/* ==========================================================================
   Kernelion — Kurumsal Site Tasarım Sistemi v2
   Marka renkleri logo.png'den birebir alınmıştır: lacivert #1F3A93, kırmızı #E4241C
   Tipografi: Space Grotesk (başlık) + IBM Plex Sans (gövde) + IBM Plex Mono (teknik etiket)
   ========================================================================== */

:root{
  --bg: #FFFFFF;
  --bg-soft: #F3F5FA;
  --surface: #EAEEF7;
  --ink: #0F1B3D;
  --ink-muted: #4E5772;
  --ink-soft: #7B84A0;

  --brand: #1F3A93;      /* logodaki lacivert, birebir */
  --brand-deep: #101B42; /* koyu bant zemini (hero, footer) */
  --brand-mid: #17285E;  /* koyu zeminde hover */
  --accent-red: #E4241C; /* logodaki kırmızı, ince vurgularda */
  --accent-red-deep: #A8180F; /* CTA bandı için koyulaştırılmış kırmızı */

  --border: #DCE1EE;
  --border-strong: #B7C0D6;
  --on-dark-border: #2C3A6B;
  --on-dark-muted: #9FADD6;

  --font-display: "Space Grotesk", "Arial Narrow", sans-serif;
  --font-body: "IBM Plex Sans", -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;

  --container: 1180px;
  --measure: 640px;
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img{ max-width: 100%; display: block; }
a{ color: inherit; }

h1, h2, h3, h4{
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.14;
  margin: 0 0 0.5em;
  color: var(--ink);
  letter-spacing: -0.01em;
}

h1{ font-size: clamp(2.3rem, 3vw + 1rem, 3.4rem); font-weight: 600; }
h2{ font-size: clamp(1.6rem, 1.4vw + 1rem, 2.15rem); }
h3{ font-size: 1.22rem; font-weight: 600; }

p{ margin: 0 0 1.1em; color: var(--ink-muted); max-width: var(--measure); }
p.lede{ font-size: 1.15rem; color: var(--ink-muted); }

.container{
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 32px;
}

:focus-visible{ outline: 2px solid var(--brand); outline-offset: 3px; }

@media (prefers-reduced-motion: reduce){
  *{ animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

/* ---------- Header ---------- */

.site-header{
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 50;
}

.site-header .container{
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo{ display: flex; align-items: center; text-decoration: none; }
.logo img{ height: 30px; width: auto; }

.main-nav{ display: flex; align-items: center; gap: 34px; }

.main-nav a{
  text-decoration: none;
  font-size: 0.96rem;
  color: var(--ink-muted);
  padding: 8px 0;
  border-bottom: 2px solid transparent;
}

.main-nav a:hover{ color: var(--ink); }

.main-nav a[aria-current="page"]{
  color: var(--ink);
  border-bottom-color: var(--accent-red);
  font-weight: 500;
}

.nav-cta{
  background: var(--brand);
  color: #fff !important;
  padding: 10px 20px !important;
  border-radius: 2px;
  border-bottom: none !important;
}
.nav-cta:hover{ background: var(--brand-mid); color: #fff !important; }

.nav-toggle{
  display: none;
  background: none;
  border: 1px solid var(--border-strong);
  border-radius: 2px;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after{
  content: ""; display: block; width: 18px; height: 1.5px; background: var(--ink); position: relative;
}
.nav-toggle span::before{ position: absolute; top: -6px; }
.nav-toggle span::after{ position: absolute; top: 6px; }

@media (max-width: 860px){
  .main-nav{
    display: none; position: absolute; top: 80px; left: 0; right: 0;
    background: var(--bg); border-bottom: 1px solid var(--border);
    flex-direction: column; align-items: flex-start; gap: 0; padding: 8px 32px 20px;
  }
  .main-nav.open{ display: flex; }
  .main-nav a{ width: 100%; padding: 12px 0; border-bottom: 1px solid var(--border); }
  .nav-cta{ margin-top: 10px; text-align: center; }
  .nav-toggle{ display: flex; }
}

/* ---------- Buttons ---------- */

.btn{
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-body); font-size: 0.97rem; font-weight: 500;
  text-decoration: none; padding: 13px 24px; border-radius: 2px;
  border: 1px solid transparent; cursor: pointer;
}

.btn-primary{ background: var(--brand); color: #fff; }
.btn-primary:hover{ background: var(--brand-mid); }

.btn-secondary{ border-color: var(--border-strong); color: var(--ink); background: transparent; }
.btn-secondary:hover{ border-color: var(--brand); color: var(--brand); }

/* on dark backgrounds */
.on-dark .btn-primary{ background: #fff; color: var(--brand-deep); }
.on-dark .btn-primary:hover{ background: #DDE3F5; }
.on-dark .btn-secondary{ border-color: var(--on-dark-border); color: #fff; }
.on-dark .btn-secondary:hover{ border-color: #fff; }

/* ---------- Hero (dark band) ---------- */

.hero{
  background: var(--brand-deep);
  color: #fff;
  padding: 92px 0 88px;
  position: relative;
  overflow: hidden;
}

.hero .container{
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero h1{ color: #fff; }
.hero p.lede{ color: var(--on-dark-muted); }
.hero-actions{ display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }

.hero-figure{ display: flex; align-items: center; justify-content: center; }

@media (max-width: 900px){
  .hero .container{ grid-template-columns: 1fr; }
  .hero{ padding: 56px 0 60px; }
}

/* ---------- Sections ---------- */

section{ padding: 76px 0; }
section.alt{ background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.section-head{ max-width: 720px; margin-bottom: 44px; }

.eyebrow{ font-family: var(--font-mono); font-size: 0.8rem; color: var(--brand); margin-bottom: 10px; display: block; }

/* ---------- Reason grid ---------- */

.reason-grid{ display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.reason{ border-top: 2px solid var(--brand); padding-top: 18px; }
@media (max-width: 800px){ .reason-grid{ grid-template-columns: 1fr; } }

/* ---------- Indexed list (services) ---------- */

.service-group{ margin-bottom: 44px; }
.service-group:last-child{ margin-bottom: 0; }

.service-group h3.group-title{
  font-family: var(--font-mono); font-size: 0.84rem; font-weight: 500; letter-spacing: 0.01em;
  color: var(--brand); margin-bottom: 18px; padding-bottom: 10px; border-bottom: 1px solid var(--border);
}

.service-item{
  display: grid; grid-template-columns: 240px 1fr; gap: 32px;
  padding: 26px 0 26px 20px; border-bottom: 1px solid var(--border);
  border-left: 3px solid transparent;
}
.service-item:first-of-type{ border-top: 1px solid var(--border); }
.service-item:hover{ border-left-color: var(--accent-red); }

.service-item h4{ font-family: var(--font-display); font-size: 1.16rem; font-weight: 600; color: var(--ink); margin: 0; }
.service-item p{ margin: 0; max-width: 560px; }

@media (max-width: 720px){ .service-item{ grid-template-columns: 1fr; gap: 8px; padding-left: 14px; } }

/* ---------- Tech tags ---------- */

.tech-tag{
  font-family: var(--font-mono); font-size: 0.76rem; color: var(--brand);
  background: var(--surface); border: 1px solid var(--border-strong);
  padding: 2px 8px; border-radius: 2px; display: inline-block; margin: 4px 6px 0 0;
}

/* ---------- CTA banner (bold red, the one saturated moment) ---------- */

.cta-banner{ background: var(--accent-red-deep); color: #fff; }
.cta-banner h2{ color: #fff; }
.cta-banner p{ color: #F4C7C2; max-width: 560px; }
.cta-banner .container{
  display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap;
}
.cta-banner .btn-primary{ background: #fff; color: var(--accent-red-deep); }
.cta-banner .btn-primary:hover{ background: #F4E0DE; }

/* ---------- Page header (subpages, dark band) ---------- */

.page-header{ background: var(--brand-deep); color: #fff; padding: 60px 0 52px; }
.page-header h1{ color: #fff; }
.page-header p.lede{ color: var(--on-dark-muted); margin-top: 12px; }

/* ---------- About page specifics ---------- */

.value-list{ display: grid; grid-template-columns: 1fr 1fr; gap: 36px 48px; }
@media (max-width: 720px){ .value-list{ grid-template-columns: 1fr; } }
.value-list dt{ font-family: var(--font-display); font-size: 1.08rem; font-weight: 600; color: var(--brand); margin-bottom: 6px; }
.value-list dd{ margin: 0; color: var(--ink-muted); }

.pillar-row{ display: flex; justify-content: space-between; gap: 24px; padding: 22px 0; border-bottom: 1px solid var(--border); }
.pillar-row:first-child{ border-top: 1px solid var(--border); }
.pillar-row .label{ font-family: var(--font-mono); font-size: 0.82rem; color: var(--brand); width: 170px; flex-shrink: 0; }

/* ---------- Contact page ---------- */

.contact-grid{ display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: start; }
@media (max-width: 900px){ .contact-grid{ grid-template-columns: 1fr; } }

.contact-detail{ margin-bottom: 26px; }
.contact-detail .label{ font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-soft); display: block; margin-bottom: 4px; }
.contact-detail a, .contact-detail span.value{ font-size: 1.06rem; color: var(--ink); text-decoration: none; }
.contact-detail a:hover{ color: var(--brand); }

.field{ margin-bottom: 20px; }
.field label{ display: block; font-size: 0.9rem; color: var(--ink-muted); margin-bottom: 6px; }
.field input, .field textarea{
  width: 100%; font-family: var(--font-body); font-size: 1rem; padding: 12px 14px;
  border: 1px solid var(--border-strong); border-radius: 2px; background: var(--bg); color: var(--ink);
}
.field input:focus, .field textarea:focus{ outline: 2px solid var(--brand); outline-offset: 1px; border-color: var(--brand); }
.field textarea{ min-height: 130px; resize: vertical; }

.form-note{ font-size: 0.85rem; color: var(--ink-soft); margin-top: 10px; }

.map-frame{ border: 1px solid var(--border); margin-top: 8px; }
.map-frame iframe{ width: 100%; height: 320px; border: 0; display: block; }

/* ---------- Footer (dark) ---------- */

.site-footer{ background: var(--brand-deep); color: var(--on-dark-muted); padding: 52px 0 32px; }

.footer-grid{ display: grid; grid-template-columns: 1.3fr 1fr 1fr; gap: 32px; margin-bottom: 36px; }
.footer-grid .logo img{ filter: brightness(0) invert(1); height: 26px; }
.footer-grid p{ color: var(--on-dark-muted); max-width: 320px; }

.footer-grid h4{ font-size: 0.84rem; color: #fff; font-weight: 600; margin-bottom: 12px; font-family: var(--font-body); }
.footer-grid a{ display: block; text-decoration: none; color: var(--on-dark-muted); padding: 4px 0; font-size: 0.95rem; }
.footer-grid a:hover{ color: #fff; }

.footer-bottom{
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px;
  padding-top: 22px; border-top: 1px solid var(--on-dark-border); font-size: 0.85rem; color: var(--ink-soft);
}

@media (max-width: 720px){ .footer-grid{ grid-template-columns: 1fr; } }