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

body {
  font-family: system-ui, sans-serif;
  height: 300vh;
  background: linear-gradient(120deg, #1a1a2e, #16213e);
  color: white;
}

/* Demo pages */
.page {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 2rem;
}

/* Bottom nav container */
.bottom-nav {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  width: 90%;
  max-width: 420px;
  height: 70px;
  display: flex;
  justify-content: space-around;
  align-items: center;

  /* Glass effect */
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);

  border-radius: 30px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  z-index: 1000;
}

/* Nav items */
.nav-item {
  position: relative;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  color: rgba(255, 255, 255, 0.6);
  cursor: pointer;
  transition: all 0.4s cubic-bezier(.4,0,.2,1);
  z-index: 2;
}

.nav-item span {
  font-size: 28px;
  transition: all 0.4s cubic-bezier(.4,0,.2,1);
}

/* Active icon */
.nav-item.active {
  color: #fff;
  transform: translateY(-20px);
}

.nav-item.active span {
  font-size: 32px;
}

/* Floating bubble indicator */
.nav-indicator {
  position: absolute;
  top: -25px;
  width: 60px;
  height: 60px;
  border-radius: 50%;

  background: rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);

  box-shadow:
    0 8px 20px rgba(255,255,255,0.3),
    inset 0 0 10px rgba(255,255,255,0.4);

  transition: left 0.4s cubic-bezier(.4,0,.2,1);
  z-index: 1;
}
.atlas-learning-wrap { padding: 40px 20px; text-align:center; }
.atlas-years-container { display:flex; justify-content:center; flex-wrap:wrap; gap:20px; }

.atlas-year-card {
  padding: 30px 40px;
  border-radius:25px;
  cursor:pointer;
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(20px);
  color:white;
  font-size:20px;
  font-weight:bold;
  transition:0.3s;
}

.atlas-year-card:hover {
  background: rgba(255,255,255,0.25);
  transform: translateY(-5px);
}