:root {
  --navy: #071a33;
  --navy-2: #0d2b50;
  --blue: #174e8c;
  --light: #f3f6f9;
  --line: #d8e0e8;
  --text: #122033;
  --muted: #627083;
  --white: #fff;
  --max: 1180px;
  --shadow: 0 20px 60px rgba(7, 26, 51, .10);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--white);
  font-family: "Noto Sans JP", "Yu Gothic", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  line-height: 1.85;
  letter-spacing: .035em;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; }
.wrap { width: min(calc(100% - 48px), var(--max)); margin-inline: auto; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 999; padding: 12px 18px; background: #fff; color: #000; }
.skip-link:focus { top: 16px; }

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  color: var(--white);
  transition: background .25s ease, box-shadow .25s ease, color .25s ease;
}
.site-header.scrolled { background: rgba(255,255,255,.96); color: var(--navy); box-shadow: 0 8px 30px rgba(7,26,51,.08); backdrop-filter: blur(12px); }
.header-inner { width: min(calc(100% - 48px), 1320px); height: 88px; margin: auto; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.brand { display: flex; align-items: baseline; gap: 16px; text-decoration: none; }
.brand-mark { font-family: Arial, Helvetica, sans-serif; font-size: 31px; font-weight: 800; letter-spacing: .08em; }
.brand-sub { font-size: 11px; letter-spacing: .09em; opacity: .78; }
.global-nav { display: flex; align-items: center; gap: 30px; }
.global-nav a { font-size: 13px; text-decoration: none; position: relative; }
.global-nav a:not(.nav-contact)::after { content: ""; position: absolute; left: 0; bottom: -7px; width: 0; height: 1px; background: currentColor; transition: width .2s ease; }
.global-nav a:hover::after { width: 100%; }
.nav-contact { padding: 10px 18px; border: 1px solid currentColor; border-radius: 999px; }
.menu-button { display: none; border: 0; background: transparent; padding: 8px; color: inherit; }
.menu-button span:not(.sr-only) { display: block; width: 26px; height: 1px; margin: 6px 0; background: currentColor; }

.hero { min-height: 790px; display: grid; align-items: center; position: relative; overflow: hidden; color: var(--white); background: linear-gradient(90deg, rgba(6,21,40,.96) 0%, rgba(6,21,40,.90) 28%, rgba(6,21,40,.64) 48%, rgba(6,21,40,.24) 68%, rgba(6,21,40,.04) 100%), url("images/hero-background.png"); background-size: cover; background-position: center center; background-repeat: no-repeat; }
.hero::after { content: ""; position: absolute; width: 520px; height: 520px; right: -110px; bottom: -240px; border: 1px solid rgba(255,255,255,.12); border-radius: 50%; box-shadow: 0 0 0 70px rgba(255,255,255,.025), 0 0 0 140px rgba(255,255,255,.018); }
.hero-grid { position: absolute; inset: 0; opacity: .08; background-image: linear-gradient(rgba(255,255,255,.6) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.6) 1px, transparent 1px); background-size: 80px 80px; mask-image: linear-gradient(to right, rgba(0,0,0,.8), transparent 90%); }
.hero-content { position: relative; z-index: 2; padding-top: 80px; }
.eyebrow { margin: 0 0 22px; font-family: Arial, Helvetica, sans-serif; font-size: 13px; text-transform: uppercase; letter-spacing: .24em; opacity: .75; }
.hero h1 { margin: 0; font-size: clamp(64px, 9.2vw, 132px); line-height: .98; letter-spacing: -.055em; font-weight: 700; }
.hero h1 span { color: #9ec8ef; }
.hero-copy { margin: 34px 0 24px; font-size: clamp(17px, 2.2vw, 26px); letter-spacing: .08em; }
.hero-tags { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-tags span { padding: 8px 13px; border: 1px solid rgba(255,255,255,.28); border-radius: 999px; font-family: Arial, sans-serif; font-size: 11px; letter-spacing: .12em; }
.scroll-link { display: inline-flex; gap: 14px; margin-top: 70px; font-size: 13px; text-decoration: none; opacity: .8; }

.section { padding: 130px 0; }
.section-label { margin: 0 0 22px; color: var(--blue); font: 700 12px/1.2 Arial, sans-serif; letter-spacing: .2em; text-transform: uppercase; }
.section h2 { margin: 0; color: var(--navy); font-size: clamp(38px, 5vw, 68px); line-height: 1.25; letter-spacing: -.035em; }
.two-column { display: grid; grid-template-columns: .9fr 1.1fr; gap: 100px; align-items: start; }
.lead-copy { max-width: 690px; font-size: 19px; line-height: 2.15; }
.lead-copy p { margin: 0 0 24px; }

.business { background: var(--light); }
.section-heading-row { display: flex; justify-content: space-between; align-items: end; gap: 60px; margin-bottom: 60px; }
.section-heading-row > p { max-width: 430px; margin: 0 0 8px; color: var(--muted); }
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card { min-height: 280px; padding: 35px; background: var(--white); border: 1px solid rgba(7,26,51,.07); transition: transform .25s ease, box-shadow .25s ease; }
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.card-number { color: #9aa8b7; font: 12px Arial, sans-serif; letter-spacing: .16em; }
.card h3 { margin: 50px 0 18px; color: var(--navy); font: 700 24px/1.2 Arial, sans-serif; letter-spacing: .02em; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.statement { padding: 135px 0; color: var(--white); background: linear-gradient(120deg, var(--navy), var(--navy-2)); }
.statement p { color: #93bce4; font: 700 13px Arial, sans-serif; letter-spacing: .18em; }
.statement p span { margin: 0 12px; color: rgba(255,255,255,.45); }
.statement h2 { max-width: 970px; margin: 35px 0 0; font-size: clamp(35px, 5.2vw, 69px); line-height: 1.45; letter-spacing: -.03em; }

.directors h2 { margin-bottom: 65px; }
.director-grid { display: grid; gap: 80px; }
.director-card { display: grid; grid-template-columns: 1fr 1fr; min-height: 560px; background: var(--light); }
.director-card.reverse .portrait { order: 2; }
.director-card.reverse .director-info { order: 1; }
.portrait { overflow: hidden; background: #dfe6ee; }
.portrait img { width: 100%; height: 100%; object-fit: cover; }
.portrait-toshiaki img { object-position: center 18%; }
.portrait-junko img { object-position: center 15%; }
.director-info { display: flex; flex-direction: column; justify-content: center; padding: clamp(42px, 7vw, 88px); }
.director-info .role { margin: 0 0 15px; color: var(--blue); font-weight: 700; font-size: 13px; }
.director-info h3 { margin: 0; color: var(--navy); font-size: clamp(31px, 4vw, 48px); letter-spacing: .08em; }
.director-info .roman { margin: 6px 0 32px; color: #7b8796; font: 12px Arial, sans-serif; letter-spacing: .13em; }
.director-info > p:last-child { margin: 0; color: var(--muted); }

.company { background: #fafbfc; }
.company-layout { display: grid; grid-template-columns: .72fr 1.28fr; gap: 90px; }
.company-intro { max-width: 380px; margin-top: 28px; color: var(--muted); }
.company-table { margin: 0; border-top: 1px solid var(--line); }
.company-table > div { display: grid; grid-template-columns: 220px 1fr; gap: 26px; padding: 23px 0; border-bottom: 1px solid var(--line); }
.company-table dt { color: var(--muted); font-size: 13px; }
.company-table dd { margin: 0; font-size: 14px; }

.contact { padding: 100px 0; }
.contact-box { padding: 70px; color: var(--white); background: linear-gradient(135deg, #0b2748, #124b7f); display: flex; align-items: center; justify-content: space-between; gap: 60px; }
.contact .section-label { color: #9ec8ef; }
.contact h2 { color: var(--white); font-size: clamp(38px, 4vw, 58px); }
.contact-box > div:first-child > p:last-child { max-width: 600px; margin-bottom: 0; color: rgba(255,255,255,.76); }
.contact-action { min-width: 310px; text-align: center; }
.button { display: flex; justify-content: space-between; gap: 20px; padding: 18px 23px; background: var(--white); color: var(--navy); text-decoration: none; font-family: Arial, sans-serif; font-weight: 700; }
.contact-action p { margin: 10px 0 0; color: rgba(255,255,255,.58); font-size: 11px; }

.site-footer { padding: 50px 0; color: rgba(255,255,255,.7); background: #041121; }
.footer-inner { display: flex; justify-content: space-between; align-items: end; gap: 40px; }
.footer-logo { margin: 0; color: var(--white); font: 800 30px Arial, sans-serif; letter-spacing: .1em; }
.footer-inner p { margin: 4px 0; font-size: 11px; }
.footer-meta { text-align: right; }

@media (max-width: 900px) {
  .header-inner { height: 72px; }
  .brand-sub { display: none; }
  .menu-button { display: block; position: relative; z-index: 3; }
  .global-nav { position: fixed; inset: 0; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; padding: 50px; background: var(--navy); color: var(--white); opacity: 0; visibility: hidden; transform: translateY(-10px); transition: .25s ease; }
  .global-nav.open { opacity: 1; visibility: visible; transform: none; }
  .global-nav a { font-size: 22px; }
  .site-header.menu-open { color: var(--white); }
  .two-column, .company-layout { grid-template-columns: 1fr; gap: 55px; }
  .section-heading-row { align-items: start; flex-direction: column; gap: 25px; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .director-card { grid-template-columns: 1fr; }
  .director-card.reverse .portrait, .director-card.reverse .director-info { order: initial; }
  .portrait { height: 620px; }
  .contact-box { align-items: flex-start; flex-direction: column; padding: 50px; }
  .contact-action { width: 100%; min-width: 0; }
}

@media (max-width: 620px) {
  .wrap, .header-inner { width: min(calc(100% - 32px), var(--max)); }
  .hero { min-height: 700px; }
  .hero-content { padding-top: 45px; }
  .hero h1 { font-size: clamp(58px, 18vw, 86px); }
  .hero-copy { max-width: 320px; font-size: 16px; }
  .scroll-link { margin-top: 50px; }
  .section { padding: 88px 0; }
  .section h2 { font-size: 41px; }
  .lead-copy { font-size: 16px; }
  .cards { grid-template-columns: 1fr; }
  .card { min-height: auto; }
  .card h3 { margin-top: 35px; }
  .statement { padding: 90px 0; }
  .statement h2 { font-size: 34px; }
  .director-grid { gap: 35px; }
  .portrait { height: 500px; }
  .director-info { padding: 38px 28px 45px; }
  .company-table > div { grid-template-columns: 1fr; gap: 6px; padding: 18px 0; }
  .company-table dt { font-weight: 700; color: var(--navy); }
  .contact { padding: 55px 0; }
  .contact-box { padding: 38px 25px; }
  .footer-inner { align-items: flex-start; flex-direction: column; }
  .footer-meta { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

/* YBDI brand update 2026-09-14 */
.header-inner { height: 156px; gap: 24px; }
.brand { align-items: center; gap: 18px; min-width: 0; }
.brand-logo { width: 198px; height: auto; flex: 0 0 auto; }
.brand-sub { display: block; max-width: 220px; font-size: 13px; line-height: 1.5; letter-spacing: .035em; opacity: 1; }
.global-nav { flex-shrink: 0; }
.hero .eyebrow { max-width: 100%; overflow-wrap: break-word; }
section[id] { scroll-margin-top: 172px; }
@media (max-width: 1100px) and (min-width: 901px) {
  .brand-sub { max-width: 160px; font-size: 12px; }
  .global-nav { gap: 18px; }
}
@media (max-width: 900px) {
  .header-inner { height: 124px; gap: 12px; }
  .brand { gap: 12px; }
  .brand-logo { width: 144px; }
  .brand-sub { max-width: 220px; font-size: 12px; }
  .menu-button { flex: 0 0 auto; }
  section[id] { scroll-margin-top: 140px; }
}
@media (max-width: 620px) {
  .brand-logo { width: 120px; }
  .brand-sub { max-width: 165px; font-size: 11px; }
  .hero-content { padding-top: 124px; }
}
@media (max-width: 360px) {
  .header-inner { gap: 8px; }
  .brand { gap: 8px; }
  .brand-logo { width: 102px; }
}

/* YBDI content renewal 2026-09-14 */
.card { min-width: 0; }
.card h3 { word-break: normal; overflow-wrap: normal; text-wrap: balance; }
.statement p { line-height: 1.8; }
@media (max-width: 620px) {
  .hero h1 { font-size: clamp(44px, 13.4vw, 80px); line-height: 1.12; }
}

.heading-phrase { display: inline-block; }
@media (max-width: 360px) { .mission h2 { font-size: 36px; } }