/* ============================================================
   Base & Reset
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --navy:    #1a2744;
    --blue:    #2563eb;
    --blue-lt: #dbeafe;
    --accent:  #0ea5e9;
    --text:    #1e293b;
    --muted:   #64748b;
    --border:  #e2e8f0;
    --bg:      #f8fafc;
    --white:   #ffffff;
    --radius:  10px;
    --shadow:  0 4px 24px rgba(30,41,59,.08);
    --shadow-hover: 0 8px 32px rgba(37,99,235,.13);
    --font-body: 'Inter', -apple-system, sans-serif;
    --font-serif: 'Crimson Text', Georgia, serif;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.75;
    color: var(--text);
    background: var(--bg);
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ============================================================
   Top Navigation
   ============================================================ */
.topnav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 0 20px;
}

.nav-inner {
    max-width: 860px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-name {
    font-weight: 700;
    font-size: .95rem;
    color: var(--navy);
    letter-spacing: .01em;
}

.nav-links { display: flex; gap: 6px; }

.nav-links a {
    font-size: .85rem;
    font-weight: 500;
    color: var(--muted);
    padding: 5px 12px;
    border-radius: 20px;
    transition: background .2s, color .2s;
}

.nav-links a:hover,
.nav-links a.active {
    background: var(--blue-lt);
    color: var(--blue);
    text-decoration: none;
}

/* ============================================================
   Page Wrapper
   ============================================================ */
.page-wrapper {
    max-width: 860px;
    margin: 0 auto;
    padding: 0 24px 60px;
}

/* ============================================================
   Hero / Header
   ============================================================ */
.hero {
    display: flex;
    align-items: center;
    gap: 40px;
    padding: 60px 0 48px;
    border-bottom: 1px solid var(--border);
}

/* Avatar */
.hero-avatar { flex-shrink: 0; }

.avatar-img {
    width: 110px;
    height: 110px;
    border-radius: 50%;
    object-fit: cover;
    object-position: center top;
    box-shadow: 0 6px 20px rgba(37,99,235,.35);
    border: 3px solid var(--white);
    outline: 2px solid var(--blue);
}

/* Info */
.hero-info h1 {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--navy);
    letter-spacing: -.02em;
    line-height: 1.2;
    margin-bottom: 6px;
}

.hero-title {
    font-size: 1.05rem;
    color: var(--blue);
    font-weight: 500;
    margin-bottom: 6px;
}

.hero-affil {
    font-size: .9rem;
    color: var(--muted);
    margin-bottom: 18px;
}

.hero-affil i { color: var(--blue); }

/* Contact buttons */
.contact-links { display: flex; flex-wrap: wrap; gap: 10px; }

.btn-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 16px;
    border: 1.5px solid var(--border);
    border-radius: 24px;
    font-size: .85rem;
    font-weight: 500;
    color: var(--text);
    background: var(--white);
    transition: all .2s;
}

.btn-link i { font-size: .8rem; color: var(--blue); }

.btn-link:hover {
    border-color: var(--blue);
    background: var(--blue-lt);
    color: var(--blue);
    text-decoration: none;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37,99,235,.15);
}

/* ============================================================
   Sections — Common
   ============================================================ */
main section {
    padding: 44px 0;
    border-bottom: 1px solid var(--border);
}

main section:last-child { border-bottom: none; }

h2 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: 22px;
    letter-spacing: -.01em;
}

.section-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--blue-lt);
    color: var(--blue);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: .85rem;
    flex-shrink: 0;
}

/* About prose */
#about p {
    color: var(--text);
    margin-bottom: 12px;
    font-size: 1rem;
}
#about p:last-child { margin-bottom: 0; }
#about strong { color: var(--navy); }
#about em { font-style: italic; color: var(--blue); }

/* ============================================================
   Research Interest Tags
   ============================================================ */
.interest-tags { display: flex; flex-wrap: wrap; gap: 10px; }

.tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--blue-lt);
    color: var(--blue);
    padding: 7px 16px;
    border-radius: 24px;
    font-size: .88rem;
    font-weight: 600;
    border: 1.5px solid transparent;
    transition: all .2s;
    cursor: default;
}

.tag:hover {
    background: var(--blue);
    color: #fff;
    box-shadow: 0 4px 12px rgba(37,99,235,.3);
}

/* ============================================================
   Biography — Timeline
   ============================================================ */
.timeline { position: relative; padding-left: 28px; }

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 6px;
    bottom: 6px;
    width: 2px;
    background: linear-gradient(to bottom, var(--blue), var(--accent));
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 28px;
}
.timeline-item:last-child { margin-bottom: 0; }

.timeline-dot {
    position: absolute;
    left: -24px;
    top: 5px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--white);
    border: 2.5px solid var(--blue);
    box-shadow: 0 0 0 3px var(--blue-lt);
}

.timeline-content {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    box-shadow: var(--shadow);
    transition: box-shadow .2s, transform .2s;
}

.timeline-content:hover {
    box-shadow: var(--shadow-hover);
    transform: translateX(3px);
}

.timeline-year {
    display: inline-block;
    font-size: .78rem;
    font-weight: 700;
    letter-spacing: .06em;
    text-transform: uppercase;
    color: var(--blue);
    background: var(--blue-lt);
    padding: 2px 10px;
    border-radius: 12px;
    margin-bottom: 6px;
}

.timeline-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--navy);
    margin: 4px 0 4px;
}

.timeline-place {
    font-size: .88rem;
    color: var(--muted);
}

.timeline-place i { color: var(--accent); }

/* ============================================================
   Services
   ============================================================ */
.service-list { display: flex; flex-direction: column; gap: 12px; }

.service-item {
    display: flex;
    align-items: center;
    gap: 14px;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 20px;
    box-shadow: var(--shadow);
    transition: box-shadow .2s, transform .2s;
}

.service-item:hover {
    box-shadow: var(--shadow-hover);
    transform: translateX(3px);
    border-color: var(--blue);
}

.service-badge {
    flex-shrink: 0;
    font-size: .75rem;
    font-weight: 700;
    letter-spacing: .05em;
    text-transform: uppercase;
    color: var(--white);
    background: linear-gradient(135deg, var(--blue), var(--accent));
    padding: 3px 10px;
    border-radius: 12px;
}

.service-venue {
    font-weight: 700;
    font-size: 1rem;
    color: var(--navy);
    flex-shrink: 0;
}

.service-type {
    font-size: .85rem;
    color: var(--muted);
}

/* ============================================================
   Publications
   ============================================================ */
.pub-item {
    display: flex;
    gap: 16px;
    background: var(--white);
    border: 1px solid var(--border);
    border-left: 4px solid transparent;
    border-radius: var(--radius);
    padding: 18px 20px;
    margin-bottom: 14px;
    box-shadow: var(--shadow);
    transition: all .2s;
}

.pub-item:hover {
    border-left-color: var(--blue);
    box-shadow: var(--shadow-hover);
    transform: translateX(3px);
}

.pub-index {
    flex-shrink: 0;
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--muted);
    padding-top: 2px;
    min-width: 30px;
}

.pub-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--navy);
    line-height: 1.45;
    margin-bottom: 5px;
}

.pub-authors {
    font-size: .875rem;
    color: var(--text);
    margin-bottom: 4px;
}

.pub-venue {
    font-size: .82rem;
    color: var(--muted);
}

.pub-venue i { color: var(--accent); }
.pub-venue strong { color: var(--navy); }

.pub-empty {
    color: var(--muted);
    font-style: italic;
    padding: 12px 0;
}

.pub-empty a { color: var(--blue); }

/* Skeleton loading */
.pub-skeleton {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 18px 20px;
}

.skeleton-line {
    height: 13px;
    border-radius: 6px;
    background: linear-gradient(90deg, #e2e8f0 25%, #f1f5f9 50%, #e2e8f0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.4s infinite;
    margin-bottom: 10px;
}

.skeleton-line.long   { width: 85%; }
.skeleton-line.medium { width: 60%; }
.skeleton-line.short  { width: 35%; }

@keyframes shimmer {
    0%   { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ============================================================
   Footer
   ============================================================ */
footer {
    text-align: center;
    padding: 40px 0 10px;
    font-size: .82rem;
    color: var(--muted);
}

footer i { color: var(--blue); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 640px) {
    .hero {
        flex-direction: column;
        align-items: flex-start;
        gap: 22px;
        padding: 40px 0 32px;
    }

    .hero-info h1 { font-size: 1.9rem; }

    .nav-links a { padding: 5px 8px; }

    .service-item { flex-wrap: wrap; }

    .pub-item { flex-direction: column; gap: 8px; }
}