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

:root {
  /* Dark Theme Colors */
  --background-color: #121212; 
  --background-overlay: rgba(0, 0, 0, 0.30); /* Dark overlay for the image (70% black - slightly darker for better contrast with transparent fg) */
  
  /* UPDATED: Container background with adjustable transparency */
  /* Base color: #1e1e1e (rgb(30, 30, 30)) */
  /* Alpha (transparency): 0.95 (95% opaque, 5% transparent). Adjust 0.95 as needed. */
  --container-bg-opacity: 0.80; 
  --container-bg: rgba(30, 30, 30, var(--container-bg-opacity)); 
  
  --container-border: rgba(255, 255, 255, 0.1); 

  --text-primary: #e0e0e0; 
  --text-secondary: #b0b0b0; 
  --heading-color: #ffffff; 

  --link-color: #61dafb; 
  --link-hover-color: #82e9ff; 

  --accent-color: var(--link-color); 
  
  --button-bg: rgba(255, 255, 255, 0.08); /* Slightly more opaque buttons */
  --button-border: rgba(255, 255, 255, 0.2);
  --button-hover-bg: var(--link-color);
  --button-hover-text: #121212; 

  /* UPDATED: Card backgrounds can also be transparent, or solid for contrast */
  /* Option 1: Transparent cards (relative to body background) */
  --card-bg-opacity: 0.9; /* Example: 90% opaque */
  --card-base-color-rgb: 42, 42, 42; /* Corresponds to #2a2a2a */
  --card-bg: rgba(var(--card-base-color-rgb), var(--card-bg-opacity));
  
  /* Option 2: Solid cards (if transparency makes them hard to read) */
  /* --card-bg: #2a2a2a; */

  --card-border: rgba(255, 255, 255, 0.08); /* Slightly less visible border for cards */
  --card-hover-bg: rgba(var(--card-base-color-rgb), calc(var(--card-bg-opacity) + 0.05)); /* Slightly more opaque on hover */
  /* --card-hover-bg: #333333; */ /* Solid hover */
  
  --featured-card-bg-opacity: 0.92;
  --featured-card-base-color-rgb: 49, 49, 49; /* Corresponds to #313131 */
  --featured-card-bg: rgba(var(--featured-card-base-color-rgb), var(--featured-card-bg-opacity));
  /* --featured-card-bg: #313131; */ /* Solid featured */


  --main-font: 'Source Sans 3', sans-serif; 
}

body {
  font-family: var(--main-font); 
  line-height: 1.6;
  color: var(--text-primary); 
  
  background-image: url('images/bg3.jpeg'); /* <<< REPLACE THIS PATH */
  background-size: cover;
  background-position: center center;
  background-attachment: fixed;
  background-repeat: no-repeat;
  background-color: var(--background-color); 

  min-height: 100vh;
  padding-top: 3rem; 
  padding-bottom: 3rem;
  position: relative; 
}

body::before {
  content: "";
  position: fixed; 
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--background-overlay);
  z-index: -1; 
}

.container {
  max-width: 1100px; 
  margin: 0 auto; 
  background: var(--container-bg); /* USING THE NEW TRANSPARENT VARIABLE */
  box-shadow: 0 8px 40px rgba(0,0,0,0.5); 
  border-radius: 10px; 
  border: 1px solid var(--container-border);
  overflow: hidden; 
}

/* ... (rest of the CSS from the previous dark theme version) ... */
/* All elements inside .container will now sit on this semi-transparent background */
/* Ensure their individual backgrounds (if any) are also considered. */
/* For example, .updates-list li and .paper-card already use --card-bg */

.hero-section {
  padding: 4rem 2.5rem; 
  text-align: center; 
  border-bottom: 1px solid var(--container-border); 
}

.hero-content {
  display: flex;
  flex-direction: column; 
  align-items: center;
  justify-content: center;
  gap: 2.5rem; 
  max-width: 700px; 
  margin: 0 auto;
}

.hero-text {
  /* No specific changes needed here based on transparency */
}

.name {
  font-size: 3.2rem; 
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--heading-color); 
}

.hero-description {
  font-size: 1.15rem; 
  line-height: 1.8;
  margin-bottom: 2.5rem;
  color: var(--text-secondary); 
}

.hero-description a {
  color: var(--link-color); 
  text-decoration: none;
  font-weight: 500; 
  transition: color 0.3s ease;
}

.hero-description a:hover {
  color: var(--link-hover-color); 
  text-decoration: underline; 
}

.profile-image {
  width: 220px; 
  height: 220px; 
  object-fit: cover;
  border-radius: 50%;
  /* Make border slightly more opaque than container or use a solid light color for definition */
  border: 4px solid rgba(var(--card-base-color-rgb), calc(var(--container-bg-opacity) + 0.03)); 
  box-shadow: 0 0 25px rgba(0,0,0,0.3); 
  transition: transform 0.3s ease;
  order: -1; 
}

.profile-image:hover {
  transform: scale(1.05);
}

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

.social-links a {
  color: var(--link-color); 
  text-decoration: none;
  padding: 0.4rem 0.9rem; 
  border: 1px solid var(--button-border); 
  background: var(--button-bg);
  border-radius: 6px; 
  transition: all 0.3s ease;
  display: inline-flex; 
  align-items: center; 
  gap: 0.5em; 
  font-size: 0.9rem; 
}

.social-links a:hover {
  background: var(--button-hover-bg); 
  color: var(--button-hover-text);
  border-color: var(--button-hover-bg); 
  transform: translateY(-2px) scale(1.02);
}

.content-section {
  padding: 3.5rem 2.5rem;
}

.section-title {
  font-size: 2.3rem; 
  font-weight: 600;
  margin-bottom: 2.5rem; 
  color: var(--heading-color); 
  position: relative;
  padding-bottom: 1rem; 
  text-align: center;
}

.section-title:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%; 
  transform: translateX(-50%); 
  width: 80px; 
  height: 3px; 
  background: var(--accent-color); 
  border-radius: 1.5px;
}

.research-intro {
  font-size: 1.15rem; 
  line-height: 1.9; 
  color: var(--text-secondary); 
  margin-bottom: 3rem;
  text-align: center;
  max-width: 750px; 
  margin-left: auto;
  margin-right: auto;
}

.updates-list {
  list-style: none;
  padding: 0;
  max-width: 700px; 
  margin: 0 auto 2rem auto;
}

.updates-list li a {
  color: var(--link-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.updates-list li a:hover {
  color: var(--link-hover-color);
  text-decoration: underline;
}

.updates-list li {
  padding: 1.2rem 1.5rem; 
  margin-bottom: 1rem;
  background: var(--card-bg); /* Uses the potentially transparent card bg */
  border-left: 4px solid var(--accent-color); 
  border-radius: 6px;
  transition: transform 0.2s ease, background-color 0.2s ease;
  box-shadow: 0 2px 5px rgba(0,0,0,0.2);
  color: var(--text-primary);
}

.updates-list li strong {
  color: var(--heading-color);
}

.updates-list li:hover {
  transform: translateX(5px);
  background: var(--card-hover-bg); 
}

.paper-grid {
  display: grid;
  gap: 2.5rem; 
  margin-top: 2rem;
}

.paper-card {
  display: flex;
  gap: 2rem; 
  padding: 2rem;
  background: var(--card-bg); /* Uses the potentially transparent card bg */
  transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease; 
  border: 1px solid var(--card-border); 
  border-radius: 8px; 
  box-shadow: 0 3px 10px rgba(0,0,0,0.2);
}

.paper-card:hover {
  transform: translateY(-5px); 
  box-shadow: 0 10px 25px rgba(0,0,0,0.3); 
  background: var(--card-hover-bg);
}

.paper-card.featured {
  background: var(--featured-card-bg); /* Uses the potentially transparent featured card bg */
  border-color: var(--accent-color); 
  box-shadow: 0 0 15px rgba(var(--accent-color), 0.15); 
}

.paper-media {
  flex-shrink: 0;
  width: 240px; 
  height: 180px; 
  overflow: hidden; 
  border-radius: 6px; 
  background-color: rgba(0,0,0,0.2); 
}

.paper-media img,
.paper-media video {
  width: 100%;
  height: 100%;
  object-fit: contain; 
}

.paper-content {
  flex: 1;
}

.paper-title {
  font-size: 1.25rem; 
  font-weight: 600; 
  color: var(--link-color); 
  text-decoration: none;
  margin-bottom: 0.75rem; 
  display: block;
  transition: color 0.3s ease;
}

.paper-title:hover {
  color: var(--link-hover-color); 
  text-decoration: underline;
}

.paper-authors {
  color: var(--text-secondary); 
  margin-bottom: 0.75rem;
  line-height: 1.6; 
  font-size: 0.9rem; 
}

.paper-authors strong { 
  color: var(--text-primary); 
  font-weight: 600;
}

.paper-authors a {
  color: var(--link-color); 
  text-decoration: none;
  transition: color 0.3s ease;
}

.paper-authors a:hover {
  color: var(--link-hover-color); 
}

.paper-venue {
  font-weight: 600; 
  font-style: italic;
  color: var(--text-secondary); 
  margin-bottom: 1.2rem; 
  font-size: 0.9rem; 
}

.paper-links {
  margin-bottom: 1rem;
}

.paper-links a {
  color: var(--link-color); 
  text-decoration: none;
  margin-right: 0.8rem; 
  font-size: 0.85rem; 
  padding: 0.35rem 0.8rem; 
  border: 1px solid var(--button-border); 
  background: var(--button-bg);
  border-radius: 5px;
  transition: all 0.3s ease;
}

.paper-links a:hover {
  background: var(--button-hover-bg); 
  color: var(--button-hover-text);
  border-color: var(--button-hover-bg);
}

.paper-description {
  color: var(--text-primary); 
  font-size: 0.95rem; 
  line-height: 1.7; 
}

.equal-contrib {
  font-style: italic;
  color: var(--text-secondary); 
  margin-bottom: 1rem;
  padding-left: 0;
  font-size: 0.85rem;
}

.footer {
  text-align: center;
  padding: 3rem 2rem; 
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-top: 1px solid var(--container-border); 
  margin-top: 2rem; 
}

.footer a {
  color: var(--link-color); 
  font-weight: 500;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer a:hover {
  color: var(--link-hover-color); 
  text-decoration: underline;
}

/* Media Queries remain largely the same as the previous dark theme version */
/* The transparency will apply across all screen sizes based on the root variables */

@media (max-width: 992px) { 
  body {
      padding-top: 2rem;
      padding-bottom: 2rem;
  }
  .container {
      max-width: 95%; 
      border-radius: 8px;
  }
  .paper-media {
      width: 200px; 
      height: 150px;
  }
  .profile-image {
      width: 200px;
      height: 200px;
  }
}

@media (max-width: 768px) { 
  body {
      padding-top: 1.5rem; 
      padding-bottom: 1.5rem;
  }
  .container {
      max-width: 95%; 
      border-radius: 6px; 
  }
  .hero-section {
    padding: 3rem 1.5rem;
  }
  .profile-image {
      width: 160px; 
      height: 160px;
  }
  .name {
    font-size: 2.5rem; 
  }
  .section-title {
      font-size: 2rem;
      padding-bottom: 0.75rem;
  }
  .paper-card {
    flex-direction: column; 
    align-items: center;
    text-align: center;
    gap: 1.5rem; 
    padding: 1.5rem; 
  }
  .paper-media {
    width: 90%; 
    max-width: 300px; 
    height: auto;    
    aspect-ratio: 4 / 3; 
    margin-bottom: 1rem; 
  }
  .content-section {
    padding: 2.5rem 1.5rem; 
  }
  .footer {
      padding: 2.5rem 1.5rem;
  }
}

@media (max-width: 480px) { 
  .name {
      font-size: 2.1rem;
  }
  .profile-image {
      width: 140px;
      height: 140px;
  }
  .section-title {
      font-size: 1.8rem;
  }
  .research-intro {
      font-size: 1.05rem;
  }
  .paper-media {
    max-width: 280px; 
  }
  .paper-title {
      font-size: 1.15rem;
  }
  .paper-description {
      font-size: 0.9rem;
  }
}