/* As you wish 1: Unified CSS for CommonSense AI Lab */
:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #1a202c;
    --header-color: #001f3f;
    --accent-color: #007BFF;
    --accent-hover: #0056b3;
    --timeline-past: #d4edda;
    --timeline-present: #fff3cd;
    --timeline-future: #f8d7da;
}
body {
    font-family: 'Work Sans', sans-serif;

    color: var(--text-color);
    margin: 0;
    padding: 0;
    overflow-x: hidden;
    overscroll-behavior-x: none;
}
body::before {
  /* As you wish 1: Subtle white overlay for all backgrounds, 15% opacity */
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  width: 100vw;
  height: 100vh;
  background: #fff;
  opacity: 0.25;
  pointer-events: none;
  z-index: 0;
}
body.topics-bg {
  background: linear-gradient(135deg, #f8fafc 0%, #e8f0fe 100%);
  background-image: url('https://images.unsplash.com/photo-1506744038136-46273834b3fb?auto=format&fit=crop&w=1500&q=80'); /* As you wish 1: Calm, yoga-like background for topics page */
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
#main-nav {
    z-index: 1001;
}
.nav-link {
    color: var(--header-color);
    padding: 0.5rem;
    border-bottom: 2px solid transparent;
    transition: border-color 0.3s ease, color 0.3s ease;
    font-weight: 500;
}
.nav-link:hover {
    color: var(--accent-color);
}
.nav-link.active {
    border-color: var(--accent-color);
    font-weight: 700;
    color: var(--accent-color);
}
.page {
    width: 100vw;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    position: relative;
    background-size: cover;
    background-position: center;
    padding: 6rem 2rem 2rem 2rem;
    overflow-y: hidden;
}
.page-content-wrapper {
    max-width: 1200px;
    width: 100%;
    min-height: 100%;
    overflow-y: auto;
    padding: 2rem;
    -ms-overflow-style: none;
    scrollbar-width: none;
}
.page-content-wrapper::-webkit-scrollbar {
    display: none;
}
.card {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    margin-bottom: 2rem;
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}
.technology-tag, .tech-tag {
    display: inline-block;
    background: linear-gradient(90deg, #f1f3f6 0%, #e2e4e8 100%);
    color: #449;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 999px;
    padding: 0.25rem 0.75rem;
    margin: 0 0.15rem 0.15rem 0;
    box-shadow: 0 1px 2px rgba(0,0,0,0.04);
    border: 1px solid #e0e0e0;
    transition: background 0.2s;
    cursor: default;
    text-align: center;
}
.technology-tag:hover, .tech-tag:hover {
    background: linear-gradient(90deg, #e2e4e8 0%, #f1f3f6 100%);
}
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}
.project-card {
    background: var(--card-bg);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    cursor: pointer;
}
.project-card:hover {
    transform: scale(1.03);
}
.progress-bar {
    background-color: #e9ecef;
    border-radius: 0.25rem;
    overflow: hidden;
}
.progress {
    background-color: var(--accent-color);
}
.page-title {
  font-size: 3rem;
  font-weight: 700;
  color: #1e3a8a; /* text-blue-900 */
  text-align: center;
  margin-bottom: 1rem;
  font-family: 'Work Sans', 'sans-serif';
  letter-spacing: -0.01em;
  line-height: 1.1;
}

/* As you wish 1: Add 18px separation before each <li> in the impact section */
#impact .card ul > li {
  margin-top: 18px;
}

/* As you wish 1: Show impact page cards horizontally, each half width on desktop */
#impact .impact-cards-row {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}
#impact .impact-cards-row .card {
  flex: 1 1 48%;
  max-width: 48%;
  min-width: 320px;
  margin-bottom: 0;
}
@media (max-width: 900px) {
  #impact .impact-cards-row {
    flex-direction: column;
    gap: 2rem;
  }
  #impact .impact-cards-row .card {
    max-width: 100%;
    flex-basis: 100%;
  }
}

/* As you wish 1: Custom styles for category filter buttons in topics.html */
.category-btn {
  padding: 0.5rem 1.25rem;
  border-radius: 0.5rem;
  font-weight: bold;
  border: 1px solid #cbd5e1;
  background: #f3f4f6;
  color: #60a5fa;
  margin: 0 0.25rem 0.5rem 0;
  transition: background 0.2s, color 0.2s;
  cursor: pointer;
}
.category-btn:hover {
  background: #e5e7eb;
}
.category-btn.active {
  background: #fff;
  color: #1d4ed8;
  border-color: #60a5fa;
}