body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background-color: #0a0d25;
  color: white;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 60px;
  background-color: #070b23;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 1000;
  padding: 0 20px;
  box-sizing: border-box;
}

/* Logo (left) */
.logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: #0ff;
}

.logo a {
  color: #0ff;
  text-decoration: none;
}

/* Center nav links */
.nav-links {
  list-style: none;
  display: flex;
  gap: 20px;
  align-items: center;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  margin-top: 7px;
}

.nav-links a {
  color: whitesmoke;
  text-decoration: none;
  font-size: 17px;
}

.nav-links a:hover {
  color: #0ff;
}

/* Right actions: login, signup, profile */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.signup-btn {
  background-color: #0ff;
  color: #000;
  padding: 6px 12px;
  border-radius: 5px;
  font-weight: bold;
  transition: 0.3s;
}

.nav-actions-links {
  color: whitesmoke;
  font-size: 17px;
}

.nav-actions a {
  text-decoration: none;
  white-space: nowrap;
}

.nav-actions a:hover {
  color: #0ff;
}

.signup-btn:hover {
  background-color: #00c9c9;
}

.hamburger {
  display: none; /* hide by default */
}

@media (max-width: 800px) {
  .hamburger {
    display: block;
    font-size: 28px;
    cursor: pointer;
    color: #0ff;
    z-index: 1001;
  }

  .mobile-nav {
    display: none;
    flex-direction: column;
    background-color: #070b23;
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 0;

  }

  .mobile-nav.active {
    display: flex;
  }

  .mobile-nav .nav-links,
  .mobile-nav .nav-actions {
    display: flex !important; /* force show in mobile dropdown */
    flex-direction: column;
    align-items: center;
    gap: 12px;
    width: 100%;
  }

  
  /* Force vertical layout */
  .nav-links,
  .nav-actions {
    position: static;      /* remove absolute from desktop */
    transform: none;       /* remove translateX from desktop */
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    width: 100%;
    margin: 0;
    padding: 0;
  }

  .nav-links li {
    width: 100%;
    text-align: center;
  }

  .nav-links a,
  .nav-actions a {
    display: block;
    width: 100%;
    padding: 10px 0;
    color: white;
    text-align: center;
  }

  /* Smaller signup button in mobile */
  .nav-actions .signup-btn {
    width: auto;
    min-width: 120px;
    max-width: 160px;
  }

  .mobile-nav a {
    color: white;
    padding: 0.75rem;
    text-align: center;
  }
}

.main-content {
  flex-grow: 1;
  padding: 50px;
  overflow-y: auto;
}

header {
  text-align: center;
  margin-bottom: 20px;
}

.steps {
  background-color: #1a1a1a;
  padding: 20px;
  border-radius: 12px;
  max-width: 600px;
  margin: auto;
}

.steps button {
  display: block;
  width: 100%;
  margin-bottom: 10px;
  font-size: 16px;
  padding: 10px;
  background-color: #263238;
  color: #80d8ff;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

.procedure {
  text-align: center;
  margin-top: 20px;
}

.lab-area {
  margin: 30px auto;
  display: flex;
  justify-content: center;
  align-items: center;
}

.slide-stage {
  position: relative;
  width: 300px;
  height: 200px;
  border: 3px dashed #90caf9;
  background-color: #1e1e1e;
  border-radius: 12px;
  overflow: hidden;
}

.layer {
  position: absolute;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.5s ease-in-out;
}

.onion-skin {
  background: repeating-linear-gradient(45deg, #8e44ad 0px, #8e44ad 2px, transparent 2px, transparent 6px);
  z-index: 1;
}

.iodine-stain {
  background-color: rgba(255, 200, 0, 0.2);
  z-index: 2;
}

.cover-slip {
  background-color: rgba(255, 255, 255, 0.1);
  z-index: 3;
}

.microscope-zoom {
  background: radial-gradient(circle at center, #ddd 2px, transparent 3px),
              radial-gradient(circle at center, #eee 2px, transparent 3px);
  background-size: 20px 20px;
  background-position: 0 0, 10px 10px;
  z-index: 4;
}

.show {
  opacity: 1;
}

.message {
  text-align: center;
  font-size: 16px;
  margin-top: 20px;
  color: #b9f6ca;
}

.hidden {
  display: none;
}

/* ***************************************** */
.complete-btn {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #00c6ff, #0072ff);
  color: white;
  font-size: 16px;
  font-weight: bold;
  border: none;
  border-radius: 50px;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(0,0,0,0.3);
  transition: all 0.3s ease;
  z-index: 1000;
}

.complete-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(0,0,0,0.4);
}

.btn-icon {
  font-size: 20px;
}

.btn-text {
  white-space: nowrap;
}