/* Gate text exits downward on click */
.center {
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.6s ease;
}

.center.exit {
  transform: translate(-50%, -50%) translateY(60px);
  opacity: 0;
  pointer-events: none;
}

/* Panels (welcome menu, about, pictures, message me, submitted) fade/slide
   in to take each other's place */
.panel {
  opacity: 0;
  transform: translate(-50%, -50%) translateY(40px);
  pointer-events: none;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1) 0.2s, opacity 0.6s ease 0.2s;
}

.panel.enter {
  opacity: 1;
  transform: translate(-50%, -50%);
  pointer-events: auto;
}

.panel.exit {
  transform: translate(-50%, -50%) translateY(60px);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.5s ease;
}

/* Buttons stagger in after the panel container arrives */
.panel .nav-btn {
  opacity: 0;
  transform: translateY(16px);
}

.panel.enter .nav-btn {
  animation: btnIn 0.5s ease forwards;
}

.panel.enter .nav-btn:nth-child(1) { animation-delay: 0.35s; }
.panel.enter .nav-btn:nth-child(2) { animation-delay: 0.45s; }
.panel.enter .nav-btn:nth-child(3) { animation-delay: 0.55s; }

@keyframes btnIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Generic staggered-item entrance, reused by the about cards and the
   pictures grid */
.stagger-item {
  opacity: 0;
  transform: translateY(20px);
}

.panel.enter .stagger-item {
  animation: itemIn 0.5s ease forwards;
}

.panel.enter .stagger-item:nth-child(1) { animation-delay: 0.32s; }
.panel.enter .stagger-item:nth-child(2) { animation-delay: 0.39s; }
.panel.enter .stagger-item:nth-child(3) { animation-delay: 0.46s; }
.panel.enter .stagger-item:nth-child(4) { animation-delay: 0.53s; }
.panel.enter .stagger-item:nth-child(5) { animation-delay: 0.6s; }
.panel.enter .stagger-item:nth-child(6) { animation-delay: 0.67s; }

@keyframes itemIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Staggered-item exit, mirrored and compressed so every item has
   finished leaving before the panel itself fades out (0.5s, see
   .panel.exit above) */
.panel.exit .stagger-item {
  animation: itemOut 0.25s ease forwards;
}

@keyframes itemOut {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(20px);
  }
}