/* ============================================
   Scott A. Bollt - Academic Website Styles
   Aesthetic: Clean, modern academic (inspired by
   Brunton, Harms, Bae websites)
   ============================================ */

/* --- CSS Variables --- */
:root {
  --color-primary: #1a365d;       /* Deep navy */
  --color-primary-light: #2d5a9e;
  --color-accent: #c45427;        /* Caltech orange (muted) */
  --color-accent-hover: #a3441e;
  --color-bg: #ffffff;
  --color-bg-alt: #f7f8fa;
  --color-bg-dark: #1a1f2e;
  --color-text: #2d3748;
  --color-text-light: #718096;
  --color-text-muted: #a0aec0;
  --color-border: #e2e8f0;
  --color-link: #2d5a9e;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --max-width: 1100px;
  --nav-height: 64px;
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

img { max-width: 100%; height: auto; display: block; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 2rem; }

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(26, 54, 93, 0.97);
  backdrop-filter: blur(8px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.02em;
}
.nav-brand:hover { color: #e2e8f0; }

.nav-links {
  list-style: none;
  display: flex;
  gap: 0.25rem;
}

.nav-links a {
  color: rgba(255,255,255,0.85);
  font-size: 0.88rem;
  font-weight: 500;
  padding: 0.5rem 0.85rem;
  border-radius: 6px;
  transition: all var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: #fff;
  background: rgba(255,255,255,0.12);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  margin: 5px 0;
  transition: var(--transition);
  border-radius: 2px;
}

/* --- Hero Section --- */
.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #f7f8fa 0%, #edf2f7 50%, #e2e8f0 100%);
}

.hero-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-text h1 {
  font-family: var(--font-serif);
  font-size: 3.2rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.15;
  margin-bottom: 0.75rem;
}

.hero-subtitle {
  font-size: 1.35rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 0.25rem;
}

.hero-affiliation {
  font-size: 1.1rem;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: 1rem;
}

.hero-tagline {
  font-size: 1rem;
  color: var(--color-text-light);
  margin-bottom: 1rem;
}

.hero-market {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 1.5rem;
}

.hero-links { display: flex; gap: 1rem; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 0.7rem 1.6rem;
  border-radius: 8px;
  font-size: 0.92rem;
  font-weight: 600;
  transition: all var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn-primary:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary-light);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn-secondary:hover {
  background: var(--color-primary);
  color: #fff;
}

.hero-image { display: flex; justify-content: center; }

.profile-photo-container {
  width: 340px;
  height: 340px;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(26, 54, 93, 0.2), 0 0 0 6px rgba(26, 54, 93, 0.08);
  border: 4px solid #fff;
}

.profile-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: rgba(255,255,255,0.7);
  font-size: 1.2rem;
  font-weight: 600;
  text-align: center;
  line-height: 1.4;
}

.hero-bg-accent {
  position: absolute;
  top: -20%;
  right: -10%;
  width: 60%;
  height: 140%;
  background: linear-gradient(135deg, rgba(26, 54, 93, 0.03), rgba(196, 84, 39, 0.04));
  border-radius: 50%;
  z-index: 1;
}

/* --- Sections --- */
.section {
  padding: 5rem 0;
}

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

.section-title {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
  position: relative;
  padding-bottom: 0.75rem;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 50px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

.section-subtitle {
  color: var(--color-text-light);
  font-size: 0.95rem;
  margin-bottom: 2.5rem;
}

/* --- About Section --- */
.about-content {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 3rem;
  margin-top: 2rem;
}

.about-text p {
  margin-bottom: 1.25rem;
  font-size: 1.02rem;
}

.about-early-research {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.about-early-research h3 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.info-card {
  background: var(--color-bg-alt);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  border: 1px solid var(--color-border);
}

.info-card h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.85rem;
}

.education-list {
  list-style: none;
}
.education-list li {
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.92rem;
  line-height: 1.5;
}
.education-list li:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }
.education-list .year { color: var(--color-text-light); font-size: 0.85rem; }

.interests-list {
  list-style: none;
}
.interests-list li {
  padding: 0.35rem 0;
  font-size: 0.9rem;
  color: var(--color-text);
  position: relative;
  padding-left: 1rem;
}
.interests-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 5px;
  height: 5px;
  background: var(--color-accent);
  border-radius: 50%;
}

/* --- Research Section --- */
.research-project {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-bottom: 4rem;
  align-items: start;
}
.research-project.reverse { direction: rtl; }
.research-project.reverse > * { direction: ltr; }

.research-media video {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  cursor: pointer;
}

.research-media img {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.media-caption {
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-top: 0.75rem;
  font-style: italic;
}

.research-text h3 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.research-text p {
  margin-bottom: 1rem;
  font-size: 0.98rem;
}

.research-figures {
  margin-top: 1.5rem;
}

.research-figures figure {
  margin: 0;
}

.research-figures img {
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.research-figures figcaption {
  font-size: 0.82rem;
  color: var(--color-text-light);
  margin-top: 0.5rem;
  font-style: italic;
}

/* --- Publications Section --- */
.pub-category {
  margin-bottom: 3rem;
}

.pub-category h3 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  color: var(--color-primary);
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-border);
}

.pub-list {
  list-style: none;
  counter-reset: pub-counter;
}

.pub-item {
  counter-increment: pub-counter;
  padding: 1.25rem 0 1.25rem 2.5rem;
  border-bottom: 1px solid var(--color-border);
  position: relative;
  transition: background var(--transition);
}
.pub-item::before {
  content: counter(pub-counter) ".";
  position: absolute;
  left: 0;
  top: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
  font-size: 0.95rem;
}
.pub-item:hover {
  background: rgba(26, 54, 93, 0.02);
}

.pub-title {
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--color-text);
  margin-bottom: 0.3rem;
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 0.2rem;
}
.pub-authors .self-author {
  font-weight: 600;
  color: var(--color-text);
}

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

.pub-meta {
  display: flex;
  gap: 1rem;
  margin-top: 0.4rem;
  font-size: 0.82rem;
}

.pub-year, .pub-citations {
  color: var(--color-text-light);
  font-weight: 500;
}

.pub-placeholder {
  color: var(--color-text-muted);
  font-style: italic;
  padding-left: 0 !important;
}
.pub-placeholder::before { display: none; }

/* --- Live Demos Section --- */
.demo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.demo-card {
  background: #fff;
  border-radius: 12px;
  padding: 2.5rem;
  text-align: center;
  border: 1px solid var(--color-border);
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  transition: transform var(--transition), box-shadow var(--transition);
}
.demo-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

a.demo-card-link {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}
a.demo-card-link:hover { color: inherit; }

.demo-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto 1.5rem;
  color: var(--color-primary);
}
.demo-icon svg { width: 100%; height: 100%; }

.demo-card h3 {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.demo-card p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  margin-bottom: 0.75rem;
}

.demo-note {
  font-size: 0.82rem !important;
  color: var(--color-text-muted) !important;
  font-style: italic;
}

/* --- People Section --- */
.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
  align-items: start;
}

.person-card {
  text-align: center;
  padding: 2rem 1.5rem;
  background: var(--color-bg-alt);
  border-radius: 12px;
  border: 1px solid var(--color-border);
}

.person-photo {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 1rem;
  border: 3px solid var(--color-border);
}

.person-photo-placeholder {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-weight: 700;
  font-size: 1.2rem;
}

.person-card h4 {
  font-size: 1rem;
  color: var(--color-text);
  margin-bottom: 0.3rem;
}

.person-role {
  font-size: 0.85rem;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: 0.3rem;
}

.person-desc {
  font-size: 0.82rem;
  color: var(--color-text-light);
}

.person-outcome {
  font-size: 0.78rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-top: 0.3rem;
}

.people-subsection, .personal-subsection {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.personal-subsection {
  margin-top: 3rem;
}

.people-note {
  color: var(--color-text-light);
  font-size: 0.95rem;
  max-width: 700px;
}

/* --- Hobbies Section --- */
/* Research Vision */
.vision-content > p {
  font-size: 1.05rem;
  color: var(--color-text);
  margin-bottom: 2rem;
}

.vision-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.vision-card {
  background: #fff;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  border-top: 3px solid var(--color-primary);
}

.vision-card h3 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
}

.vision-card p {
  font-size: 0.92rem;
  color: var(--color-text);
  line-height: 1.6;
}

/* Teaching */
.teaching-content > p {
  font-size: 1rem;
  color: var(--color-text);
  margin-bottom: 2rem;
  max-width: 800px;
}

.teaching-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.hobby-item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.hobby-image img {
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.12);
}

.hobby-caption {
  font-size: 0.82rem;
  color: var(--color-text-light);
  margin-top: 0.5rem;
  font-style: italic;
}

.hobby-text h3 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.hobby-text p {
  font-size: 0.98rem;
  margin-bottom: 1rem;
}

/* --- Contact Section --- */
.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-top: 2rem;
}

.contact-item {
  margin-bottom: 1.5rem;
}
.contact-item strong {
  display: block;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-bottom: 0.3rem;
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  justify-content: center;
}

.contact-link-btn {
  display: block;
  padding: 1rem 1.5rem;
  border: 2px solid var(--color-border);
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-primary);
  text-align: center;
  transition: all var(--transition);
}
.contact-link-btn:hover {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: #fff;
}

/* --- Early Research Section --- */
.early-research-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-top: 2rem;
  align-items: start;
}

.early-research-text p {
  margin-bottom: 1.25rem;
  font-size: 1.02rem;
}

.early-research-media figure {
  margin: 0 0 2rem 0;
}

.early-research-media img {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.12);
}

.early-research-media figcaption {
  font-size: 0.82rem;
  color: var(--color-text-light);
  margin-top: 0.5rem;
  font-style: italic;
  text-align: center;
}

@media (max-width: 900px) {
  .early-research-content { grid-template-columns: 1fr; }
}

/* --- Footer --- */
.footer {
  background: var(--color-bg-dark);
  color: rgba(255,255,255,0.6);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.85rem;
}

/* --- Responsive --- */
@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2rem;
  }
  .hero-text h1 { font-size: 2.4rem; }
  .hero-links { justify-content: center; }
  .hero-image { order: -1; }
  .profile-photo-container { width: 250px; height: 250px; }

  .about-content { grid-template-columns: 1fr; }
  .about-sidebar { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }

  .research-project,
  .research-project.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .hobby-item { grid-template-columns: 1fr; }
  .contact-content { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  html { font-size: 15px; }

  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-primary);
    flex-direction: column;
    padding: 1rem;
    border-top: 1px solid rgba(255,255,255,0.1);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    display: block;
    padding: 0.75rem 1rem;
  }

  .section { padding: 3.5rem 0; }
  .section-title { font-size: 1.8rem; }
  .hero { min-height: 70vh; }
  .hero-text h1 { font-size: 2rem; }

  .about-sidebar { grid-template-columns: 1fr; }
  .container { padding: 0 1.25rem; }
}

/* --- Animations --- */
@media (prefers-reduced-motion: no-preference) {
  .section-title,
  .research-project,
  .pub-item,
  .demo-card,
  .person-card,
  .hobby-item {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
  }
  .section-title.visible,
  .research-project.visible,
  .pub-item.visible,
  .demo-card.visible,
  .person-card.visible,
  .hobby-item.visible {
    opacity: 1;
    transform: translateY(0);
  }
}