/* ==========================================================================
   Union Corporation — Main Stylesheet
   ========================================================================== */

@import url('https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.css');
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,500;0,600;0,700;1,400&display=swap');

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

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

body {
  min-height: 100vh;
  overflow-x: hidden;
}

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

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

ul,
ol {
  list-style: none;
}

button,
input {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
}

button {
  cursor: pointer;
}

/* --------------------------------------------------------------------------
   2. Design Tokens
   -------------------------------------------------------------------------- */
:root {
  /* Colors */
  --color-bg: #F5F3EF;
  --color-surface: #FFFFFF;
  --color-primary: #1C1C1C;
  --color-secondary: #4A4A4A;
  --color-accent: #8B7355;
  --color-accent-light: #A9906F;
  --color-line: #E5E1DA;
  --color-muted: #9A9689;

  /* Typography */
  --font-kr: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Malgun Gothic', sans-serif;
  --font-en: 'Playfair Display', serif;

  /* Layout */
  --max-width: 1200px;
  --section-padding-y: 120px;
  --section-padding-y-mobile: 60px;
  --header-height: 84px;
  --header-height-mobile: 64px;

  /* Motion */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.35s var(--ease);
}

/* --------------------------------------------------------------------------
   3. Base Typography
   -------------------------------------------------------------------------- */
body {
  font-family: var(--font-kr);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 400;
  color: var(--color-secondary);
  background-color: var(--color-bg);
}

h1, h2, h3, h4 {
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.3;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-en);
  font-size: 0.95rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.caption {
  font-weight: 300;
  color: var(--color-muted);
}

/* --------------------------------------------------------------------------
   4. Layout Utilities
   -------------------------------------------------------------------------- */
.container {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
}

.section {
  padding-block: var(--section-padding-y);
  position: relative;
  scroll-margin-top: var(--header-height-mobile);
}

.section--surface {
  background-color: var(--color-surface);
}

.section-head {
  margin-bottom: 64px;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
}

.divider {
  width: 60px;
  height: 2px;
  background-color: var(--color-accent);
  margin-block: 20px;
  border: none;
}

/* Scroll-reveal animation (lightweight AOS replacement, driven by main.js IntersectionObserver) */
[data-aos] {
  opacity: 0;
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
  will-change: opacity, transform;
}

[data-aos="fade-up"] {
  transform: translateY(32px);
}

[data-aos="fade-in"] {
  transform: none;
}

[data-aos].aos-visible {
  opacity: 1;
  transform: none;
}

/* --------------------------------------------------------------------------
   5. Header
   -------------------------------------------------------------------------- */
.header {
  position: fixed;
  inset-block-start: 0;
  inset-inline: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background-color: transparent;
  transition: background-color var(--transition-base), box-shadow var(--transition-base), height var(--transition-base);
}

.header.is-scrolled {
  background-color: var(--color-surface);
  box-shadow: 0 4px 24px rgba(28, 28, 28, 0.08);
  height: var(--header-height-mobile);
}

.header__inner {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-en);
  font-weight: 700;
  font-size: 1.6rem;
  letter-spacing: 0.02em;
  color: var(--color-primary);
}

.header.is-scrolled .logo,
.nav__link {
  color: var(--color-primary);
}

.header:not(.is-scrolled) .logo,
.header:not(.is-scrolled) .nav__link {
  color: #FFFFFF;
}

.nav {
  display: flex;
}

.nav__list {
  display: flex;
  gap: 40px;
}

.nav__link {
  position: relative;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  padding-block: 6px;
  transition: color var(--transition-base);
}

.nav__link::after {
  content: '';
  position: absolute;
  inset-block-end: 0;
  inset-inline-start: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.nav__link:hover::after,
.nav__link.is-active::after {
  transform: scaleX(1);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  z-index: 1100;
}

.hamburger__bar {
  width: 100%;
  height: 2px;
  background-color: currentColor;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.header:not(.is-scrolled) .hamburger {
  color: #FFFFFF;
}

.header.is-scrolled .hamburger,
.nav-open .hamburger {
  color: var(--color-primary);
}

.nav-open .hamburger__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-open .hamburger__bar:nth-child(2) {
  opacity: 0;
}

.nav-open .hamburger__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   6. Hero
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  height: 100vh;
  min-height: 560px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #FFFFFF;
  overflow: hidden;
  background: linear-gradient(160deg, #2b2620 0%, #1c1c1c 55%, #12110f 100%);
}

.hero__bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(180deg, rgba(18, 17, 15, 0.35) 0%, rgba(18, 17, 15, 0.75) 100%),
    radial-gradient(circle at 30% 20%, rgba(139, 115, 85, 0.35), transparent 55%);
  background-size: cover;
  background-position: center;
}

.hero__content {
  position: relative;
  z-index: 2;
  padding-inline: 24px;
  max-width: 860px;
}

.hero__chip {
  display: inline-block;
  font-family: var(--font-en);
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 8px 20px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 999px;
  margin-bottom: 28px;
}

.hero__main {
  font-family: var(--font-en);
  font-size: clamp(2.2rem, 5.5vw, 4.5rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 24px;
  color: #FFFFFF;
}

.hero__sub {
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  font-weight: 300;
  color: rgba(255, 255, 255, 0.85);
}

.hero__scroll {
  position: absolute;
  inset-block-end: 40px;
  inset-inline-start: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  font-family: var(--font-en);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.75);
}

.hero__scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.9), transparent);
  animation: scrollLine 2s var(--ease) infinite;
}

@keyframes scrollLine {
  0% { transform: scaleY(0); transform-origin: top; }
  50% { transform: scaleY(1); transform-origin: top; }
  50.01% { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* --------------------------------------------------------------------------
   7. Chapter 1 — History (#history)
   -------------------------------------------------------------------------- */
.history {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.history__since {
  font-family: var(--font-en);
  font-size: clamp(3.5rem, 9vw, 7rem);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}

.history__label {
  margin-top: 20px;
  font-size: 1.1rem;
  color: var(--color-secondary);
}

.history__list {
  border-top: 1px solid var(--color-line);
}

.history__row {
  display: flex;
  padding-block: 20px;
  border-bottom: 1px solid var(--color-line);
  gap: 24px;
}

.history__term {
  flex: 0 0 110px;
  font-weight: 700;
  color: var(--color-primary);
}

.history__desc {
  color: var(--color-secondary);
}

/* --------------------------------------------------------------------------
   8. Chapter 2 — Greeting (#greeting)
   -------------------------------------------------------------------------- */
.greeting {
  text-align: center;
}

.greeting__inner {
  max-width: 760px;
  margin-inline: auto;
  position: relative;
}

.greeting__quote-mark {
  font-family: var(--font-en);
  font-size: 6rem;
  color: var(--color-accent);
  line-height: 1;
  opacity: 0.5;
}

.greeting__text {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  color: var(--color-primary);
  font-weight: 400;
  line-height: 1.9;
  margin-block: 32px;
  white-space: pre-line;
}

.greeting__signature {
  margin-top: 40px;
  font-family: var(--font-en);
  font-style: italic;
  font-size: 1.15rem;
  color: var(--color-accent);
}

/* --------------------------------------------------------------------------
   9. Chapter 3 — Business Areas (#business)
   -------------------------------------------------------------------------- */
.business__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.business-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: 4px;
  padding: 48px 36px;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.business-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(28, 28, 28, 0.08);
}

.business-card__num {
  font-family: var(--font-en);
  font-size: 0.9rem;
  color: var(--color-muted);
  letter-spacing: 0.1em;
}

.business-card__icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background-color: var(--color-bg);
  color: var(--color-accent);
  margin-block: 24px 20px;
}

.business-card__icon svg {
  width: 26px;
  height: 26px;
}

.business-card__title {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.business-card__desc {
  font-size: 0.95rem;
  color: var(--color-secondary);
}

/* --------------------------------------------------------------------------
   10. Chapter 4 — Portfolio (#portfolio)
   -------------------------------------------------------------------------- */
.portfolio__filters {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 48px;
}

.filter-btn {
  padding: 10px 22px;
  border: 1px solid var(--color-line);
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--color-secondary);
  background-color: var(--color-surface);
  transition: all var(--transition-base);
}

.filter-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.filter-btn.is-active {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: #FFFFFF;
}

.portfolio__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.portfolio-card {
  position: relative;
  border-radius: 4px;
  overflow: hidden;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.portfolio-card.is-hidden {
  display: none;
}

.portfolio-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 48px rgba(28, 28, 28, 0.12);
}

.portfolio-card__thumb {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
}

.portfolio-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease);
}

.portfolio-card:hover .portfolio-card__thumb img {
  transform: scale(1.06);
}

.portfolio-card__label {
  position: absolute;
  inset-block-start: 16px;
  inset-inline-start: 16px;
  padding: 6px 14px;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  background-color: rgba(255, 255, 255, 0.92);
  color: var(--color-primary);
  border-radius: 999px;
}

.portfolio-card__body {
  padding: 22px 24px 26px;
}

.portfolio-card__title {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.portfolio-card__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-en);
  font-size: 0.85rem;
  color: var(--color-accent);
  transition: gap var(--transition-base);
}

.portfolio-card:hover .portfolio-card__link {
  gap: 10px;
}

/* --------------------------------------------------------------------------
   11. Chapter 5 — Business Registration (#registration)
   -------------------------------------------------------------------------- */
.registration {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 60px;
  align-items: center;
}

.registration__image-wrap {
  border: 1px solid var(--color-line);
  background-color: var(--color-surface);
  padding: 16px;
  cursor: zoom-in;
  position: relative;
}

.registration__image-wrap img {
  width: 100%;
}

.registration__zoom-hint {
  position: absolute;
  inset-inline-end: 28px;
  inset-block-end: 28px;
  background-color: rgba(28, 28, 28, 0.75);
  color: #fff;
  font-size: 0.75rem;
  padding: 6px 12px;
  border-radius: 999px;
}

.registration__info {
  border-top: 1px solid var(--color-line);
}

.registration__row {
  display: flex;
  padding-block: 18px;
  border-bottom: 1px solid var(--color-line);
  gap: 24px;
}

.registration__term {
  flex: 0 0 140px;
  font-weight: 700;
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   12. Footer
   -------------------------------------------------------------------------- */
.footer {
  background-color: var(--color-primary);
  color: var(--color-bg);
  padding-block: 64px 32px;
  border-top: 2px solid var(--color-accent);
  text-align: center;
}

.footer__logo {
  font-family: var(--font-en);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: 24px;
}

.footer__info {
  font-size: 0.9rem;
  color: rgba(245, 243, 239, 0.75);
  line-height: 2;
}

.footer__info a {
  transition: color var(--transition-base);
}

.footer__info a:hover {
  color: var(--color-accent-light);
}

.footer__copyright {
  margin-top: 32px;
  font-size: 0.8rem;
  color: rgba(245, 243, 239, 0.5);
}

/* --------------------------------------------------------------------------
   13. Modal / Lightbox
   -------------------------------------------------------------------------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background-color: rgba(18, 17, 15, 0.88);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.modal-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.modal__content {
  position: relative;
  max-width: min(1000px, 92vw);
  max-height: 88vh;
  transform: scale(0.96);
  transition: transform var(--transition-base);
}

.modal-overlay.is-open .modal__content {
  transform: scale(1);
}

.modal__content img {
  max-width: 100%;
  max-height: 88vh;
  object-fit: contain;
  border: 4px solid var(--color-surface);
}

.modal__caption {
  text-align: center;
  color: #fff;
  margin-top: 16px;
  font-size: 0.95rem;
}

.modal__close {
  position: absolute;
  inset-block-start: -48px;
  inset-inline-end: 0;
  width: 36px;
  height: 36px;
  color: #fff;
  font-size: 1.8rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-base);
}

.modal__close:hover {
  transform: rotate(90deg);
}

/* --------------------------------------------------------------------------
   14. Placeholder image blocks (used until real photography is dropped in)
   -------------------------------------------------------------------------- */
.img-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 12px;
  font-family: var(--font-en);
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.85);
  background: linear-gradient(135deg, #8B7355 0%, #6f5c44 45%, #3a3229 100%);
}

.img-placeholder--light {
  color: var(--color-muted);
  background: repeating-linear-gradient(135deg, #EFEBE3 0 2px, #F5F3EF 2px 14px);
}

.img-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --------------------------------------------------------------------------
   15. Responsive Breakpoints
   -------------------------------------------------------------------------- */

/* Laptop: 992px – 1199px — tighter spacing */
@media (max-width: 1199px) {
  :root {
    --section-padding-y: 96px;
  }

  .container {
    padding-inline: 32px;
  }
}

/* Tablet: 768px – 991px — 2-column grids */
@media (max-width: 991px) {
  .business__grid,
  .portfolio__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .history,
  .registration {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .nav {
    display: none;
  }

  .hamburger {
    display: flex;
  }
}

/* Mobile: ≤767px — 1-column grids + hamburger nav */
@media (max-width: 767px) {
  :root {
    --section-padding-y: var(--section-padding-y-mobile);
  }

  .business__grid,
  .portfolio__grid {
    grid-template-columns: 1fr;
  }

  .section-head {
    margin-bottom: 40px;
  }

  .header__inner {
    padding-inline: 20px;
  }

  .nav {
    position: fixed;
    inset-block-start: 0;
    inset-inline-end: 0;
    width: min(80vw, 320px);
    height: 100vh;
    background-color: var(--color-surface);
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding-inline: 40px;
    box-shadow: -8px 0 32px rgba(28, 28, 28, 0.12);
    transform: translateX(100%);
    transition: transform var(--transition-base);
  }

  .nav-open .nav {
    display: flex;
    transform: translateX(0);
  }

  .nav__list {
    flex-direction: column;
    gap: 28px;
  }

  .nav__link {
    font-size: 1.1rem;
    color: var(--color-primary) !important;
  }

  .registration__row,
  .history__row {
    flex-direction: column;
    gap: 4px;
  }

  .registration__term,
  .history__term {
    flex: none;
  }
}