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

body {
  font-family: sans-serif;
}

.container {
  display: flex;
  gap: 1.5rem;
  padding: 1rem;
}

.sidebar {
  width: 300px;
  flex: 0 0 300px;
  position: sticky;
  top: 1rem;
  max-height: calc(100vh - 2rem);
  overflow: auto;
  padding: 1rem;
  background: #ADD8E6;
  border-radius: 8px;
}

.content {
  flex-grow: 1;
  flex-shrink: 1;
  flex-basis: auto;
  max-width: 800px;
}

html {
  scroll-behavior: smooth;
}

section {
  padding: 2rem;
  margin-bottom: 2rem;
  background: white;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  scroll-margin-top: 1rem;
  position: relative;
}

.deco {
  position: absolute;
  pointer-events: none;
}

.deco img {
  width: 150px;
  height: auto;
  opacity: 0.20;
  filter: grayscale(100%);
}

#deco-1 {
  top: 50%; 
  right: 5%;
}

#deco-2 {
  top: 50%;
  right: 5%;
}

#deco-3 {
  top: 50%;
  right: 5%;
}

#deco-4 {
  top: 50%;
  right: 5%;
}

#deco-5 {
  top: 50%;
  right: 5%;
}

:focus-visible {
  outline: 2px solid #3b82f6;
  outline-offset: 2px;
  border-radius: 4px;
}

:hover {
  background-color: rgb(12, 12, 63);
}

.back-to-top {
  display: inline-block;
  margin-top: 2rem;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  text-decoration: none;
}

footer {
  text-align: center;
}