/* ============================================
   PORTFOLIO WEBSITE STYLES
   Dynamic scroll-based design with responsive layout
   ============================================ */

/* ============================================
   CSS VARIABLES - EDIT COLORS & FONTS HERE
   ============================================ */
:root {
    /* Primary Colors - Change these to customize your theme */
    --primary-color: #2c3e50;
    --primary-light: #34495e;
    --primary-dark: #1a252f;
    
    /* Accent Colors */
    --accent-color: #e74c3c;
    --accent-light: #ec7063;
    --accent-dark: #c0392b;
    
    /* Neutral Colors */
    --white: #ffffff;
    --light-gray: #ecf0f1;
    --medium-gray: #95a5a6;
    --dark-gray: #2c3e50;
    --black: #000000;
    
    /* Background Colors for Sections */
    --bg-overlay: rgba(0, 0, 0, 0.5);
    --bg-overlay-light: rgba(0, 0, 0, 0.3);
    
    /* Typography */
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Source Sans 3', sans-serif;
    
    /* Font Sizes */
    --font-size-small: 0.875rem;
    --font-size-base: 1rem;
    --font-size-large: 1.125rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 3rem;
    --font-size-4xl: 4rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.3);
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

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

/* ============================================
   NAVIGATION BAR
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: background-color var(--transition-base), padding var(--transition-base);
    padding: var(--spacing-sm) 0;
    background-color: transparent;
}

/* Navbar background appears on scroll */
.navbar.scrolled {
    background-color: rgba(44, 62, 80, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    padding: 0.5rem 0;
}

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

.nav-logo {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--white);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-base);
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent-color);
}

/* Hamburger Menu for Mobile */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger .bar {
    width: 25px;
    height: 3px;
    background-color: var(--white);
    transition: all var(--transition-base);
    border-radius: 2px;
}

/* ============================================
   SECTION BASE STYLES
   ============================================ */
.section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) var(--spacing-md);
    overflow: hidden;
}

/* Background Image Container - Changes on Scroll */
.background-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    transition: transform 0.6s ease-out, opacity 0.6s ease-out;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

/* Background images for each section - EDIT THESE URLs */
.background-image[data-image="1"] {
    background-image: linear-gradient(135deg, #667eea 0%, #764ba2 100%),
                      url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

.background-image[data-image="2"] {
    background-image: linear-gradient(135deg, #f093fb 0%, #f5576c 100%),
                      url('https://images.unsplash.com/photo-1519389950473-47ba0277781c?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

.background-image[data-image="3"] {
    background-image: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%),
                      url('https://images.unsplash.com/photo-1523050854058-8df90110c9f1?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

.background-image[data-image="4"] {
    background-image: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%),
                      url('https://images.unsplash.com/photo-1517694712202-14dd9538aa97?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

.background-image[data-image="5"] {
    background-image: linear-gradient(135deg, #fa709a 0%, #fee140 100%),
                      url('https://images.unsplash.com/photo-1497032628192-86f99bcd76bc?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

.background-image[data-image="6"] {
    background-image: linear-gradient(135deg, #30cfd0 0%, #330867 100%),
                      url('https://images.unsplash.com/photo-1423666639041-f56000c27a9a?w=1920&h=1080&fit=crop');
    background-blend-mode: overlay;
}

/* Parallax effect on scroll */
.background-image.parallax {
    transform: translateY(-50px);
}

/* Content Overlay */
.content-overlay {
    position: relative;
    z-index: 2;
    width: 100%;
    background-color: var(--bg-overlay);
    padding: var(--spacing-lg) 0;
}

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

/* ============================================
   TYPOGRAPHY
   ============================================ */
.section-title {
    font-family: var(--font-heading);
    font-size: var(--font-size-4xl);
    font-weight: 900;
    color: var(--white);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.section-subtitle {
    font-size: var(--font-size-xl);
    color: var(--light-gray);
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border-color: var(--white);
}

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

.btn-full {
    width: 100%;
}

/* ============================================
   HOME SECTION
   ============================================ */
.home-section .container {
    text-align: center;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 900;
    color: var(--white);
    margin-bottom: var(--spacing-sm);
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.hero-subtitle {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    color: var(--accent-light);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

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

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

/* ============================================
   ABOUT SECTION
   ============================================ */
.about-content {
    color: var(--white);
}

.about-text {
    font-size: var(--font-size-large);
    line-height: 1.8;
}

.lead-text {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--accent-light);
}

.about-text p {
    margin-bottom: var(--spacing-md);
}

/* Skills Container */
.skills-container {
    margin-top: var(--spacing-lg);
}

.skills-container h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-md);
    color: var(--white);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.skill-category {
    background-color: rgba(255, 255, 255, 0.1);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    transition: transform var(--transition-base);
}

.skill-category:hover {
    transform: translateY(-5px);
    background-color: rgba(255, 255, 255, 0.15);
}

.skill-category h4 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
    color: var(--accent-light);
}

.skill-category ul {
    list-style: none;
}

.skill-category li {
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.skill-category li:last-child {
    border-bottom: none;
}

/* ============================================
   TIMELINE (Education & Experience)
   ============================================ */
.timeline {
    position: relative;
    max-width: 900px;
    margin: var(--spacing-lg) auto;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    height: 100%;
    width: 2px;
    background: linear-gradient(180deg, var(--accent-color), var(--accent-light));
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
    opacity: 0;
    transform: translateX(-50px);
}

.timeline-item.visible {
    animation: slideInLeft 0.6s ease forwards;
}

.timeline-marker {
    position: absolute;
    left: -30px;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 4px solid var(--white);
    box-shadow: var(--shadow-md);
}

.timeline-marker.certification {
    background-color: var(--accent-light);
}

.timeline-content {
    background-color: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-xl);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.timeline-header h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.timeline-header h4 {
    font-size: var(--font-size-large);
    color: var(--accent-color);
    font-weight: 600;
}

.timeline-date {
    font-size: var(--font-size-base);
    color: var(--medium-gray);
    font-weight: 600;
    white-space: nowrap;
}

.timeline-content p {
    color: var(--dark-gray);
    margin-bottom: var(--spacing-sm);
}

.achievement-list,
.certification-list {
    list-style: none;
    margin-top: var(--spacing-sm);
}

.achievement-list li,
.certification-list li {
    padding: 0.5rem 0 0.5rem 1.5rem;
    position: relative;
    color: var(--dark-gray);
}

.achievement-list li::before,
.certification-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: bold;
}

/* ============================================
   PROJECTS SECTION
   ============================================ */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.project-card {
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
    opacity: 0;
    transform: scale(0.9);
}

.project-card.visible {
    animation: scaleIn 0.5s ease forwards;
}

.project-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.project-image {
    position: relative;
    width: 100%;
    height: 250px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    opacity: 0;
    transition: opacity var(--transition-base);
}

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

.project-link {
    padding: 0.75rem 1.5rem;
    background-color: var(--accent-color);
    color: var(--white);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.project-link:hover {
    background-color: var(--accent-dark);
    transform: translateY(-2px);
}

.project-link.github {
    background-color: var(--primary-color);
}

.project-link.github:hover {
    background-color: var(--primary-light);
}

.project-info {
    padding: var(--spacing-md);
}

.project-info h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.project-info p {
    color: var(--dark-gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

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

.tech-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--light-gray);
    color: var(--primary-color);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-small);
    font-weight: 600;
}

/* ============================================
   EXPERIENCE SECTION
   ============================================ */
.experience-timeline {
    position: relative;
    max-width: 900px;
    margin: var(--spacing-lg) auto;
    padding-left: 50px;
}

.experience-timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    height: 100%;
    width: 2px;
    background: linear-gradient(180deg, var(--accent-color), var(--accent-light));
}

.experience-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
    opacity: 0;
    transform: translateX(-50px);
}

.experience-item.visible {
    animation: slideInLeft 0.6s ease forwards;
}

.experience-marker {
    position: absolute;
    left: -30px;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 4px solid var(--white);
    box-shadow: var(--shadow-md);
}

.experience-content {
    background-color: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.experience-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-xl);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.experience-header h3 {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.experience-header h4 {
    font-size: var(--font-size-large);
    color: var(--accent-color);
    font-weight: 600;
}

.experience-date {
    font-size: var(--font-size-base);
    color: var(--medium-gray);
    font-weight: 600;
    white-space: nowrap;
}

.experience-description {
    color: var(--dark-gray);
    margin-bottom: var(--spacing-sm);
    line-height: 1.7;
}

.experience-achievements {
    list-style: none;
    margin: var(--spacing-sm) 0;
}

.experience-achievements li {
    padding: 0.5rem 0 0.5rem 1.5rem;
    position: relative;
    color: var(--dark-gray);
}

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

.experience-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: var(--spacing-sm);
}

.tech-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--accent-light);
    color: var(--white);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-small);
    font-weight: 600;
}

/* ============================================
   CONTACT SECTION
   ============================================ */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

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

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    background-color: rgba(255, 255, 255, 0.1);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
}

.contact-item:hover {
    background-color: rgba(255, 255, 255, 0.15);
    transform: translateX(10px);
}

.contact-icon {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background-color: var(--accent-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
}

.contact-details h3 {
    font-size: var(--font-size-large);
    color: var(--white);
    margin-bottom: 0.25rem;
}

.contact-details a,
.contact-details p {
    color: var(--light-gray);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.contact-details a:hover {
    color: var(--accent-light);
}

/* Social Links */
.social-links {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.social-link {
    width: 50px;
    height: 50px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
}

.social-link:hover {
    background-color: var(--accent-color);
    transform: translateY(-5px);
}

/* Contact Form */
.contact-form-container {
    background-color: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

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

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    color: var(--primary-color);
    font-size: var(--font-size-base);
}

.form-group input,
.form-group textarea {
    padding: 0.75rem;
    border: 2px solid var(--light-gray);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background-color: var(--primary-dark);
    color: var(--light-gray);
    text-align: center;
    padding: var(--spacing-md);
}

.footer p {
    margin: 0.5rem 0;
}

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

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

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

/* Reveal Animations - Triggered by JavaScript */
.fade-in-up {
    animation: fadeInUp 0.8s ease forwards;
}

.reveal-text {
    opacity: 0;
    transform: translateY(30px);
}

.reveal-text.visible {
    animation: fadeInUp 0.8s ease forwards;
}

.reveal-fade {
    opacity: 0;
}

.reveal-fade.visible {
    animation: fadeInUp 0.8s ease forwards 0.2s;
}

.reveal-slide {
    opacity: 0;
    transform: translateX(-50px);
}

.reveal-slide.visible {
    animation: slideInLeft 0.6s ease forwards;
}

.reveal-scale {
    opacity: 0;
    transform: scale(0.9);
}

.reveal-scale.visible {
    animation: scaleIn 0.5s ease forwards;
}

/* ============================================
   RESPONSIVE DESIGN - TABLET
   ============================================ */
@media screen and (max-width: 968px) {
    :root {
        --font-size-3xl: 2.5rem;
        --font-size-4xl: 3.5rem;
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: rgba(44, 62, 80, 0.98);
        width: 100%;
        text-align: center;
        transition: left var(--transition-base);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md) 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    .contact-content {
        grid-template-columns: 1fr;
    }

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

/* ============================================
   RESPONSIVE DESIGN - MOBILE
   ============================================ */
@media screen and (max-width: 640px) {
    :root {
        --font-size-2xl: 1.5rem;
        --font-size-3xl: 2rem;
        --font-size-4xl: 2.5rem;
        --spacing-md: 1rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }

    .section {
        padding: var(--spacing-lg) var(--spacing-sm);
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .hero-buttons {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .hero-buttons .btn {
        width: 100%;
    }

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

    .timeline,
    .experience-timeline {
        padding-left: 30px;
    }

    .timeline::before,
    .experience-timeline::before {
        left: 10px;
    }

    .timeline-marker,
    .experience-marker {
        left: -20px;
        width: 16px;
        height: 16px;
    }

    .timeline-content,
    .experience-content {
        padding: var(--spacing-sm);
    }

    .timeline-header,
    .experience-header {
        flex-direction: column;
    }

    .timeline-date,
    .experience-date {
        width: 100%;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
    .navbar,
    .hamburger,
    .background-image,
    .footer {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }
}