:root {
    --primary-color: #970747;
    --primary-light: #b83869;
    --primary-dark: #7a0339;
    --white: #FFFFFF;
    --black: #000000;
    --light-gray: #f5f5f5;
    --medium-gray: #e0e0e0;
    --dark-gray: #333333;
    --transition: all 0.3s ease-in-out;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.7; 
    color: var(--black);
    background-color: var(--white);
    font-size: 16px; 
}

.container {
    width: 95%; 
    max-width: 1400px; 
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
    font-size: 1rem;  
}

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

ul {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    margin-bottom: 18px;                      
    line-height: 1.3;                      
}

h1 {
    font-size: 2.5rem;             
}

h2 {
    font-size: 1.8rem;          
}

h3 {
    font-size: 1.2rem;            
}

h4 {
    font-size: 1rem;  
}

section {
    padding: 55px 0; 
}

.section-title {
    text-align: center;
    margin-bottom: 40px;             
    font-size: 1.8rem; 
    color: var(--primary-color);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 90px;              
    height: 5px; 
    background-color: var(--primary-color);
    margin: 18px auto 0;           
}

p {
    margin-bottom: 12px;
    font-size: 0.8rem;              
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 15px 33px;                       
    border-radius: 30px;
    text-transform: uppercase;
    font-weight: bold;
    letter-spacing: 1px;
    transition: var(--transition);
    border: 1px solid var(--primary-color);
    cursor: pointer;
    font-size: 0.75rem;               
}

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

.btn-outline {
    display: inline-block;
    background-color: transparent;
    color: var(--primary-color);
    padding: 10px 25px;                       
    border-radius: 20px;
    text-transform: uppercase;
    font-weight: bold;
    letter-spacing: 1px;
    transition: var(--transition);
    border: 2px solid var(--primary-color);
    cursor: pointer;
    font-size: 0.7rem;      
    margin-right: 18px;                      
    margin-bottom: 8px;                      
}

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

/* Header styles */
header {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 75px;              
}

.logo {
    font-size: 1.8rem;          
    font-weight: bold;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
}

.nav-links li {
    margin-left: 35px;      
}

.nav-links a {
    color: var(--black);
    font-weight: 500;
    position: relative;
    font-size: 0.95rem;                        
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 3px;          
    background-color: var(--primary-color);
    transition: var(--transition);
}

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

.nav-links a.active {
    color: var(--primary-color);
}

.hamburger {
    display: none;
    cursor: pointer;
}

.hamburger .bar {
    display: block;
    width: 30px;         
    height: 4px; 
    margin: 6px auto;            
    background-color: var(--black);
    transition: var(--transition);
}

/* Hero section styles */
img {
    max-width: 100%;
    height: auto;
    display: block;
    margin-right: 160px;  
}

.hero {
    padding: 180px 0 100px; 
    background-color: var(--light-gray);
}

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

.hero-content {
    flex: 1;
    margin-left: 150px;     
}

.hero-image {
    flex: 1;
    text-align: right;
}

.hero-image img {
    border-radius: 60%;
    border: 6px solid var(--primary-color);            
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    max-width: 310px;               
    margin-left: auto;
}

.hero h1 {
    font-size: 2.5rem;                    
    margin-bottom: 5px;      
    color: var(--primary-color);
}

.hero .subtitle {
    font-size: 1.3rem;                    
    margin-bottom: 15px;      
    color: var(--dark-gray);
}

.contact-info {
    margin-bottom: 35px;      
}

.contact-info p {
    margin-bottom: 5px;      
    display: flex;
    align-items: center;
    font-size: 1rem;        
}

.contact-info i {
    margin-right: 12px;      
    color: var(--primary-color);
    font-size: 1rem;      
}

/* Timeline styles */
.timeline {
    position: relative;
    max-width: 1000px; 
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 5px; 
    background-color: var(--primary-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -2.5px;                        
}

.timeline-item {
    padding: 8px 50px; 
    position: relative;
    width: 50%;
    margin-bottom: 10px;      
}

.timeline-item:nth-child(odd) {
    left: 0;
}

.timeline-item:nth-child(even) {
    left: 50%;
}

.timeline-dot {
    position: absolute;
    width: 24px;      
    height: 24px;      
    background-color: var(--primary-color);
    border-radius: 50%;
    top: 15px;
    right: -12px; 
    z-index: 1;
}

.timeline-item:nth-child(even) .timeline-dot {
    left: -12px; 
}

.timeline-content {
    padding: 25px;      
    background-color: var(--white);
    border-radius: 8px; 
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
    position: relative;
}

.timeline-content h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 1.1rem;       
}

.timeline-date {
    font-weight: bold;
    color: var(--primary-color);   
    font-size: 0.8rem;          
}

/* Experience styles */
.experience-items {
    max-width: 1000px; 
    margin: 0 auto;
}

.experience-item {
    margin-bottom: 50px;        
    padding: 30px;      
    background-color: var(--white);
    border-radius: 10px;       
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);                      
    transition: var(--transition);
}

.experience-item:hover {
    transform: translateY(-8px); 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);             
}

.experience-item h3 {
    color: var(--primary-color);
    margin-bottom: 8px;            
    font-size: 1.4rem;          
}

.company {
    font-weight: 500;
    margin-bottom: 8px;            
    font-size: 1rem;        
}

.experience-date {
    color: var(--dark-gray);
    font-size: 0.8rem;      
    margin-bottom: 20px;           
    display: block;
}

.experience-item ul {
    padding-left: 25px;      
}

.experience-item li {
    margin-bottom: 12px;       
    position: relative;
    padding-left: 20px;           
    list-style-type: none;
    font-size: 0.95rem;     
}

.experience-item li::before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-size: 0.95rem;              
}

/* Skills styles */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 35px;  
    padding: 0 3rem 0 3rem;    
}

.skill-category {
    margin-bottom: 35px;      
}

.skill-category h3 {
    color: var(--primary-color);
    margin-bottom: 18px;           
    border-bottom: 3px solid var(--primary-light);          
    padding-bottom: 8px;            
    font-size: 1.1rem;       
}

.skill-category ul {
    padding-left: 25px;      
}

.skill-category li {
    margin-bottom: 12px;       
    position: relative;
    padding-left: 22px;           
    font-size: 0.95rem;     
}

.skill-category li::before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-size: 0.95rem;              
}

/* Achievement styles */
.achievements-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));               
    gap: 35px;      
}

.achievement-item {
    background-color: var(--white);
    padding: 25px;      
    border-radius: 10px;       
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);             
    transition: var(--transition);
    display: flex;
    align-items: flex-start;
}

.achievement-item:hover {
    transform: translateY(-8px); 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);             
}

.achievement-item i {
    font-size: 1.3rem;                     
    color: var(--primary-color);
    margin-right: 18px;           
    margin-top: 6px;            
}

.achievement-item p {
    font-size: 0.95rem;     
}

/* Social styles */
.socials {
    background-color: var(--light-gray);
    text-align: center;
}

.social-icons {
    display: flex;
    justify-content: center;
    gap: 25px;      
    margin-top: 25px;      
}

.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;                   
    height: 60px;                   
    background-color: var(--white);
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);             
    transition: var(--transition);
}

.social-icon i {
    font-size: 1.2rem;               
    color: var(--primary-color);
}

.social-icon:hover {
    background-color: var(--primary-color);
    transform: translateY(-8px); 
}

.social-icon:hover i {
    color: var(--white);
}

/* Footer styles */
footer {
    background-color: var(--dark-gray);
    color: var(--white);
    padding: 20px 0;      
    text-align: center;
    font-size: 0.9rem;     
}

/* Page header styles */
.page-header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 150px 0 80px; 
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;                            
    margin-bottom: 15px;      
}

.page-header p {
    font-size: 1rem;  
    max-width: 800px;                 
    margin: 0 auto;
}

/* Publications styles */
.publication-item {
    display: flex;
    margin-bottom: 70px;                   
    background-color: var(--white);
    border-radius: 10px;       
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.05);             
    overflow: hidden;
    padding: 0 7.5rem 0 7.5rem;
}

.publications-container {
    width: 95%; 
}

.publication-image {
    flex: 1;
    max-width: 600px;                  
}

.publication-image img {
    width: 100%;
    height: 95%;
    object-fit: cover;
}

.publication-content {
    flex: 2;
    padding: 35px;      
}

.publication-content h2 {
    color: var(--primary-color);
    margin-bottom: 12px;      
    font-size: 1.2rem; 
}

.authors {
    font-style: italic;
    margin-bottom: 12px;
    font-size: 0.95rem;     
}

.publication-details {
    margin-bottom: 15px; 
    color: var(--dark-gray);
    font-size: 0.8rem;          
}

.publication-abstract {
    margin-bottom: 22px; 
    font-size: 0.8rem;          
}

.publication-abstract h3 {
    font-size: 0.9rem;              
    margin-bottom: 12px; 
}

.publication-keywords {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.publication-keywords span {
    background-color: var(--primary-light);
    color: var(--white);
    padding: 6px 12px; 
    border-radius: 20px;
    font-size: 0.75rem;               
}

/* Research interests styles */
.research-interests {
    margin-top: 180px;  
    padding: 0 4rem 0 4rem;
}

.interest-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); 
    gap: 35px; 
    margin-top: 35px; 
}

.interest-item {
    background-color: var(--white);
    padding: 35px; 
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05); 
    text-align: center;
    transition: var(--transition);
}

.interest-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1); 
}

.interest-item i {
    font-size: 1.9rem; 
    color: var(--primary-color);
    margin-bottom: 25px;
}

.interest-item h3 {
    margin-bottom: 18px; 
    font-size: 0.9rem;              
}

.interest-item p {
    font-size: 0.85rem;      
}

/* Project styles */
.project-card {
    background-color: var(--white);
    border-radius: 15px; 
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);
    margin-bottom: 50px; 
    overflow: hidden;
    transition: var(--transition);
    padding: 0 5.2rem 0 5.2rem;
}

.project-card:hover {
    transform: translateY(-8px); 
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.1);
}

.project-image img {
    width: 100%;
    height: 280px;
    padding: 10px 25px 0 25px;
}

.project-content {
    padding: 15px 40px 25px 40px; 
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 18px;
}

.project-header h2 {
    color: var(--primary-color);
    margin-bottom: 0;
    font-size: 1.2rem;                 
}

.project-date {
    color: var(--dark-gray);
    font-size: 0.8rem;      
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px; 
    margin-bottom: 25px; 
}

.project-tags span {
    background-color: var(--light-gray);
    color: var(--primary-color);
    padding: 6px 12px; 
    border-radius: 20px;
    font-size: 0.75rem;               
    font-weight: 500;
}

.project-description ul {
    padding-left: 25px; 
    margin-bottom: 25px; 
}

.project-description li {
    margin-bottom: 12px; 
    position: relative;
    padding-left: 20px; 
    list-style-type: none;
    font-size: 0.95rem;              
}

.project-description li::before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-size: 0.95rem;              
}

.project-links {
    display: flex;
    flex-wrap: wrap;
}

/* Technical skills showcase */
.skills-showcase {
    background-color: var(--white);
    padding: 35px;
    border-radius: 10px; 
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05); 
    padding: 1.5rem 4.5rem 1rem 4.5rem;
}

.skill-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 12px; 
    margin-bottom: 25px;
}

.skill-pill {
    background-color: var(--primary-light);
    color: var(--white);
    padding: 10px 18px; 
    border-radius: 20px;
    font-size: 0.85rem;      
}

/* Media gallery styles */
.filter-controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 18px; 
    margin-bottom: 35px;
}

.filter-btn {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 8px 20px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    font-size: 0.7rem;                
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

.filter-btn2 {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 8px 20px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    font-size: 0.7rem;                
}

.filter-btn2.active, .filter-btn2:hover {
    background-color: var(--primary-color);
    color: var(--white);
}


.media-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); 
    gap: 35px; 
    width: 85%;
    margin: 0 auto;
}

.media-item {
    background-color: var(--white);
    border-radius: 10px; 
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05); 
    overflow: hidden;
    transition: var(--transition);
    height: 25rem;
}

.media-item:hover {
    transform: translateY(-8px); 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1); 
}

.media-image img {
    width: 100%;
    height: 260px; 
    object-fit: contain;
}

.media-content {
    padding: 15px 20px 8px 20px; 
}

.media-content h3 {
    color: var(--primary-color);
    margin-bottom: 1px;
    font-size: 0.9rem; 
}

.media-date {
    color: var(--dark-gray);
    font-size: 0.7rem;
    margin-bottom: 1px; 
}

.media-link {
    display: inline-block;
    margin-top: 1px; 
    font-weight: 500;
    font-size: 0.7rem;                
}

.media-content p {
    margin-bottom: 0.5px;
}

.media-content .btn-outline {
    padding: 5px 20px;  
    font-size: 0.6rem;      
    margin-right: 18px;                      
    margin-bottom: 8px;      
    margin-top: 8px; 
}

.media-item2 {
    background-color: var(--white);
    border-radius: 10px; 
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05); 
    overflow: hidden;
    transition: var(--transition);
    height: 21rem;
}

.carousel-container1,  .carousel-container2,  .carousel-container3{
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    overflow: hidden;
}

.carousel-track1, .carousel-track2, .carousel-track3{
    display: flex;
    transition: transform 0.3s ease-in-out;
}

.carousel-slide1, .carousel-slide2, .carousel-slide3 {
    min-width: 100%;
    flex: 1 0 100%;
}

.carousel-slide1 img, .carousel-slide2 img, .carousel-slide3 img {
    /* width: 100%; */
    /* height: auto; */
    display: block;
}

.carousel-button1, .carousel-button2, .carousel-button3 {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    cursor: pointer;
    padding: 10px 15px;
    font-size: 0.9rem; 
    border-radius: 50%;
    z-index: 10;
}

.prev-button1, .prev-button2, .prev-button3 {
    left: 10px;
}

.next-button1, .next-button2, .next-button3 {
    right: 10px;
}

.carousel-dots1, .carousel-dots2, .carousel-dots3 {
    display: flex;
    justify-content: center;
    margin-top: 5px;
}

.carousel-dot1, .carousel-dot2, .carousel-dot3 {
    width: 8px;
    height: 8px;
    background: #ccc;
    border-radius: 50%;
    margin: 0 5px;
    cursor: pointer;
}

.carousel-dot1.active, .carousel-dot2.active, .carousel-dot3.active {
    background: #333;
}



/* responsiveness */
@media (max-width: 1200px) {
    body {
        font-size: 15px; 
    }
    
    .container {
        width: 95%;
    }
    
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2.3rem;
    }

    .publication-item {
        padding: 0 4.2rem 0 4.2rem;
    }

    .project-card {
        padding: 0 4.2rem 0 4.2rem;
    }

    .research-interests {
        padding: 0 4rem 0 4rem;
    }

    .skills-showcase {
        padding: 1rem 5rem 0 5rem;
    }
}

@media (max-width: 992px) {
    body {
        font-size: 15px; 
    }
    
    h1 {
        font-size: 2.5rem;
    }
    
    .hero .container {
        flex-direction: column-reverse;
        text-align: center;
    }

    .hero-content {
        padding-right: 0;
        margin-top: 50px; 
        margin-left: 15px; 
    }

    .hero-image img {
        margin: 0 auto;
    }

    .contact-info p {
        justify-content: center;
    }

    .publication-item {
        flex-direction: column;
    }

    .publication-image {
        max-width: 100%;
    }

    .timeline::after {
        left: 31px;
    }

    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }

    .timeline-item:nth-child(even) {
        left: 0;
    }

    .timeline-dot {
        left: 15px;
        right: auto;
    }

    .timeline-item:nth-child(even) .timeline-dot {
        left: 15px;
    }
    
    .section-title {
        font-size: 2.3rem;
    }

    .publication-item {
        padding: 0 3.2rem 0 3.2rem;
    }

    .project-card {
        padding: 0 3.1rem 0 3.1rem;
    }

    .research-interests {
        padding: 0 3.5rem 0 3.5rem;
    }

    .skills-showcase {
        padding: 1rem 4.3rem 0 4.3rem;
    }
}

@media (max-width: 768px) {
    body {
        font-size: 13px; 
    }
    
    .container {
        width: 95%; 
        padding: 0 15px;
    }
    
    h1 {
        font-size: 2.3rem;
    }
    
    h2 {
        font-size: 1.8rem;
    }
    
    h3 {
        font-size: 1.3rem;
    }

    .nav-links {
        position: fixed;
        left: -100%;
        top: 80px; 
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 10px rgba(0, 0, 0, 0.1);
        padding: 25px 0; 
    }

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

    .nav-links li {
        margin: 18px 0; 
    }
    
    .nav-links a {
        font-size: 1.2rem; 
    }

    .hamburger {
        display: block;
    }

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

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero h1 {
        font-size: 2.6rem; 
    }

    .hero .subtitle {
        font-size: 1.3rem; 
    }

    .section-title {
        font-size: 2.1rem;
    }

    .skills-grid,
    .achievements-list,
    .interest-grid,
    .media-grid {
        grid-template-columns: 1fr;
    }

    .publication-item {
        padding: 0 1.9rem 0 1.9rem;
    }

    .project-card {
        padding: 0 1.4rem 0 1.4rem;
    }

    .project-content {
        padding: 1rem 1.3rem 1rem 1.3rem; 
    }

    .project-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .project-date {
        margin-top: 6px;
    }

    .skills-showcase {
        padding: 1rem 3.2rem 0 3.2rem;
    }

    .footer > p{
        font-size: 0.4rem;  
    }
}