/* =========================
   NAVBAR (PERFORMANCE OPTIMIZED)
========================= */

:root{
  --blue-950:#071127;
  --blue-900:#0B1B3A;
  --blue-800:#0F2B66;
  --blue-700:#1D4ED8;
  --blue-600:#2563EB;
  --blue-500:#3B82F6;
  --blue-300:#93C5FD;

  --yellow-500:#F59E0B;
  --yellow-400:#FBBF24;
  --yellow-200:#FDE68A;

  --nav-text: rgba(255,255,255,0.92);
  --nav-muted: rgba(255,255,255,0.72);

  --nav-bg: rgba(15, 43, 102, 0.82);
  --nav-bg-strong: rgba(15, 43, 102, 0.94);
  --nav-border: rgba(255,255,255,0.14);

  --nav-max: 1200px;
  --nav-pad-x: 18px;
  --nav-h: 98px;
}

/* Stable scrollbar */
html{ scrollbar-gutter: stable; }
body{ overflow-y: scroll; padding-top: var(--nav-h); }

/* Fixed header */
.main-header{
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 99999;
  width: 100%;
  padding: 14px 0;

  background: var(--nav-bg);
  backdrop-filter: blur(8px); /* hafifletildi */
  -webkit-backdrop-filter: blur(8px);

  border-bottom: 1px solid var(--nav-border);
  box-shadow: 0 8px 24px rgba(2,6,23,0.15); /* hafifletildi */

  transition: background .25s ease, box-shadow .25s ease, padding .25s ease;
  isolation: isolate;

  will-change: background, box-shadow, padding; /* GPU optimizasyonu */
}

/* top & bottom strips */
.main-header::before,
.main-header::after{
  content:"";
  position:absolute;
  left:0; right:0;
  pointer-events:none;
  z-index:1;
}

.main-header::before{
  top:0;
  height:2px;
  background: linear-gradient(90deg, transparent, rgba(59,130,246,.95), transparent);
  opacity:0.95;
}

.main-header::after{
  bottom:0;
  height:3px;
  background: linear-gradient(90deg,
    rgba(37,99,235,1) 0%,
    rgba(96,165,250,0.95) 22%,
    rgba(251,191,36,1) 50%,
    rgba(245,158,11,1) 72%,
    rgba(37,99,235,1) 100%
  );
  background-size: 240% 100%;
  background-position: 0% 50%;
  opacity:0.85;
  transform: translateZ(0); /* GPU layer */
  /* Animasyon opsiyonel, CPU yükünü azaltmak için devre dışı bırakılabilir */
}

/* Nav container */
.main-header .nav-container{
  max-width: var(--nav-max);
  margin:0 auto;
  padding:0 var(--nav-pad-x);

  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  position: relative;
  z-index:2;
}

/* Logo */
.main-header .logo{
  display:flex;
  align-items:center;
  flex:0 0 auto;
  min-width:170px;
}

.main-header .logo img{
  height:70px;
  width:auto;
  max-height:70px;
  border-radius:12px;
  box-shadow:0 6px 18px rgba(2,6,23,.12);
  object-fit: contain;
  transition: transform .2s ease, filter .2s ease;
}

.main-header .logo img:hover{
  transform: scale(1.02);
  filter: saturate(1.03);
}

/* Menu */
.main-header .main-nav{
  flex:1 1 auto;
  display:flex;
  justify-content:flex-end;
  will-change: transform; /* hover performansı */
}

.main-header .main-nav ul{
  display:flex;
  gap:12px;
  list-style:none;
  margin:0;
  padding:0;
  align-items:center;
}

/* Links */
.main-header .main-nav a{
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;

  text-decoration:none;
  font-weight: 800;
  font-size: 14.5px;
  color:#FFFFFF;

  padding: 10px 14px;
  border-radius: 14px;

  background: linear-gradient(135deg, rgba(37,99,235,0.25), rgba(245,158,11,0.12));
  border:1px solid rgba(255,255,255,0.12);
  box-shadow:0 8px 14px rgba(2,6,23,0.12);
  transform-style: preserve-3d;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}

/* Hover */
.main-header .main-nav a:hover{
  background: linear-gradient(135deg, rgba(37,99,235,0.45), rgba(245,158,11,0.25));
  box-shadow:0 10px 20px rgba(2,6,23,0.14);
  transform: translateY(-1px);
}

/* Active page */
.main-header .main-nav a[aria-current="page"]{
  background: linear-gradient(135deg, rgba(37,99,235,0.55), rgba(245,158,11,0.20));
}

/* CTA */
.main-header .nav-btn{
  padding:10px 18px !important;
  font-weight: 900 !important;
  color:#fefefe !important;
  background: linear-gradient(135deg, var(--yellow-500), var(--yellow-400));
  border:1px solid rgba(255,255,255,0.15);
  box-shadow:0 12px 24px rgba(245,158,11,0.20);
}

.main-header .nav-btn:hover{
  box-shadow:0 16px 32px rgba(245,158,11,0.26);
  transform: translateY(-2px);
}

/* Mobile */
.main-header .menu-toggle{
  display:none;
  flex-direction:column;
  gap:6px;
  cursor:pointer;
  padding:10px;
  border-radius:12px;
  transition: background .18s ease;
}
.main-header .menu-toggle:hover{ background: rgba(255,255,255,0.08); }
.main-header .menu-toggle span{
  width:26px;
  height:2px;
  background: var(--nav-text);
  transition: .25s ease;
}


@media (max-width: 900px){

  :root{ --nav-h: 74px; }

  .main-header .menu-toggle{
    display:flex;
  }

  .main-header .logo{
    min-width:130px;
  }

  .main-header .logo img{
    height:46px;
    max-height:46px;
  }

  .main-header .main-nav{
    position: fixed;
    top: var(--nav-h);
    right:0;

    width:280px;
    height: calc(100vh - var(--nav-h));

    background: var(--nav-bg-strong);
    backdrop-filter: blur(8px);

    border-left:1px solid var(--nav-border);
    box-shadow: -16px 0 32px rgba(2,6,23,0.18);

    padding:28px 18px;

    display:flex;
    justify-content:flex-start;

    transform: translateX(100%);
    transition: transform .35s ease;

    z-index:99999;
  }

  .main-header .main-nav.active{
    transform: translateX(0);
  }

  .main-header .main-nav.active ul{
    display:flex;
}

  .main-header .main-nav ul{
    display:none;
    flex-direction: column;
    gap:12px;
    align-items:stretch;
    width:100%;
  }

  .main-header .main-nav a{
    width:100%;
    justify-content:flex-start;
    font-size:16px;
    padding:12px 14px;
    border-radius:14px;
  }

  .main-header .nav-btn{
    width:100%;
    justify-content:center !important;
  }

}


/* Reduced motion preference */
@media (prefers-reduced-motion: reduce){
  .main-header::after{ animation:none !important; }
}


/* hamburger animasyonu */

.menu-toggle.active span:nth-child(1){
  transform: rotate(45deg) translate(5px,5px);
}

.menu-toggle.active span:nth-child(2){
  opacity:0;
}

.menu-toggle.active span:nth-child(3){
  transform: rotate(-45deg) translate(6px,-6px);
}

body.menu-open{
  overflow:hidden;
}