/* ============================================
   鉄心建設 - Bold Industrial Construction
   Black #111 + Red #C41E3A + Zen Kaku Gothic
   Giant typography hero, numbered editorial
   ============================================ */

:root {
  --black: #111111;
  --black-soft: #1A1A1A;
  --dark-gray: #222222;
  --mid-gray: #333333;
  --red: #C41E3A;
  --red-dark: #9B1830;
  --red-light: #E8354F;
  --text: #111111;
  --text-secondary: #666666;
  --text-light: #999999;
  --border: #E0E0E0;
  --bg: #FAFAFA;
  --white: #FFFFFF;
  --font-main: 'Zen Kaku Gothic New', 'Noto Sans JP', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-main);
  color: var(--text);
  background: var(--white);
  line-height: 1.8;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 32px; }
a { text-decoration: none; color: inherit; }

/* ===== HEADER ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 32px;
  transition: box-shadow 0.3s;
}
.header.scrolled { box-shadow: 0 1px 12px rgba(0,0,0,0.06); }
.header-inner {
  max-width: 1200px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  font-size: 20px; font-weight: 900;
  color: var(--black);
  letter-spacing: 0.05em;
}
.logo-sub {
  font-size: 9px; font-weight: 500;
  color: var(--text-light);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.nav { display: flex; align-items: center; gap: 4px; }
.nav-list { display: flex; list-style: none; gap: 0; }
.nav-link {
  padding: 8px 12px; font-size: 12px; font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
  transition: color 0.2s;
}
.nav-link:hover { color: var(--black); }
.nav-cta {
  margin-left: 16px; padding: 8px 20px;
  background: var(--black); color: var(--white);
  font-size: 12px; font-weight: 700;
  letter-spacing: 0.05em;
  transition: background 0.2s;
}
.nav-cta:hover { background: var(--red); }

.hamburger {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 8px;
}
.hamburger span {
  width: 24px; height: 2px; background: var(--black);
  transition: all 0.3s;
}
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ===== HERO: GIANT TYPOGRAPHY ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex; align-items: center;
  background: var(--white);
  overflow: hidden;
  padding: 0 32px;
}
.hero-content {
  max-width: 1200px; margin: 0 auto;
  padding: 120px 0 80px;
  position: relative; z-index: 2;
  width: 100%;
}
.hero-overline {
  display: flex; align-items: center; gap: 16px;
  margin-bottom: 40px;
}
.hero-line {
  width: 48px; height: 2px;
  background: var(--red);
  display: block;
}
.hero-overline span:last-child {
  font-size: 12px; font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 0.15em;
}
.hero-giant {
  margin-bottom: 40px;
}
.hero-giant-line {
  display: block;
  font-size: clamp(52px, 10vw, 120px);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--black);
}
.hero-dot { color: var(--red); }
.hero-sub {
  font-size: 15px; line-height: 2;
  color: var(--text-secondary);
  margin-bottom: 48px;
  max-width: 500px;
}
.hero-cta { display: flex; gap: 12px; }

.hero-bg-text {
  position: absolute;
  bottom: -5%; right: -2%;
  font-size: clamp(120px, 20vw, 300px);
  font-weight: 900;
  color: rgba(0,0,0,0.03);
  letter-spacing: -0.03em;
  line-height: 1;
  user-select: none;
  pointer-events: none;
}
.hero-red-line {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 4px;
  background: var(--red);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 32px;
  font-size: 13px; font-weight: 700;
  border: 2px solid transparent;
  transition: all 0.2s; cursor: pointer;
  font-family: var(--font-main);
  letter-spacing: 0.05em;
}
.btn--red { background: var(--red); color: var(--white); border-color: var(--red); }
.btn--red:hover { background: var(--red-dark); border-color: var(--red-dark); }
.btn--ghost { background: transparent; color: var(--black); border-color: var(--black); }
.btn--ghost:hover { background: var(--black); color: var(--white); }
.btn--large { padding: 16px 40px; font-size: 15px; }

/* ===== NUMBERED SECTIONS ===== */
.section { padding: 100px 0; }
.section--black { background: var(--black); color: var(--white); }
.section--dark-gray { background: var(--dark-gray); color: var(--white); }
.section--red { background: var(--red); color: var(--white); }

.section-header {
  display: flex; align-items: center; gap: 20px;
  margin-bottom: 56px;
}
.num-label {
  font-size: 14px; font-weight: 900;
  color: var(--red);
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
}
.num-label--light { color: var(--red-light); }
.red-accent { width: 32px; height: 2px; background: var(--red); }
.section-header h2 {
  font-size: 24px; font-weight: 900;
  letter-spacing: 0.05em;
}
.section-title--light { color: var(--white); }

/* ===== ABOUT: SPLIT SCREEN ===== */
.about-split {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 80px;
  max-width: 1200px; margin: 0 auto;
  padding: 0 32px;
}
.about-left {
  display: flex; flex-direction: column;
  justify-content: center; gap: 20px;
}
.about-left h2 {
  font-size: 36px; font-weight: 900;
  letter-spacing: 0.05em;
}
.about-right { display: flex; flex-direction: column; gap: 20px; }
.about-lead {
  font-size: 24px; font-weight: 900;
  line-height: 1.6;
  margin-bottom: 8px;
}
.about-right p {
  font-size: 14px; line-height: 2.1;
  color: var(--text-secondary);
}

/* ===== SERVICES ===== */
.services-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.service-item {
  padding: 36px 28px;
  border: 1px solid rgba(255,255,255,0.08);
  transition: border-color 0.3s;
}
.service-item:hover { border-color: var(--red); }
.service-icon-wrap {
  width: 48px; height: 48px;
  color: var(--red-light);
  margin-bottom: 24px;
}
.service-icon-wrap svg { width: 100%; height: 100%; }
.service-item h3 {
  font-size: 18px; font-weight: 900;
  margin-bottom: 12px;
  letter-spacing: 0.03em;
}
.service-item p {
  font-size: 13px; line-height: 1.9;
  color: rgba(255,255,255,0.6);
}

/* ===== PROJECTS ===== */
.projects-list { display: flex; flex-direction: column; gap: 48px; }
.project-row {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 48px; align-items: center;
}
.project-row--reverse { direction: rtl; }
.project-row--reverse > * { direction: ltr; }
.project-img {
  height: 360px;
  background-size: cover; background-position: center;
  position: relative;
}
.project-img::after {
  content: ''; position: absolute;
  bottom: 0; left: 0; width: 60px; height: 4px;
  background: var(--red);
}
.project-info { padding: 24px 0; }
.project-tag {
  display: inline-block;
  font-size: 11px; font-weight: 700;
  color: var(--red);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.project-info h3 {
  font-size: 24px; font-weight: 900;
  margin-bottom: 16px;
  letter-spacing: 0.03em;
}
.project-info p {
  font-size: 14px; line-height: 2;
  color: var(--text-secondary);
  margin-bottom: 20px;
}
.project-specs {
  display: flex; gap: 24px;
}
.project-specs span {
  font-size: 12px; font-weight: 700;
  color: var(--text-light);
  letter-spacing: 0.05em;
  padding: 4px 0;
  border-bottom: 1px solid var(--border);
}

/* ===== STRENGTH ===== */
.strength-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.strength-card {
  padding: 40px 32px;
  border: 1px solid rgba(255,255,255,0.08);
  border-top: 3px solid var(--red);
}
.strength-num {
  display: block;
  font-size: 48px; font-weight: 900;
  color: var(--red-light);
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.strength-card h3 {
  font-size: 17px; font-weight: 900;
  margin-bottom: 12px;
}
.strength-card p {
  font-size: 13px; line-height: 1.9;
  color: rgba(255,255,255,0.55);
}

/* ===== STATS BAR ===== */
.stats-bar {
  display: flex; justify-content: center;
  gap: 48px; align-items: center;
  padding: 20px 0;
}
.stat-item { text-align: center; }
.stat-val {
  display: block;
  font-size: clamp(40px, 5vw, 56px);
  font-weight: 900;
  letter-spacing: -0.02em;
}
.stat-unit { font-size: 18px; font-weight: 700; }
.stat-label {
  display: block; font-size: 12px;
  opacity: 0.7; margin-top: 4px;
  letter-spacing: 0.1em;
}
.stat-divider {
  width: 1px; height: 48px;
  background: rgba(255,255,255,0.25);
}

/* ===== COMPANY ===== */
.company-table { margin-top: 8px; }
.company-row {
  display: flex;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
}
.company-th {
  width: 160px; flex-shrink: 0;
  font-size: 13px; font-weight: 700;
  color: var(--text);
}
.company-td {
  font-size: 14px; color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== RECRUIT ===== */
.recruit-split {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 64px;
}
.recruit-msg h3 {
  font-size: 32px; font-weight: 900;
  line-height: 1.5;
  margin-bottom: 20px;
}
.recruit-msg p {
  font-size: 14px; line-height: 2;
  color: rgba(255,255,255,0.6);
}
.recruit-jobs { display: flex; flex-direction: column; gap: 16px; }
.job-card {
  padding: 24px;
  border: 1px solid rgba(255,255,255,0.1);
  transition: border-color 0.3s;
}
.job-card:hover { border-color: var(--red); }
.job-card-header { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.job-type {
  font-size: 10px; font-weight: 700;
  color: var(--white);
  background: var(--red);
  padding: 2px 8px;
  letter-spacing: 0.05em;
}
.job-card h4 { font-size: 15px; font-weight: 900; }
.job-card p { font-size: 13px; color: rgba(255,255,255,0.5); }

/* ===== CTA ===== */
.section--cta {
  background: var(--bg);
  color: var(--text);
  text-align: center;
}
.cta-content h2 {
  font-size: clamp(26px, 3vw, 38px);
  font-weight: 900; line-height: 1.5;
  margin-bottom: 16px;
}
.cta-content p {
  font-size: 14px; color: var(--text-secondary);
  line-height: 2; margin-bottom: 32px;
}
.cta-actions { display: flex; justify-content: center; gap: 16px; margin-bottom: 16px; flex-wrap: wrap; }
.cta-note { font-size: 12px; color: var(--text-light); }

/* ===== FOOTER ===== */
.footer {
  background: var(--black);
  color: rgba(255,255,255,0.5);
  padding: 60px 0 0;
}
.footer-inner {
  display: flex; justify-content: space-between;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-logo {
  font-size: 22px; font-weight: 900;
  color: var(--white);
  letter-spacing: 0.05em;
}
.footer-corp {
  font-size: 12px; color: rgba(255,255,255,0.5);
  letter-spacing: 0.1em;
}
.footer-brand p { font-size: 12px; line-height: 1.8; margin-top: 8px; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: flex-start; }
.footer-nav a {
  font-size: 12px; letter-spacing: 0.05em;
  transition: color 0.2s;
}
.footer-nav a:hover { color: var(--red-light); }
.footer-bottom { text-align: center; padding: 24px 0; font-size: 11px; opacity: 0.4; }

/* ===== ANIMATIONS ===== */
[data-anim] { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
[data-anim].visible { opacity: 1; transform: translateY(0); }
[data-delay="1"] { transition-delay: 0.15s; }
[data-delay="2"] { transition-delay: 0.3s; }
[data-delay="3"] { transition-delay: 0.45s; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .project-row { grid-template-columns: 1fr; gap: 24px; }
  .project-row--reverse { direction: ltr; }
  .project-img { height: 280px; }
  .strength-grid { grid-template-columns: 1fr; }
  .about-split { grid-template-columns: 1fr; gap: 40px; }
  .recruit-split { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 768px) {
  .container { padding: 0 20px; }
  .header { padding: 0 20px; }
  .hero { padding: 0 20px; }
  .nav { display: none; }
  .nav.open {
    display: flex; flex-direction: column;
    position: fixed; top: 64px; left: 0; right: 0; bottom: 0;
    background: var(--white);
    padding: 32px 24px;
    z-index: 999;
  }
  .nav.open .nav-list { flex-direction: column; gap: 0; }
  .nav.open .nav-link { padding: 14px 0; font-size: 15px; color: var(--text); }
  .nav.open .nav-cta { margin: 16px 0 0; text-align: center; display: block; }
  .hamburger { display: flex; }

  .hero-giant-line { font-size: 40px; }
  .hero-bg-text { font-size: 100px; }
  .hero-cta { flex-direction: column; }

  .services-grid { grid-template-columns: 1fr; }
  .stats-bar { flex-wrap: wrap; gap: 32px; }
  .stat-divider { display: none; }

  .company-row { flex-direction: column; gap: 4px; }
  .company-th { width: auto; }

  .cta-actions { flex-direction: column; align-items: center; }
  .footer-inner { flex-direction: column; gap: 32px; }
  .about-split { padding: 0 20px; }
}