/* =========================================================
   GOKDENIZ OS — HERO INTRO
   Sayfa açılışında slit-scan mascot + "GÖKDENİZ OS" patlar.
   Sekme başına bir kez oynar (sessionStorage).
   Boot intro'dan gelindiyse atlanır.
   ========================================================= */

#gokdeniz-hero {
  position: fixed; inset: 0; z-index: 9999;
  background: #000; color: #39ff14;
  font-family: 'Segoe UI', sans-serif;
  display: grid;
  grid-template-rows: 1fr auto 1fr;
  justify-items: center; align-items: center;
  overflow: hidden;
  pointer-events: auto;
}
#gokdeniz-hero::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: repeating-linear-gradient(to bottom, rgba(57,255,20,.05) 0 1px, transparent 1px 3px);
  mix-blend-mode: screen;
}
#gokdeniz-hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(ellipse at center, transparent 55%, rgba(0,0,0,.75) 100%);
}

#gokdeniz-hero .hero-reveal {
  grid-row: 2;
  position: relative;
  width: min(520px, 65vw);
  aspect-ratio: 1 / 1;
  margin-bottom: 20px;
}
#gokdeniz-hero .hero-slice {
  position: absolute;
  top: 0; height: 100%;
  background-image: url('resim/Gökdenizpog.png');
  background-size: 520px 520px;
  background-repeat: no-repeat;
  filter: drop-shadow(0 0 10px rgba(57,255,20,.5));
  opacity: 0;
  transform: translateY(-120vh);
  animation: heroSliceDrop 1.3s cubic-bezier(.2,.9,.2,1) forwards;
}
@keyframes heroSliceDrop {
  0%   { opacity: 0; transform: translateY(-120vh); }
  65%  { opacity: 1; }
  82%  { transform: translateY(10px); }
  100% { transform: translateY(0); opacity: 1; }
}

#gokdeniz-hero .hero-title {
  grid-row: 2;
  align-self: end;
  font-family: 'Courier New', monospace;
  font-size: clamp(70px, 14vw, 180px);
  letter-spacing: .08em;
  color: #fff;
  text-shadow: 0 0 14px rgba(255,255,255,.25);
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s, transform .7s;
  margin-top: 30px;
  text-align: center;
  line-height: .95;
}
#gokdeniz-hero .hero-title.show { opacity: 1; transform: translateY(0); }
#gokdeniz-hero .hero-title .os {
  color: #39ff14;
  text-shadow: 0 0 12px rgba(57,255,20,.6), 0 0 32px rgba(57,255,20,.35);
}
#gokdeniz-hero .hero-title.show .os { animation: heroFlicker 3s steps(1,end) infinite 1s; }
@keyframes heroFlicker {
  0%, 88%, 100% { opacity: 1 }
  88.4%, 88.7% { opacity: .4 }
  89%, 96% { opacity: 1 }
  96.2%, 96.4% { opacity: .75 }
}

#gokdeniz-hero .hero-prompt {
  position: absolute;
  bottom: 44px; left: 50%; transform: translateX(-50%);
  font-family: 'Segoe UI', sans-serif;
  font-size: 1.25rem;
  letter-spacing: .16em;
  color: #39ff14;
  text-shadow: 0 0 6px rgba(57,255,20,.6);
  opacity: 0;
  transition: opacity .5s;
}
#gokdeniz-hero .hero-prompt.show { opacity: 1; }
#gokdeniz-hero .hero-prompt .cur { animation: heroBlink 1s steps(1) infinite; }
@keyframes heroBlink { 50% { opacity: 0 } }

#gokdeniz-hero.exit {
  animation: heroCrtOff .55s ease-in forwards;
}
@keyframes heroCrtOff {
  0%   { filter: brightness(1) contrast(1); transform: scale(1); }
  40%  { filter: brightness(3) contrast(.5); transform: scaleY(.02); }
  100% { filter: brightness(0); transform: scaleY(0) scaleX(0); opacity: 0; }
}