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

:root {
    --primary-color: #2d3e50;      /* Deep charcoal blue */
    --secondary-color: #1a252f;    /* Darker charcoal */
    --text-color: #2c3e50;         /* Soft black */
    --bg-color: #f8f9fa;           /* Off-white */
    --card-bg: #ffffff;            /* Pure white */
    --border-color: #e9ecef;       /* Light gray */
    --accent-color: #7fb069;       /* Sage green */
    --hover-bg: rgba(127, 176, 105, 0.08); /* Subtle sage hover */
}

/* Base Styles */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 3rem 0;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 3rem;
}

.profile-image {
    flex-shrink: 0;
}

.profile-image img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    border: 4px solid rgba(255, 255, 255, 0.9);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    object-fit: cover;
    animation: fadeInUp 0.8s ease-out;
}

.header-text {
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    animation: fadeInUp 0.8s ease-out;
}

.tagline {
    font-size: 1.2rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.location {
    margin-top: 1rem;
    font-size: 1rem;
    opacity: 0.8;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.social-links {
    margin-top: 1.5rem;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.social-links a {
    color: white;
    text-decoration: none;
    margin: 0 1rem;
    padding: 0.5rem 1rem;
    border: 2px solid rgba(255, 255, 255, 0.8);
    border-radius: 25px;
    transition: all 0.3s ease;
    display: inline-block;
}

.social-links a:hover {
    background-color: white;
    color: var(--primary-color);
    transform: translateY(-2px);
    border-color: white;
}

/* Navigation Styles */
nav {
    background-color: var(--card-bg);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
    position: sticky;
    position: -webkit-sticky;
    top: 0;
    z-index: 100;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    transform: translateZ(0);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    padding: 1rem 0;
    transition: transform 0.3s ease;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Sections */
section {
    margin-bottom: 4rem;
    animation: fadeIn 0.8s ease-out;
    scroll-margin-top: 80px;
}

h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--accent-color);
    display: inline-block;
}

h3.section-subtitle {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-top: 3rem;
    margin-bottom: 1.5rem;
}

/* Summary Section */
.summary {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    margin-bottom: 3rem;
    border: 1px solid var(--border-color);
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.skill-category {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
    border-color: var(--accent-color);
}

.skill-category h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background-color: var(--hover-bg);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-color);
    border: 1px solid rgba(127, 176, 105, 0.2);
    transition: all 0.3s ease;
}

.skill-tag:hover {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

/* Experience Section */
.experience-item {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent-color);
}

.experience-item:hover {
    transform: translateX(5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.company-name {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.job-title {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-top: 0.3rem;
}

.date {
    color: #6b7280;
    font-style: italic;
}

.experience-details ul {
    list-style-position: inside;
    margin-top: 1rem;
}

.experience-details li {
    margin-bottom: 0.5rem;
    line-height: 1.8;
    color: var(--text-color);
}

/* Education Section */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.education-item {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
}

.education-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
    border-color: var(--accent-color);
}

.education-item h3 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.education-item p strong {
    color: var(--accent-color);
    font-weight: 600;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.project-card {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
    border-color: var(--accent-color);
}

.project-card h4 {
    color: var(--secondary-color);
    margin-bottom: 0.8rem;
    font-size: 1.2rem;
}

.project-link {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s ease;
    position: relative;
}

.project-link:hover {
    color: var(--accent-color);
}

.project-link::after {
    content: ' ↗';
    font-size: 0.9rem;
    opacity: 0.7;
}

.project-tech {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.project-card p:last-child {
    flex-grow: 1;
}

/* Publications Section */
.publication-item {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.publication-item:hover {
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.publication-item h4 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.publication-item p {
    margin-bottom: 0.5rem;
}

.publication-item p:last-of-type {
    margin-bottom: 1rem;
}

.publication-item ul {
    margin-bottom: 0;
}

.publication-item a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

.publication-item a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Contact Page Styles */
.main-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4rem 2rem;
    min-height: calc(100vh - 300px);
}

.contact-container {
    max-width: 600px;
    width: 100%;
    background-color: var(--card-bg);
    padding: 3rem;
    border-radius: 10px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
    animation: fadeInUp 0.8s ease-out;
}

.contact-header {
    text-align: center;
    margin-bottom: 2rem;
}

.contact-header h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.contact-header p {
    color: var(--text-color);
    opacity: 0.8;
}

/* Form Styling */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.form-group label {
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.3s ease;
    background-color: var(--bg-color);
}

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

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.submit-btn {
    background-color: var(--accent-color);
    color: white;
    padding: 1rem 2rem;
    border: none;
    border-radius: 25px;
    font-size: 1.1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 1rem;
}

.submit-btn:hover {
    background-color: #6ea058;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(127, 176, 105, 0.3);
}

.submit-btn:active {
    transform: translateY(0);
}

.success-message {
    display: none;
    background-color: #d4edda;
    border: 1px solid #c3e6cb;
    color: #155724;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    text-align: center;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Responsive Design */
@media (max-width: 768px) {
    /* Disable animations on mobile */
    * {
        animation-duration: 0s !important;
        animation-delay: 0s !important;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }

    .header-text {
        text-align: center;
    }

    .profile-image img {
        width: 120px;
        height: 120px;
    }

    h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
        padding: 0.8rem 0;
    }
    
    .nav-links a {
        padding: 0.5rem;
    }

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

    .container {
        padding: 1rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .education-grid {
        grid-template-columns: 1fr;
    }
    
    section {
        margin-bottom: 3rem;
    }
    
    .summary {
        padding: 1.5rem;
    }
    
    .experience-item {
        padding: 1.5rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .contact-container {
        padding: 2rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .main-content {
        padding: 2rem 1rem;
    }
    
    /* Disable hover effects on touch devices */
    .skill-tag:hover,
    .skill-category:hover,
    .experience-item:hover,
    .education-item:hover,
    .project-card:hover,
    .publication-item:hover {
        transform: none;
    }
}

/* Mobile-specific improvements */
@media (max-width: 480px) {
    /* Very small mobile devices */
    .container {
        padding: 0.75rem;
    }
    
    .header-content {
        padding: 0 1rem;
    }
    
    .profile-image img {
        width: 100px;
        height: 100px;
    }
    
    h1 {
        font-size: 1.75rem;
    }
    
    .tagline {
        font-size: 0.95rem;
    }
    
    .location {
        font-size: 0.9rem;
    }
    
    .social-links a {
        padding: 0.4rem 0.8rem;
        font-size: 0.9rem;
    }
    
    .nav-links {
        gap: 0.3rem;
        padding: 0.75rem 0;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .nav-links a {
        font-size: 0.8rem;
        padding: 0.35rem 0.5rem;
        margin: 0.2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    h3.section-subtitle {
        font-size: 1.25rem;
    }
    
    .skill-category {
        padding: 1rem;
    }
    
    .skill-tags {
        gap: 0.4rem;
    }
    
    .skill-tag {
        padding: 0.25rem 0.6rem;
        font-size: 0.85rem;
    }
    
    .experience-item {
        padding: 1.25rem;
    }
    
    .company-name {
        font-size: 1.15rem;
    }
    
    .job-title {
        font-size: 1rem;
    }
    
    .date {
        font-size: 0.9rem;
    }
    
    .experience-details {
        font-size: 0.95rem;
    }
    
    .project-card {
        padding: 1.25rem;
    }
    
    .publication-item {
        padding: 1.25rem;
    }
    
    .education-item {
        padding: 1.25rem;
    }
    
    /* Contact form adjustments */
    .contact-container {
        padding: 1.5rem;
        margin: 0 0.5rem;
    }
    
    .form-group input,
    .form-group textarea,
    .form-group select {
        padding: 0.6rem 0.8rem;
    }
    
    .submit-btn {
        padding: 0.8rem 1.5rem;
        font-size: 1rem;
    }
}

/* Touch-friendly improvements */
@media (hover: none) and (pointer: coarse) {
    /* Remove hover effects on touch devices */
    .skill-tag:hover,
    .skill-category:hover,
    .experience-item:hover,
    .education-item:hover,
    .project-card:hover,
    .publication-item:hover,
    .social-links a:hover {
        transform: none;
        box-shadow: none;
    }
    
    /* Make touch targets larger */
    .nav-links a {
        padding: 0.75rem;
        margin: 0 0.25rem;
    }
    
    .social-links a {
        padding: 0.6rem 1.2rem;
    }
    
    .skill-tag {
        padding: 0.4rem 0.9rem;
    }
}

/* Ensure proper spacing for all sections */
section {
    padding-top: 1rem;
    padding-bottom: 1rem;
}

/* Fix alignment issues */
.experience-details ul,
.publication-item ul {
    padding-left: 1.2rem;
    margin-top: 0.5rem;
}

.experience-details li,
.publication-item li {
    text-align: left;
    padding-left: 0.5rem;
}

/* Ensure consistent card heights in grids */
.projects-grid,
.skills-grid,
.education-grid {
    align-items: stretch;
}

/* Fix any text overflow issues on mobile */
@media (max-width: 768px) {
    * {
        word-wrap: break-word;
        overflow-wrap: break-word;
    }
    
    h1, h2, h3, h4 {
        hyphens: auto;
    }
}

/* iOS Safari specific fixes */
@supports (-webkit-touch-callout: none) {
    nav {
        position: -webkit-sticky;
    }
    
    * {
        -webkit-tap-highlight-color: transparent;
    }
    
    input, textarea, select {
        font-size: 16px;
    }
}