* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

/* Full-page background */
body {
  background:url(asset/ChatGPT\ Image\ Aug\ 8\,\ 2025\,\ 03_28_08\ PM.png);
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

header {
  width: 100%;
  padding: 15px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  left: 0;
  z-index: 10;
}

header .logo {
  text-decoration: none;
  font-size: 22px;
  font-weight: bold;
  color: white;
}
#darkModeToggle {
  font-size: 18px;
  padding: 6px 10px;
  background: transparent;
  border: none;
  color: white;
  cursor: pointer;
}
.collaboration-page {
  max-width: 1200px;
  margin: auto;
  padding: 100px 20px 50px;
}

.intro {
  text-align: center;
  max-width: 800px;
  margin: auto;
}

.intro h1 {
  font-size: 2.5rem;
  margin-bottom: 15px;
}

.intro p {
  font-size: 2.1rem;
  color: black;
}

/* Collaboration cards grid */
.collab-list {
  margin-top: 50px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.collab-card {
  background: rgba(255, 255, 255, 0.9);
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  transition: transform 0.3s;
}


.collab-card h2 {
  font-size: 1.4rem;
  margin-bottom: 10px;
}

.collab-card p {
  font-size: 0.95rem;
  margin-bottom: 15px;
}

.collab-card a {
  text-decoration: none;
  background: #2575fc;
  color: white;
  padding: 10px 15px;
  border-radius: 6px;
  transition: background 0.3s;
}

.collab-card a:hover {
  background: #1a5ed0;
}

.collab-card:hover {
  transform: translateY(-5px);
}

/* Dark mode */
body.dark-mode .collab-card {
  background: rgba(40, 40, 40, 0.9);
  color: #f5f5f5;
}

body.dark-mode .intro p {
  color: #ccc;
}



/* Dark mode background image & colors */
body.dark-mode {
  background: url(asset/ChatGPT\ Image\ Aug\ 11\,\ 2025\,\ 07_29_20\ AM.png) no-repeat center center/cover;
}

body.dark-mode header {
  background: rgba(0, 0, 0, 0.7);
}

body.dark-mode .logo,
body.dark-mode #darkModeToggle {
  color: #fff;
}

body.dark-mode .collab-card {
  background: rgba(30, 30, 30, 0.9);
  color: #f5f5f5;
}

body.dark-mode .intro h1,
body.dark-mode .intro p {
  color: #ddd;
}