/* Shared base geometry, loaded before yildiz-system.css and header.css. */
.header{position:fixed;z-index:100;inset:0 0 auto;display:grid;grid-template-columns:minmax(140px,1fr) auto minmax(220px,1fr);align-items:center;min-height:var(--header-h);padding:0 var(--page-pad);border-bottom:1px solid color-mix(in srgb, var(--color-white) 20%, transparent);color:var(--white);background:transparent;text-shadow:0 1px 18px color-mix(in srgb, var(--color-dark) 62%, transparent);transition:color 180ms ease-out,background-color 180ms ease-out,border-color 180ms ease-out}.header.is-open{color:var(--ink);background:var(--paper);border-bottom-color:var(--line-dark);text-shadow:none}
.site-brand{position:relative;z-index:3;display:block;width:clamp(128px,8.5vw,160px);height:42px}.site-brand__logo{position:absolute;top:50%;left:0;width:100%;max-height:42px;object-fit:contain;object-position:left center;transform:translateY(-50%);transition:opacity 140ms ease-out}.site-brand__logo--dark,.header.is-open .site-brand__logo--light{opacity:0}.header.is-open .site-brand__logo--dark{opacity:1}
.desktop-nav{position:relative;z-index:3;display:flex;align-items:center;gap:clamp(13px,1vw,22px);height:var(--header-h)}.nav-trigger,.nav-link{position:relative;display:inline-flex;align-items:center;padding:0;color:inherit;background:transparent;font-size:var(--fs-navigation);font-weight:var(--fw-navigation);letter-spacing:var(--ls-body);white-space:nowrap;cursor:auto}.nav-trigger::after,.nav-link::after{position:absolute;right:0;bottom:-1px;left:0;height:2px;background:var(--orange);content:"";transform:scaleX(0);transform-origin:left;transition:transform 160ms var(--ease)}.nav-trigger:hover::after,.nav-trigger[aria-expanded="true"]::after,.nav-link:hover::after,.nav-link:focus-visible::after{transform:scaleX(1)}
.header-actions{position:relative;z-index:3;display:flex;justify-self:end;align-items:center;gap:5px}.utility-link{display:inline-flex;align-items:center;justify-content:center;min-height:44px;overflow:hidden;color:var(--white);background:color-mix(in srgb, var(--color-dark) 58%, transparent);border:1px solid color-mix(in srgb, var(--color-white) 38%, transparent);font-size:var(--fs-button);font-weight:var(--fw-button);line-height:var(--lh-ui);white-space:nowrap;transition:background-color 160ms ease-out,border-color 160ms ease-out,transform 120ms ease-out}.utility-link{padding:0 15px}.utility-link:hover,.utility-link:focus-visible{background:var(--blue);border-color:color-mix(in srgb, var(--color-white) 72%, transparent)}.utility-link:active{transform:translateY(1px)}
.utility-link img{width:0;height:17px;margin-left:0;object-fit:contain;opacity:0;transform:rotate(-28deg) scale(.55);transition:width 180ms var(--ease),margin-left 180ms var(--ease),opacity 120ms ease-out,transform 200ms var(--ease)}.utility-link:hover img,.utility-link:focus-visible img{width:17px;margin-left:10px;opacity:1;transform:rotate(0) scale(1)}.header.is-open .utility-link{color:var(--ink);background:color-mix(in srgb, var(--green-800) 5%, transparent);border-color:color-mix(in srgb, var(--green-800) 26%, transparent)}.header.is-open .utility-link:hover,.header.is-open .utility-link:focus-visible{color:var(--white);background:var(--blue);border-color:var(--blue)}
.mega-menu{position:fixed;z-index:2;top:var(--header-h);right:0;left:0;color:var(--ink);background:var(--paper);border-bottom:1px solid var(--line-dark);opacity:0;visibility:hidden;transform:translateY(-14px);transition:opacity 160ms ease-out,transform 240ms var(--ease),visibility 160ms}.mega-menu.is-visible{opacity:1;visibility:visible;transform:translateY(0)}.mega-panel{display:none;grid-template-columns:minmax(250px,.64fr) minmax(520px,1.36fr);gap:clamp(70px,10vw,170px);min-height:430px;padding:50px var(--page-pad) 56px}.mega-panel.is-active{display:grid}.mega-heading{position:relative;align-self:start;min-height:300px}.mega-heading h2{position:relative;z-index:1;max-width:8ch;margin:0;color:var(--blue);font-size:var(--fs-h2);font-weight:var(--fw-heading);line-height:var(--lh-h2);letter-spacing:var(--ls-h2)}.mega-symbol{position:absolute;right:1vw;bottom:-24px;width:clamp(120px,13vw,208px);height:clamp(120px,13vw,208px);opacity:.1;transform:rotate(-10deg)}.mega-links{display:grid;align-content:start}.mega-links--columns{grid-template-columns:repeat(2,minmax(0,1fr));column-gap:50px}.mega-family{display:grid}.mega-links>a,.mega-family>a{display:flex;align-items:center;min-height:54px;border-bottom:1px solid var(--line-dark);font-size:var(--fs-navigation);font-weight:var(--fw-navigation);line-height:var(--lh-ui);letter-spacing:var(--ls-body);transition:color 140ms ease-out,transform 180ms var(--ease)}.mega-links>a:hover,.mega-links>a:focus-visible,.mega-family>a:hover,.mega-family>a:focus-visible{color:var(--orange);transform:translateX(8px)}.mega-family .mega-child{min-height:42px;padding-left:22px;color:var(--color-text);font-size:var(--fs-navigation)}

    .header, .header * { box-sizing:border-box; }
    /* index-revize geometrisi: sabit, tam genişlikte, scroll ile daralma yok. */
    .header { border:0; transition:transform 360ms cubic-bezier(.22,1,.36,1),color 180ms ease-out,background-color 180ms ease-out,border-color 180ms ease-out; }
    .header.is-open { color:var(--flow-ink); background:var(--color-white); border:0; text-shadow:none; box-shadow:none; }
    .header .header-actions { gap:24px; }
    .header .utility-link, .header.is-open .utility-link,
    .header .utility-link:hover, .header .utility-link:focus-visible {
      min-height:44px; padding:0; color:inherit; background:none;
      border:0; border-radius:0; box-shadow:none; text-shadow:none; transform:none;
    }
    /* Panel ve semboller üzerinde hiçbir gölge/filtre yok. */
    .header .mega-menu { position:absolute; top:100%; left:0; right:0; width:100%;
      background:var(--color-white); color:var(--flow-ink); border:0; box-shadow:none; text-shadow:none; }
    .mega-heading, .mega-symbol, .mega-symbol use { box-shadow:none; text-shadow:none; filter:none; }
    .nav-trigger, .nav-link { font-size:var(--fs-navigation); font-weight:var(--fw-navigation); line-height:var(--lh-ui); letter-spacing:var(--ls-body); cursor:pointer; }
    .utility-link { font-size:var(--fs-navigation); font-weight:var(--fw-navigation); line-height:var(--lh-ui); }
    .mega-heading h2 { font-size:var(--fs-h2); font-weight:var(--fw-heading); line-height:var(--lh-h2); letter-spacing:var(--ls-h2); }
    .mega-links>a, .mega-family>a { font-size:var(--fs-navigation); font-weight:var(--fw-navigation); line-height:var(--lh-ui); letter-spacing:var(--ls-body); }
    .mega-family .mega-child { font-size:var(--fs-navigation); line-height:var(--lh-ui); letter-spacing:var(--ls-body); }
    .header .mega-menu { max-height:calc(100dvh - 110px); overflow-y:auto; }

    @media(max-width:1240px) {
      .header {
        top:14px; left:14px; right:auto; grid-template-columns:1fr auto; width:calc(100% - 28px);
        min-height:58px; padding:0 16px; column-gap:16px;
      }
      .desktop-nav, .header-actions { display:none; }
      .header .mega-menu { display:none; }
    }

    /* Ortak renk, tipografi ve hizalama: assets/css/yildiz-system.css */
    @media(prefers-reduced-motion:reduce) { .header, .header *, .header *::after { transition:none!important; } }