/* ===================================
   Cloud & DevOps Roadmap - Dark Theme
   Modern Tech-Focused Design 2025
   =================================== */

/* CSS Variables - Tech Industry Color Scheme */
:root {
    /* Primary Colors - Deep Blues & Teals */
    --primary-dark: #0a192f;
    --primary-blue: #0d47a1;
    --primary-teal: #00acc1;
    --primary-cyan: #00bcd4;
    
    /* Accent Colors */
    --accent-orange: #ff6b35;
    --accent-green: #4caf50;
    --accent-purple: #7c4dff;
    --accent-yellow: #ffc107;
    
    /* Neutral Colors */
    --bg-dark: #0f1419;
    --bg-darker: #0a0e14;
    --bg-card: #1a1f2e;
    --bg-card-hover: #242938;
    --text-primary: #e6f1ff;
    --text-secondary: #8892b0;
    --text-muted: #64748b;
    
    /* Borders & Shadows */
    --border-color: #233554;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --glow-blue: 0 0 20px rgba(13, 71, 161, 0.4);
    --glow-teal: 0 0 20px rgba(0, 172, 193, 0.4);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Droid Sans Mono', 'Source Code Pro', monospace;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

a {
    color: var(--primary-cyan);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-teal);
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, var(--primary-cyan), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-teal));
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), var(--glow-blue);
}

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    background: rgba(10, 25, 47, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-sm) 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.brand-icon {
    width: 28px;
    height: 28px;
    color: var(--primary-cyan);
}

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

.nav-menu a {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-cyan);
    transition: width var(--transition-normal);
}

.nav-menu a:hover {
    color: var(--primary-cyan);
}

.nav-menu a:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: var(--spacing-xs);
}

/* Hero Section */
.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--bg-darker) 0%, var(--primary-dark) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(13, 71, 161, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 172, 193, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content {
    animation: fadeInUp 0.8s ease;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.5rem 1rem;
    background: rgba(0, 172, 193, 0.1);
    border: 1px solid var(--primary-cyan);
    border-radius: 50px;
    color: var(--primary-cyan);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.hero-stats {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.stat-item i {
    width: 40px;
    height: 40px;
    color: var(--primary-cyan);
}

.stat-item strong {
    display: block;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.stat-item span {
    display: block;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeIn 1s ease;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    filter: drop-shadow(0 10px 30px rgba(0, 172, 193, 0.3));
}

/* Section Styles */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* Timeline */
.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-cyan), var(--accent-purple));
}

.timeline-item {
    position: relative;
    padding-left: 80px;
    margin-bottom: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: 18px;
    top: 0;
    width: 24px;
    height: 24px;
    background: var(--bg-dark);
    border: 3px solid var(--primary-cyan);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.timeline-marker i {
    width: 12px;
    height: 12px;
    color: var(--primary-cyan);
}

.timeline-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.timeline-content:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-cyan);
}

.timeline-badge {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-sm);
}

.timeline-badge.beginner {
    background: rgba(76, 175, 80, 0.2);
    color: var(--accent-green);
    border: 1px solid var(--accent-green);
}

.timeline-badge.intermediate {
    background: rgba(255, 193, 7, 0.2);
    color: var(--accent-yellow);
    border: 1px solid var(--accent-yellow);
}

.timeline-badge.advanced {
    background: rgba(255, 107, 53, 0.2);
    color: var(--accent-orange);
    border: 1px solid var(--accent-orange);
}

.timeline-content h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.timeline-skills {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.timeline-skills li {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
}

.timeline-skills i {
    width: 16px;
    height: 16px;
    color: var(--accent-green);
}

/* Roadmap Stage */
.roadmap-stage {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.stage-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.stage-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.stage-icon.beginner {
    background: linear-gradient(135deg, rgba(76, 175, 80, 0.2), rgba(76, 175, 80, 0.1));
    border: 2px solid var(--accent-green);
}

.stage-icon.intermediate {
    background: linear-gradient(135deg, rgba(255, 193, 7, 0.2), rgba(255, 193, 7, 0.1));
    border: 2px solid var(--accent-yellow);
}

.stage-icon.advanced {
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.2), rgba(255, 107, 53, 0.1));
    border: 2px solid var(--accent-orange);
}

.stage-icon i {
    width: 32px;
    height: 32px;
}

.stage-icon.beginner i { color: var(--accent-green); }
.stage-icon.intermediate i { color: var(--accent-yellow); }
.stage-icon.advanced i { color: var(--accent-orange); }

.stage-header h3 {
    font-size: 2rem;
    margin-bottom: 0.25rem;
}

.stage-header p {
    color: var(--text-muted);
    margin: 0;
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.skill-card {
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
    cursor: pointer;
    position: relative;
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-cyan);
}

.skill-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-teal));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.skill-icon i {
    width: 28px;
    height: 28px;
    color: white;
}

.skill-card h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.skill-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.skill-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

.duration {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.duration i {
    width: 16px;
    height: 16px;
}

.click-hint {
    font-size: 0.875rem;
    color: var(--primary-cyan);
    font-weight: 600;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.skill-card:hover .click-hint {
    opacity: 1;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10000;
    overflow-y: auto;
}

.modal.active {
    display: block;
}

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 25, 47, 0.95);
    backdrop-filter: blur(10px);
}

.modal-container {
    position: relative;
    max-width: 900px;
    margin: var(--spacing-xl) auto;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.4s ease;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
    position: sticky;
    top: 0;
    background: var(--bg-card);
    z-index: 10;
}

.modal-header h2 {
    margin: 0;
    font-size: 1.75rem;
}

.modal-close {
    width: 40px;
    height: 40px;
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.modal-close:hover {
    background: var(--accent-orange);
    border-color: var(--accent-orange);
    transform: rotate(90deg);
}

.modal-close i {
    width: 24px;
    height: 24px;
    color: var(--text-primary);
}

.modal-body {
    padding: var(--spacing-xl);
}

/* Modal Content Sections */
.content-section {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--border-color);
}

.content-section:last-child {
    border-bottom: none;
}

.content-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary-cyan);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.content-section h3 i {
    width: 24px;
    height: 24px;
}

.content-text {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.content-text ul {
    list-style: none;
    margin: var(--spacing-md) 0;
}

.content-text li {
    padding-left: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    position: relative;
}

.content-text li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-cyan);
    font-weight: bold;
}

.content-text code {
    background: var(--bg-darker);
    padding: 0.2em 0.5em;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: var(--primary-cyan);
}

/* Video Grid */
.video-grid {
    display: grid;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.video-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    transition: all var(--transition-normal);
    text-decoration: none;
}

.video-card:hover {
    border-color: var(--primary-cyan);
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

.video-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-teal));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.video-icon i {
    width: 28px;
    height: 28px;
    color: white;
}

.video-info strong {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.video-info span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Resource List */
.resource-list {
    display: grid;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.resource-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    transition: all var(--transition-normal);
    text-decoration: none;
}

.resource-item:hover {
    border-color: var(--primary-cyan);
    transform: translateX(4px);
}

.resource-item i {
    width: 20px;
    height: 20px;
    color: var(--primary-cyan);
    flex-shrink: 0;
}

.resource-item strong {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.resource-item span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Exercise List */
.exercise-list {
    display: grid;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.exercise-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(76, 175, 80, 0.05);
    border: 1px solid rgba(76, 175, 80, 0.2);
    border-radius: 8px;
    color: var(--text-secondary);
}

.exercise-item i {
    width: 20px;
    height: 20px;
    color: var(--accent-green);
    flex-shrink: 0;
    margin-top: 2px;
}

/* Certifications */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.cert-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.cert-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.cert-header i {
    width: 28px;
    height: 28px;
    color: var(--primary-cyan);
}

.cert-header h3 {
    font-size: 1.25rem;
    margin: 0;
}

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

.cert-level {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.cert-level strong {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--primary-cyan);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.cert-level span {
    font-size: 0.95rem;
    color: var(--text-secondary);
    padding-left: var(--spacing-md);
}

/* Projects */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-cyan);
}

.project-level {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-md);
}

.project-level.beginner {
    background: rgba(76, 175, 80, 0.2);
    color: var(--accent-green);
}

.project-level.intermediate {
    background: rgba(255, 193, 7, 0.2);
    color: var(--accent-yellow);
}

.project-level.advanced {
    background: rgba(255, 107, 53, 0.2);
    color: var(--accent-orange);
}

.project-card h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.project-card p {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-md);
}

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

.project-tech span {
    padding: 0.375rem 0.75rem;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Career */
.career-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.career-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
}

.career-card i {
    width: 32px;
    height: 32px;
    color: var(--primary-cyan);
    margin-bottom: var(--spacing-md);
}

.career-card h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

.career-card ul {
    list-style: none;
}

.career-card li {
    padding: var(--spacing-sm) 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.career-card li:last-child {
    border-bottom: none;
}

/* Footer */
.footer {
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer p {
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.footer-note {
    font-size: 0.875rem;
}

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

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

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

/* Responsive */
@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
    }
    
    .hero-image {
        order: -1;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-card);
        border-top: 1px solid var(--border-color);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: 0;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-menu li {
        padding: var(--spacing-sm) 0;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-menu li:last-child {
        border-bottom: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .skills-grid,
    .cert-grid,
    .project-grid,
    .career-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline::before {
        left: 15px;
    }
    
    .timeline-item {
        padding-left: 50px;
    }
    
    .timeline-marker {
        left: 6px;
    }
}