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

:root {
    /* Colors */
    --bg-primary: #0a0a0a;
    --bg-secondary: #111111;
    --bg-tertiary: #1a1a1a;
    --text-primary: #e4e4e7;
    --text-secondary: #a1a1aa;
    --text-tertiary: #71717a;
    --accent-primary: #00ff88;
    --accent-secondary: #0066ff;
    --accent-tertiary: #ff6b6b;
    --border-color: #27272a;
    --shadow-color: rgba(0, 255, 136, 0.1);
    --nav-bg-rgb: 10, 10, 10;
    
    /* Typography - System fonts for optimal performance */
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    
    /* Spacing */
    --section-padding: 6rem 0;
    --container-padding: 0 2rem;
    --border-radius: 0.5rem;
    
    /* Minimal transitions */
    --transition: 0.2s ease;
}

/* Light theme */
[data-theme="light"] {
    --bg-primary: #fafafa;
    --bg-secondary: #f4f4f5;
    --bg-tertiary: #e4e4e7;
    --text-primary: #18181b;
    --text-secondary: #3f3f46;
    --text-tertiary: #71717a;
    --accent-primary: #059669;
    --accent-secondary: #0284c7;
    --accent-tertiary: #dc2626;
    --border-color: #d4d4d8;
    --shadow-color: rgba(5, 150, 105, 0.15);
    --nav-bg-rgb: 250, 250, 250;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding);
}


/* Navigation */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(var(--nav-bg-rgb), 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 4rem;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
}

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

.nav-logo:hover .terminal-prompt {
    color: var(--accent-primary);
}

.terminal-prompt {
    color: var(--accent-primary);
    font-size: 1.2rem;
}

.logo-text {
    font-size: 1rem;
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    transition: var(--transition);
    position: relative;
}

.nav-link::before {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: var(--transition);
}

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

.nav-link:hover::before {
    width: 100%;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 0.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 0.25rem;
    padding: 0.5rem;
    background: none;
    border: none;
    position: relative;
    z-index: 1001;
}

.nav-toggle span {
    width: 1.5rem;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
    border-radius: 1px;
}

.nav-toggle:hover span {
    background: var(--accent-primary);
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--section-padding);
    position: relative;
    overflow: hidden;
}



.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1rem;
    font-family: var(--font-mono);
    color: var(--accent-primary);
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-family: var(--font-mono);
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-tertiary);
    margin-bottom: 2rem;
    max-width: 500px;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background: #00cc6a;
}

.btn-secondary {
    background: transparent;
    color: var(--accent-primary);
    border: 1px solid var(--accent-primary);
}

.btn-secondary:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
}

/* Terminal Window */
.terminal-window {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.terminal-header {
    background: var(--bg-tertiary);
    padding: 0.75rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
}

.terminal-controls {
    display: flex;
    gap: 0.5rem;
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.red { background: #ff5f57; }
.control.yellow { background: #ffbd2e; }
.control.green { background: #28ca42; }

.terminal-title {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

.terminal-body {
    padding: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.8;
}

.terminal-line {
    margin-bottom: 0.5rem;
}

.prompt {
    color: var(--accent-primary);
    margin-right: 0.5rem;
}

.command {
    color: var(--text-primary);
}

.output {
    color: var(--text-secondary);
}

.typing-cursor {
    color: var(--accent-primary);
    animation: blink 1s infinite;
}

/* Section Styles */
section {
    padding: var(--section-padding);
    position: relative;
    background: var(--bg-primary);
    z-index: 1;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.section-number {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    color: var(--accent-primary);
}

/* About Section */
.about {
    background: var(--bg-primary);
    position: relative;
    z-index: 1;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.tech-stack {
    margin-top: 2rem;
}

.tech-stack h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 0.5rem;
}

.tech-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.5rem;
    border-radius: var(--border-radius);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-align: center;
    transition: var(--transition);
    word-wrap: break-word;
    hyphens: auto;
}

.tech-item:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.image-container {
    position: relative;
}

.code-snippet {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.code-header {
    background: var(--bg-tertiary);
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.filename {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

.code-content {
    padding: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
}

.code-line {
    margin-bottom: 0.5rem;
}

.indent {
    margin-left: 1.5rem;
}

.keyword { color: #ff6b9d; }
.variable { color: #4ecdc4; }
.operator { color: #feca57; }
.punctuation { color: var(--text-tertiary); }
.property { color: #48cae4; }
.string { color: #95e1d3; }
.function { color: #a8e6cf; }

/* Experience Section */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-marker {
    position: absolute;
    left: -2rem;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    background: var(--accent-primary);
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
    z-index: 1;
}

.timeline-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-left: 1rem;
}

.timeline-header {
    margin-bottom: 1rem;
}

.job-title {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.company {
    color: var(--accent-primary);
    font-weight: 500;
    margin-right: 1rem;
}

.duration {
    color: var(--text-tertiary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.job-description {
    list-style: none;
    margin-bottom: 1.5rem;
}

.job-description li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1rem;
}

.job-description li::before {
    content: '▶';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-size: 0.8rem;
}

.job-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.5rem;
    border-radius: calc(var(--border-radius) / 2);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

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

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    border-color: var(--accent-primary);
}

.project-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    padding: 0.75rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
}

.project-link:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.1);
}

.project-placeholder {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
}

.code-preview {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.api-preview {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    text-align: center;
}

.method {
    color: var(--accent-primary);
    font-weight: bold;
    margin-right: 0.5rem;
}

.endpoint {
    color: var(--text-primary);
}

.status {
    color: var(--accent-primary);
    margin-right: 0.5rem;
}

.response {
    color: var(--text-secondary);
}

.dashboard-preview {
    width: 100px;
    height: 60px;
}

.chart-placeholder {
    display: flex;
    align-items: end;
    justify-content: center;
    gap: 0.5rem;
    height: 100%;
}

.bar {
    width: 12px;
    background: var(--accent-primary);
    border-radius: 2px;
    opacity: 0.7;
}

.project-content {
    padding: 1.5rem;
}

.project-title {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* Contact Section */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
    min-width: 250px;
    justify-content: flex-start;
}

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

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

/* Footer */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-tertiary);
    font-size: 0.9rem;
}

.footer-links a {
    color: var(--text-tertiary);
    text-decoration: none;
    font-family: var(--font-mono);
    transition: var(--transition);
}

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

/* --- New Styles for Course Layout --- */
.course-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    gap: 2rem;
}

.course-sidebar {
    width: 280px;
    flex-shrink: 0;
}

.sidebar-nav {
    position: sticky;
    top: 6rem; /* (4rem nav height + 2rem padding) */
    height: calc(100vh - 8rem);
    overflow-y: auto;
    padding-right: 1rem;
}

.sidebar-nav h3 {
    font-size: 1.2rem;
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-nav li a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
    border-left: 2px solid transparent;
}

.sidebar-nav li a:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.sidebar-nav li a.active {
    background-color: var(--bg-secondary);
    color: var(--accent-primary);
    border-left: 2px solid var(--accent-primary);
    font-weight: 500;
}

.course-content {
    flex-grow: 1;
    min-width: 0; /* Prevents flexbox overflow */
}

.lesson {
    margin-bottom: 6rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.lesson:first-child {
    padding-top: 0;
    border-top: none;
}

.lesson h2 {
    font-size: 2rem;
    color: var(--accent-primary);
    margin-bottom: 1rem;
    font-family: var(--font-mono);
}

.lesson h3 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.lesson p, .lesson li {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.lesson ul {
    padding-left: 1.5rem;
}

.lesson strong {
    color: var(--text-primary);
    font-weight: 500;
}

/* Code Block Styles */
.code-block-wrapper {
    position: relative;
    margin: 2rem 0;
}

pre {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
}

.copy-code-btn {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: calc(var(--border-radius) / 2);
    cursor: pointer;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    opacity: 0.6;
    transition: var(--transition);
}

.copy-code-btn:hover {
    opacity: 1;
    background-color: var(--accent-primary);
    color: var(--bg-primary);
}

/* Responsive adjustments for course layout */
@media (max-width: 1024px) {
    .course-container {
        flex-direction: column;
    }
    .course-sidebar {
        width: 100%;
    }
    .sidebar-nav {
        position: static;
        height: auto;
        overflow-y: visible;
        border-bottom: 1px solid var(--border-color);
        padding-bottom: 1rem;
        margin-bottom: 2rem;
    }
}


/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --section-padding: 4rem 0;
        --container-padding: 0 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-bottom: 1px solid var(--border-color);
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        transform: translateY(-100%);
        opacity: 0;
        transition: var(--transition);
        z-index: 1000;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .contact-links {
        align-items: stretch;
    }
    
    .contact-link {
        min-width: auto;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
        max-width: 250px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .cursor {
        animation: none;
    }
    
    .typing-cursor {
        animation: none;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --border-color: #ffffff;
        --text-secondary: #ffffff;
        --text-tertiary: #cccccc;
    }
}

/* Focus styles for accessibility */
*:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

.nav-link:focus::before {
    width: 100%;
}

/* Smooth scrolling for reduced motion users */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}