/* ============================================================
   Louis Kurdyk — Researcher Portfolio
   ============================================================ */

/* Variables */
:root {
  --primary:       #1e3a5f;
  --primary-dark:  #112030;
  --accent:        #2f6eb5;
  --accent-light:  #4d8fd4;
  --text:          #2c3e50;
  --text-muted:    #6c757d;
  --bg-alt:        #f4f7fa;
  --border:        #e2e8f0;
  --white:         #ffffff;
  --shadow:        0 2px 14px rgba(0, 0, 0, 0.07);
  --font:          'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  line-height: 1.75;
  padding-top: 68px;
}

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

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

/* ============================================================
   Navbar
   ============================================================ */
.navbar-custom {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 0.8rem 0;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.05);
  transition: box-shadow 0.25s;
}

.navbar-custom.scrolled {
  box-shadow: 0 2px 18px rgba(0, 0, 0, 0.10);
}

.navbar-brand {
  font-weight: 700;
  color: var(--primary) !important;
  font-size: 1.12rem;
  letter-spacing: -0.02em;
}

.navbar-custom .nav-link {
  color: var(--text) !important;
  font-weight: 500;
  font-size: 0.9rem;
  padding: 0.45rem 0.8rem !important;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}

.navbar-custom .nav-link:hover {
  color: var(--accent) !important;
  background: rgba(47, 110, 181, 0.07);
}

.navbar-custom .nav-link.active-link {
  color: var(--accent) !important;
}

.navbar-custom .dropdown-item.active,
.navbar-custom .dropdown-item:active {
  background-color: var(--primary);
}

/* ============================================================
   Hero
   ============================================================ */
.hero {
  background: linear-gradient(140deg, #0d1f35 0%, var(--primary) 55%, #1a4e82 100%);
  color: var(--white);
  padding: 96px 0 82px;
  position: relative;
  overflow: hidden;
}

/* Decorative circles */
.hero::before,
.hero::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}

.hero::before {
  width: 700px;
  height: 700px;
  top: -40%;
  right: -8%;
  background: rgba(255, 255, 255, 0.025);
}

.hero::after {
  width: 420px;
  height: 420px;
  bottom: -30%;
  left: -4%;
  background: rgba(255, 255, 255, 0.02);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.45rem;
}

.hero .subtitle {
  font-size: 1.25rem;
  font-weight: 400;
  opacity: 0.85;
  margin-bottom: 0.3rem;
}

.hero .institution {
  font-size: 0.98rem;
  opacity: 0.68;
}

.hero .contact-email {
  font-size: 0.93rem;
  opacity: 0.72;
  margin-top: 1.2rem;
}

.hero-social {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-social-link {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.88rem;
  text-decoration: none;
  transition: color 0.2s;
}

.hero-social-link:hover {
  color: var(--white);
  text-decoration: none;
}

.hero-social-link i {
  font-size: 1rem;
  vertical-align: -0.1em;
}

.hero-tags {
  margin-top: 1.6rem;
}

.tag {
  display: inline-block;
  background: rgba(255, 255, 255, 0.09);
  border: 1px solid rgba(255, 255, 255, 0.22);
  color: rgba(255, 255, 255, 0.88);
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 0.81rem;
  margin: 4px 3px;
  transition: background 0.2s;
}

.tag:hover {
  background: rgba(255, 255, 255, 0.17);
}

.btn-hero {
  display: inline-block;
  background: var(--white);
  color: var(--primary);
  font-weight: 600;
  padding: 0.6rem 1.65rem;
  border-radius: 100px;
  border: 2px solid var(--white);
  font-size: 0.93rem;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-hero:hover {
  background: transparent;
  color: var(--white);
  text-decoration: none;
}

.btn-hero-outline {
  display: inline-block;
  background: transparent;
  color: rgba(255, 255, 255, 0.88);
  font-weight: 600;
  padding: 0.6rem 1.65rem;
  border-radius: 100px;
  border: 2px solid rgba(255, 255, 255, 0.42);
  font-size: 0.93rem;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-hero-outline:hover {
  border-color: var(--white);
  background: rgba(255, 255, 255, 0.1);
  color: var(--white);
  text-decoration: none;
}

/* ============================================================
   Sections
   ============================================================ */
section {
  padding: 72px 0;
}

section.alt {
  background-color: var(--bg-alt);
}

.section-title {
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 2rem;
  padding-bottom: 0.55rem;
  border-bottom: 3px solid var(--accent);
  display: inline-block;
  letter-spacing: -0.025em;
}

/* ============================================================
   About — Info Cards
   ============================================================ */
.info-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.2rem 1.4rem;
}

.info-card-title {
  font-weight: 600;
  color: var(--primary);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 0.7rem;
}

.research-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.research-list li {
  padding: 0.22rem 0;
  font-size: 0.9rem;
  color: var(--text);
}

.research-list li::before {
  content: '→';
  color: var(--accent);
  margin-right: 0.45rem;
  font-size: 0.82rem;
}

/* ============================================================
   Publications
   ============================================================ */
.pub-category {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.85rem;
}

.pub-list {
  list-style: none;
  padding: 0;
  margin: 0 0 0.5rem;
}

.pub-list li {
  padding: 0.95rem 0;
  border-bottom: 1px solid var(--border);
}

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

.pub-title {
  font-weight: 600;
  font-size: 0.98rem;
  color: var(--text);
  margin-bottom: 0.2rem;
}

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

.pub-link {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 2px 11px;
  border-radius: 100px;
  transition: all 0.2s;
  text-decoration: none;
}

.pub-link:hover {
  background: var(--accent);
  color: var(--white);
  text-decoration: none;
}

/* ============================================================
   Teaching
   ============================================================ */
.teaching-card {
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-bottom: 1.25rem;
}

.teaching-card-header {
  background: var(--primary);
  color: var(--white);
  padding: 0.8rem 1.25rem;
  font-weight: 600;
  font-size: 0.92rem;
}

.teaching-card-body {
  background: var(--white);
}

.teaching-item {
  padding: 0.8rem 1.25rem;
  border-bottom: 1px solid var(--border);
}

.teaching-item:last-child {
  border-bottom: none;
}

.teaching-course {
  font-weight: 600;
  font-size: 0.93rem;
  color: var(--text);
}

.teaching-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.12rem;
}

.teaching-link {
  color: var(--accent);
  font-size: 0.82rem;
  text-decoration: none;
}

.teaching-link:hover {
  text-decoration: underline;
}

/* ============================================================
   Footer
   ============================================================ */
footer {
  background: var(--primary-dark);
  color: rgba(255, 255, 255, 0.6);
  text-align: center;
  padding: 2.5rem 0;
  font-size: 0.88rem;
}

footer a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
}

footer a:hover {
  color: var(--white);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 768px) {
  body { padding-top: 62px; }
  .hero { padding: 70px 0 60px; }
  .hero h1 { font-size: 2.2rem; }
  .hero .subtitle { font-size: 1.05rem; }
  section { padding: 52px 0; }
  .section-title { font-size: 1.4rem; }
}