header {
  display: flex;
  justify-content: space-between;
  align-items: center;

  padding: 12px 18px;

  background: linear-gradient(180deg, rgba(40,22,18,.92), rgba(22,14,20,.90));
  border-bottom: 1px solid rgba(255,255,255,.10);

  box-shadow:
    0 12px 30px rgba(0,0,0,.45),
    inset 0 0 0 1px rgba(255,255,255,.04);

  position: sticky;
  top: 0;
  z-index: 10;

  backdrop-filter: blur(6px);
}

header::after{
  content:"";
  position:absolute;
  left:0; right:0; bottom:-1px;
  height:1px;
  background: linear-gradient(90deg, transparent, rgba(247,211,122,.35), transparent);
  opacity:.85;
  pointer-events:none;
}

.logo {
  font-size: 1.3rem;
  font-weight: 800;

  cursor: pointer;
  padding: 7px 12px;
  border-radius: 999px;

  color: #fff2d2;

  border: 1px solid rgba(255,255,255,.12);
  background: rgba(2,6,23,.12);

  box-shadow:
    0 10px 28px rgba(0,0,0,.35),
    inset 0 0 0 1px rgba(255,255,255,.06);

  letter-spacing: .3px;
  text-shadow: 0 2px 14px rgba(255,180,90,.14);
}

.logo:hover {
  filter: brightness(1.06);
  background: rgba(247,211,122,.10);
  border-color: rgba(247,211,122,.20);
}

nav button {
  margin-left: 8px;

  padding: 7px 12px;
  border-radius: 999px;

  border: 1px solid rgba(255,255,255,.12);
  background: linear-gradient(180deg, #374151, #1f2937);

  color: #ffffff;

  cursor: pointer;

  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: .2px;

  box-shadow:
    0 10px 22px rgba(0,0,0,.40),
    inset 0 0 0 1px rgba(255,255,255,.06);
}

nav button:hover {
  filter: brightness(1.08);
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px;
}

.page-section { display: none; }
.page-section.active { display: block; }

footer {
  text-align: center;

  padding: 16px;
  margin-top: 24px;

  background: linear-gradient(180deg, rgba(22,14,20,.60), rgba(12,8,10,.55));
  border-top: 1px solid rgba(255,255,255,.10);

  box-shadow: inset 0 1px 0 rgba(255,255,255,.04);

  font-size: 0.85rem;
  color: #cfc4ae;
}