:root {
  --bg-dark: #121212;
  --card-bg: #1e1e1e;
  --card-border: rgba(255, 255, 255, 0.08);

  --text-light: #f5f5f5;
  --text-muted: rgba(245, 245, 245, 0.6);
  --text-highlight: #ffffff;

  --primary: #64b5f6;
  --primary-light: #90caf9;
  --primary-dark: #42a5f5;

  --accent: #ff8a65;
  --teal: #4db6ac;
  --success: #81c784;
  --warning: #ffb74d;
  --error: #e57373;

  --shadow-primary: 0 4px 15px rgba(66, 165, 245, 0.2);
  --shadow-card: 0 2px 10px rgba(0, 0, 0, 0.3);

  --border-light: 1px solid rgba(255, 255, 255, 0.1);
  --border-radius: 8px;
}

html {
  scroll-behavior: smooth;
}

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

body {
  background-color: var(--bg-dark);
  color: var(--text-light);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--card-bg);
  padding: 0 2rem;
  border-bottom: var(--border-light);
  z-index: 1000;
  height: 70px;
  display: flex;
  align-items: center;
  box-shadow: var(--shadow-card);
}

.navbar-container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-light);
}

.navbar-logo {
  height: 4.5rem;
  width: auto;
  transition: transform 0.3s ease;
}

.navbar-brand:hover .navbar-logo {
  transform: scale(1.05);
}

.navbar-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link:hover {
  color: var(--text-light);
}

.nav-link.active {
  color: var(--primary-light);
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary-light);
  border-radius: 2px;
}

.nav-button {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: var(--bg-dark) !important;
  padding: 0.5rem 1.25rem;
  border-radius: var(--border-radius);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
  text-decoration: none;
  border: none;
  cursor: pointer;
}

.nav-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-light);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu {
  position: fixed;
  top: 70px;
  left: 0;
  right: 0;
  background: var(--card-bg);
  padding: 1.5rem;
  border-top: var(--border-light);
  display: none;
  flex-direction: column;
  gap: 1.5rem;
  z-index: 999;
  transform: translateY(-100%);
  transition: transform 0.3s ease;
  box-shadow: var(--shadow-card);
}

.mobile-menu.open {
  transform: translateY(0);
  display: flex;
}

.app-content {
  margin-top: 90px;
  padding: 2rem;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.study-card {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  border: var(--border-light);
  box-shadow: var(--shadow-card);
  transition: transform 0.3s ease;
}

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

@media (max-width: 768px) {
  .navbar-links {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .navbar {
    padding: 0 1rem;
    height: 60px;
  }

  .navbar-logo {
    height: 2rem;
  }

  .app-content {
    margin-top: 80px;
    padding: 1rem;
  }
}