/* ---------- Base ---------- */

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
                 Roboto, Helvetica, Arial, sans-serif;
    background-color: #f7f8fa;
    color: #2c2f33;
    line-height: 1.6;
}

/* ---------- Layout ---------- */



header {
    background-color: #ffffff;
    border-bottom: 1px solid #e1e4e8;
}

h1 {
    font-size: 1.5rem;
    margin: 0;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
}



/* ---------- Navigation ---------- */

nav a {
    margin-left: 1.5rem;
    text-decoration: none;
    color: #4a5d73;
    font-weight: 500;
}

nav a:hover {
    text-decoration: underline;
}

/* ---------- Sections ---------- */

section {
    margin: 3rem 0;
}

h2 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    color: #3b4c63;
}

/* ---------- About ---------- */

.scholar-link a {
    text-decoration: none;
    color: #4a5d73;
    font-weight: 500;
}

.scholar-link a:hover {
    text-decoration: underline;
}

.scholar-link {
    display: flex;
    flex-direction: column;   /* image above text */
    align-items: center;      /* 👈 horizontal centering */
    text-align: center;       /* center the text itself */
    gap: 0.3rem;
}


.about-content {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.about-content img {
    width: 180px;
    border-radius: 4px;
    border: 1px solid #d0d4d9;
}

.about-content .scholar-link img {
    width: 70px;
    height: auto;
}


.about-content p {
    margin: 0;
}

/* ---------- Research ---------- */

.research-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.research-buttons button {
    padding: 0.6rem 1.2rem;
    background-color: #e9edf2;
    border: 1px solid #cfd6df;
    color: #3b4c63;
    font-size: 0.95rem;
    cursor: pointer;
}

.research-buttons button:hover {
    background-color: #dfe5ec;
}


.research-area {
    margin-bottom: 1.5rem;
    border: 1px solid #e1e4e8;
    border-radius: 6px;
    padding: 0.8rem 1rem;
    background: #ffffff;
}

.research-area summary {
    font-size: 1.1rem;
    font-weight: 600;
    color: #3b4c63;
    cursor: pointer;
    list-style: none;
}

.research-area summary::marker {
    display: none;
}

.research-area[open] summary {
    margin-bottom: 0.8rem;
}

.research-area summary::before {
    content: "▸ ";
    display: inline-block;
    transition: transform 0.2s ease;
}

.research-area[open] summary::before {
    transform: rotate(90deg);
}

.research-area ul {
    padding-left: 1.2rem; /* optional: controls indent */
}

.research-area li {
    margin-bottom: 1.2rem; /* 👈 space between list items */
}


/* ---------- Teaching ---------- */

.teaching-list {
    list-style: none;
    padding: 0;
}

.teaching-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #e1e4e8;
}

/* ---------- Footer ---------- */

footer {
    border-top: 1px solid #e1e4e8;
    text-align: center;
    padding: 1.5rem;
    font-size: 0.9rem;
    color: #6b7280;
}

/* ---------- Responsive ---------- */

@media (max-width: 600px) {
    .about-content {
        flex-direction: column;
    }

    nav a {
        margin-left: 1rem;
    }
}