/* ============================================================
   H·STEEL — Style System
   Deep Navy + Orange Accent | Industrial Cinematic
   ============================================================ */

/* --- Design Tokens --- */
:root {
  /* Colors (IR 덱 승계) */
  --color-primary: #1B2A4A;
  --color-primary-deep: #10203A;
  --color-primary-light: #263A63;
  --color-white: #FFFFFF;
  --color-offwhite: #FBFAF5;
  --color-accent: #E76B2C;
  --color-accent-light: #F5A06B;
  --color-text-gray: #6B7280;
  --color-text-light: #B8BFCC;
  --color-border: rgba(255, 255, 255, 0.10);
  --color-border-dark: rgba(27, 42, 74, 0.12);

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

  /* Layout */
  --section-padding: 110px 24px;
  --max-width: 1200px;

  /* Motion */
  --ease: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --duration: 0.7s;
}

/* --- 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;
  word-break: keep-all;
  overflow-wrap: break-word;
}

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

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

ul {
  list-style: none;
}

section {
  scroll-margin-top: 72px;
}

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

.pc-br {
  display: block;
}

/* --- Section Label / Title --- */
.section-label {
  font-size: 13px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  margin-bottom: 24px;
}

.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: var(--fw-bold);
  line-height: 1.3;
  letter-spacing: -0.03em;
  color: var(--color-primary);
  margin-bottom: 20px;
}

.section-title--light {
  color: var(--color-white);
}

/* --- Scroll Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity var(--duration) var(--ease),
              transform var(--duration) var(--ease);
}

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

.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; }
.fade-in-group > .fade-in:nth-child(5) { transition-delay: 0.48s; }

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .fade-in {
    opacity: 1;
    transform: none;
    transition: none;
  }
}


/* ============================================================
   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: box-shadow 0.3s var(--ease);
}

.nav.scrolled {
  box-shadow: 0 4px 24px rgba(16, 32, 58, 0.35);
}

.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 {
  display: flex;
  align-items: center;
}

.nav__logo img {
  height: 27px;
  width: auto;
  display: block;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav__links a {
  font-size: 15px;
  font-weight: var(--fw-semibold);
  color: var(--color-text-light);
  letter-spacing: -0.01em;
  transition: color 0.25s var(--ease);
}

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

.nav__cta {
  font-size: 14px !important;
  font-weight: var(--fw-bold) !important;
  color: var(--color-white) !important;
  background: var(--color-accent);
  padding: 10px 26px;
  letter-spacing: 0.02em !important;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.nav__cta:hover {
  background: #F07B3F;
  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;
  min-height: 100svh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: var(--color-primary-deep);
}

.hero__bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/hero.webp');
  background-size: cover;
  background-position: center;
}

@media (prefers-reduced-motion: no-preference) {
  .hero__bg {
    animation: heroZoom 14s var(--ease) forwards;
  }

  @keyframes heroZoom {
    from { transform: scale(1.08); }
    to   { transform: scale(1); }
  }
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(16, 32, 58, 0.92) 0%, rgba(16, 32, 58, 0.55) 45%, rgba(16, 32, 58, 0.15) 100%),
    linear-gradient(0deg, rgba(16, 32, 58, 0.55) 0%, transparent 35%);
}

.hero__content {
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 120px 24px 80px;
  position: relative;
  z-index: 1;
}

.hero__eyebrow {
  font-size: 13px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent-light);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: 24px;
}

.hero__tagline {
  font-size: clamp(34px, 5.2vw, 62px);
  font-weight: var(--fw-bold);
  color: var(--color-white);
  line-height: 1.28;
  letter-spacing: -0.035em;
  margin-bottom: 26px;
}

.hero__sub {
  font-size: clamp(16px, 1.8vw, 19px);
  font-weight: var(--fw-light);
  color: var(--color-text-light);
  line-height: 1.75;
  max-width: 560px;
  margin-bottom: 48px;
}

.hero__cta {
  display: inline-block;
  font-size: 15px;
  font-weight: var(--fw-semibold);
  color: var(--color-white);
  background: var(--color-accent);
  padding: 15px 40px;
  letter-spacing: 0.01em;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.hero__cta:hover {
  background: #F07B3F;
  transform: translateY(-2px);
}

.hero__divider {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
  z-index: 1;
}


/* ============================================================
   STATS
   ============================================================ */
.stats {
  background: var(--color-primary-deep);
  padding: 84px 24px;
}

.stats__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.stat {
  border-left: 2px solid var(--color-accent);
  padding-left: 24px;
}

.stat__value {
  font-size: clamp(34px, 3.6vw, 46px);
  font-weight: var(--fw-bold);
  color: var(--color-white);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  margin-bottom: 12px;
  white-space: nowrap;
}

.stat__unit {
  font-size: 0.5em;
  font-weight: var(--fw-semibold);
  color: var(--color-accent-light);
  margin-left: 5px;
}

.stat__label {
  font-size: 16px;
  font-weight: var(--fw-semibold);
  color: var(--color-white);
  line-height: 1.4;
  margin-bottom: 4px;
}

.stat__note {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.5;
}


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

.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
  margin-bottom: 72px;
}

.about__lead {
  font-size: clamp(24px, 2.8vw, 34px);
  font-weight: var(--fw-bold);
  line-height: 1.35;
  color: var(--color-primary);
  letter-spacing: -0.03em;
}

.about__body p {
  font-size: 16px;
  color: #3D4656;
  margin-bottom: 20px;
  line-height: 1.85;
}

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

.about__visual {
  margin-bottom: 72px;
  overflow: hidden;
}

.about__visual img {
  width: 100%;
  height: auto;
  display: block;
}

.about__info {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0 48px;
  border-top: 1px solid var(--color-border-dark);
}

.about__info-item {
  padding: 22px 0;
  border-bottom: 1px solid var(--color-border-dark);
}

.about__info-key {
  font-size: 13px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent);
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.about__info-val {
  font-size: 15px;
  font-weight: var(--fw-regular);
  color: var(--color-primary);
  line-height: 1.55;
}


/* ============================================================
   INTERLUDE
   ============================================================ */
.interlude {
  position: relative;
  min-height: 480px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-primary-deep);
}

.interlude__bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/coil.webp');
  background-size: cover;
  background-position: center;
}

.interlude__overlay {
  position: absolute;
  inset: 0;
  background: rgba(16, 32, 58, 0.55);
}

.interlude__bg--surface {
  background-image: url('../images/surface.webp');
}

.interlude--surface .interlude__overlay {
  background: rgba(16, 32, 58, 0.45);
}

.interlude__copy {
  position: relative;
  z-index: 1;
  text-align: center;
  font-size: clamp(22px, 2.8vw, 32px);
  font-weight: var(--fw-light);
  color: var(--color-white);
  line-height: 1.55;
  letter-spacing: -0.02em;
  padding: 80px 24px;
}


/* ============================================================
   PRODUCTS VISUAL
   ============================================================ */
.products__visual {
  margin-top: 28px;
}

.products__visual img {
  width: 100%;
  height: auto;
  display: block;
}

.products__visual-caption {
  font-size: 13px;
  font-weight: var(--fw-semibold);
  color: var(--color-text-light);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 14px;
}


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

.products .section-title {
  color: var(--color-white);
  margin-bottom: 56px;
}

.products__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.product-card {
  background: var(--color-primary-light);
  border: 1px solid var(--color-border);
  padding: 44px 40px;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

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

.product-card__std {
  display: inline-block;
  font-size: 13px;
  font-weight: var(--fw-bold);
  color: var(--color-accent-light);
  letter-spacing: 0.12em;
  border: 1px solid rgba(245, 160, 107, 0.4);
  padding: 6px 14px;
  margin-bottom: 26px;
}

.product-card__title {
  font-size: 26px;
  font-weight: var(--fw-bold);
  color: var(--color-white);
  letter-spacing: -0.02em;
  line-height: 1.3;
  margin-bottom: 8px;
}

.product-card__sub {
  font-size: 15px;
  font-weight: var(--fw-regular);
  color: var(--color-text-light);
  letter-spacing: 0.04em;
}

.product-card__type {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 26px;
}

.product-card__features {
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  margin-bottom: 28px;
}

.product-card__features li {
  position: relative;
  font-size: 15px;
  color: #D5DAE4;
  line-height: 1.6;
  padding-left: 18px;
  margin-bottom: 10px;
}

.product-card__features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 7px;
  height: 2px;
  background: var(--color-accent);
}

.product-card__use {
  background: rgba(16, 32, 58, 0.5);
  padding: 18px 22px;
}

.product-card__use-key {
  font-size: 12px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent-light);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.product-card__use-val {
  font-size: 15px;
  font-weight: var(--fw-semibold);
  color: var(--color-white);
  line-height: 1.5;
}


/* ============================================================
   PRODUCTION
   ============================================================ */
.production {
  position: relative;
  padding: 130px 0;
  overflow: hidden;
  background: var(--color-primary-deep);
}

.production__bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/production.webp');
  background-size: cover;
  background-position: center;
}

.production__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(16, 32, 58, 0.93) 0%, rgba(16, 32, 58, 0.72) 55%, rgba(16, 32, 58, 0.45) 100%);
}

.production__content {
  position: relative;
  z-index: 1;
}

.production__desc {
  font-size: clamp(16px, 1.8vw, 18px);
  font-weight: var(--fw-light);
  color: var(--color-text-light);
  line-height: 1.8;
  max-width: 620px;
  margin-bottom: 64px;
}

.production__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: 980px;
}

.production__item {
  border-top: 2px solid var(--color-accent);
  padding-top: 20px;
}

.production__item-title {
  font-size: 19px;
  font-weight: var(--fw-bold);
  color: var(--color-white);
  letter-spacing: -0.02em;
  line-height: 1.4;
  margin-bottom: 10px;
}

.production__item-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.65;
}


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

.quality .section-title {
  margin-bottom: 56px;
}

.quality__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.cert {
  background: var(--color-white);
  border: 1px solid var(--color-border-dark);
  overflow: hidden;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.cert:hover {
  border-color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(16, 32, 58, 0.10);
}

.cert__doc {
  display: block;
  background: #EDEFF2;
  padding: 20px 28px;
}

.cert__doc img {
  width: 100%;
  height: auto;
  display: block;
  box-shadow: 0 5px 16px rgba(16, 32, 58, 0.14);
}

.cert__body {
  padding: 20px 24px 24px;
}

.cert--wide {
  grid-column: span 4;
  display: flex;
  align-items: stretch;
}

.cert__doc--wide {
  flex: 0 0 200px;
  display: flex;
  align-items: center;
  padding: 20px;
}

.cert__body--wide {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 28px 32px;
}

.cert__code {
  font-size: 19px;
  font-weight: var(--fw-bold);
  color: var(--color-primary);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.cert__name {
  font-size: 14px;
  color: #3D4656;
  line-height: 1.6;
  margin-bottom: 10px;
}

.cert__meta {
  font-size: 13px;
  color: var(--color-text-gray);
  line-height: 1.5;
}

.quality__note {
  margin-top: 24px;
  font-size: 13px;
  color: var(--color-text-gray);
}


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

.contact__inner {
  text-align: center;
  max-width: 620px;
  margin: 0 auto;
}

.contact__sub {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: var(--fw-bold);
  color: var(--color-white);
  line-height: 1.4;
  letter-spacing: -0.03em;
  margin-bottom: 48px;
}

.contact__info {
  display: table;
  margin: 0 auto 48px;
  text-align: left;
}

.contact__row {
  display: flex;
  gap: 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
}

.contact__row:last-child {
  border-bottom: none;
}

.contact__key {
  flex: 0 0 48px;
  font-size: 14px;
  font-weight: var(--fw-semibold);
  color: var(--color-accent-light);
}

.contact__val {
  font-size: 16px;
  color: var(--color-white);
  line-height: 1.6;
}

.contact__val a {
  transition: color 0.25s var(--ease);
}

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

.contact__cta {
  display: inline-block;
  font-size: 15px;
  font-weight: var(--fw-semibold);
  color: var(--color-white);
  background: var(--color-accent);
  padding: 15px 44px;
  letter-spacing: 0.01em;
  transition: background 0.25s var(--ease), transform 0.2s var(--ease);
}

.contact__cta:hover {
  background: #F07B3F;
  transform: translateY(-2px);
}


/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--color-primary-deep);
  border-top: 1px solid var(--color-border);
  padding: 40px 24px;
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.footer__company {
  font-size: 14px;
  font-weight: var(--fw-semibold);
  color: var(--color-text-light);
  margin-bottom: 6px;
}

.footer__address {
  font-size: 13px;
  color: var(--color-text-gray);
  margin-bottom: 16px;
}

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


/* ============================================================
   RESPONSIVE — 1024px
   ============================================================ */
@media (max-width: 1024px) {
  .stats__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 40px 32px;
  }

  .about__info {
    grid-template-columns: repeat(2, 1fr);
  }

  .quality__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .cert--wide {
    grid-column: span 2;
  }
}


/* ============================================================
   RESPONSIVE — 768px
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --section-padding: 76px 20px;
  }

  .pc-br {
    display: none;
  }

  /* Nav mobile */
  .nav__links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    height: calc(100dvh - 72px);
    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: 20px;
  }

  .nav__toggle {
    display: block;
  }

  /* Hero */
  .hero__content {
    padding: 110px 20px 70px;
  }

  .hero__tagline {
    font-size: clamp(30px, 8vw, 38px);
    line-height: 1.32;
  }

  .hero__sub {
    font-size: 15px;
  }

  /* Stats */
  .stats {
    padding: 64px 20px;
  }

  .stat__value {
    font-size: 32px;
  }

  .stat__label {
    font-size: 15px;
  }

  /* About */
  .about__grid {
    grid-template-columns: 1fr;
    gap: 24px;
    margin-bottom: 52px;
  }

  .about__visual {
    margin-bottom: 52px;
  }

  .about__lead {
    font-size: 23px;
  }

  .about__body p {
    font-size: 15px;
  }

  .about__info {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .about__info-item {
    padding: 16px 0;
  }

  /* Interlude */
  .interlude {
    min-height: 380px;
  }

  .interlude__copy {
    font-size: 21px;
    padding: 64px 20px;
  }

  /* Products */
  .products__grid {
    grid-template-columns: 1fr;
  }

  .product-card {
    padding: 34px 26px;
  }

  .product-card__title {
    font-size: 22px;
  }

  /* Production */
  .production {
    padding: 84px 0;
  }

  .production__overlay {
    background: rgba(16, 32, 58, 0.82);
  }

  .production__desc {
    margin-bottom: 44px;
  }

  .production__grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  /* Quality */
  .quality__grid {
    grid-template-columns: 1fr;
  }

  .cert--wide {
    grid-column: span 1;
    flex-direction: column;
  }

  .cert__doc--wide {
    flex: none;
    padding: 20px 28px;
  }

  .cert__doc--wide img {
    max-width: 260px;
    margin: 0 auto;
  }

  .cert__body--wide {
    padding: 20px 24px 24px;
  }

  /* Contact */
  .contact__sub {
    font-size: 22px;
  }

  .contact__row {
    flex-direction: column;
    gap: 4px;
  }

  /* Footer */
  .footer__address {
    line-height: 1.7;
  }
}


/* ============================================================
   RESPONSIVE — 480px
   ============================================================ */
@media (max-width: 480px) {
  .nav__inner {
    height: 64px;
  }

  .nav__links {
    top: 64px;
    height: calc(100dvh - 64px);
  }

  section {
    scroll-margin-top: 64px;
  }

  .nav__logo img {
    height: 22px;
  }

  .stats__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero__cta,
  .contact__cta {
    width: 100%;
    text-align: center;
    padding: 15px 24px;
  }
}