body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #ffffff;
  display: flex;
}

/* Sidebar */
#sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: 150px;
  height: 100vh;
  background-color: #000000;
  color: #ffffff;
  padding: 1rem;
  box-sizing: border-box;
  transition: transform 0.3s ease;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#sidebar.collapsed {
  transform: translateX(-100%);
}

/* Sidebar top image */
#sidebar img.cortex-logo {
  width: 128px;
  height: auto;
  margin-bottom: 2rem;
}

/* Sidebar link */
#sidebar a {
  display: block;
  color: #ffffff;
  text-decoration: none;
  margin: 0.5rem 0;
  text-align: center;
}

#sidebar a:hover {
  opacity: 0.8;
}

/* Toggle arrow button */
#toggle-btn {
  position: fixed;
  left: 150px;
  top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
  transition: left 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100px;
}

#toggle-btn.collapsed {
  left: 0;
}

#toggle-btn img {
  width: 32px;
  height: 32px;
  display: block;
}

/* Main content area */
#content {
  margin-left: 200px;
  padding: 2rem;
  transition: margin-left 0.3s ease;
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

#sidebar.collapsed + #toggle-btn + #content {
  margin-left: 0;
}

/* Hand-drawn images */
img.handdrawn {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}

img.top-image {
  max-width: 300px;
  margin-bottom: 2rem;
}

img.cortex-text {
  width: 64px;
  height: auto;
  vertical-align: middle;
}

img.bottom-image {
  max-width: 128px;
  height: auto;
  display: block;
  margin: 0 auto;
}

/* Footer */
footer {
  text-align: center;
  font-size: 0.9rem;
  margin-top: auto;
  color: #555555;
}

/* Paragraph styling */
p {
  margin-top: 1rem;
  text-align: center;
  max-width: 600px;
  align-self: center;
}

/* Header 1 */
h1 {
  margin-top: 1rem;
  text-align: center;
  max-width: 600px;
  align-self: center;
}

/* Spacer for bottom image */
.spacer {
  flex-grow: 1;
}