:root {
  --tech-accent: #4a90e2; /* Blue accent from the original site */
  --tech-accent-hover: #60a5fa;
  --tech-border: rgba(255, 255, 255, 0.1);
  --glass-bg: rgba(0, 0, 0, 0.4);
  --glass-border: rgba(255, 255, 255, 0.05);
  --text-primary: #ffffff;
  --text-secondary: #9ca3af;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: #050505;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* Background Effects */
body::before, body::after {
  content: '';
  position: fixed;
  width: 60vw;
  height: 60vw;
  border-radius: 50%;
  pointer-events: none;
  z-index: -1;
  filter: blur(120px);
  opacity: 0.6;
  animation: float 20s infinite alternate ease-in-out;
}

body::before {
  top: -20%;
  left: -10%;
  background: radial-gradient(circle, rgba(74, 144, 226, 0.25) 0%, rgba(0,0,0,0) 60%);
}

body::after {
  bottom: -20%;
  right: -10%;
  background: radial-gradient(circle, rgba(236, 72, 153, 0.15) 0%, rgba(0,0,0,0) 60%); /* Un toque rosado/morado */
  animation-delay: -10s;
  animation-duration: 25s;
}

@keyframes float {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(5%, 5%) scale(1.1); }
  100% { transform: translate(-5%, 10%) scale(0.9); }
}

h1, h2, h3, h4, h5, h6, .font-poppins {
  font-family: 'Poppins', sans-serif;
}

/* Navbar / Header */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--tech-border);
  padding: 1rem 0;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-group {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2px;
  width: 24px;
  height: 24px;
}

.logo-node {
  width: 100%;
  height: 100%;
  background-color: #333;
  border-radius: 1px;
}
.logo-node.active {
  background-color: var(--tech-accent);
  box-shadow: 0 0 5px var(--tech-accent);
}

.logo-text {
  font-family: 'Poppins', sans-serif;
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: 0.1em;
  display: flex;
  gap: 0.3rem;
}

.brand-text {
  color: var(--tech-accent);
}

.back-btn {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  transition: all 0.3s ease;
}

.back-btn:hover {
  color: var(--tech-accent);
  background: rgba(255, 255, 255, 0.05);
}

/* Social Icons */
.social-icons {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-right: 1.5rem;
}

.social-icons a {
  color: var(--text-secondary);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.social-icons a:hover {
  color: var(--tech-accent);
  transform: translateY(-2px);
  filter: drop-shadow(0 0 8px rgba(74, 144, 226, 0.6));
}

.social-icons svg {
  width: 1.25rem;
  height: 1.25rem;
  fill: currentColor;
}

/* Main Content */
.main-content {
  padding: 4rem 0;
}

.page-header {
  text-align: center;
  margin-bottom: 4rem;
}

.page-title {
  font-size: 2.5rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

@media (min-width: 768px) {
  .page-title {
    font-size: 3.5rem;
  }
}

.page-description {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--tech-border);
}

.mb-12 {
  margin-bottom: 3rem;
}

/* Grid Layouts */
.studies-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

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

@media (min-width: 768px) {
  .studies-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pdf-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .studies-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .pdf-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* New PDF Card Style */
.pdf-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 0.75rem;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all 0.3s ease;
}

.pdf-card:hover {
  border-color: rgba(74, 144, 226, 0.6);
  transform: translateY(-4px) scale(1.02);
  background: rgba(74, 144, 226, 0.1);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.4), 0 0 15px rgba(74, 144, 226, 0.2);
}

.pdf-card:hover .pdf-icon svg {
  fill: #f87171;
  filter: drop-shadow(0 0 8px rgba(239, 68, 68, 0.6));
}

.pdf-icon svg {
  width: 2rem;
  height: 2rem;
  fill: #ef4444; /* Red color for PDF */
  transition: all 0.3s ease;
}

.pdf-info {
  flex: 1;
}

.pdf-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: #fff;
}

.pdf-link {
  font-size: 0.85rem;
  color: var(--tech-accent);
  text-decoration: none;
  font-weight: 500;
}

.pdf-link:hover {
  text-decoration: underline;
}


/* Study/Video Card Style (Glassmorphism) */
.study-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 1rem;
  overflow: hidden;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.study-card:hover {
  border-color: rgba(74, 144, 226, 0.5);
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.6), 0 0 25px rgba(74, 144, 226, 0.2);
}

/* NotebookLM Section */
.notebooklm-link {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  height: 100%;
}

.notebooklm-header {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, rgba(74, 144, 226, 0.2), rgba(236, 72, 153, 0.2)), #111;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: center;
}

.notebooklm-icon svg {
  width: 4rem;
  height: 4rem;
  fill: rgba(255, 255, 255, 0.6);
  transition: all 0.3s ease;
}

.study-card:hover .notebooklm-icon svg {
  transform: scale(1.15);
  fill: #fff;
  filter: drop-shadow(0 0 12px rgba(74, 144, 226, 0.8));
}

/* NotebookLM Badge */
.ai-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: 2rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
  z-index: 10;
}

.ai-badge::before {
  content: '✨';
  font-size: 0.8rem;
}

/* Card Content */
.card-content {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.study-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: #fff;
  line-height: 1.3;
}

.study-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  flex: 1;
}

/* Messages */
.empty-msg, .error-msg {
  grid-column: 1 / -1;
  text-align: center;
  color: var(--text-secondary);
  padding: 2rem;
}
.error-msg {
  color: #ef4444;
}

/* Loader */
.loader-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
  width: 100%;
}

.loader {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255,255,255,0.1);
  border-radius: 50%;
  border-top-color: var(--tech-accent);
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}