/* =============================================
   Zhiyong Li Academic Website — Modern Style
   ============================================= */

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

:root {
  --navy:      #1a2e4a;
  --accent:    #2563a8;
  --accent-lt: #e8f0fb;
  --text:      #222222;
  --muted:     #555555;
  --border:    #d8dce2;
  --bg:        #ffffff;
  --max-w:     860px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Georgia', 'Times New Roman', serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  color: var(--navy);
}

/* --- Layout Wrapper --- */
.site-wrapper {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Site Header --- */
.site-header {
  border-bottom: 2px solid var(--navy);
  padding: 28px 0 16px;
  text-align: center;
}

.site-header h1 {
  font-family: 'Georgia', serif;
  font-size: 2rem;
  font-weight: bold;
  color: var(--navy);
  letter-spacing: 0.5px;
  margin-bottom: 18px;
}

/* --- Navigation --- */
nav {
  display: flex;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
}

nav a {
  display: inline-block;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 0.82rem;
  font-weight: bold;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--navy);
  text-decoration: none;
  padding: 6px 20px;
  border: 1px solid transparent;
  border-radius: 2px;
  transition: background 0.2s, color 0.2s;
}

nav a:hover,
nav a.active {
  background: var(--navy);
  color: #fff;
  text-decoration: none;
}

nav a + a {
  border-left: 1px solid var(--border);
}

/* --- Page Main --- */
.page-main {
  padding: 40px 0 60px;
}

/* --- Home: Profile Section --- */
.profile-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 36px;
  align-items: start;
  margin-bottom: 36px;
}

.profile-photo {
  width: 170px;
  height: auto;
  border-radius: 3px;
  border: 1px solid var(--border);
  display: block;
}

.profile-name {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--navy);
  margin-bottom: 6px;
}

.profile-title {
  font-size: 1rem;
  color: var(--muted);
  margin-bottom: 20px;
  line-height: 1.5;
}

.profile-section h3 {
  font-size: 1rem;
  font-weight: bold;
  color: var(--navy);
  margin-bottom: 4px;
  margin-top: 16px;
}

.profile-section p {
  font-size: 0.97rem;
  color: var(--text);
}

/* --- Divider --- */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

/* --- Section Headings --- */
h2.section-title {
  font-family: Georgia, serif;
  font-size: 1.25rem;
  color: var(--navy);
  font-weight: bold;
  margin-bottom: 20px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}

h3.subsection-title {
  font-size: 1rem;
  font-weight: bold;
  color: var(--navy);
  margin: 28px 0 12px;
}

/* --- Publication List --- */
.pub-list {
  list-style: none;
  padding: 0;
}

.pub-list li {
  font-size: 0.95rem;
  line-height: 1.65;
  padding: 10px 0;
  border-bottom: 1px dotted var(--border);
  color: var(--text);
}

.pub-list li:last-child {
  border-bottom: none;
}

.pub-num {
  color: var(--muted);
  font-size: 0.85rem;
  margin-right: 4px;
}

.pub-title {
  font-weight: bold;
  color: #8b1c1c;
}

.pub-journal {
  font-style: italic;
}

.pub-meta {
  color: var(--muted);
  font-size: 0.88rem;
}

/* --- Teaching / Course List --- */
.course-list {
  list-style: none;
  padding: 0;
}

.course-list li {
  font-size: 0.97rem;
  padding: 10px 14px;
  border-left: 3px solid var(--accent-lt);
  margin-bottom: 10px;
  background: #fafbfc;
  line-height: 1.5;
}

.course-list li:hover {
  border-left-color: var(--accent);
}

.course-level {
  display: inline-block;
  font-size: 0.75rem;
  background: var(--accent-lt);
  color: var(--accent);
  border-radius: 2px;
  padding: 1px 7px;
  margin-left: 8px;
  font-family: Arial, sans-serif;
  vertical-align: middle;
}

/* --- About: Timeline --- */
.edu-list {
  list-style: none;
  padding: 0;
}

.edu-list li {
  position: relative;
  padding: 10px 0 10px 20px;
  font-size: 0.97rem;
  border-bottom: 1px dotted var(--border);
  line-height: 1.55;
}

.edu-list li:last-child {
  border-bottom: none;
}

.edu-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 0.8rem;
  top: 13px;
}

/* --- Footer --- */
.site-footer {
  text-align: center;
  font-size: 0.82rem;
  color: var(--muted);
  font-family: Arial, sans-serif;
  padding: 20px 0 32px;
  border-top: 1px solid var(--border);
}

/* --- Responsive --- */
@media (max-width: 600px) {
  body {
    font-size: 15px;
  }

  .site-header h1 {
    font-size: 1.6rem;
  }

  .profile-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .profile-photo {
    width: 130px;
    margin: 0 auto;
  }

  nav a {
    padding: 7px 12px;
    font-size: 0.78rem;
    letter-spacing: 0.8px;
  }
}