/*
  Beatrice Michaeli Academic Website - Design System & Stylesheet
  Clean, Semantic, Responsive, and Highly Customizable.
  Uses modern CSS features (Variables, Flexbox, Grid, Backdrop-filters).
*/

/* -----------------------------------------
   1. Design System & Variables
   ----------------------------------------- */
:root {
  /* Colors */
  --bg-color-solid: #fafaf8;
  --text-color: #2a2a28;
  --text-light: #6b6b66;
  --primary-accent: #1a5f7a; /* Teal accent for research/academic content */
  --primary-accent-hover: #0d3d52;
  --consulting-accent: #a88a5e; /* Warm tan accent marking consulting content */
  --border-color: rgba(0, 0, 0, 0.08);
  --sidebar-bg: #f5f3f0;
  --intro-box-bg: #fffaf6;
  --card-bg: #ffffff;

  /* Fonts */
  --font-serif: "Crimson Text", Georgia, serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Layout Sizing */
  --max-width: 1000px;
  --sidebar-width: 320px;
  --transition-speed: 0.25s;

  /* Shadows & Radius */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
  --radius-sm: 4px;
  --radius-md: 8px;
}

/* -----------------------------------------
   2. Reset & Global Styles
   ----------------------------------------- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color-solid);
  color: var(--text-color);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.25;
  color: #1e1e1e;
  margin-bottom: 1rem;
}

p {
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
}

a {
  color: var(--primary-accent);
  text-decoration: none;
  transition: color var(--transition-speed), border-color var(--transition-speed);
}

a:hover {
  color: var(--primary-accent-hover);
}

/* -----------------------------------------
   3. Layout Elements
   ----------------------------------------- */
.container {
  inline-size: 100%;
  max-inline-size: var(--max-width);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

/* Page Shell: persistent sidebar + scrolling content area */
.page-shell {
  display: flex;
  min-height: 100vh;
  align-items: flex-start;
}

/* Sidebar */
.sidebar {
  flex: 0 0 var(--sidebar-width);
  background-color: var(--sidebar-bg);
  padding: 3rem 2rem;
  min-height: 100vh;
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 2.5rem;
}

.sidebar-profile {
  text-align: center;
  margin-bottom: 2rem;
}

.sidebar-profile-img {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 1.25rem;
  display: block;
  box-shadow: var(--shadow-md);
}

.site-logo {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 600;
  line-height: 1.2;
  color: #1a1a1a;
  display: block;
  margin-bottom: 0.4rem;
}

.site-logo:hover {
  color: var(--primary-accent);
}

.sidebar-tagline {
  font-size: 0.95rem;
  color: var(--text-light);
  font-weight: 500;
  margin-bottom: 0;
}

.sidebar-intro {
  padding: 1.1rem 1.25rem;
  background-color: var(--intro-box-bg);
  border-left: 3px solid var(--primary-accent);
  margin-bottom: 2rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.sidebar-intro p {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-color);
  margin-bottom: 0;
}

/* Navigation Menu */
.nav-menu {
  display: flex;
  flex-direction: column;
  list-style: none;
  gap: 0.35rem;
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--text-color);
  padding: 0.45rem 0;
  border-bottom: 1px solid transparent;
  transition: color var(--transition-speed), border-bottom var(--transition-speed);
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-accent);
  border-bottom-color: var(--primary-accent);
}

.sidebar-contact {
  border-top: 1px solid var(--border-color);
  padding-top: 1.25rem;
}

.sidebar-contact-label {
  font-size: 0.75rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.sidebar-contact a {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

/* Content Area */
.content-area {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Main Content Area */
main {
  flex-grow: 1;
  padding: 3.5rem 3.5rem 4rem;
}

/* Footer Section */
footer {
  padding-block: 2.5rem;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-color-solid);
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.footer-copyright {
  font-size: 0.85rem;
  color: var(--text-light);
}

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social-link {
  font-size: 0.85rem;
  color: var(--text-light);
  border-bottom: 1px dashed var(--text-light);
}

.footer-social-link:hover {
  color: var(--primary-accent);
  border-bottom-color: var(--primary-accent);
}

/* -----------------------------------------
   4. Page-Specific Layouts & Components
   ----------------------------------------- */

/* Home Page styling */
.hero-text {
  font-family: var(--font-serif);
  color: var(--text-color);
  max-width: 720px;
}

.hero-text p {
  font-size: 1.2rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.home-section {
  margin-top: 4rem;
}

.home-section h2 {
  font-size: 1.75rem;
}

.home-section-link {
  display: inline-block;
  margin-top: 1.5rem;
  font-weight: 600;
  padding-bottom: 0.2rem;
  border-bottom: 2px solid var(--primary-accent);
}

.featured-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.75rem;
}

/* Consulting Teaser */
.consulting-teaser {
  margin-top: 4rem;
  padding: 2rem 2.25rem;
  background-color: var(--intro-box-bg);
  border-left: 4px solid var(--consulting-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.consulting-teaser h2 {
  color: var(--consulting-accent);
  font-size: 1.5rem;
}

.consulting-teaser p {
  font-size: 1.02rem;
  max-width: 640px;
}

.consulting-teaser .home-section-link {
  border-bottom-color: var(--consulting-accent);
  color: var(--consulting-accent);
}

/* Research Page / Publication Lists */
.research-section {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.paper-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.paper-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.paper-title {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: #1e1e1e;
}

.paper-meta {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.paper-meta strong {
  color: var(--text-color);
}

.paper-meta a {
  border-bottom: 1px solid transparent;
}

.paper-meta a:hover {
  border-bottom-color: var(--primary-accent);
}

/* Detail accordion block for abstract */
.abstract-details {
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  margin-top: 1.25rem;
}

.abstract-summary {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-light);
  cursor: pointer;
  outline: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.abstract-summary::-webkit-details-marker {
  display: none;
}

.abstract-summary::before {
  content: "▶";
  font-size: 0.7rem;
  transition: transform var(--transition-speed);
}

.abstract-details[open] .abstract-summary::before {
  transform: rotate(90deg);
}

.abstract-content {
  padding-top: 1rem;
  font-size: 0.95rem;
  color: #4a5568;
  line-height: 1.6;
  text-align: justify;
}

/* Styled download buttons */
.button-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color var(--transition-speed), color var(--transition-speed), border-color var(--transition-speed);
}

.btn-primary {
  background-color: var(--primary-accent);
  color: #ffffff;
  border: 1px solid var(--primary-accent);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--text-color);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: #f1f5f9;
  border-color: var(--text-light);
  color: #1e1e1e;
}

/* Talks Page layout */
.talks-grid {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 3.5rem;
}

.talks-gallery {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: sticky;
  top: 2rem;
}

.gallery-card {
  width: 100%;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  background-color: #eaeaea;
  transition: transform var(--transition-speed);
}

.gallery-card:hover {
  transform: scale(1.02);
}

.gallery-card img {
  width: 100%;
  height: auto;
  display: block;
}

.talks-timeline {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.timeline-year-group {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
}

.timeline-year-title {
  font-size: 1.5rem;
  font-family: var(--font-serif);
  color: var(--primary-accent);
  margin-bottom: 1rem;
}

.timeline-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.timeline-item {
  font-size: 1rem;
  color: var(--text-color);
  line-height: 1.4;
  padding-left: 1rem;
  position: relative;
}

.timeline-item::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--primary-accent);
}

/* Biography Page Layout */
.bio-wrapper {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.bio-block {
  font-size: 1.05rem;
  line-height: 1.7;
}

.bio-block p {
  text-align: justify;
  margin-bottom: 1.5rem;
}

.bio-images-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-block: 1rem;
}

.bio-img-container {
  width: 100%;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.bio-img {
  width: 100%;
  height: 350px;
  object-fit: cover;
  display: block;
}

/* CV Page Layout */
.cv-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-block: 4rem;
}

.cv-icon {
  font-size: 4rem;
  color: var(--primary-accent);
  margin-bottom: 1.5rem;
}

.cv-title {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.cv-subtitle {
  color: var(--text-light);
  margin-bottom: 2rem;
}

/* Links Page Layout */
.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.link-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.link-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.link-card-icon {
  font-size: 1.5rem;
  color: var(--primary-accent);
}

.link-card-title {
  font-size: 1.15rem;
  font-family: var(--font-serif);
  font-weight: 600;
  color: #1e1e1e;
}

.link-card-desc {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.5rem;
}

.link-card-action {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  color: var(--primary-accent);
  margin-top: auto;
}

.link-card-action::after {
  content: "→";
  transition: transform var(--transition-speed);
}

.link-card:hover .link-card-action::after {
  transform: translateX(3px);
}

/* Contact Page Layout */
.contact-container {
  max-width: 600px;
  margin-inline: auto;
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 3rem;
  box-shadow: var(--shadow-sm);
}

.contact-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.contact-header h2 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.contact-item {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
}

.contact-icon {
  font-size: 1.5rem;
  color: var(--primary-accent);
  flex-shrink: 0;
  margin-top: 0.2rem;
}

.contact-details h3 {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-light);
  margin-bottom: 0.35rem;
}

.contact-details p {
  font-size: 1.05rem;
  margin-bottom: 0;
  color: var(--text-color);
  white-space: pre-line;
}

.contact-details a {
  border-bottom: 1px solid transparent;
}

.contact-details a:hover {
  border-bottom-color: var(--primary-accent);
}

/* -----------------------------------------
   5. Responsive Media Queries
   ----------------------------------------- */
@media (max-width: 900px) {
  .talks-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .talks-gallery {
    position: static;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
  }

  .featured-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  /* Stack sidebar above content on small screens */
  .page-shell {
    flex-direction: column;
  }

  .sidebar {
    position: static;
    min-height: auto;
    width: 100%;
    flex: none;
    padding: 2rem 1.75rem;
  }

  .sidebar-profile {
    margin-bottom: 1.5rem;
  }

  .nav-menu {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.5rem 1.25rem;
  }

  .sidebar-contact {
    border-top: none;
    padding-top: 0.5rem;
  }

  main {
    padding: 2.5rem 1.5rem 3rem;
  }

  .bio-images-row {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .bio-img-container {
    max-width: 450px;
    margin-inline: auto;
  }

  .bio-img {
    height: 280px;
  }

  .contact-container {
    padding: 2rem;
  }
}