:root {
  --bg-color: #ffffff;
  --text-color: #111111;
  --card-bg: #f4f4f4;
  --hero-bg: #f4f4f4;
}

body.dark {
  --bg-color: #111111;
  --text-color: #ffffff;
  --card-bg: #1e1e1e;
  --hero-bg: #1a1a1a;
}

body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s ease, color 0.3s ease;
}

header {
  background: #111;
  color: #fff;
  padding: 25px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

nav a {
  margin: 0 10px 0 20px;
  color: #fff;
  text-decoration: none;
}

#theme-toggle {
  background-color: transparent;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  margin-left: auto;
}

.hero {
  padding: 50px;
  text-align: center;
  background-color: var(--hero-bg);
  transition: background-color 0.3s ease;
}

section {
  padding: 30px;
  max-width: 900px;
  margin: auto;
}

.project-grid, .testimonial-grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.project-card, .testimonial-card {
  background-color: var(--card-bg);
  padding: 20px;
  border-radius: 10px;
  transition: background-color 0.3s ease;
}

.testimonial-card {
  border-left: 4px solid #ff6b6b;
  font-style: italic;
}

footer {
  text-align: center;
  padding: 20px;
  background: #111;
  color: #fff;
}