/* ============================================================
   BORAN — Paylaşılan stil sistemi (Yön B / Sade)
   Açık + Koyu tema. [data-theme="dark"] ile koyu mod.
   ============================================================ */
:root{
  --accent:#5BBCF2; --accent-deep:#364677; --accent-soft:#E3F3FC; --on-accent:#101B30;
  --maxw:1180px;
  --ff-head:'IBM Plex Sans',sans-serif; --ff-body:'IBM Plex Sans',sans-serif; --ff-mono:'IBM Plex Mono',monospace;
  --radius:6px; --error:#B42332; --error-bg:#FFF0F0;
  /* açık tema (varsayılan) */
  --bg:#F4F7FC; --surface:#FFFFFF; --surface-2:#E8EEF7;
  --ink:#364677; --body:#34435D; --faint:#53627A;
  --line:#D4DEEC; --line-2:#B8C8DF;
  --shadow:0 30px 60px -42px rgba(20,18,30,.34);
  --band-bg:#364677; --band-ink:#FFFFFF; --band-faint:#D7E7F7; --band-line:rgba(255,255,255,.14);
}
[data-theme="dark"]{
  --accent:#5BBCF2; --accent-deep:#5BBCF2; --accent-soft:#233951; --on-accent:#101B30; --error:#FF9CA5; --error-bg:#341C22;
  --bg:#0B1220; --surface:#121E30; --surface-2:#1B2940;
  --ink:#F4F8FF; --body:#CED9EB; --faint:#A6B6CE;
  --line:rgba(255,255,255,.08); --line-2:rgba(255,255,255,.14);
  --shadow:0 30px 70px -40px rgba(0,0,0,.8);
  --band-bg:#364677; --band-ink:#FFFFFF; --band-faint:#D7E7F7; --band-line:rgba(255,255,255,.1);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:96px}
body{background:var(--bg);color:var(--ink);font-family:var(--ff-body);line-height:1.65;-webkit-font-smoothing:antialiased;overflow-x:hidden;transition:background .25s,color .25s}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
h1,h2,h3,h4{font-family:var(--ff-head);font-weight:600;line-height:1.1;letter-spacing:-.02em;color:var(--ink)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 32px}
.eyebrow{font-family:var(--ff-head);font-size:12.5px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:var(--accent-deep)}
.btn{display:inline-flex;align-items:center;gap:9px;font-family:var(--ff-head);font-weight:600;font-size:15px;padding:13px 24px;border-radius:var(--radius);transition:.2s;cursor:pointer;border:1px solid transparent;background:none;white-space:nowrap}
.btn-primary{background:var(--ink);color:var(--bg)}
.btn-primary:hover{background:var(--accent);color:var(--on-accent)}
.btn-ghost{border-color:var(--line-2);color:var(--ink)}
.btn-ghost:hover{border-color:var(--ink)}
.btn-accent{background:var(--accent);color:var(--on-accent)}
.btn-accent:hover{background:var(--accent);box-shadow:0 0 0 3px var(--accent-soft);transform:translateY(-1px)}

/* ---------- HEADER ---------- */
.bh{position:sticky;top:0;z-index:60;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.bh-in{display:flex;align-items:center;gap:30px;height:74px;max-width:var(--maxw);margin:0 auto;padding:0 32px}
.bh-logo{height:32px;display:block}
.bh-nav{display:flex;gap:28px;margin-left:4px}
.bh-nav a{font-size:15px;font-weight:500;color:var(--body);transition:.16s;white-space:nowrap}
.bh-nav a:hover,.bh-nav a.active{color:var(--ink)}
.bh-right{margin-left:auto;flex-shrink:0;display:flex;align-items:center;gap:12px}
@media(max-width:1080px){.bh-right .btn-primary{display:none}}

/* tema anahtarı */
.theme-tog{display:flex;background:var(--surface-2);border:1px solid var(--line);border-radius:var(--radius);padding:3px;gap:2px}
.theme-tog button{flex:0 0 44px;width:44px;height:44px;border:0;background:none;border-radius:var(--radius);cursor:pointer;color:var(--faint);display:grid;place-items:center;transition:.16s}
.theme-tog button.on{background:var(--surface);color:var(--accent-deep);box-shadow:0 1px 3px rgba(0,0,0,.12)}
.theme-tog button:hover:not(.on){color:var(--ink)}
.theme-tog svg{width:15px;height:15px}

/* dil combo */
.lang-combo{position:relative}
.lang-btn{display:flex;align-items:center;gap:8px;background:var(--surface-2);border:1px solid var(--line);border-radius:var(--radius);padding:7px 12px;cursor:pointer;font-family:var(--ff-head);font-weight:600;font-size:13.5px;color:var(--ink);transition:.16s}
.lang-btn:hover{border-color:var(--line-2)}
.lang-btn .flag{font-size:16px;line-height:1}
.lang-btn .chev{width:14px;height:14px;color:var(--faint);transition:transform .2s}
.lang-combo.open .chev{transform:rotate(180deg)}
.lang-menu{position:absolute;top:calc(100% + 8px);right:0;background:var(--surface);border:1px solid var(--line-2);border-radius:13px;box-shadow:var(--shadow);padding:6px;min-width:172px;opacity:0;visibility:hidden;transform:translateY(-6px);transition:.18s;z-index:80}
.lang-combo.open .lang-menu{opacity:1;visibility:visible;transform:translateY(0)}
.lang-menu button{display:flex;align-items:center;gap:11px;width:100%;background:none;border:0;padding:10px 12px;border-radius:9px;cursor:pointer;font-family:var(--ff-body);font-size:14.5px;font-weight:500;color:var(--body);transition:.14s;text-align:left}
.lang-menu button .flag{font-size:18px}
.lang-menu button:hover{background:var(--surface-2);color:var(--ink)}
.lang-menu button.on{color:var(--ink);font-weight:600}
.lang-menu button.on .check{margin-left:auto;color:var(--accent-deep)}
.lang-menu button .check{margin-left:auto;opacity:0}
.lang-menu button.on .check{opacity:1}

/* mobil menü butonu */
.bh-burger{display:none;width:44px;height:44px;border:1px solid var(--line);border-radius:11px;background:var(--surface-2);cursor:pointer;color:var(--ink);place-items:center}

/* ---------- FOOTER ---------- */
.bf{border-top:1px solid var(--line-2);padding:72px 0 36px;margin-top:96px;background:var(--bg)}
.bf-grid{display:grid;grid-template-columns:1.7fr 1fr 1fr 1.3fr;gap:44px}
.bf-logo{height:30px;margin-bottom:20px}
.bf p{font-size:14.5px;color:var(--body);line-height:1.7}
.bf-col h4{font-family:var(--ff-head);font-size:12.5px;text-transform:uppercase;letter-spacing:.1em;color:var(--faint);margin-bottom:18px;font-weight:600}
.bf-col a{display:block;font-size:14.5px;color:var(--body);padding:6px 0;transition:.15s}
.bf-col a:hover{color:var(--accent-deep)}
.bf-contact div{font-size:14px;color:var(--body);margin-bottom:13px;display:flex;gap:10px}
.bf-contact div svg{color:var(--accent-deep);flex-shrink:0;margin-top:2px}
.bf-bottom{border-top:1px solid var(--line);margin-top:48px;padding-top:26px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;font-size:13.5px;color:var(--faint)}
.bf-social{display:flex;gap:10px}
.bf-social a{width:38px;height:38px;border-radius:50%;border:1px solid var(--line-2);display:grid;place-items:center;color:var(--body);transition:.18s}
.bf-social a:hover{color:var(--bg);background:var(--ink);border-color:var(--ink)}
[data-theme="dark"] .bf-social a:hover{color:var(--bg)}

/* ---------- ortak bölüm yapıları ---------- */
.sec{padding:104px 0}
.sec-head{max-width:640px;margin-bottom:60px}
.sec-head.center{margin:0 auto 64px;text-align:center}
.sec-head h2{font-size:clamp(30px,4vw,48px);font-weight:600;margin:16px 0 18px;letter-spacing:-.025em}
.sec-head p{font-size:18px;color:var(--body)}
.page-hero{padding:72px 0 16px}
.page-hero .crumb{font-size:13.5px;color:var(--faint);font-family:var(--ff-head);font-weight:500;margin-bottom:16px;display:flex;gap:8px;align-items:center}
.page-hero .crumb a:hover{color:var(--accent-deep)}
.page-hero h1{font-size:clamp(34px,5vw,56px);font-weight:600;letter-spacing:-.03em;max-width:14ch}

@media(max-width:920px){
  .bh-nav{display:none}
  .bh-burger{display:grid}
  .bf-grid{grid-template-columns:1fr 1fr}
  .sec{padding:72px 0}
}
@media(max-width:560px){
  .bf-grid{grid-template-columns:1fr}
  .wrap,.bh-in{padding-left:20px;padding-right:20px}
  .bh-in{gap:10px}.bh-right{gap:8px}.bh-logo{width:64px;height:auto}.lang-btn{padding:8px}.lang-btn .flag{display:none}.bh-right>.theme-tog button{width:44px}.bh-right>.theme-tog{padding:0;gap:0}
}

/* ==========================================================================
   Erişilebilirlik: hareketi azalt
   İşletim sisteminde "reduce motion" açık olan kullanıcıda animasyon ve
   yumuşak kaydırma kapanır. WCAG 2.3.3; vestibüler rahatsızlığı olan
   kullanıcılar için gerekli.
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Direction A: engineering surfaces, control states and mobile navigation. */
:focus-visible{outline:2px solid var(--accent-deep);outline-offset:4px}
button,input,select,textarea{font:inherit}
button{min-height:44px}
button:disabled{opacity:.65;cursor:wait}
.eyebrow,.page-hero .crumb,.bf-col h4{font-family:var(--ff-mono)}
.bh-logo,.bf-logo{object-fit:contain;width:100px;height:auto}
.bh-in{gap:20px}.bh-nav{gap:18px}.bh-nav a{font-size:14px}
.bf{background:var(--surface-2)}
.bm-overlay{position:fixed;inset:0;z-index:90;background:var(--bg);padding:24px;overflow:auto;overscroll-behavior:contain}
.bm-overlay a{display:block;font-family:var(--ff-head);font-weight:600;font-size:22px;color:var(--ink);padding:12px 0;border-bottom:1px solid var(--line)}
.bm-x{display:block;margin-left:auto;width:44px;height:44px;border:1px solid var(--line-2);border-radius:var(--radius);background:var(--surface-2);font-size:22px;color:var(--ink);cursor:pointer}
.bm-controls{display:flex;gap:20px;align-items:center;flex-wrap:wrap;padding-top:24px}
.bm-langs{display:flex;gap:8px;flex-wrap:wrap}.bm-langs button{border:1px solid var(--line-2);background:var(--surface);color:var(--ink);padding:8px 12px;border-radius:var(--radius);cursor:pointer}
.bm-langs button[aria-pressed="true"]{border-color:var(--accent-deep);text-decoration:underline;text-underline-offset:5px}
body.menu-open{overflow:hidden}
.engineering-art{background-image:linear-gradient(var(--line) 1px,transparent 1px),linear-gradient(90deg,var(--line) 1px,transparent 1px);background-size:32px 32px}
.engineering-art .ring{border-radius:4px;transform:rotate(0deg);border-color:var(--line-2)}
.engineering-art .ring.r2{border-style:dashed;border-color:var(--accent-deep)}
.engineering-art .label{background:var(--surface);border:1px solid var(--line-2);padding:24px;max-width:85%;overflow-wrap:anywhere}
.engineering-art .label small{display:block;font-family:var(--ff-mono);letter-spacing:.06em}
.page-hero{border-bottom:1px solid var(--line-2);padding-bottom:32px;margin-bottom:40px}
.doc{border-left:3px solid var(--accent);padding-left:28px}
.fr .is-err{border-color:var(--error)}
.field-error{display:block;color:var(--error);font-size:13px;margin-top:6px}
.form .ok.is-err{background:var(--error-bg);color:var(--error);border:1px solid var(--error)}
@media(max-width:560px){
 .bh-logo{width:64px}.bh-in{height:70px}.bh-right{flex-shrink:0}
 .lang-btn{gap:3px}.lang-btn .chev{width:12px}
 .form{padding:22px}.doc{padding-left:18px}
}