/*
 * Global styles for Yanlin Qi’s academic homepage.  The design is kept
 * clean and minimalistic, inspired by Zhao (Bill) Xu’s personal site.  A
 * sidebar anchors the visitor with key information while the right panel
 * contains the substantive narrative.  Colours are chosen to be
 * accessible and professional: dark grey for primary text, muted
 * accents for secondary information and a blue accent for interactivity.
 */

:root {
  --accent: #005ecb;
  --text-primary: #333333;
  --text-secondary: #666666;
  --border-colour: #e0e0e0;
  --background-light: #fafafa;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  color: var(--text-primary);
  background-color: #ffffff;
  line-height: 1.6;
}

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

/* Sidebar styles */
/* Sidebar width reduced for a sleeker look */
.sidebar {
  width: 220px;
  background-color: var(--background-light);
  border-right: 1px solid var(--border-colour);
  padding: 1.5rem;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  overflow-y: auto;
}

.profile-photo {
  width: 100%;
  height: auto;
  border-radius: 50%;
  margin-bottom: 1rem;
  display: block;
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.1);
}

.name {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.affiliation {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.location {
  display: flex;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.location img {
  width: 16px;
  height: 16px;
  margin-right: 0.4rem;
}

/* Contact list: display vertically with icons and labels */
.contact-list {
  list-style: none;
  margin-top: 1rem;
}

.contact-list li {
  margin-bottom: 0.6rem;
}

.contact-list li a {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.contact-list li a img {
  width: 22px;
  height: 22px;
  margin-right: 0.4rem;
  transition: transform 0.2s;
}

.contact-list li a:hover img {
  transform: scale(1.1);
}

/* Main content area */
.content {
  flex: 1;
  margin-left: 220px;
  padding: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Navigation bar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: #ffffff;
  border-bottom: 1px solid var(--border-colour);
}

.navbar ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  padding: 0.5rem 1rem;
}

.navbar li {
  margin-right: 1rem;
}

.navbar a {
  text-decoration: none;
  color: var(--text-primary);
  padding: 0.35rem 0.6rem;
  border-bottom: 3px solid transparent;
  transition: color 0.2s, border-color 0.2s;
  font-weight: 500;
}

.navbar a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* Hero banner */
.hero {
  position: relative;
  margin: 1.2rem 1rem;
  border-radius: 6px;
  overflow: hidden;
  height: 200px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
}

.hero-bg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.hero-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  color: #ffffff;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);
}

.hero-text h2 {
  font-size: 1.6rem;
  margin-bottom: 0.25rem;
  font-weight: 600;
}

.hero-text p {
  font-size: 0.95rem;
  letter-spacing: 0.3px;
}

/* Section styling */
.section {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-colour);
}

.section h2 {
  font-size: 1.4rem;
  margin-bottom: 0.6rem;
  color: var(--accent);
  font-weight: 600;
}

.section p,
.section ul {
  margin-bottom: 0.8rem;
}

.section ul {
  padding-left: 1.2rem;
}

.section ul li {
  margin-bottom: 0.5rem;
}

.edu-item,
.project-item {
  margin-bottom: 1rem;
}

.edu-item h3,
.project-item h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.edu-dates,
.project-dates {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

/* About section photo styling */
.about-photo {
  width: 100%;
  border-radius: 8px;
  margin-top: 1rem;
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.1);
}

.footer {
  padding: 1rem 1.5rem;
  margin-top: auto;
  background-color: var(--background-light);
  border-top: 1px solid var(--border-colour);
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.footer .quote {
  font-style: italic;
  margin-top: 0.6rem;
  color: var(--text-primary);
}

@media (max-width: 768px) {
  /* Collapse sidebar on small screens */
  .sidebar {
    position: relative;
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--border-colour);
  }
  .content {
    margin-left: 0;
  }
  .navbar ul {
    justify-content: space-around;
  }
  .hero {
    margin: 1rem 0.5rem;
    height: 180px;
  }
}