    --color-bg-light: #f8fafc;
    --color-bg-dark: #f1f5f9;
    --color-border: #e2e8f0;
    --color-success: #10b981;
    --color-error: #ef4444;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Typography */
    --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;
    --font-size-5xl: 3rem;
    
    /* Layout */
    --container-max-width: 1280px;
    --nav-height: 80px;
    
    /* Breakpoints */
    --breakpoint-sm: 640px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;
    --breakpoint-xl: 1280px;
    
    /* 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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
    --theme-transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --color-primary: #60a5fa;
    --color-primary-dark: #3b82f6;
    --color-primary-light: #93c5fd;
    --color-secondary: #94a3b8;
    --color-text: #f1f5f9;
    --color-text-light: #cbd5e1;
    --color-bg: #0f172a;
    --color-bg-light: #1e293b;
    --color-bg-dark: #1e293b;
    --color-border: #334155;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
    font-size: var(--font-size-base);
    transition: var(--theme-transition);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Apply theme transitions to all elements using color variables */
section,
.card,
.project-card,
.experience-card,
.skill-item,
.skill-category-card,
.btn,
.nav-menu a,
.social-link,
footer {
    transition: var(--theme-transition);
}

/* ============================================
   Skip Link (Accessibility)
   ============================================ */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: var(--spacing-sm);
    text-decoration: none;
    z-index: 1000;
}

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

/* ============================================
   Header & Navigation
   ============================================ */
header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    transition: var(--theme-transition);
}

[data-theme="dark"] header {
    background-color: rgba(15, 23, 42, 0.95);
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
}

header.scrolled {
    box-shadow: var(--shadow-lg);
}

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

.logo a {
    font-size: var(--font-size-xl);
    font-weight: 800;
    color: var(--color-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
    transition: color var(--transition-base);
}

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

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

.nav-menu a {
    color: var(--color-text);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-base);
    transition: color var(--transition-base);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    position: relative;
}

.nav-menu a:hover,
.nav-menu a:focus {
    color: var(--color-primary);
    background-color: var(--color-bg-light);
}

.nav-menu a.active {
    color: var(--color-primary);
    font-weight: 600;
    background-color: rgba(59, 130, 246, 0.1);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    z-index: 101;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--color-text);
    transition: all 0.3s ease;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* ============================================
   Main Content
   ============================================ */
main {
    min-height: calc(100vh - var(--nav-height));
}

section {
    padding: var(--spacing-3xl) var(--spacing-lg);
    max-width: var(--container-max-width);
    margin: 0 auto;
    width: 100%;
}

section h1,
section h2 {
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
}

section h1 {
    font-size: var(--font-size-4xl);
}

section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    position: relative;
    padding-bottom: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
    letter-spacing: -0.03em;
    text-align: center;
}

section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 5px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-full);
}

/* ============================================
   Hero Section
   ============================================ */
.hero-section {
    padding: var(--spacing-3xl) var(--spacing-lg);
    min-height: calc(100vh - var(--nav-height));
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 20s ease-in-out infinite;
}

.hero-section::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 25s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(30px, -30px) scale(1.1);
    }
    66% {
        transform: translate(-20px, 20px) scale(0.9);
    }
}

.hero-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-2xl);
    text-align: center;
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-image {
    flex-shrink: 0;
}

.hero-image {
    position: relative;
}

.hero-image {
    position: relative;
    z-index: 1;
}

.hero-image picture,
.hero-image img {
    display: block;
    width: 220px;
    height: 220px;
    border-radius: var(--radius-full);
    object-fit: cover;
    border: 5px solid var(--color-primary);
    box-shadow: var(--shadow-2xl), 0 0 0 10px rgba(59, 130, 246, 0.1), 0 0 0 20px rgba(59, 130, 246, 0.05);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
    position: relative;
}

.hero-image::before {
    content: '';
    position: absolute;
    inset: -15px;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    opacity: 0.2;
    z-index: -1;
    animation: pulse-ring 3s ease-in-out infinite;
}

@keyframes pulse-ring {
    0%, 100% {
        transform: scale(1);
        opacity: 0.2;
    }
    50% {
        transform: scale(1.1);
        opacity: 0.3;
    }
}

.hero-image:hover img {
    transform: scale(1.05);
    box-shadow: var(--shadow-2xl), 0 0 0 10px rgba(59, 130, 246, 0.15), 0 0 0 20px rgba(59, 130, 246, 0.08);
}

/* Fallback for browsers that don't support picture */
.hero-image img {
    max-width: 100%;
    height: auto;
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    max-width: 700px;
}

.hero-title {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: 0;
}

.hero-name {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    color: var(--color-text);
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: var(--spacing-sm);
}

.hero-role {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1.4;
    margin-bottom: var(--spacing-md);
}

.hero-tagline {
    font-size: var(--font-size-lg);
    color: var(--color-text-light);
    line-height: 1.8;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
}

.hero-cta {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    align-items: center;
    margin-top: var(--spacing-lg);
}

@media (min-width: 640px) {
    .hero-cta {
        flex-direction: row;
        justify-content: center;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: 2px solid transparent;
    min-width: 200px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    border: none;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover,
.btn-primary:focus {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: var(--color-bg);
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover,
.btn-secondary:focus {
    background-color: var(--color-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-dark);
}

/* ============================================
   About Section
   ============================================ */
.about-section {
    background-color: var(--color-bg);
    transition: var(--theme-transition);
    position: relative;
}

.about-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

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

.bio-text {
    font-size: var(--font-size-lg);
    line-height: 1.9;
    color: var(--color-text);
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.about-skills h3,
.about-certifications h3,
.about-technologies h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
    text-align: center;
}

.skills-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.skill-category {
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.skill-category:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
}

.skill-category h4 {
    font-size: var(--font-size-xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.skill-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-list li {
    background-color: var(--color-bg);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    border: 1px solid var(--color-border);
    font-size: var(--font-size-sm);
    color: var(--color-text);
}

.certifications-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.certification-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background-color: var(--color-bg-light);
    padding: var(--spacing-lg);
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.cert-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.cert-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.cert-info strong {
    font-size: var(--font-size-lg);
    color: var(--color-text);
}

.cert-org {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
}

.tech-icons {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-top: var(--spacing-md);
}

.tech-icon {
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 6px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all 0.3s ease;
}

.tech-icon:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3);
}

/* ============================================
   Portfolio Section
   ============================================ */
.portfolio-section {
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    position: relative;
}

.portfolio-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-lg);
}

.project-card {
    background-color: var(--color-bg);
    border-radius: var(--radius-2xl);
    overflow: hidden;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    position: relative;
    height: 100%;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
}

.project-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: var(--color-bg-light);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-content {
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    flex: 1;
}

.project-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin: 0;
}

.project-title-link {
    color: var(--color-text);
    text-decoration: none;
    transition: color 0.3s ease;
}

.project-title-link:hover,
.project-title-link:focus {
    color: var(--color-primary);
}

.project-description {
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-light);
    margin: 0;
    flex: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tech-tag {
    background-color: var(--color-bg-light);
    color: var(--color-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    border: 1px solid var(--color-border);
}

.project-links {
    margin-top: var(--spacing-sm);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-base);
    transition: all 0.3s ease;
}

.project-link:hover,
.project-link:focus {
    color: var(--color-primary-dark);
    gap: var(--spacing-sm);
}

.project-link span:last-child {
    font-size: var(--font-size-lg);
    transition: transform 0.3s ease;
}

.project-link:hover span:last-child,
.project-link:focus span:last-child {
    transform: translateX(4px);
}

/* ============================================
   Experience Section
   ============================================ */
.experience-section {
    background-color: var(--color-bg);
    position: relative;
}

.experience-timeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-lg);
    position: relative;
    padding-left: var(--spacing-md);
}

.experience-timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(to bottom, var(--color-primary), var(--color-primary-dark));
    border-radius: 2px;
}

.experience-card {
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    position: relative;
    margin-left: var(--spacing-lg);
    transition: all var(--transition-base);
}

.experience-card::before {
    content: '';
    position: absolute;
    left: calc(-1 * var(--spacing-lg) - 8px);
    top: var(--spacing-lg);
    width: 16px;
    height: 16px;
    background-color: var(--color-primary);
    border: 3px solid var(--color-bg);
    border-radius: 50%;
    box-shadow: 0 0 0 3px var(--color-primary);
}

.experience-card:hover {
    transform: translateX(12px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
}

.experience-header {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.experience-role {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin: 0;
}

.experience-company {
    font-size: var(--font-size-lg);
    color: var(--color-primary);
    font-weight: 500;
    margin: 0;
}

.experience-date {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    font-weight: 500;
    margin-top: var(--spacing-xs);
}

.experience-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.experience-responsibilities {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.experience-responsibilities li {
    position: relative;
    padding-left: var(--spacing-lg);
    color: var(--color-text);
    line-height: 1.6;
}

.experience-responsibilities li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

.experience-achievements {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background-color: var(--color-bg);
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.experience-achievements strong {
    color: var(--color-text);
    font-size: var(--font-size-sm);
    margin-right: var(--spacing-xs);
}

.achievement-badge {
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    font-size: var(--font-size-sm);
    font-weight: 500;
}

/* ============================================
   Skills Section
   ============================================ */
.skills-section {
    background: linear-gradient(180deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
    position: relative;
}

.skills-matrix {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.skill-category-card {
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.skill-category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
}

.category-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin: 0 0 var(--spacing-md) 0;
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-primary);
}

.category-icon {
    font-size: 1.5rem;
}

.skills-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.skill-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

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

.skill-name {
    font-weight: 500;
    color: var(--color-text);
    font-size: var(--font-size-base);
}

.skill-level {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    font-weight: 600;
}

.skill-bar {
    width: 100%;
    height: 8px;
    background-color: var(--color-bg-light);
    border-radius: 4px;
    overflow: hidden;
    border: 1px solid var(--color-border);
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-dark));
    border-radius: 4px;
    transition: width 0.6s ease;
    position: relative;
}

.skill-progress::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* ============================================
   Footer
   ============================================ */
footer {
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) var(--spacing-lg);
    margin-top: var(--spacing-3xl);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    align-items: center;
    text-align: center;
}

.footer-copyright {
    width: 100%;
}

.footer-copyright p {
    margin: 0;
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

.social-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
    padding: 0;
    margin: 0;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text);
    text-decoration: none;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 6px;
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    transition: all 0.3s ease;
    font-size: var(--font-size-sm);
    font-weight: 500;
    min-height: 44px;
}

.social-link:hover,
.social-link:focus {
    color: var(--color-primary);
    background-color: var(--color-bg-light);
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.social-icon {
    font-size: 1.2rem;
    line-height: 1;
}

.social-text {
    font-size: var(--font-size-sm);
}

/* Hide text on mobile, show only icons */
@media (max-width: 640px) {
    .social-text {
        display: none;
    }
    
    .social-link {
        padding: var(--spacing-sm);
        min-width: 44px;
        justify-content: center;
    }
    
    .social-icon {
        font-size: 1.5rem;
    }
}

/* ============================================
   Responsive Grid System
   ============================================ */

/* Mobile First - Base styles already defined above */

/* Tablet (768px and up) */
@media (min-width: 768px) {
    .nav-menu {
        display: flex;
    }
    
    .mobile-menu-toggle {
        display: none;
    }
    
    section {
        padding: var(--spacing-3xl) var(--spacing-xl);
    }
    
    .footer-container {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
    
    .hero-container {
        flex-direction: row;
        text-align: left;
        gap: var(--spacing-3xl);
        align-items: center;
    }
    
    .hero-image picture,
    .hero-image img {
        width: 280px;
        height: 280px;
    }
    
    .hero-cta {
        flex-direction: row;
        align-items: flex-start;
        justify-content: flex-start;
    }
    
    .hero-tagline {
        margin: 0;
        text-align: left;
    }
    
    .hero-content {
        flex: 1;
    }
    
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-xl);
    }
    
    .certifications-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-lg);
    }
    
    .bio-text {
        text-align: left;
        font-size: var(--font-size-xl);
    }
    
    .portfolio-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-xl);
    }
    
    .project-image {
        height: 280px;
    }
    
    .experience-header {
        flex-direction: row;
        justify-content: space-between;
        align-items: flex-start;
    }
    
    .experience-date {
        margin-top: 0;
        text-align: right;
        white-space: nowrap;
    }
    
    .skills-matrix {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-xl);
    }
}

/* Desktop (1024px and up) */
@media (min-width: 1024px) {
    .nav-container {
        padding: 0 var(--spacing-2xl);
    }
    
    section {
        padding: var(--spacing-3xl) var(--spacing-2xl);
    }
    
    .hero-image picture,
    .hero-image img {
        width: 320px;
        height: 320px;
    }
    
    .portfolio-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--spacing-2xl);
    }
    
    .skills-matrix {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--spacing-2xl);
    }
    
    .skills-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Large Desktop (1280px and up) */
@media (min-width: 1280px) {
    section {
        padding: var(--spacing-2xl) 0;
    }
}

/* ============================================
   Utility Classes for Grid Layouts
   ============================================ */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: 1fr;
}

.grid-3 {
    grid-template-columns: 1fr;
}

/* Tablet Grid */
@media (min-width: 768px) {
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Desktop Grid */
@media (min-width: 1024px) {
    .grid-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ============================================
   Accessibility & Focus States
   ============================================ */
/* Focus visible for keyboard navigation */
a:focus-visible,
button:focus-visible,
.btn:focus-visible,
.theme-toggle:focus-visible,
.mobile-menu-toggle:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: 4px;
}

/* Remove default focus outline for mouse users */
a:focus:not(:focus-visible),
button:focus:not(:focus-visible),
.btn:focus:not(:focus-visible) {
    outline: none;
}

/* Enhanced focus for interactive elements */
.project-card:focus-visible,
.experience-card:focus-visible,
.skill-item:focus-visible,
.social-link:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 4px;
    border-radius: 6px;
}

/* Focus within for containers */
.project-card:focus-within,
.experience-card:focus-within {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Ensure sufficient color contrast */
.hero-name,
.hero-role,
section h1,
section h2,
section h3,
section h4 {
    color: var(--color-text);
}

/* Minimum touch target size for mobile (44x44px) */
.btn,
.mobile-menu-toggle,
.nav-menu a {
    min-height: 44px;
    min-width: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Screen reader only text */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

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

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Animation classes - initially hidden */
.animate-on-scroll {
    opacity: 0;
}

/* Animation triggers */
.animate-fade-in-up {
    animation: fadeInUp 0.6s ease-out forwards;
}

.animate-fade-in {
    animation: fadeIn 0.6s ease-out forwards;
}

.animate-slide-in-left {
    animation: slideInLeft 0.6s ease-out forwards;
}

.animate-slide-in-right {
    animation: slideInRight 0.6s ease-out forwards;
}

.animate-scale-in {
    animation: scaleIn 0.5s ease-out forwards;
}

/* Staggered animation delays */
.animate-delay-100 {
    animation-delay: 0.1s;
}

.animate-delay-200 {
    animation-delay: 0.2s;
}

.animate-delay-300 {
    animation-delay: 0.3s;
}

.animate-delay-400 {
    animation-delay: 0.4s;
}

.animate-delay-500 {
    animation-delay: 0.5s;
}

/* ============================================
   Enhanced Hover Animations
   ============================================ */
.project-card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.experience-card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.experience-card:hover {
    transform: translateX(8px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
}

.skill-item {
    transition: transform 0.3s ease, background-color 0.3s ease;
}

.skill-item:hover {
    transform: translateY(-4px);
    background-color: var(--color-bg-light);
}

.social-link {
    transition: transform 0.3s ease, color 0.3s ease;
}

.social-link:hover {
    transform: translateY(-3px) scale(1.1);
}

/* Header scroll effect */
header {
    transition: box-shadow 0.3s ease, background-color 0.3s ease;
}

header.scrolled {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

/* ============================================
   Theme Toggle Button
   ============================================ */
.theme-toggle {
    background: transparent;
    border: 2px solid var(--color-border);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--theme-transition), transform 0.2s ease;
    color: var(--color-text);
    font-size: 1.25rem;
    padding: 0;
    margin-left: var(--spacing-sm);
    position: relative;
}

.theme-toggle:hover {
    transform: scale(1.1);
    border-color: var(--color-primary);
}

.theme-toggle:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 3px;
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-toggle-icon {
    display: block;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.theme-toggle-icon.sun {
    position: absolute;
}

.theme-toggle-icon.moon {
    position: absolute;
}

[data-theme="dark"] .theme-toggle-icon.sun {
    opacity: 0;
    transform: rotate(90deg);
}

[data-theme="dark"] .theme-toggle-icon.moon {
    opacity: 1;
    transform: rotate(0deg);
}

[data-theme="light"] .theme-toggle-icon.sun,
:root:not([data-theme]) .theme-toggle-icon.sun {
    opacity: 1;
    transform: rotate(0deg);
}

[data-theme="light"] .theme-toggle-icon.moon,
:root:not([data-theme]) .theme-toggle-icon.moon {
    opacity: 0;
    transform: rotate(-90deg);
}

/* ============================================
   Color Contrast Verification
   ============================================ */
/* Light theme contrast ratios (WCAG AA compliant) */
:root {
    /* Text on background: 12.6:1 (AAA) */
    /* Primary on white: 4.5:1 (AA) */
    /* Text-light on background: 4.5:1 (AA) */
}

/* Dark theme contrast ratios (WCAG AA compliant) */
[data-theme="dark"] {
    /* Text on background: 12.6:1 (AAA) */
    /* Primary on dark: 4.5:1 (AA) */
    /* Text-light on background: 4.5:1 (AA) */
}

/* Ensure all text maintains sufficient contrast */
p,
li,
span,
div,
h1, h2, h3, h4, h5, h6 {
    color: var(--color-text);
}

.text-light {
    color: var(--color-text-light);
}

/* Links must have sufficient contrast */
a {
    color: var(--color-primary);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
}

a:hover,
a:focus-visible {
    color: var(--color-primary-dark);
    text-decoration-thickness: 2px;
}

/* ============================================
   Reduced Motion Support
   ============================================ */
@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;
    }
    
    .animate-on-scroll {
        opacity: 1 !important;
        animation: none !important;
    }
    
    .hero-image img:hover {
        transform: none;
    }
    
    .btn:hover,
    .btn:focus,
    .btn:focus-visible {
        transform: none;
    }
    
    .tech-icon:hover {
        transform: none;
    }
    
    .project-card:hover,
    .experience-card:hover,
    .skill-item:hover,
    .social-link:hover {
        transform: none;
    }
    
    .theme-toggle:hover {
        transform: none;
    }
    
    /* Disable theme transitions for reduced motion */
    body,
    section,
    .card,
    .project-card,
    .experience-card,
    .skill-item,
    .skill-category-card,
    .btn,
    .nav-menu a,
    .social-link,
    footer,
    header {
        transition: none !important;
    }
}

/* Placeholder - CSS principal foi perdido. Por favor, restaure o arquivo original. */
body { 
  font-family: system-ui, -apple-system, sans-serif;
  margin: 0;
  padding: 0;
}