:root {
  --turquoise: #00ced1;
  --pale-turquoise: #afeeee;
  --ink: #0f2530;
  --stone: #f7f7f2;
}

body {
  margin: 0;
  font-family: "Palatino Linotype", "Book Antiqua", Palatino, serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 20% 20%, rgba(0, 206, 209, 0.18), transparent 45%),
    radial-gradient(circle at 80% 0%, rgba(175, 238, 238, 0.35), transparent 40%),
    linear-gradient(120deg, #f6f9fb, var(--stone));
}

.nav-toggle {
  position: absolute;
  left: -9999px;
}

.nav-toggle-btn {
  position: fixed;
  top: 1.25rem;
  left: 1.25rem;
  z-index: 3;
  padding: 0.6rem 0.9rem;
  border-radius: 999px;
  border: 1px solid rgba(15, 37, 48, 0.18);
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(8px);
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  cursor: pointer;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 240px;
  height: 100vh;
  padding: 5.5rem 1.5rem 2rem;
  background: linear-gradient(160deg, var(--pale-turquoise), #ffffff 80%);
  border-right: 1px solid rgba(15, 37, 48, 0.08);
  transform: translateX(0);
  transition: transform 0.25s ease;
}

.nav-toggle:checked ~ .sidebar {
  transform: translateX(-190px);
}

.sidebar h3 {
  margin: 0 0 1.5rem;
  font-size: 0.9rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
}

.sidebar a {
  display: block;
  color: var(--ink);
  text-decoration: none;
  margin-bottom: 0.75rem;
  font-size: 1rem;
}

.main {
  margin-left: 240px;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  transition: margin-left 0.25s ease;
}

.nav-toggle:checked ~ .main {
  margin-left: 60px;
}

.center-card {
  max-width: 640px;
  background: rgba(255, 255, 255, 0.8);
  padding: 2.5rem;
  border-radius: 24px;
  border: 1px solid rgba(15, 37, 48, 0.12);
  box-shadow: 0 20px 60px rgba(15, 37, 48, 0.12);
}

.center-card h2 {
  font-size: 2.6rem;
  margin-top: 0;
}

.center-card p {
  line-height: 1.7;
  font-size: 1.05rem;
}

.accent {
  display: inline-block;
  padding: 0.15rem 0.45rem;
  background: var(--turquoise);
  color: #ffffff;
  border-radius: 999px;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

@media (max-width: 900px) {
  .sidebar {
    width: 200px;
  }
  .main {
    margin-left: 200px;
  }
  .nav-toggle:checked ~ .sidebar {
    transform: translateX(-150px);
  }
  .nav-toggle:checked ~ .main {
    margin-left: 50px;
  }
}

@media (max-width: 640px) {
  .sidebar {
    transform: translateX(-190px);
  }
  .nav-toggle:checked ~ .sidebar {
    transform: translateX(0);
  }
  .main {
    margin-left: 60px;
  }
  .center-card {
    padding: 1.75rem;
  }
}