@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  /* Clean Light Mode Colors */
  --bg-color: #f8fafc;
  --surface-color: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
  
  /* Theme Colors */
  --color-bio: #10b981;    /* Emerald Green */
  --color-science: #3b82f6; /* Blue */
  --color-activism: #ef4444; /* Red */
  
  --active-theme-color: var(--color-bio); /* Default, overridden per page */
  
  --navbar-height: 70px;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
}

/* --- Navigation Bar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--navbar-height);
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 5%;
  z-index: 1000;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.logo {
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-link {
  font-weight: 500;
  font-size: 1rem;
  position: relative;
  padding: 0.5rem 0;
  transition: color 0.3s ease;
  cursor: pointer;
}

/* Hover colors */
.nav-link[data-page="bio"]:hover { color: var(--color-bio); }
.nav-link[data-page="science"]:hover { color: var(--color-science); }
.nav-link[data-page="activism"]:hover { color: var(--color-activism); }

/* Active State Underline */
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--active-theme-color);
  border-radius: 2px;
}

/* --- Sweep Animation Overlay --- */
#sweep-overlay {
  position: fixed;
  top: 0;
  left: 0;
  height: var(--navbar-height);
  width: 0;
  background-color: transparent;
  z-index: 1001; /* Above navbar but below anything else */
  pointer-events: none; /* Let clicks pass through if needed */
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  mix-blend-mode: multiply; /* Looks cool on a white navbar */
  opacity: 0.2;
}

/* Active Page Top Border Hint */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: var(--active-theme-color);
  z-index: 1002;
}

/* --- Main Layout --- */
main {
  margin-top: var(--navbar-height);
  padding: 4rem 5%;
  min-height: calc(100vh - var(--navbar-height) - 100px); /* Adjust for footer */
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeIn 0.8s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Hero Section --- */
.hero {
  display: flex;
  align-items: center;
  gap: 4rem;
  margin-bottom: 5rem;
}

.hero-text {
  flex: 1;
}

.hero-text h1 {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
}

.hero-text h1 span {
  color: var(--active-theme-color);
}

.hero-text p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 600px;
}

.hero-image {
  flex: 1;
  display: flex;
  justify-content: flex-end;
}

.hero-image img {
  width: 100%;
  max-width: 400px;
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.1);
  object-fit: cover;
  aspect-ratio: 4/5;
}

.btn {
  display: inline-block;
  padding: 0.8rem 2rem;
  background-color: var(--text-primary);
  color: white;
  border-radius: 30px;
  font-weight: 500;
  transition: all 0.3s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.btn-primary {
  background-color: var(--active-theme-color);
}

/* --- Content Sections --- */
.section {
  margin-bottom: 5rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 2rem;
  color: var(--text-primary);
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
  display: inline-block;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.card {
  background-color: var(--surface-color);
  border-radius: 16px;
  padding: 2rem;
  border: 1px solid var(--border-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.05);
  border-color: var(--active-theme-color);
}

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.featured-image {
  width: 100%;
  border-radius: 12px;
  margin-bottom: 1.5rem;
  object-fit: cover;
  background-color: #f1f5f9;
}

.science-svg {
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
  display: block;
}

/* --- Footer --- */
footer {
  text-align: center;
  padding: 3rem 5%;
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.social-links a {
  font-weight: 500;
  transition: color 0.2s ease;
}

.social-links a:hover {
  color: var(--active-theme-color);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .hero {
    flex-direction: column-reverse;
    text-align: center;
    gap: 2rem;
  }
  
  .hero-text h1 {
    font-size: 2.5rem;
  }
  
  .hero-image {
    justify-content: center;
  }
  
  .hero-text p {
    margin: 0 auto 2rem auto;
  }
  
  .nav-links {
    gap: 1rem;
  }
}