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

body {
    font-family: Georgia, 'Times New Roman', serif;
    line-height: 1.6;
    color: #001f3f;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('images/Cosmic_Microwave_Background_(CMB).jpeg');
    background-size: 200%;
    background-position: center;
    opacity: 0.1;
    z-index: -1;
}

/* Home Button */
.home-button {
    position: fixed;
    top: 20px;
    left: 20px;
    background-color: #001f3f;
    color: #fff;
    padding: 10px 15px;
    text-decoration: none;
    font-weight: bold;
    z-index: 100;
}

.home-button:hover {
    background-color: #003366;
}

/* Header */
header {
    margin-bottom: 60px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
}

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

.header-title {
    text-align: center;
    flex-grow: 1;
}

.header-title h1 {
    font-size: 3.0rem;
    font-weight: normal;
    color: #001f3f;
    margin-bottom: 5px;
}

.tagline {
    font-size: 1.6rem;
    color: #001f3f;
    font-weight: bold;
}

/* Placeholder images */
.placeholder-img {
    width: 100px;
    height: 100px;
    border: 2px solid #001f3f;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: #001f3f;
    background-color: #fff;
}

/* Sections */
section {
    margin-bottom: 50px;
}

h2 {
    font-size: 1.7rem;
    font-weight: bold;
    margin-bottom: 20px;
    color: #001f3f;
}

/* About */
#about p {
    color: #001f3f;
    line-height: 1.8;
}

/* Projects */
.project-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.project-info {
    flex-grow: 1;
}

.project-info h3 {
    font-size: 1.3rem;
    font-weight: normal;
    color: #001f3f;
    margin-bottom: 5px;
}

.project-info p {
    color: #001f3f;
}

.project-list {
    list-style: square;
    margin-top: 10px;
    margin-left: 20px;
}

.project-list li {
    margin-bottom: 8px;
}

.project-list a {
    color: #001f3f;
    text-decoration: none;
}

.project-list a:hover {
    text-decoration: underline;
}

.project-image {
    flex-shrink: 0;
    margin-left: 40px;
}

.project-image .placeholder-img {
    width: 80px;
    height: 60px;
}

/* Publications */
.publication-list {
    list-style: none;
}

.publication-list li {
    margin-bottom: 10px;
}

.publication-list a {
    color: #001f3f;
    text-decoration: none;
}

.publication-list a:hover {
    text-decoration: underline;
}

/* Teaching */
#teaching h3 {
    font-size: 1.3rem;
    margin-top: 15px;
    margin-bottom: 10px;
    color: #001f3f;
}

.teaching-list {
    list-style: none;
    margin-bottom: 15px;
}

.teaching-list li {
    margin-bottom: 8px;
}

/* Contact */
#contact a {
    color: #001f3f;
    text-decoration: none;
}

#contact a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    margin-top: 60px;
    padding-top: 20px;
    border-top: 1px solid #ddd;
    text-align: center;
    color: #001f3f;
    font-size: 1.3rem;
}

/* Responsive */
@media (max-width: 600px) {
    .header-content {
        flex-direction: column;
        align-items: center;
    }

    .header-title h1 {
        font-size: 2.2rem;
    }

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

    .project-image {
        margin-left: 0;
        margin-top: 15px;
    }
}