/* ============================================================
   AJ STANDARD — Style System
   Deep Navy + White + Gold Accent | MBB Consulting Aesthetic
   ============================================================ */

/* --- Design Tokens --- */
:root {
  /* Colors */
  --color-primary: #0A1628;
  --color-primary-light: #1B2A4A;
  --color-white: #FFFFFF;
  --color-offwhite: #F7F8FA;
  --color-accent: #C9A96E;
  --color-text-gray: #8892A0;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-light: rgba(10, 22, 40, 0.08);

  /* Typography */
  --font-primary: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --fw-light: 300;
  --fw-regular: 400;
  --fw-semibold: 600;
  --fw-bold: 700;

  /* Spacing */
  --section-padding: 100px 24px;
  --max-width: 1200px;
  --gap: 28px;

  /* Transitions */
  --ease: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --duration: 0.6s;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-weight: var(--fw-regular);
  color: var(--color-primary);
  background-color: var(--color-white);
  line-height: 1.7;
  font-size: 16px;
}

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

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

/* --- Utility --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Scroll Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--duration) var(--ease),
              transform var(--duration) var(--ease);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.fade-in-group > .fade-in:nth-child(1) { transition-delay: 0s; }
.fade-in-group > .fade-in:nth-child(2) { transition-delay: 0.12s; }
.fade-in-group > .fade-in:nth-child(3) { transition-delay: 0.24s; }
.fade-in-group > .fade-in:nth-child(4) { transition-delay: 0.36s; }


/* ============================================================
   NAV
   ============================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-primary);
  border-bottom: 1px solid var(--color-border);
  transition: background 0.3s var(--ease);
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo img {
  height: 36px;
  width: auto;
  filter: brightness(0) invert(1);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 36px;
  list-style: none;
}

.nav__links a {
  font-size: 14px;
  font-weight: var(--fw-regular);
  color: var(--color-text-gray);
  letter-spacing: 0.03em;
  transition: color 0.25s var(--ease);
}

.nav__links a:hover {
  color: var(--color-white);
}

.nav__cta {
  font-size: 13px;
  font-weight: var(--fw-semibold);
  color: var(--color-primary) !important;
  background: var(--color-accent);
  padding: 10px 24px;
  letter-spacing: 0.04em;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.nav__cta:hover {
  background: #D4B97D;
  transform: translateY(-1px);
}

/* Mobile menu toggle */
.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-white);
  margin: 5px 0;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

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

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

.nav__toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}


/* ============================================================
   HERO
   ============================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--color-primary);
  position: relative;
  overflow: hidden;
}

/* Subtle grid texture */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.015) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
}

.hero__content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

.hero__tagline {
  font-size: clamp(40px, 5.5vw, 72px);
  font-weight: var(--fw-bold);
  color: var(--color-white);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.hero__tagline .accent {
  color: var(--color-accent);
}

.hero__sub {
  font-size: clamp(17px, 2vw, 20px);
  font-weight: var(--fw-light);
  color: var(--color-text-gray);
  line-height: 1.6;
  max-width: 560px;
  margin-bottom: 48px;
}

.hero__cta {
  display: inline-block;
  font-size: 14px;
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  background: var(--color-accent);
  padding: 14px 36px;
  letter-spacing: 0.05em;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.hero__cta:hover {
  background: #D4B97D;
  transform: translateY(-2px);
}

/* Gold divider line */
.hero__divider {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
}


/* ============================================================
   ABOUT
   ============================================================ */
.about {
  background: var(--color-offwhite);
  padding: var(--section-padding);
}

.section-label {
  font-size: 12px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 32px;
}

.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.about__lead {
  font-size: clamp(22px, 2.5vw, 28px);
  font-weight: var(--fw-semibold);
  line-height: 1.4;
  color: var(--color-primary);
  letter-spacing: -0.01em;
}

.about__body p {
  font-size: 16px;
  color: #3A4555;
  margin-bottom: 20px;
  line-height: 1.8;
}

.about__body p:last-child {
  margin-bottom: 0;
}

.about__founder {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border-light);
  font-size: 14px;
  color: var(--color-text-gray);
  line-height: 1.7;
}


/* ============================================================
   SERVICES
   ============================================================ */
.services {
  background: var(--color-primary);
  padding: var(--section-padding);
}

.services .section-label {
  color: var(--color-accent);
}

.services__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  margin-top: 48px;
}

.service-card {
  background: var(--color-primary-light);
  border: 1px solid var(--color-border);
  padding: 40px 32px;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

.service-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
}

.service-card__number {
  font-size: 12px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent);
  letter-spacing: 0.15em;
  margin-bottom: 20px;
}

.service-card__title {
  font-size: 20px;
  font-weight: var(--fw-semibold);
  color: var(--color-white);
  margin-bottom: 16px;
  line-height: 1.3;
}

.service-card__desc {
  font-size: 15px;
  font-weight: var(--fw-regular);
  color: var(--color-text-gray);
  line-height: 1.7;
}


/* ============================================================
   RESEARCH
   ============================================================ */
.research {
  background: var(--color-offwhite);
  padding: var(--section-padding);
}

.research__content {
  max-width: 680px;
}

.research__text {
  font-size: 17px;
  color: #3A4555;
  line-height: 1.8;
}


/* ============================================================
   CONTACT
   ============================================================ */
.contact {
  background: var(--color-primary);
  padding: var(--section-padding);
}

.contact__inner {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.contact .section-label {
  color: var(--color-accent);
}

.contact__heading {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: var(--fw-bold);
  color: var(--color-white);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.contact__sub {
  font-size: 16px;
  color: var(--color-text-gray);
  margin-bottom: 40px;
}

.contact__email {
  display: inline-block;
  font-size: 16px;
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  background: var(--color-accent);
  padding: 14px 36px;
  letter-spacing: 0.03em;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.contact__email:hover {
  background: #D4B97D;
  transform: translateY(-2px);
}


/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--color-primary);
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer__copy {
  font-size: 13px;
  color: var(--color-text-gray);
}

.footer__links a {
  font-size: 13px;
  color: var(--color-text-gray);
  transition: color 0.25s var(--ease);
}

.footer__links a:hover {
  color: var(--color-white);
}


/* ============================================================
   RESPONSIVE — 768px
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --section-padding: 72px 20px;
  }

  /* Nav mobile */
  .nav__links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-primary);
    flex-direction: column;
    justify-content: center;
    gap: 32px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s var(--ease), visibility 0.3s var(--ease);
  }

  .nav__links.open {
    opacity: 1;
    visibility: visible;
  }

  .nav__links a {
    font-size: 18px;
  }

  .nav__toggle {
    display: block;
  }

  /* Hero */
  .hero {
    min-height: 85vh;
  }

  /* About */
  .about__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  /* Services */
  .services__grid {
    grid-template-columns: 1fr;
  }

  /* Footer */
  .footer__inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .nav__inner {
    height: 64px;
  }

  .nav__logo img {
    height: 28px;
  }

  .hero__cta,
  .contact__email {
    display: block;
    text-align: center;
  }
}