/* ==========================================
   CSS Variables & Reset
   ========================================== */
:root {
    /* Colors - Professional Blue & Tech Grey */
    --primary-blue: #2563eb;
    --primary-blue-dark: #1e40af;
    --primary-blue-light: #3b82f6;
    --accent-blue: #60a5fa;
    
    --grey-dark: #1f2937;
    --grey-medium: #4b5563;
    --grey-light: #9ca3af;
    --grey-lighter: #e5e7eb;
    --grey-bg: #f3f4f6;
    
    --white: #ffffff;
    --black: #111827;
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', Courier, monospace;
    
    /* Spacing */
    --section-padding: 100px 0;
    --container-max-width: 1200px;
    
    /* Transitions */
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--grey-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ==========================================
   Navigation - Left Sidebar
   ========================================== */
.navbar {
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    width: 200px;
    background: var(--white);
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    padding: 40px 0;
}

.nav-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.nav-menu {
    display: flex;
    flex-direction: column;
    list-style: none;
    gap: 0;
    padding: 0 20px;
}

.nav-menu li {
    width: 100%;
}

.nav-link {
    display: block;
    text-decoration: none;
    color: var(--grey-dark);
    font-weight: 500;
    padding: 16px 20px;
    position: relative;
    transition: var(--transition-smooth);
    border-radius: 8px;
    margin-bottom: 8px;
}

.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-blue);
    background: rgba(37, 99, 235, 0.05);
}

.nav-link:hover::before,
.nav-link.active::before {
    width: 4px;
}

.hamburger {
    display: none;
    position: fixed;
    top: 20px;
    left: 20px;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
    z-index: 1001;
    background: var(--white);
    padding: 10px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--grey-dark);
    transition: var(--transition-smooth);
}

/* Adjust main content for sidebar */
body {
    margin-left: 200px;
}

.hero,
section {
    margin-left: 0;
}

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

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #1e40af 0%, #2563eb 50%, #60a5fa 100%);
    opacity: 0.05;
    z-index: -1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text h1 {
    font-size: 56px;
    font-weight: 700;
    color: var(--grey-dark);
    margin-bottom: 10px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--primary-blue);
    font-weight: 600;
    margin-bottom: 10px;
}

.hero-tagline {
    font-size: 18px;
    color: var(--grey-medium);
    margin-bottom: 30px;
}

.hero-cta {
    display: flex;
    gap: 20px;
    margin-top: 40px;
}

.btn {
    padding: 14px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-smooth);
    display: inline-block;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: var(--primary-blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.3);
}

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

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

.btn-download {
    background: var(--grey-dark);
    color: var(--white);
    border: 2px solid var(--grey-dark);
}

.btn-download:hover {
    background: transparent;
    color: var(--grey-dark);
    border-color: var(--grey-dark);
}

.hero-image {
    display: flex;
    justify-content: center;
}

.profile-img {
    width: 350px;
    height: 350px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--primary-blue);
    box-shadow: 0 20px 40px rgba(37, 99, 235, 0.2);
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
}

.scroll-indicator span {
    display: block;
    width: 2px;
    height: 40px;
    background: var(--primary-blue);
    animation: scroll-down 2s infinite;
}

@keyframes scroll-down {
    0%, 100% { opacity: 0; transform: translateY(0); }
    50% { opacity: 1; transform: translateY(10px); }
}

/* ==========================================
   Section Styles
   ========================================== */
section {
    padding: var(--section-padding);
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 20px;
    color: var(--grey-dark);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--primary-blue);
    margin: 20px auto 0;
}

.section-intro {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
    color: var(--grey-medium);
    font-size: 18px;
}

/* ==========================================
   About Section
   ========================================== */
.about {
    background: var(--grey-bg);
}

.about-text {
    max-width: 800px;
    margin: 0 auto 60px;
}

.about-text .lead {
    font-size: 22px;
    font-weight: 600;
    color: var(--grey-dark);
    margin-bottom: 20px;
    line-height: 1.5;
}

.about-text p {
    font-size: 18px;
    color: var(--grey-medium);
    margin-bottom: 20px;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 60px;
}

.highlight-card {
    background: var(--white);
    padding: 30px;
    text-align: center;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: var(--transition-smooth);
}

.highlight-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.1);
}

.highlight-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.highlight-label {
    color: var(--grey-medium);
    font-weight: 500;
}

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

.subsection-title {
    font-size: 28px;
    font-weight: 600;
    color: var(--grey-dark);
    margin-bottom: 30px;
}

.education-item {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    padding: 20px;
    background: var(--white);
    border-radius: 8px;
    transition: var(--transition-smooth);
}

.education-item:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.education-icon {
    font-size: 32px;
}

.education-item h4 {
    color: var(--grey-dark);
    margin-bottom: 5px;
}

.education-item p {
    color: var(--grey-medium);
}

/* ==========================================
   Experience Section - Timeline
   ========================================== */
.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--grey-lighter);
}

.timeline-item {
    position: relative;
    margin-bottom: 50px;
}

.timeline-marker {
    position: absolute;
    left: -34px;
    top: 8px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-blue);
    border: 3px solid var(--white);
    box-shadow: 0 0 0 3px var(--grey-lighter);
}

.timeline-content {
    background: var(--white);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: var(--transition-smooth);
}

.timeline-content:hover {
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.timeline-date {
    display: inline-block;
    color: var(--primary-blue);
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 10px;
}

.timeline-content h3 {
    font-size: 24px;
    color: var(--grey-dark);
    margin-bottom: 5px;
}

.timeline-content h4 {
    font-size: 18px;
    color: var(--grey-medium);
    margin-bottom: 5px;
}

.location {
    color: var(--grey-light);
    font-size: 14px;
    margin-bottom: 15px;
}

.description {
    color: var(--grey-medium);
    line-height: 1.7;
    margin-bottom: 20px;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tech-tags span {
    background: var(--grey-bg);
    color: var(--grey-dark);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

/* ==========================================
   Skills Section
   ========================================== */
.skills {
    background: var(--grey-bg);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.skill-category {
    background: var(--white);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.skill-category h3 {
    color: var(--grey-dark);
    margin-bottom: 20px;
    font-size: 20px;
    border-bottom: 2px solid var(--primary-blue);
    padding-bottom: 10px;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-item {
    background: var(--grey-bg);
    color: var(--grey-dark);
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition-smooth);
}

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

.skill-item.highlight {
    background: var(--primary-blue);
    color: var(--white);
    font-weight: 600;
}

/* ==========================================
   Projects Section
   ========================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.project-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: var(--transition-smooth);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.project-header {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    color: var(--white);
    padding: 25px;
}

.project-header h3 {
    font-size: 22px;
    margin-bottom: 5px;
}

.project-company {
    opacity: 0.9;
    font-size: 14px;
}

.project-content {
    padding: 25px;
}

.project-section {
    margin-bottom: 20px;
}

.project-section h4 {
    color: var(--primary-blue);
    font-size: 14px;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.project-section p {
    color: var(--grey-medium);
    line-height: 1.6;
}

.project-tags {
    padding: 0 25px 25px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.project-tags span {
    background: var(--grey-bg);
    color: var(--grey-dark);
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 12px;
}

.project-card.placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    border: 2px dashed var(--grey-lighter);
}

.placeholder-content {
    text-align: center;
    color: var(--grey-light);
    padding: 20px;
}

.placeholder-content p:first-child {
    font-size: 48px;
    margin-bottom: 10px;
}

.placeholder-note {
    font-size: 14px;
    margin-top: 15px;
    color: var(--grey-medium);
    font-style: italic;
}

.project-period {
    font-size: 13px;
    opacity: 0.8;
}

.projects-note {
    max-width: 800px;
    margin: 60px auto 0;
    padding: 25px;
    background: var(--grey-bg);
    border-left: 4px solid var(--primary-blue);
    border-radius: 8px;
}

.projects-note p {
    color: var(--grey-medium);
    line-height: 1.7;
    margin: 0;
}

.projects-note strong {
    color: var(--grey-dark);
}

/* ==========================================
   Interests Section
   ========================================== */
.interests {
    background: var(--grey-bg);
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.interest-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: var(--transition-smooth);
}

.interest-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.1);
}

.interest-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.interest-card h3 {
    color: var(--grey-dark);
    margin-bottom: 10px;
    font-size: 20px;
}

.interest-card p {
    color: var(--grey-medium);
    line-height: 1.6;
}

/* ==========================================
   Contact Section
   ========================================== */
.contact {
    background: linear-gradient(135deg, var(--primary-blue-dark), var(--primary-blue));
    color: var(--white);
}

.contact .section-title,
.contact .section-intro {
    color: var(--white);
}

.contact .section-title::after {
    background: var(--white);
}

.contact-content {
    max-width: 1000px;
    margin: 0 auto;
}

/* LinkedIn Featured Card */
.contact-primary {
    margin-bottom: 60px;
}

.linkedin-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    padding: 50px;
    text-align: center;
    transition: var(--transition-smooth);
}

.linkedin-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.linkedin-icon {
    font-size: 64px;
    margin-bottom: 20px;
    animation: float 3s ease-in-out infinite;
}

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

.linkedin-card h3 {
    font-size: 32px;
    margin-bottom: 15px;
    color: var(--white);
}

.linkedin-card p {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.9;
}

.btn-linkedin {
    display: inline-block;
    padding: 16px 40px;
    background: var(--white);
    color: var(--primary-blue);
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 18px;
    transition: var(--transition-smooth);
}

.btn-linkedin:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
    background: var(--accent-blue);
    color: var(--white);
}

/* Contact Info Grid */
.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
}

.contact-item {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(5px);
    padding: 25px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    transition: var(--transition-smooth);
}

.contact-item:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
}

.contact-icon {
    font-size: 32px;
}

.contact-item h4 {
    margin-bottom: 5px;
    font-size: 16px;
    font-weight: 600;
}

.contact-item a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.9;
    transition: var(--transition-smooth);
    font-weight: 500;
}

.contact-item a:hover {
    opacity: 1;
    text-decoration: underline;
}

.contact-item p {
    opacity: 0.9;
    margin: 0;
}

.contact-note {
    font-size: 13px;
    opacity: 0.7;
    margin-top: 5px;
}

.download-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.download-link::before {
    content: '⬇';
    font-size: 16px;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--grey-dark);
    color: var(--grey-light);
    text-align: center;
    padding: 40px 20px;
}

.footer-note {
    margin-top: 10px;
    font-size: 14px;
    opacity: 0.7;
}

/* ==========================================
   Animations
   ========================================== */
.fade-in {
    animation: fadeIn 1s ease-in;
}

.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

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

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 768px) {
    /* Remove sidebar margin on mobile */
    body {
        margin-left: 0;
    }
    
    /* Hide sidebar by default on mobile */
    .navbar {
        left: -200px;
        transition: left 0.3s ease;
    }
    
    /* Show sidebar when active */
    .navbar.active {
        left: 0;
    }
    
    /* Show hamburger on mobile */
    .hamburger {
        display: flex;
    }
    
    /* Overlay when menu is open */
    .navbar.active::after {
        content: '';
        position: fixed;
        top: 0;
        left: 200px;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: -1;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-text h1 {
        font-size: 36px;
    }
    
    .profile-img {
        width: 250px;
        height: 250px;
    }
    
    .about-highlights {
        grid-template-columns: 1fr;
    }
    
    .timeline {
        padding-left: 30px;
    }
    
    .timeline::before {
        left: 10px;
    }
    
    .timeline-marker {
        left: -24px;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        grid-template-columns: 1fr;
    }
    
    .linkedin-card {
        padding: 30px 20px;
    }
    
    .linkedin-card h3 {
        font-size: 24px;
    }
    
    .hero-cta {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero-cta .btn {
        flex: 1;
        min-width: 150px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-cta .btn {
        width: 100%;
    }
}