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

:root {
  --accent: #3b5998;
  --accent-light: #eef1f8;
  --text: #1a1a1a;
  --text-muted: #555;
  --border: #e0e0e0;
  --bg: #f7f8fa;
  --sidebar-width: 260px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}

/* ── Layout ─────────────────────────────────────── */

.layout {
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ─────────────────────────────────────── */

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: #fff;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 2.5rem 1.75rem;
  overflow-y: auto;
}

.profile-photo {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  overflow: hidden;
  margin: 0 auto 1.25rem;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 600;
  color: var(--accent);
  border: 3px solid var(--accent-light);
}

.profile-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.profile-name {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
  margin-bottom: 0.3rem;
}

.profile-title {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
  margin-bottom: 0.15rem;
}

.profile-dept {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
  margin-bottom: 2rem;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  margin-bottom: auto;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.5rem 0.6rem;
  border-radius: 6px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.84rem;
  transition: background 0.15s, color 0.15s;
}

.sidebar-nav a:hover {
  background: var(--accent-light);
  color: var(--accent);
}

.sidebar-nav a svg,
.sidebar-nav a i {
  width: 16px;
  text-align: center;
  flex-shrink: 0;
  opacity: 0.7;
}

.sidebar-divider {
  height: 1px;
  background: var(--border);
  margin: 1.25rem 0;
}

/* ── Main Content ────────────────────────────────── */

.main {
  margin-left: var(--sidebar-width);
  flex: 1;
  padding: 3.5rem 4rem;
  max-width: 820px;
}

section {
  margin-bottom: 3rem;
}

section h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-light);
}

section p,
.interest-list li {
  font-size: 0.95rem;
}

section p {
  color: var(--text);
  font-size: 0.95rem;
  margin-bottom: 0.75rem;
}

section p:last-child {
  margin-bottom: 0;
}

section a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s;
}

section a:hover {
  border-bottom-color: var(--accent);
}

/* ── Research interests list ─────────────────────── */

.interest-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.interest-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-size: 0.93rem;
  color: var(--text);
}

.interest-list li::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  margin-top: 0.55rem;
  flex-shrink: 0;
}

/* ── Education ───────────────────────────────────── */

.edu-item {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.1rem;
}

.edu-item:last-child {
  margin-bottom: 0;
}

.edu-year {
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  padding-top: 0.15rem;
  min-width: 75px;
}

.edu-body strong {
  font-size: 0.93rem;
  display: block;
  margin-bottom: 0.15rem;
}

.edu-body span {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ── Responsive ──────────────────────────────────── */

@media (max-width: 768px) {
  .layout {
    flex-direction: column;
  }

  .sidebar {
    position: static;
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 2rem 1.5rem 1.5rem;
  }

  .profile-photo {
    width: 90px;
    height: 90px;
    font-size: 1.6rem;
  }

  .sidebar-nav {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.4rem;
  }

  .sidebar-nav a {
    flex-direction: row;
  }

  .main {
    margin-left: 0;
    padding: 2rem 1.5rem;
    max-width: 100%;
  }
}