/* ============================================
   CDPH - Factory Introduction Page
   Modern Industrial Design · Responsive
   English Typography Optimized
   ============================================ */

:root {
  /* Primary - Industrial Deep Blue */
  --c-primary: #0d3b66;
  --c-primary-light: #1a5490;
  --c-primary-deep: #072544;
  --c-accent: #0084ff;
  --c-accent-2: #00b4d8;
  --c-warm: #f59e0b;
  --c-warm-2: #ea580c;

  /* Neutrals */
  --c-bg: #ffffff;
  --c-bg-soft: #f7f9fc;
  --c-bg-gray: #eef2f7;
  --c-line: #e5e9f0;
  --c-text: #0a1f3a;
  --c-text-2: #4a5568;
  --c-text-3: #6b7280;
  --c-text-light: #9ca3af;

  /* Font sizes */
  --fz-hero: clamp(2.4rem, 5vw, 4.5rem);
  --fz-h1: clamp(2rem, 3.5vw, 3rem);
  --fz-h2: clamp(1.6rem, 2.5vw, 2.2rem);
  --fz-h3: clamp(1.2rem, 1.6vw, 1.4rem);
  --fz-body: 16px;
  --fz-small: 14px;

  /* Spacing */
  --sp-1: 8px;
  --sp-2: 16px;
  --sp-3: 24px;
  --sp-4: 32px;
  --sp-5: 48px;
  --sp-6: 72px;
  --sp-7: 96px;

  /* Container */
  --container: 1440px;

  /* Shadows */
  --sh-1: 0 2px 8px rgba(13, 59, 102, 0.06);
  --sh-2: 0 6px 24px rgba(13, 59, 102, 0.08);
  --sh-3: 0 16px 48px rgba(13, 59, 102, 0.12);

  /* Border radius */
  --r-1: 4px;
  --r-2: 8px;
  --r-3: 12px;
  --r-4: 16px;
  --r-5: 24px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  font-size: var(--fz-body);
  line-height: 1.65;
  color: var(--c-text);
  background: var(--c-bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; cursor: pointer; border: none; background: none; }
ul { list-style: none; }

.container {
  margin: 0 auto;
}

/* ============================================
   Common Typography
   ============================================ */
.section-head {
  text-align: center;
  max-width: 820px;
  margin: 0 auto var(--sp-6);
}
.section-head__eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--c-accent);
  margin-bottom: var(--sp-2);
  text-transform: uppercase;
}
.section-head__title {
  font-size: var(--fz-h1);
  font-weight: 700;
  line-height: 1.2;
  color: var(--c-text);
  margin-bottom: var(--sp-3);
  letter-spacing: -0.02em;
}
.section-head__desc {
  font-size: 16px;
  color: var(--c-text-2);
  line-height: 1.75;
}
.section-head--light .section-head__eyebrow { color: var(--c-accent-2); }
.section-head--light .section-head__title { color: #fff; }
.section-head--light .section-head__desc { color: rgba(255, 255, 255, 0.85); }

/* ============================================
   Animations - Scroll Reveal
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}





/* ============================================
   Navigation Bar
   ============================================ */
.tab-nav {
  position: fixed;
  top: 145px;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all 0.3s ease;
}
.tab-nav.is-scrolled {
  background: rgba(255, 255, 255, 0.98);
  border-bottom-color: var(--c-line);
  box-shadow: var(--sh-1);
  top: 95px;
}
.nav__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--sp-3);
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}
.nav__logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-accent) 100%);
  color: #fff;
  border-radius: 8px;
  font-size: 13px;
  letter-spacing: 0.04em;
  font-weight: 800;
}
.nav__logo-text {
  font-size: 15px;
  color: var(--c-primary);
  white-space: nowrap;
}
.nav__menu {
  display: flex;
  gap: var(--sp-3);
  width: 100%;
  justify-content: center;
}
.nav__menu a {
  font-size: 14px;
  color: var(--c-text-2);
  font-weight: 500;
  position: relative;
  padding: 4px 0;
  transition: color 0.2s;
}
.nav__menu a:hover { color: var(--c-primary); }
.nav__menu a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--c-accent);
  transition: width 0.25s;
}
.nav__menu a:hover::after { width: 100%; }

.nav__toggle {
  display: none;
  width: 32px;
  height: 32px;
  flex-direction: column;
  justify-content: space-around;
  padding: 4px;
}
.nav__toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--c-primary);
  border-radius: 2px;
  transition: 0.3s;
}

/* ============================================
   Responsive - Navigation
   ============================================ */
@media (max-width: 768px) {
  .nav__menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: var(--sp-3);
    gap: 12px;
    border-bottom: 1px solid var(--c-line);
    box-shadow: var(--sh-2);
  }
  .nav__menu.is-open { display: flex; }
  .nav__toggle { display: flex; }
  .nav__menu a { padding: 8px 0; }
}

@media (max-width: 480px) {
  .nav__logo-text { display: none; }
}