:root {
  /* Light mode colors */
  --primary-color: #3a3a3a;       /* charcoal gray navbar */
  --accent-color: #c0392b;       /* dark red accent */
  --light-bg: #fff4e7;
  --dark-text: #343a40;
  --light-nav: #fff4e7;
  --brand-color: #343a40;       /* light-mode name color */
  /* Dark mode colors */
  --dark-bg: #3a3a3a;
  --light-text: #ecf0f1;
  --primary-color-dark: #3a3a3a; /* near-black navbar */
  --brand-color-dark: #ecf0f1;  /* dark-mode name color */
}
html { scroll-behavior: smooth; }
body {
  font-family: 'Montserrat', sans-serif;
  color: var(--dark-text);
  background: var(--light-bg);
  transition: background .3s, color .3s;
}
/* Dark mode overrides */
body.dark-mode {
  background: var(--dark-bg);
  color: var(--light-text);
}
.navbar-brand {
  color: var(--brand-color);
  transition: color .3s;
}
body.dark-mode .navbar .navbar-brand {
  color: var(--brand-color-dark);
}
.navbar {
  background: var(--light-nav);
  transition: background .3s;
}
.navbar.dark-mode {
  background: var(--primary-color-dark);
}
.navbar-nav .nav-link {
  color: var(--dark-text);
  font-weight: 600;
  transition: color .3s;
}
.navbar.dark-mode .nav-link {
  color: var(--light-text);
}
.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--accent-color);
}
header {
  text-align: center;
  padding: 100px 0;
  background: url('https://raw.githubusercontent.com/srigas/mdweb/refs/heads/main/static/images/bg-light.jpg') center/cover no-repeat;
  position: relative;
  margin-bottom: 40px;
  transition: background .3s;
}
/* dark-mode header fallback color */
body.dark-mode header {
  background: url('https://raw.githubusercontent.com/srigas/mdweb/refs/heads/main/static/images/bg-light.jpg') center/cover no-repeat;
}
header::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.0); /* rgba(0,0,0,0.3) */
}
header h1, header p {
  position: relative;
  z-index: 1;
}
header h1 {
  font-size: 3rem;
  margin-bottom: .5rem;
  color: var(--dark-text);
}
header p {
  font-size: 1.25rem;
  color: var(--dark-text);
}
body.dark-mode header p {
  font-size: 1.25rem;
  color: var(--light-text);
}
body.dark-mode header h1 {
  font-size: 3rem;
  margin-bottom: .5rem;
  color: var(--dark-text);
}
section {
  padding: 60px 0;
}
section h2 {
  position: relative;
  display: inline-block;
  margin-bottom: 2rem;
}
section h2::after {
  content: '';
  position: absolute;
  width: 50%;
  height: 3px;
  background: var(--accent-color);
  bottom: -5px;
  left: 0;
}
/* Timeline styling */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.timeline-year {
  display: block;
  font-weight: 600;
  /* color: var(--accent-color); */
  color: var(--dark-text);
  margin-bottom: 1.5rem;
}

.timeline-item .timeline-title {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 600;
}

.timeline-item .timeline-subtitle {
  margin: 0;
  color: var(--dark-text);
  font-size: 0.95rem;
}

/* Dark-mode subtitle color */
body.dark-mode .timeline-item .timeline-subtitle {
  color: var(--light-text);
}
a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color .3s;
}
a:hover {
  text-decoration: underline;
}
/* ensure dark mode keeps the same accent */
body.dark-mode a {
  color: var(--accent-color);
}

.research-year-group {
  margin-bottom: 1.5rem;  /* space between year‐groups */
}

.research-list {
  margin: 0;
  padding-left: 3.5rem;   /* indent list relative to year */
  list-style: disc;
}

.research-list li {
  margin-bottom: .5rem;    /* spacing between items */
  color: var(--dark-text);
  font-size: .95rem;
}

/* dark‐mode text color */
body.dark-mode .research-list li {
  color: var(--light-text);
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.contact-list li {
  margin-bottom: .75rem;
}
.contact-list a {
  color: var(--dark-text);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  transition: color .3s;
}
.contact-list a:hover {
  color: var(--accent-color);
}
.contact-list i {
  margin-right: .5rem;
  color: var(--accent-color);
}
/* dark mode */
body.dark-mode .contact-list a {
  color: var(--light-text);
}

.divider { display:none; }