/* CSS Variables - Design System */
:root {
    --color-background: hsl(215, 30%, 8%);
    --color-foreground: hsl(0, 0%, 98%);
    --color-card: hsl(215, 25%, 12%);
    --color-primary: hsl(210, 100%, 60%);
    --color-primary-foreground: hsl(0, 0%, 100%);
    --color-primary-glow: hsl(210, 100%, 75%);
    --color-secondary: hsl(215, 25%, 18%);
    --color-muted: hsl(215, 25%, 15%);
    --color-muted-foreground: hsl(215, 15%, 65%);
    --color-accent: hsl(195, 85%, 55%);
    --color-border: hsl(215, 25%, 20%);
    
    --gradient-primary: linear-gradient(135deg, hsl(210, 100%, 60%), hsl(195, 85%, 55%));
    --gradient-soft: linear-gradient(180deg, hsl(215, 30%, 8%), hsl(215, 25%, 10%));
    
    --shadow-elegant: 0 10px 30px -10px hsla(210, 100%, 60%, 0.3);
    --shadow-soft: 0 4px 20px -4px hsla(0, 0%, 0%, 0.3);
    
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    --border-radius: 0.75rem;
    --border-radius-sm: 0.5rem;
    --border-radius-lg: 1rem;
}

/* Light Mode Theme */
:root[data-theme="light"] {
    --color-background: hsl(0, 0%, 100%);
    --color-foreground: hsl(215, 25%, 27%);
    --color-card: hsl(0, 0%, 100%);
    --color-primary: hsl(210, 100%, 50%);
    --color-primary-glow: hsl(210, 100%, 70%);
    --color-secondary: hsl(215, 20%, 95%);
    --color-muted: hsl(215, 20%, 96%);
    --color-muted-foreground: hsl(215, 15%, 50%);
    --color-accent: hsl(195, 85%, 50%);
    --color-border: hsl(215, 20%, 90%);
    
    --gradient-primary: linear-gradient(135deg, hsl(210, 100%, 50%), hsl(195, 85%, 50%));
    --gradient-soft: linear-gradient(180deg, hsl(0, 0%, 100%), hsl(215, 20%, 98%));
    
    --shadow-elegant: 0 10px 30px -10px hsla(210, 100%, 50%, 0.2);
    --shadow-soft: 0 4px 20px -4px hsla(215, 25%, 27%, 0.08);
}

:root[data-theme="light"] .navbar.scrolled {
    background: hsla(0, 0%, 100%, 0.8);
}

:root[data-theme="light"] .hero-bg {
    background: linear-gradient(135deg, 
        hsla(210, 100%, 50%, 0.05), 
        var(--color-background), 
        hsla(195, 85%, 50%, 0.05)
    );
}

:root[data-theme="light"] .section-alt {
    background: linear-gradient(135deg, 
        hsla(215, 20%, 95%, 0.3), 
        var(--color-background), 
        hsla(195, 85%, 50%, 0.05)
    );
}

:root[data-theme="light"] .highlight-icon,
:root[data-theme="light"] .contact-icon {
    background: hsla(210, 100%, 50%, 0.1);
}

:root[data-theme="light"] .project-tag {
    background: hsla(210, 100%, 50%, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    background: var(--color-background);
    color: var(--color-foreground);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 700;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(20px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

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

.fade-in-up {
    animation: fadeInUp 0.6s ease-out forwards;
}

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

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

.slide-in-right {
    animation: slideInRight 0.5s ease-out forwards;
}

/* Utility Classes */
.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.container-sm {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: var(--transition-smooth);
}

.navbar.scrolled {
    background: hsla(215, 30%, 8%, 0.8);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-soft);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    border: none;
    background-color: transparent;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.nav-logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-muted-foreground);
    text-decoration: none;
    transition: var(--transition-smooth);
    text-transform: capitalize;
}

.nav-link:hover {
    color: var(--color-primary);
}

.mobile-menu-btn {
    display: none;
    border: none;
    background: none;
    cursor: pointer;
    color: var(--color-foreground);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-soft);
    flex-direction: column;
    padding: 1rem;
    gap: 1rem;
    z-index: 999;
}

.mobile-menu.active {
    display: flex;
}

.mobile-link {
    padding: 0.75rem;
    color: var(--color-foreground);
    text-decoration: none;
    text-align: center;
    transition: var(--transition-smooth);
}

.mobile-link:hover {
    background: var(--color-secondary);
    border-radius: var(--border-radius-sm);
}

/* Theme Toggle Button */
.theme-toggle {
    border: none;
    background: var(--color-secondary);
    color: var(--color-foreground);
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: var(--color-muted);
    transform: scale(1.05);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-smooth);
    text-decoration: none;
}

.btn-primary {
    background: var(--color-primary);
    color: var(--color-primary-foreground);
    box-shadow: var(--shadow-soft);
}

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

.btn-outline {
    background: transparent;
    color: var(--color-foreground);
    border: 1px solid var(--color-border);
}

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1rem;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 2rem 1rem;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, 
        hsla(210, 100%, 60%, 0.08), 
        var(--color-background), 
        hsla(195, 85%, 55%, 0.08)
    );
}

.hero-content {
    max-width: 1000px;
    text-align: center;
    position: relative;
    z-index: 10;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    margin-bottom: 1rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--color-muted-foreground);
    margin-bottom: 0.5rem;
}

.hero-description {
    font-size: clamp(1rem, 2vw, 1.125rem);
    color: var(--color-muted-foreground);
    max-width: 700px;
    margin: 0 auto 3rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

.social-link {
    color: var(--color-muted-foreground);
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
}

.social-link:hover {
    color: var(--color-primary);
    transform: scale(1.1);
}

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

/* Sections */
.section {
    padding: 6rem 1rem;
}

.section-alt {
    background: linear-gradient(135deg, 
        hsla(215, 25%, 18%, 0.3), 
        var(--color-background), 
        hsla(195, 85%, 55%, 0.05)
    );
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    margin-bottom: 1rem;
}

.section-divider {
    width: 5rem;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto;
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-muted-foreground);
    margin-top: 1.5rem;
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    align-items: center;
}

.about-text {
    max-width: 600px;
}

.about-paragraph {
    font-size: 1.125rem;
    color: var(--color-muted-foreground);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.highlights-grid {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.highlight-card {
    background: var(--color-card);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    display: flex;
    gap: 1rem;
    transition: var(--transition-smooth);
}

.highlight-card:hover {
    box-shadow: var(--shadow-elegant);
    transform: scale(1.05);
}

.highlight-icon {
    padding: 0.75rem;
    background: hsla(210, 100%, 60%, 0.15);
    border-radius: var(--border-radius-sm);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.highlight-title {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.highlight-description {
    color: var(--color-muted-foreground);
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.skill-card {
    background: var(--color-card);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-soft);
    transition: var(--transition-smooth);
}

.skill-card:hover {
    box-shadow: var(--shadow-elegant);
}

.skill-category {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: 1.5rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    padding: 0.5rem 1rem;
    background: var(--color-secondary);
    color: var(--color-foreground);
    border-radius: var(--border-radius-sm);
    font-size: 0.875rem;
    transition: var(--transition-smooth);
    cursor: default;
}

.skill-tag:hover {
    background: var(--color-primary);
    color: var(--color-primary-foreground);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    transition: var(--transition-smooth);
}

.project-card:hover {
    box-shadow: var(--shadow-elegant);
    transform: translateY(-8px);
}

.project-header {
    padding: 1.5rem;
}

.project-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.project-description {
    color: var(--color-muted-foreground);
}

.project-content {
    padding: 0 1.5rem 1.5rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.project-tag {
    padding: 0.25rem 0.75rem;
    background: hsla(210, 100%, 60%, 0.15);
    color: var(--color-primary);
    border-radius: 9999px;
    font-size: 0.75rem;
}

.project-actions {
    display: flex;
    gap: 0.75rem;
}

.project-actions .btn {
    flex: 1;
}

/* Contact Section */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.contact-card {
    background: var(--color-card);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    display: flex;
    gap: 1rem;
    transition: var(--transition-smooth);
}

.contact-card:hover {
    box-shadow: var(--shadow-elegant);
}

.contact-icon {
    padding: 0.75rem;
    background: hsla(210, 100%, 60%, 0.15);
    border-radius: var(--border-radius-sm);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-title {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.contact-link {
    color: var(--color-muted-foreground);
    text-decoration: none;
    transition: var(--transition-smooth);
}

.contact-link:hover {
    color: var(--color-primary);
}

.contact-text {
    color: var(--color-muted-foreground);
}

.contact-cta {
    text-align: center;
}

.contact-cta .btn {
    margin-bottom: 2rem;
}

/* Footer */
.footer {
    padding: 2rem 1rem;
    border-top: 1px solid var(--color-border);
}

.footer-text {
    text-align: center;
    color: var(--color-muted-foreground);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 768px) {
    .about-grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* Scroll Animation Classes */
.hidden {
    opacity: 0;
    transform: translateY(20px);
}

.show {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease-out;
}