/* ---------- Tokens ---------- */
:root {
    --primary-color: #08263f;
    --accent-color: #1f6feb;
    --text-color: #2a2a2a;
    --muted-color: #6a6a6a;
    --light-bg: #fafafa;
    --light-text: #f5f5f5;
    --rule: #ececec;
    --section-padding: 44px;
    --font-body: 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-head: 'Roboto Slab', Georgia, serif;
    font-family: var(--font-body);
    line-height: 1.6;
}

h1, h2, h3, h4, h5, h6, .logo {
    font-family: var(--font-head);
}

* { box-sizing: border-box; }

body {
    margin: 0;
    color: var(--text-color);
    background-color: #ffffff;
    padding-top: 56px; /* offset for fixed navbar */
}

.container {
    width: 90%;
    max-width: 900px;
    margin: 0 auto;
}

a { color: var(--accent-color); }
.accent { color: var(--accent-color); font-weight: 500; font-style: normal; }

/* ---------- Navbar ---------- */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    width: 100%;
    background-color: #ffffff;
    color: var(--primary-color);
    z-index: 1100;
    box-shadow: 0 1px 0 var(--rule);
}
.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 0;
}
.logo {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}
.nav-links {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.2rem;
    flex-wrap: wrap;
}
.nav-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
    color: var(--accent-color);
}
.nav-toggle {
    display: none;
    background: transparent;
    border: none;
    font-size: 1.3rem;
    cursor: pointer;
    color: var(--primary-color);
}

/* ---------- Hero ---------- */
.hero-section {
    background: #ffffff;
    padding: 18px 0 8px;
    color: var(--primary-color);
    /* defensive: never inherit any leftover flex/height that would center vertically */
    display: block;
    height: auto;
    min-height: 0;
}
.hero-content { padding-top: 0; }
.hero-top {
    display: flex;
    align-items: center;
    gap: 1.6rem;
    flex-wrap: wrap;
}
.profile-pic-wrap {
    width: 150px;
    height: 200px;
    border-radius: 12px;
    overflow: hidden;
    flex: 0 0 150px;
    box-shadow: 0 6px 18px rgba(8,38,63,0.08);
    border: 1px solid var(--rule);
    animation: picIn 700ms ease both;
    background: var(--light-bg);
}
.profile-pic { width: 100%; height: 100%; object-fit: cover; object-position: center 20%; display: block; }
@keyframes picIn {
    from { opacity: 0; transform: scale(0.92); }
    to { opacity: 1; transform: scale(1); }
}
.hero-content h1 {
    font-size: 2.4rem;
    margin: 0 0 0.3rem;
    font-weight: 700;
}
.hero-content h1 .highlight { color: var(--accent-color); }
.tagline {
    font-size: 1.1rem;
    margin: 0;
    color: var(--primary-color);
}
.affiliation {
    margin: 0.2rem 0 0;
    font-size: 1rem;
    color: var(--muted-color);
}
.affiliation a {
    text-decoration: none;
}
.affiliation a:hover {
    text-decoration: underline;
}
#typed-text {
    color: var(--accent-color);
    border-right: 2px solid var(--accent-color);
    padding-right: 2px;
    display: inline-block;
    min-width: 240px;
    animation: blinkCursor 0.8s steps(1) infinite;
}
@keyframes blinkCursor {
    0%, 50% { border-color: var(--accent-color); }
    51%, 100% { border-color: transparent; }
}
.social-icons {
    display: flex;
    gap: 1rem;
    margin-top: 0.9rem;
}
.social-icons a img {
    width: 22px;
    height: 22px;
    opacity: 0.65;
    transition: opacity 0.2s ease;
}
.social-icons a img:hover { opacity: 1; }

/* publications page slim header (no hero) */
.page-header { background: transparent; }

/* ---------- Sections ---------- */
section { padding: var(--section-padding) 0; }
section h2 {
    font-size: 1.7rem;
    margin: 0 0 0.8rem;
    color: var(--primary-color);
    font-weight: 700;
}
section h3 {
    font-size: 1.15rem;
    color: var(--primary-color);
    margin: 0 0 0.4rem;
}
.section-intro {
    color: var(--muted-color);
    margin: 0 0 1.5rem;
    max-width: 720px;
}
.note {
    color: var(--muted-color);
    font-size: 0.92rem;
}

.about-section { background-color: var(--light-bg); }
.about-section p {
    max-width: 720px;
    font-size: 1.02rem;
    margin: 0 0 0.9rem;
}

/* ---------- Research topics ---------- */
/* collapsible topics (using native <details>/<summary>) */
.research-section .topic {
    border-top: 1px solid var(--rule);
}
.research-section .topic:first-of-type {
    border-top: none;
}
.research-section .topic > summary {
    list-style: none;            /* hide default marker */
    cursor: pointer;
    padding: 1rem 1.8rem 1rem 0;
    font-family: var(--font-head);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    position: relative;
    user-select: none;
}
.research-section .topic > summary::-webkit-details-marker { display: none; }
.research-section .topic > summary::after {
    content: "+";
    position: absolute;
    right: 0.2rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.3rem;
    color: var(--muted-color);
    transition: transform 0.2s ease;
}
.research-section .topic[open] > summary::after {
    content: "−";
}
.research-section .topic > summary:hover {
    color: var(--accent-color);
}
.research-section .topic[open] > summary {
    color: var(--accent-color);
}
.research-section .topic > p {
    margin: 0 0 1.1rem;
    max-width: 720px;
}

/* ---------- Selected publications (curated list on home) ---------- */
.selected-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.selected-item {
    padding: 0.9rem 0;
    border-top: 1px solid var(--rule);
}
.selected-item:first-child { border-top: none; }
.selected-item h3 {
    font-size: 1.05rem;
    margin: 0 0 0.25rem;
    font-weight: 600;
}
.selected-item .venue {
    margin: 0;
    font-size: 0.95rem;
    color: var(--muted-color);
}
.selected-item .pub-authors {
    margin: 0.15rem 0 0;
    font-size: 0.9rem;
    color: var(--muted-color);
}

/* ---------- Background timeline ---------- */
.education-section { background-color: #ffffff; }
.subhead {
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--muted-color);
    margin: 1.2rem 0 0.6rem;
    font-weight: 600;
}
.timeline {
    list-style: none;
    padding: 0;
    margin: 0 0 0.5rem;
}
.timeline li {
    display: flex;
    gap: 1rem;
    padding: 0.5rem 0;
    border-top: 1px solid var(--rule);
    font-size: 0.98rem;
}
.timeline li:first-child { border-top: none; }
.timeline .date {
    flex: 0 0 130px;
    color: var(--muted-color);
    font-variant-numeric: tabular-nums;
    font-size: 0.93rem;
}
.timeline .role { flex: 1; }

/* ---------- Publications page (auto-rendered) ---------- */
.publications-section { background-color: #ffffff; }
.publications-section h1 {
    font-size: 1.8rem;
    margin: 0 0 0.5rem;
    color: var(--primary-color);
}
.subhead-section {
    font-size: 1.2rem;
    margin: 2rem 0 0.6rem;
    color: var(--primary-color);
    padding-bottom: 0.3rem;
    border-bottom: 1px solid var(--rule);
}
.publications-section h3 {
    margin-top: 1.6rem;
    margin-bottom: 0.4rem;
    font-size: 1.2rem;
    color: var(--primary-color);
    border-bottom: 2px solid var(--accent-color);
    display: inline-block;
}
.publication-list {
    margin: 0 0 1rem 1rem;
    padding-left: 1rem;
}
.publication-item {
    margin-bottom: 0.9rem;
    line-height: 1.5;
}
.publication-item em { font-style: italic; }
.publication-item a { text-decoration: none; }
.publication-item a:hover { text-decoration: underline; }
.pub-authors {
    margin: 0.1rem 0 0;
    font-size: 0.93rem;
    color: var(--muted-color);
}

/* ---------- Diagnostics / warnings ---------- */
.warning { color: #b33; font-style: italic; }
.diagnostics { font-size: 0.85rem; color: var(--muted-color); }

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

/* ---------- Responsive ---------- */
/* ---------- Tablet & phone ---------- */
@media screen and (max-width: 768px) {
    .hero-content h1 { font-size: 1.7rem; }
    .tagline { font-size: 1rem; }
    #typed-text { min-width: 140px; }
    section { padding: 36px 0; }
    section h2 { font-size: 1.45rem; }

    .hero-top { gap: 1rem; }
    .profile-pic-wrap { width: 120px; height: 160px; flex: 0 0 120px; }

    .nav-toggle { display: inline-block; }
    .nav-links {
        display: none;
        flex-direction: column;
        gap: 0;
        background: #fff;
        padding: 8px 0;
        position: absolute;
        right: 10px;
        top: 56px;
        box-shadow: 0 4px 12px rgba(0,0,0,0.08);
        border-radius: 6px;
        min-width: 220px;
    }
    .nav-links.open { display: flex; }
    /* bigger tap targets for nav links inside the dropdown */
    .nav-links li { width: 100%; }
    .nav-links a {
        display: block;
        padding: 12px 18px;
        font-size: 1rem;
    }

    /* bigger tap targets for social icons */
    .social-icons { gap: 0.4rem; }
    .social-icons a {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        padding: 10px;
    }

    .timeline li { flex-direction: column; gap: 0.1rem; padding: 0.6rem 0; }
    .timeline .date { flex: none; }

    /* prevent long titles / urls from overflowing */
    .publication-item,
    .selected-item h3 {
        overflow-wrap: anywhere;
        word-break: break-word;
    }

    /* publication list a touch less indented on mobile */
    .publication-list {
        margin: 0 0 1rem 0;
        padding-left: 1.2rem;
    }
}

/* ---------- Very small phones ---------- */
@media screen and (max-width: 480px) {
    body { padding-top: 52px; }
    .container { width: 92%; }
    .hero-content h1 { font-size: 1.45rem; }
    .tagline { font-size: 0.95rem; }
    #typed-text { min-width: 110px; }
    .profile-pic-wrap { width: 96px; height: 128px; flex: 0 0 96px; }
    section h2 { font-size: 1.3rem; }
    .selected-item h3 { font-size: 1rem; }
    .research-section .topic > summary { font-size: 1rem; }
    .nav-links { top: 52px; }
}