.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(8px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: transform 0.3s ease-in-out;

}

/* Theme variables (light by default) */
:root {
  --bg: #ffffff;
  --text: #0b1220;
  --nav-bg: rgba(15, 23, 42, 0.95);
  --surface: rgba(255,255,255,0.9);
  --muted: rgba(255,255,255,0.6);
}

/* Dark theme overrides */
[data-theme="dark"] {
  --bg: #071025;
  --text: #e6eef8;
  --nav-bg: rgba(2, 6, 23, 0.9);
  --surface: rgba(255,255,255,0.06);
  --muted: rgba(255,255,255,0.85);
}

.navbar nav {
  padding: 0.75rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

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

.logo-container {
  display: flex;
  align-items: center;
  gap: 1rem;
  text-decoration: none;
  color: white;
  transition: opacity 0.3s ease;
}

.logo-container:hover {
  opacity: 0.9;
}

.nav-logo {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 1px;
  color: white;
}

/* Nav actions (theme toggle + back-to-top) */
.nav-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.theme-toggle {
  background: transparent;
  border: 1px solid rgba(255,255,255,0.12);
  color: var(--muted);
  padding: 6px 8px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
}

.theme-toggle.active {
  background: rgba(255,255,255,0.92);
  color: #071025;
  border-color: rgba(0,0,0,0.06);
}

.back-to-top {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.06);
  border: none;
  color: var(--muted);
  cursor: pointer;
}

.back-to-top:hover {
  transform: translateY(-2px);
}

.navbar nav ul {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0.5rem 0;
}

.hamburger {
  display: none;
  cursor: pointer;
  background: none;
  border: none;
  padding: 10px;
  position: absolute;
  right: 15px;
  top: 15px;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 3px;
  background-color: #fff;
  margin: 5px 0;
  transition: 0.3s;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(-45deg) translate(-5px, 6px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(45deg) translate(-5px, -6px);
}

@media screen and (max-width: 1024px) {
  .hamburger {
    display: block;
    z-index: 1001;
  }

  .nav-container {
    position: relative;
  }

  .logo-container {
    gap: 0.5rem;
  }

  .nav-logo {
    width: 32px;
    height: 32px;
  }

  .logo-text {
    font-size: 1.1rem;
  }

  .navbar nav ul {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(15, 23, 42, 0.98);
    padding: 4rem 0;
    gap: 0.75rem;
    text-align: center;
    z-index: 1000;
    overflow-y: auto;
  }

  .navbar nav ul.active {
    display: flex;
    animation: slideIn 0.3s ease-out forwards;
  }

  .navbar nav ul li {
    width: 100%;
    padding: 0.5rem 2rem;
  }

  .navbar nav ul li a {
    display: block;
    width: 100%;
  }

  .navbar nav ul li .header_btn {
    width: 100%;
    padding: 0.75rem;
  }

  .navbar nav ul li .download {
    width: 100%;
    margin: 0.5rem 0;
  }

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

.navbar nav ul li a {
  text-decoration: none;
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
}

.navbar nav ul li a:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.1);
}

.download {
  background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  text-decoration: none;
  display: inline-block;
}

.download:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 8px rgba(0, 0, 0, 0.2);
}

.header_btn {
  background: transparent;
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
  border: none;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  transition: all 0.3s ease;
  cursor: pointer;
}

.header_btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #ffffff;
}