:root {
    --primary-color: #1a1a1a;
    --secondary-color: #4a4a4a;
    --accent-color: #000080;
    --background-color: #ffffff;
    --border-color: #e0e0e0;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--primary-color);
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    position: relative;
}

header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background-color: var(--background-color);
}

.profile-img {
    margin-right: 2rem;
}

.profile-img img {
    width: 250px;
    height: auto;
    border-radius: 4px;
}

.profile-info h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.profile-info h2 {
    font-size: 1.8rem;
    color: var(--secondary-color);
    margin-bottom: 0.3rem;
}

.profile-info h3 {
    font-size: 1.4rem;
    color: var(--secondary-color);
    margin-bottom: 0.2rem;
}

.profile-info h4 {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 2rem;
    background-color: var(--background-color);
    padding: 10px;
    border-bottom: 2px solid var(--border-color);
}

.tab {
    padding: 10px 20px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 1rem;
    color: var(--secondary-color);
    transition: color 0.3s ease;
}

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

.tab.active {
    color: var(--accent-color);
    border-bottom: 2px solid var(--accent-color);
}

main {
    padding: 2rem;
    background-color: var(--background-color);
}

.tab-content {
    display: none;
}

.tab-content h2 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.tab-content p {
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.tab-content ul {
    list-style-type: none;
    margin-bottom: 1.5rem;
}

.tab-content ul ul {
    list-style-type: disc;
    margin-left: 20px;
    margin-top: 1rem;
}

.tab-content li {
    margin-bottom: 1.5rem;
}

.tab-content strong {
    color: var(--primary-color);
}

.contact-pane {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    background-color: var(--background-color);
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.contact-pane h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.contact-pane ul {
    list-style-type: none;
}

.contact-pane li {
    margin-bottom: 0.5rem;
}

.contact-pane a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-pane a:hover {
    color: var(--primary-color);
}

.student-feedback {
    padding: 1rem 0;
}

.student-feedback h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.student-feedback p {
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    line-height: 1.6;
}

.student-feedback p:last-child {
    margin-bottom: 0;
}

.research-interests {
    margin-top: 2rem;
}

.research-interests h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.research-interests p {
    margin-bottom: 1rem;
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--secondary-color);
    border-top: 1px solid var(--border-color);
    margin-top: 2rem;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header {
        flex-direction: column;
        text-align: center;
    }

    .profile-img {
        margin-right: 0;
        margin-bottom: 1rem;
    }

    .tabs {
        justify-content: center;
    }

    .contact-pane {
        position: static;
        transform: none;
        margin-top: 2rem;
        text-align: center;
    }

    main {
        padding: 1rem;
    }
}