/* ============================================================
   İleri Şirketler Grubu — Premium Corporate Landing
   Dark, editorial, mobile-first. Vanilla CSS.
   ============================================================ */

/* ---------- Design Tokens ---------- */
:root {
  /* Color system */
  --bg-primary: #090909;
  --bg-secondary: #111111;
  --surface: #161616;
  --text-primary: #F4F2ED;
  --text-secondary: #A3A3A3;
  --line: #2A2A2A;
  --accent: #D8D1C3;

  /* Typography */
  --font-head: "Manrope", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  /* Layout */
  --max-width: 1440px;
  --content-width: 1280px;
  --pad-x: 20px;

  /* Motion */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 600ms;
}

/* ---------- Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }

a { color: inherit; text-decoration: none; }

h1, h2, h3 {
  font-family: var(--font-head);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0;
}

p { margin: 0; }

ul { margin: 0; padding: 0; list-style: none; }

button { font-family: inherit; cursor: pointer; }

::selection { background: var(--accent); color: #0a0a0a; }

/* ---------- Accessibility helpers ---------- */
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 1000;
  background: var(--accent);
  color: #0a0a0a;
  padding: 12px 20px;
  border-radius: 0 0 6px 0;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

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

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.section {
  padding-block: clamp(72px, 12vw, 160px);
  position: relative;
}

.label {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0;
}

.eyebrow {
  font-family: var(--font-head);
  font-size: clamp(11px, 2.6vw, 13px);
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 22px;
}

.only-desktop { display: none; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 0 30px;
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  border: 1px solid transparent;
  border-radius: 4px;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.btn--primary {
  background: var(--text-primary);
  color: #0a0a0a;
}
.btn--primary:hover { background: var(--accent); }
.btn--ghost {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--line);
}
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:active { transform: translateY(1px); }

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
              backdrop-filter var(--dur) var(--ease);
  border-bottom: 1px solid transparent;
}
.site-header.is-stuck {
  background: rgba(9, 9, 9, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* Brand */
.brand {
  display: inline-flex;
  align-items: center;
  z-index: 120;
}
.brand__logo {
  height: 30px;
  width: auto;
  display: block;
}
@media (min-width: 900px) {
  .brand__logo { height: 34px; }
}

/* Desktop nav */
.nav { display: none; }
.nav__list { display: flex; gap: 38px; }
.nav__link {
  position: relative;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  padding-block: 6px;
  transition: color 300ms var(--ease);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 400ms var(--ease);
}
.nav__link:hover { color: var(--text-primary); }
.nav__link:hover::after { transform: scaleX(1); }

/* Mobile toggle */
.nav-toggle {
  position: relative;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  gap: 6px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 4px;
  z-index: 120;
}
.nav-toggle__line {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--text-primary);
  transition: transform 400ms var(--ease), opacity 300ms var(--ease);
}
.nav-toggle__line + .nav-toggle__line { margin-top: 5px; }
.nav-toggle.is-open .nav-toggle__line:nth-child(1) { transform: translateY(3.25px) rotate(45deg); }
.nav-toggle.is-open .nav-toggle__line:nth-child(2) { transform: translateY(-3.25px) rotate(-45deg); }

/* ---------- Mobile full-screen menu ---------- */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 110;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 100px var(--pad-x) 40px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity 500ms var(--ease), transform 500ms var(--ease), visibility 0s linear 500ms;
}
.mobile-menu.is-open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: opacity 500ms var(--ease), transform 500ms var(--ease), visibility 0s;
}
.mobile-menu__nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: auto;
}
.mobile-menu__link {
  display: flex;
  align-items: baseline;
  gap: 16px;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: clamp(30px, 11vw, 46px);
  letter-spacing: -0.02em;
  padding-block: 10px;
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(14px);
}
.mobile-menu.is-open .mobile-menu__link {
  animation: menuItemIn 500ms var(--ease) forwards;
}
.mobile-menu.is-open .mobile-menu__link:nth-child(1) { animation-delay: 120ms; }
.mobile-menu.is-open .mobile-menu__link:nth-child(2) { animation-delay: 180ms; }
.mobile-menu.is-open .mobile-menu__link:nth-child(3) { animation-delay: 240ms; }
.mobile-menu.is-open .mobile-menu__link:nth-child(4) { animation-delay: 300ms; }
@keyframes menuItemIn {
  to { opacity: 1; transform: translateY(0); }
}
.mobile-menu__idx {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.mobile-menu__foot {
  display: flex;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 40px;
  font-size: 14px;
  color: var(--text-secondary);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: flex-end;
  padding-bottom: clamp(80px, 12vh, 130px);
  padding-top: 120px;
  overflow: hidden;
}
.hero__media { position: absolute; inset: 0; z-index: -2; }
.hero__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.06);
  animation: heroScale 12s var(--ease) forwards;
}
@keyframes heroScale { to { transform: scale(1); } }
.hero__overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(9,9,9,0.55) 0%, rgba(9,9,9,0.15) 32%, rgba(9,9,9,0.75) 78%, var(--bg-primary) 100%),
    linear-gradient(90deg, rgba(9,9,9,0.7) 0%, rgba(9,9,9,0.15) 60%);
}
.hero__grain {
  position: absolute;
  inset: 0;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
  pointer-events: none;
}
.hero__content { position: relative; }
.hero__title {
  font-size: clamp(2.8rem, 12vw, 7rem);
  font-weight: 600;
  line-height: 0.98;
  letter-spacing: -0.035em;
  margin-bottom: 26px;
}
.hero__title span { display: block; }
.hero__title-accent { color: var(--accent); }
.hero__text {
  max-width: 46ch;
  font-size: clamp(1rem, 2.6vw, 1.18rem);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 34px;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero__actions .btn { flex: 1 1 auto; min-width: 0; }

.hero__scroll {
  position: absolute;
  right: var(--pad-x);
  bottom: clamp(30px, 6vh, 54px);
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
}
.hero__scroll-line {
  width: 1px;
  height: 54px;
  background: linear-gradient(var(--accent), transparent);
}
.hero__scroll-label {
  writing-mode: vertical-rl;
  font-family: var(--font-head);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* ============================================================
   REVEAL ANIMATION
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 800ms var(--ease), transform 800ms var(--ease);
  will-change: opacity, transform;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   GROUP INTRO
   ============================================================ */
.intro { background: var(--bg-primary); }
.intro__grid { display: grid; gap: 28px; }
.intro__title {
  font-size: clamp(2rem, 8vw, 4.2rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.02;
}
.intro__body p {
  max-width: 54ch;
  font-size: clamp(1rem, 2.4vw, 1.15rem);
  color: var(--text-secondary);
}

/* ============================================================
   COMPANIES
   ============================================================ */
.companies { background: var(--bg-secondary); }
.section-head { margin-bottom: clamp(40px, 6vw, 72px); }
.section-head .label { margin-bottom: 18px; }
.section-head__title {
  font-size: clamp(2.4rem, 9vw, 5rem);
  font-weight: 600;
  letter-spacing: -0.035em;
}

.companies__list { display: flex; flex-direction: column; gap: 0; }

.company {
  border-top: 1px solid var(--line);
}
.company:last-child { border-bottom: 1px solid var(--line); }
.company__link {
  display: grid;
  gap: 0;
  padding-block: clamp(28px, 5vw, 40px);
}
.company__media {
  position: relative;
  overflow: hidden;
  border-radius: 6px;
  aspect-ratio: 16 / 10;
  background: var(--surface);
  margin-bottom: 26px;
}
.company__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 900ms var(--ease);
}
.company__body { display: flex; flex-direction: column; }
.company__meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}
.company__index {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.company__category {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-secondary);
}
.company__name {
  font-size: clamp(2rem, 8vw, 3.4rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}
.company__desc {
  max-width: 48ch;
  color: var(--text-secondary);
  font-size: clamp(0.98rem, 2.4vw, 1.1rem);
  margin-bottom: 26px;
}
.company__cta {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 15px;
  color: var(--text-primary);
}
.company__arrow {
  color: var(--accent);
  transition: transform 500ms var(--ease);
}
.company__link:hover .company__arrow { transform: translateX(8px); }
.company__link:hover .company__img { transform: scale(1.05); }

/* ============================================================
   PHILOSOPHY
   ============================================================ */
.philosophy { background: var(--bg-primary); }
.philosophy__list {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}
.philosophy__item {
  display: grid;
  gap: 12px;
  padding-block: clamp(30px, 5vw, 44px);
  border-bottom: 1px solid var(--line);
}
.philosophy__num {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--accent);
}
.philosophy__title {
  font-size: clamp(1.6rem, 6vw, 2.4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
}
.philosophy__text {
  max-width: 52ch;
  color: var(--text-secondary);
  font-size: clamp(0.98rem, 2.4vw, 1.1rem);
}

/* ============================================================
   STATEMENT
   ============================================================ */
.statement {
  background: var(--bg-secondary);
  padding-block: clamp(90px, 18vw, 220px);
  border-block: 1px solid var(--line);
  overflow: hidden;
}
.statement__text {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: clamp(3rem, 18vw, 12rem);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--text-primary);
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact { background: var(--bg-primary); }
.contact__grid { display: grid; gap: 48px; }
.contact__title {
  font-size: clamp(2.4rem, 9vw, 4.6rem);
  font-weight: 600;
  letter-spacing: -0.035em;
  margin: 18px 0 20px;
}
.contact__body {
  max-width: 46ch;
  color: var(--text-secondary);
  font-size: clamp(1rem, 2.4vw, 1.12rem);
  margin-bottom: 32px;
}
.contact__details { display: grid; gap: 0; }
.contact__details li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-block: 22px;
  border-top: 1px solid var(--line);
}
.contact__details li:last-child { border-bottom: 1px solid var(--line); }
.contact__key {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-secondary);
}
.contact__val {
  font-family: var(--font-head);
  font-size: clamp(1.2rem, 5vw, 1.7rem);
  font-weight: 600;
  letter-spacing: -0.01em;
  transition: color 300ms var(--ease);
}
a.contact__val:hover { color: var(--accent); }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--line);
  padding-block: clamp(56px, 8vw, 96px);
}
.footer__inner {
  display: grid;
  gap: 48px;
  padding-bottom: clamp(48px, 7vw, 80px);
}
.footer__logo {
  width: clamp(180px, 42vw, 240px);
  height: auto;
  display: block;
}
.footer__location {
  margin-top: 20px;
  font-family: var(--font-head);
  font-size: 15px;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}
.footer__social { display: flex; flex-direction: column; gap: 14px; }
.footer__col-title {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}
.footer__link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 500;
  transition: color 300ms var(--ease);
}
.footer__link svg { color: var(--text-secondary); transition: color 300ms var(--ease); }
.footer__link:hover,
.footer__link:hover svg { color: var(--accent); }
.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  justify-content: space-between;
  padding-top: 32px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--text-secondary);
}

/* ============================================================
   RESPONSIVE — tablet & up
   ============================================================ */
@media (min-width: 640px) {
  .hero__actions .btn { flex: 0 0 auto; }
  .company__link {
    grid-template-columns: 1.1fr 1fr;
    gap: 48px;
    align-items: center;
  }
  .company__media { margin-bottom: 0; aspect-ratio: 4 / 3; }
  .contact__details li {
    flex-direction: row;
    align-items: baseline;
    justify-content: space-between;
    gap: 20px;
  }
}

@media (min-width: 900px) {
  :root { --pad-x: 40px; }

  .nav { display: block; }
  .nav-toggle { display: none; }
  .mobile-menu { display: none; }
  .only-desktop { display: inline; }
  .hero__scroll { display: flex; }

  .intro__grid {
    grid-template-columns: 0.7fr 1.3fr;
    grid-template-areas:
      "label title"
      ".     body";
    column-gap: 60px;
    row-gap: 34px;
    align-items: start;
  }
  .intro__grid .label { grid-area: label; padding-top: 14px; }
  .intro__title { grid-area: title; }
  .intro__body { grid-area: body; }

  .philosophy__list { grid-template-columns: repeat(3, 1fr); }
  .philosophy__item {
    border-bottom: none;
    padding-right: 30px;
  }
  .philosophy__item + .philosophy__item { border-left: 1px solid var(--line); padding-left: 40px; }

  .contact__grid {
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: start;
  }
  .footer__inner {
    grid-template-columns: 1.2fr 2fr;
    align-items: start;
  }
  .footer__nav { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1200px) {
  .company__link { gap: 80px; }
  .company__name { font-size: clamp(2.6rem, 4vw, 3.6rem); }
}

/* ============================================================
   REDUCED MOTION
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
  .hero__img { transform: none; animation: none; }
}