/* styles.css */
/* Root color variables */
:root {
  --dark-bg: #13212b;
  --light-bg: #eef3f3;
  --hero-text: #F9FAF8;
  --muted-text: #E5E7EB;
  --primary-btn: #147d75;
  --info-text: #1F2937;
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.5;
  background-color: #fff;
  color: var(--info-text);
}
a:focus-visible {
  outline: 3px solid #34cbb9;
  outline-offset: 3px;
}

/* Hero section */
.hero {
  background-color: var(--dark-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 64px 20px;
}
.hero .profile-img {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 24px;
}
.hero h1 {
  font-size: 48px;
  font-weight: 900;
  margin-bottom: 10px;
}
.hero .hero-subtitle {
  font-size: 18px;
  color: var(--muted-text);
  margin-bottom: 20px;
}
.hero .btn {
  display: inline-block;
  background-color: var(--primary-btn);
  color: var(--hero-text);
  font-size: 18px;
  padding: 12px 24px;
  text-decoration: none;
  border-radius: 4px;
  font-weight: 400;
}

/* Main content */
main {
  max-width: 920px;
  margin: 48px auto;
  padding: 0 20px;
}
main section {
  margin-bottom: 48px;
}
main h2 {
  margin-bottom: 18px;
  font-size: 1.6rem;
}

/* Summary Card */
.summary-card {
  background-color: var(--light-bg);
  border-left: 4px solid var(--primary-btn);
  padding: 20px;
  border-radius: 4px;
  margin-bottom: 20px;
}

/* Timeline Styles */
.timeline {
  position: relative;
  margin: 20px 0;
  padding-left: 20px;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--primary-btn);
}
.timeline-item {
  position: relative;
  margin-bottom: 30px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -10px;
  top: 8px;
  width: 20px;
  height: 20px;
  background: var(--primary-btn);
  border-radius: 50%;
}
.timeline-content {
  background: #fff;
  padding: 15px 20px;
  border-radius: 4px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.timeline-content h3 {
  margin: 0 0 5px;
  font-size: 24px;
  color: var(--info-text);
}
.timeline-content .date {
  font-size: 14px;
  color: #555;
  margin-bottom: 8px;
}

/* Projects */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 16px;
}
.project-card {
  display: block;
  min-height: 220px;
  padding: 24px;
  background: var(--light-bg);
  border-radius: 10px;
  color: var(--info-text);
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease;
}
.project-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(19, 33, 43, .12);
}
.project-card h3 { margin-bottom: 10px; }
.project-card p { margin-bottom: 18px; }
.project-card span { color: #355b59; font-size: .9rem; }
#teaching p { max-width: 720px; }
@media (max-width: 600px) {
  .hero h1 { font-size: 2rem; }
  .hero .profile-img { width: 116px; height: 116px; }
  .timeline-content h3 { font-size: 1.2rem; }
}

/* Footer */
footer {
  background-color: var(--dark-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 40px 20px;
}
footer h2 {
  font-size: 24px;
  font-weight: 900;
  margin-bottom: 15px;
}
footer .contact { list-style: none; }
footer .contact li {
  margin-bottom: 8px;
}
footer .contact a {
  color: var(--muted-text);
  font-size: 16px;
  text-decoration: none;
}
footer .contact a:hover {
  color: var(--primary-btn);
}