/* 
 * Jatin Mehra - Professional Academic Portfolio
 * Clean, Paper-like Theme
 */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,300;0,400;0,500;0,600;0,700;1,300;1,400&family=Inter:wght@300;400;500;600&display=swap');

:root {
    --color-bg: #fdfcfb;
    --color-paper: #ffffff;
    --color-text: #2c2c2c;
    --color-text-secondary: #555555;
    --color-text-muted: #777777;
    --color-border: #e5e5e5;
    --color-border-light: #f0f0f0;
    --color-accent: #1a365d;
    --color-accent-light: #2c5282;
    --color-link: #2b6cb0;
    --color-link-hover: #1a365d;
    --font-serif: 'Crimson Pro', Georgia, 'Times New Roman', serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --max-width: 900px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-serif);
    font-size: 18px;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-sans);
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 1.75rem;
    margin-top: var(--spacing-2xl);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-border);
}

h3 {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
}

h4 {
    font-size: 1.1rem;
    font-weight: 500;
}

p {
    margin-bottom: var(--spacing-md);
    text-align: justify;
    hyphens: auto;
}

a {
    color: var(--color-link);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-link-hover);
    text-decoration: underline;
}

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

/* Header / Navigation */
header {
    background: var(--color-paper);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.nav-brand {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
}

.nav-brand:hover {
    text-decoration: none;
    color: var(--color-accent);
}

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

.nav-links a {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: var(--spacing-xs) 0;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width 0.3s ease;
}

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

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-accent);
    text-decoration: none;
}

/* Mobile Navigation */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    margin: 5px 0;
    transition: 0.3s;
}

@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-paper);
        flex-direction: column;
        padding: var(--spacing-md);
        border-bottom: 1px solid var(--color-border);
        gap: var(--spacing-sm);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-links a {
        padding: var(--spacing-sm) 0;
    }
}

/* Main Content */
main {
    padding: var(--spacing-2xl) 0 var(--spacing-3xl);
}

/* Page Header */
.page-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
}

.page-header h1 {
    margin-bottom: var(--spacing-sm);
}

.page-header .subtitle {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    font-style: italic;
    color: var(--color-text-secondary);
}

/* Profile Section */
.profile-section {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: var(--spacing-xl);
    align-items: start;
    margin-bottom: var(--spacing-2xl);
}

.profile-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--color-border);
    filter: grayscale(20%);
}

.profile-info h1 {
    margin-bottom: var(--spacing-xs);
}

.profile-title {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.profile-affiliations {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.contact-info {
    font-family: var(--font-sans);
    font-size: 0.9rem;
}

.contact-info p {
    margin-bottom: var(--spacing-xs);
    text-align: left;
}

.contact-info i {
    width: 20px;
    color: var(--color-text-muted);
    margin-right: var(--spacing-sm);
}

@media (max-width: 768px) {
    .profile-section {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .profile-image {
        margin: 0 auto;
    }
    
    .contact-info p {
        text-align: center;
    }
}

/* Section Styles */
section {
    margin-bottom: var(--spacing-2xl);
}

section:last-child {
    margin-bottom: 0;
}

/* Bio/About */
.bio p {
    font-size: 1.05rem;
}

/* Research Interests / Skills */
.interests-list,
.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    list-style: none;
    margin-top: var(--spacing-md);
}

.interests-list li,
.skills-list li {
    background: var(--color-border-light);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 2px;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
}

/* Skills Categories */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.skill-category {
    background: var(--color-paper);
    border: 1px solid var(--color-border);
    padding: var(--spacing-lg);
}

.skill-category h4 {
    color: var(--color-accent);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border-light);
}

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

.skill-category li {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) 0;
}

/* Timeline / Experience */
.timeline {
    position: relative;
    padding-left: var(--spacing-xl);
}

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border-light);
}

.timeline-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: calc(-1 * var(--spacing-xl) - 4px);
    top: 8px;
    width: 10px;
    height: 10px;
    background: var(--color-paper);
    border: 2px solid var(--color-accent);
    border-radius: 50%;
}

.timeline-date {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
}

.timeline-title {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.timeline-org {
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.timeline-desc {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

.timeline-desc ul {
    margin-top: var(--spacing-sm);
    margin-left: var(--spacing-lg);
}

.timeline-desc li {
    margin-bottom: var(--spacing-xs);
}

/* Projects */
.projects-grid {
    display: grid;
    gap: var(--spacing-xl);
}

.project-item {
    background: var(--color-paper);
    border: 1px solid var(--color-border);
    padding: var(--spacing-lg);
    transition: box-shadow 0.2s ease;
}

.project-item:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

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

.project-title {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin: 0;
}

.project-badge {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-accent);
    color: white;
    border-radius: 2px;
    white-space: nowrap;
}

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

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

.project-tech span {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    color: var(--color-text-muted);
    background: var(--color-border-light);
    padding: 2px var(--spacing-sm);
    border: 1px solid var(--color-border);
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-links a {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.project-links a i {
    font-size: 0.9rem;
}

/* Certifications */
.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.cert-item {
    background: var(--color-paper);
    border: 1px solid var(--color-border);
    padding: var(--spacing-lg);
    text-align: center;
}

.cert-item img {
    width: 60px;
    height: auto;
    margin-bottom: var(--spacing-md);
    filter: grayscale(30%);
}

.cert-item h4 {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.cert-item p {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-align: center;
    margin: 0;
}

/* Contact Form */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-2xl);
}

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

.contact-details h3 {
    margin-bottom: var(--spacing-lg);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-item i {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-border-light);
    border: 1px solid var(--color-border);
    color: var(--color-accent);
    flex-shrink: 0;
}

.contact-item div h4 {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.contact-item div p {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin: 0;
    text-align: left;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-border-light);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    transition: all 0.2s ease;
}

.social-links a:hover {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
    text-decoration: none;
}

/* Form Styles */
.contact-form h3 {
    margin-bottom: var(--spacing-lg);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    border: 1px solid var(--color-border);
    background: var(--color-paper);
    color: var(--color-text);
    transition: border-color 0.2s ease;
}

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

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.btn {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-xl);
    border: 2px solid var(--color-accent);
    background: var(--color-accent);
    color: white;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn:hover {
    background: var(--color-accent-light);
    border-color: var(--color-accent-light);
    text-decoration: none;
    color: white;
}

.btn-outline {
    background: transparent;
    color: var(--color-accent);
}

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

/* Message Status */
.message-status {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    display: none;
}

.message-status.success {
    display: block;
    background: #f0fdf4;
    border: 1px solid #86efac;
    color: #166534;
}

.message-status.error {
    display: block;
    background: #fef2f2;
    border: 1px solid #fca5a5;
    color: #991b1b;
}

/* Footer */
footer {
    background: var(--color-paper);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-3xl);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-content p {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin: 0;
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-links a {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

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

/* Journey / Learning Path */
.journey-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-2xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.journey-step {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border-light);
}

.journey-step:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--color-accent);
    color: white;
    font-family: var(--font-sans);
    font-size: 1.25rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.step-content h3 {
    font-size: 1.1rem;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.step-period {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.step-content ul {
    margin-left: var(--spacing-lg);
    color: var(--color-text-secondary);
}

.step-content li {
    margin-bottom: var(--spacing-xs);
    font-size: 0.95rem;
}

/* Stats Section */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: var(--color-border-light);
    border: 1px solid var(--color-border);
}

@media (max-width: 768px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-family: var(--font-sans);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-accent);
}

.stat-label {
    font-family: var(--font-sans);
    font-size: 0.8rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Publications / Academic Note */
.academic-note {
    background: var(--color-border-light);
    border-left: 4px solid var(--color-accent);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.academic-note h4 {
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
}

.academic-note p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin: 0;
}

/* Responsive Typography */
@media (max-width: 768px) {
    body {
        font-size: 16px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    main {
        padding: var(--spacing-xl) 0 var(--spacing-2xl);
    }
}

/* Print Styles */
@media print {
    header, footer, .nav-toggle {
        display: none;
    }
    
    body {
        font-size: 12pt;
        background: white;
    }
    
    .container {
        max-width: 100%;
    }
    
    a {
        color: var(--color-text);
        text-decoration: none;
    }
    
    a[href^="http"]:after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
    }
}

/* Animation for page load */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

main {
    animation: fadeIn 0.5s ease-out;
}