/* Previous CSS remains the same; added for document gallery expansion */
.document-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    justify-content: center;
}

@media (max-width: 768px) {
    .document-gallery {
        grid-template-columns: 1fr;
    }
    .research-item {
        text-align: left;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Open Sans', sans-serif;
}

body {
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: #1a252f;
    color: white;
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.logo {
    font-family: 'Roboto Slab', serif;
    font-size: 1.5rem;
    font-weight: 700;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    list-style: none;
    display: flex;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #00aaff;
}

.burger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.burger span {
    width: 25px;
    height: 3px;
    background-color: white;
    margin: 2px 0;
    transition: all 0.3s ease;
}

.hero {
    height: 100vh;
    background: linear-gradient(rgba(26, 37, 47, 0.7), rgba(26, 37, 47, 0.7)), url('images/hero-bg.jpg') no-repeat center center/cover;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
    position: relative;
    animation: fadeIn 2s ease-in;
}

.hero-content h1 {
    font-family: 'Roboto Slab', serif;
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.profile-img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    margin-bottom: 1.5rem;
    animation: bounceIn 1.5s ease;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: #00aaff;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #0088cc;
}

.section {
    padding: 4rem 0;
    background-color: #f9f9f9;
}

.section h2 {
    font-family: 'Roboto Slab', serif;
    font-size: 2.5rem;
    color: #1a252f;
    margin-bottom: 2rem;
    text-align: center;
}

.content {
    max-width: 800px;
    margin: 0 auto;
    text-align: left;
}

.content ul {
    list-style: none;
    padding-left: 20px;
}

.content ul li {
    margin-bottom: 0.5rem;
    position: relative;
}

.content ul li:before {
    content: "•";
    color: #00aaff;
    font-weight: bold;
    position: absolute;
    left: -20px;
}

.experience-item, .research-item {
    margin-bottom: 2rem;
    animation: slideIn 1s ease;
}

.research-img, .doc-img {
    width: 100%;
    max-width: 300px;
    height: auto;
    margin: 1rem 0;
    border: 2px solid #1a252f;
    border-radius: 5px;
}

.document-gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}

.document-item {
    text-align: center;
    flex: 1 1 200px;
}

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

.skill-item {
    background: white;
    padding: 1rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    animation: slideIn 1s ease;
}

.references, .network {
    margin-top: 2rem;
    padding: 1rem;
    background: white;
    border-radius: 5px;
}

.contact .social-links a {
    color: #00aaff;
    margin: 0 1rem;
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact .social-links a:hover {
    color: #0088cc;
}

footer {
    background-color: #1a252f;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

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

@keyframes bounceIn {
    0% { transform: scale(0); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

@keyframes slideIn {
    from { transform: translateX(-100%); }
    to { transform: translateX(0); }
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        width: 100%;
        position: absolute;
        top: 60px;
        left: 0;
        background-color: #1a252f;
        text-align: center;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        margin: 1rem 0;
    }

    .burger {
        display: flex;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .profile-img {
        width: 100px;
        height: 100px;
    }

    .section {
        padding: 2rem 0;
    }

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

    .research-img, .doc-img {
        max-width: 200px;
    }

    .document-gallery {
        flex-direction: column;
        align-items: center;
    }
}