/* KSTI: image-led, restrained editorial theme. */
:root {
  --navy: #163f35;
  --navy-deep: #102d26;
  --navy-soft: #315d4e;
  --accent: #80632b;
  --accent-dark: #654c1e;
  --ink: #233a32;
  --ink-soft: #65736b;
  --paper: #f7f7f2;
  --line: #dfe4d9;
  --radius: 3px;
  --shadow: 0 4px 24px -16px rgba(22,63,53,.15);
  --shadow-lg: 0 16px 38px -22px rgba(22,63,53,.25);
  --gold: #d8c18b;
}

body { letter-spacing: -.025em; }
.wrap { width: min(1200px, calc(100% - 64px)); }
:focus-visible { outline: 3px solid #a48646; outline-offset: 4px; }
[id] { scroll-margin-top: 110px; }
.site-header { background: #fcfcf8; }
.header-inner { padding: 20px 0; }
.logo-img { height: 48px; }
.main-nav > a, .nav-group-btn { color: var(--navy); font-weight: 500; }
.main-nav > a:hover, .nav-group-btn:hover { color: var(--accent); }
.main-nav > .nav-cta { background: var(--navy); border-radius: 2px; font-size: 13px !important; }
.main-nav > .nav-cta:hover { background: var(--navy-deep); color: #fff !important; }
.nav-drop { border-radius: 3px; }
.btn { border-radius: 2px; font-size: 14px; padding: 15px 25px; gap: 28px; transition: background .18s ease, border-color .18s ease; }
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-deep); }
.hero .btn-primary, .section-contact .btn-primary { background: var(--gold); color: #193b30; }
.hero .btn-primary:hover, .section-contact .btn-primary:hover { background: #ebd6a6; }
.btn-ghost { background: transparent; border-color: #c1c8b5; }

.hero { position: relative; isolation: isolate; overflow: hidden; padding: 80px 0 0; background: var(--navy-deep); }
.hero-image { position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; object-fit: cover; object-position: center 55%; }
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background: linear-gradient(90deg, rgba(8,32,26,.9), rgba(8,32,26,.61) 46%, rgba(8,32,26,.08)),
    linear-gradient(0deg, rgba(8,32,26,.6), transparent 40%);
}
.hero-inner { position: relative; }
.hero-eyebrow { margin-bottom: 25px; color: #ead5a6; letter-spacing: .24em; font-size: 11px; font-weight: 500; }
.hero-badge { background: none; padding: 0; border-radius: 0; font-size: 14px; color: #e3e9dc; margin-bottom: 18px; }
.hero h1 { max-width: 720px; font-size: clamp(34px, 3.9vw, 54px); font-weight: 500; line-height: 1.4; letter-spacing: -.06em; margin-bottom: 25px; text-wrap: balance; }
.hero-lead { max-width: 620px; line-height: 1.95; font-size: 15px; color: #ecede2; margin-bottom: 32px; }
.hero-actions { gap: 12px; }
.hero-bottom { display: flex; justify-content: space-between; align-items: center; gap: 20px; border-top: 1px solid rgba(240,238,215,.3); padding: 20px 0; margin-top: 64px; font-size: 10px; color: #eee9d4; letter-spacing: .08em; }
.hero-bottom p { margin: 0; }
.hero-bottom a { display: inline-flex; align-items: center; gap: 28px; font-size: 11px; }
.hero-bottom a:hover { color: #fff; text-decoration: underline; }
.credentials { background: #edf0e7; border-bottom: 1px solid var(--line); }
.credentials-inner { display: flex; align-items: center; gap: 32px; padding: 27px 0; }
.credentials-label { flex: none; font-size: 9px; letter-spacing: .1em; color: #6d785f; margin: 0; padding-right: 30px; border-right: 1px solid #cfd7c6; }
.credentials-label strong { font-size: 13px; font-weight: 500; color: var(--navy); letter-spacing: -.02em; }
.hero-certs { margin: 0; flex: 1; justify-content: space-between; gap: 12px 24px; }
.hero-certs li { border: 0; padding: 0; color: #344f3f; font-size: 12px; border-radius: 0; }
.hero-certs li span { color: #80632b; margin-right: 6px; }

.section { padding: 82px 0; }
.section-alt { background: #edf1e8; }
.section-kicker { color: var(--accent); letter-spacing: .18em; font-size: 10px; font-weight: 500; margin-bottom: 13px; }
.section-title { font-size: 32px; font-weight: 500; letter-spacing: -.055em; margin-bottom: 18px; }
.section-lead { font-size: 15px; margin-bottom: 36px; max-width: 720px; }
.area-grid, .cert-grid, .strength-grid, .service-grid { gap: 20px; }
.area-card { padding: 28px 23px; border-top: 2px solid #bda574; }
.area-no { font-size: 30px; font-weight: 400; letter-spacing: -.04em; line-height: 1; margin-bottom: 27px; color: #907847; }
.area-card h3, .cert-card h3, .strength-card h3 { font-weight: 500; font-size: 18px; }
.area-summary, .cert-card p, .strength-card p { font-size: 14px; line-height: 1.85; }
.area-items { margin-top: 24px; }
.area-items a { font-size: 13px; padding: 13px 16px 13px 0; position: relative; }
.area-items a::after { content: "↗"; position: absolute; right: 0; color: #897043; }
.cert-card { background: transparent; box-shadow: none; padding: 26px 22px; border-color: #ccd6c5; }
.cert-number { display: block; color: #7b6945; font-size: 9px; letter-spacing: .13em; margin-bottom: 26px; }
.strength-card { border: 0; border-left: 1px solid #cbd5c4; border-radius: 0; background: transparent; box-shadow: none; padding: 4px 22px; }
.strength-number { display: block; font-size: 11px; letter-spacing: .12em; color: #8a744a; margin-bottom: 18px; }
.strength-grid { margin-top: 36px; }
.section-contact { background: var(--navy); border-top: 1px solid #355648; }
.section-contact .section-kicker { color: var(--gold); font-size: 10px; margin-bottom: 18px; }
.section-contact h2 { font-size: 30px; font-weight: 500; }
.section-contact .btn-mail { font-size: 16px; }
.contact-inner { gap: 36px; }

.page-head { position: relative; background: #eaf0e5; padding: 65px 0 58px; overflow: hidden; }
.page-head::after { content: "KSTI"; position: absolute; right: 4%; bottom: -45px; font-size: 180px; font-weight: 900; letter-spacing: -.08em; line-height: 1; color: rgba(22,63,53,.035); pointer-events: none; }
.page-head .wrap { position: relative; z-index: 1; }
.page-head h1 { font-size: 38px; font-weight: 500; letter-spacing: -.055em; margin-bottom: 18px; }
.page-badge { font-size: 12px; font-weight: 500; }
.page-head-en { font-weight: 400; color: #6b7d6d; }
.page-lead { font-size: 15px; }
.breadcrumb { font-size: 12px; margin-bottom: 22px; }
.page-head-photo { background-color: var(--navy-deep); background-size: cover; background-position: center; }
.banner-about { background-image: url("../img/const01.png"); }
.banner-services { background-image: url("../img/const02.png"); }
.banner-construction { background-image: url("../img/const03.png"); }
.banner-iso45001 { background-image: url("../img/const04.png"); }
.banner-kosha-ms { background-image: url("../img/const05.png"); }
.banner-esg { background-image: url("../img/const06.png"); }
.page-head-photo::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(8,32,26,.88), rgba(8,32,26,.66) 55%, rgba(8,32,26,.42));
}
.page-head-photo::after { color: rgba(255,255,255,.06); }
.page-head-photo h1 { color: #fff; }
.page-head-photo .page-head-en, .page-head-photo .page-lead, .page-head-photo .breadcrumb { color: #edf0e4; }
.page-head-photo .section-kicker, .page-head-photo .page-badge { color: #efd8a4; }
.page-head-photo .breadcrumb a:hover { color: #efd8a4; }
.area-block { margin-bottom: 56px; }
.area-block:last-child { margin-bottom: 0; }
.area-block-head { padding: 30px; background: #edf1e7; border-left-width: 2px; box-shadow: none; }
.area-block-head .area-no { font-size: 24px; margin-bottom: 14px; }
.area-block-head h2 { font-size: 25px; font-weight: 500; }
.service-card { padding: 25px; }
.service-card h3 { font-size: 18px; font-weight: 500; }
.service-card p { font-size: 14px; }
.service-more { font-size: 12px; padding-top: 16px; }
.detail-lead { font-size: 18px; line-height: 1.9; padding-left: 22px; border-color: #b79a5b; }
.detail-main .check-list { background: #eef2e8; padding: 14px 22px; margin-bottom: 40px; }
.detail-section { margin-bottom: 36px; }
.detail-section h2 { font-size: 22px; font-weight: 500; }
.detail-section p, .about-text p, .info-list dd, .step-list, .plain-list { color: #495d50; }
.side-card, .about-side { padding: 26px; border-top: 2px solid #b79a5b; }
.law-note { background: #ecf0e5; }
.about-grid { gap: 52px; }
.about-text p { line-height: 2.05; margin-bottom: 22px; }
.about-text .ceo-signature { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--line); font-size: 14px; color: var(--navy); }
.ceo-signature span { font-size: 12px; color: var(--ink-soft); }
.ceo-signature strong { font-size: 20px; margin-left: 12px; letter-spacing: .15em; font-weight: 500; }
.site-footer { padding: 50px 0 28px; }
.footer-logo { font-weight: 500; }
.footer-label { color: var(--gold); font-size: 11px; font-weight: 500; letter-spacing: .1em; }
.footer-note, .footer-list { font-size: 12px; }
.footer-bottom { margin-top: 40px; padding-top: 22px; padding-bottom: 28px; }
.copyright { font-size: 11px; }
.mail-dock { background: var(--navy); border: 1px solid #6d856e; font-size: 13px; border-radius: 4px; right: 24px; bottom: 24px; }
.mail-dock:hover { background: var(--navy-deep); }

@media (min-width: 1000px) and (max-width: 1200px) {
  .main-nav > a, .nav-group-btn { padding-left: 8px; padding-right: 8px; font-size: 13px; }
  .logo-img { height: 42px; }
}
@media (max-width: 999px) {
  .credentials-inner { align-items: flex-start; }
  .hero-certs { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .wrap { width: calc(100% - 40px); }
  .header-inner { padding: 14px 0; gap: 14px; }
  .logo-img { height: 40px; }
  .nav-toggle { border-radius: 2px; font-size: 12px; }
  .main-nav { max-height: calc(100svh - 100px); overflow-y: auto; }
  .main-nav > a, .nav-group-btn { font-size: 14px; }
  .nav-cta { margin-bottom: 8px; }
  .hero { padding: 48px 0 0; }
  .hero-image { object-position: 60% center; }
  .hero::after { background: linear-gradient(90deg, rgba(8,32,26,.87), rgba(8,32,26,.4)), linear-gradient(0deg, rgba(8,32,26,.65), transparent); }
  .hero-eyebrow { font-size: 9px; letter-spacing: .18em; margin-bottom: 24px; }
  .hero-badge { font-size: 12px; }
  .hero h1 { font-size: 32px; line-height: 1.45; margin-bottom: 22px; }
  .hero-lead { font-size: 13px; line-height: 1.9; margin-bottom: 28px; }
  .hero-actions { flex-wrap: nowrap; gap: 8px; }
  .hero-actions .btn { width: auto; flex: 1; font-size: 12px; padding: 13px 10px; gap: 12px; }
  .hero-bottom { margin-top: 38px; padding: 18px 0; align-items: flex-start; }
  .hero-bottom p { max-width: 135px; font-size: 8px; }
  .hero-bottom a { font-size: 10px; gap: 10px; white-space: nowrap; }
  .credentials-inner { padding: 24px 0; display: block; }
  .credentials-label { padding: 0; margin-bottom: 18px; border: 0; }
  .credentials-label br { display: none; }
  .credentials-label strong { display: inline-block; margin-left: 14px; font-size: 12px; }
  .hero-certs { gap: 12px 8px; }
  .hero-certs li { font-size: 10px; }
  .hero-certs li span { margin-right: 2px; }
  .section { padding: 48px 0; }
  .section-kicker { font-size: 9px; }
  .section-title { font-size: 26px; }
  .section-lead { font-size: 13px; margin-bottom: 26px; }
  .area-grid, .cert-grid, .strength-grid, .service-grid { gap: 16px; }
  .area-card, .cert-card, .strength-card, .service-card, .side-card, .about-side { padding: 24px; }
  .area-no { margin-bottom: 20px; }
  .strength-grid { margin-top: 28px; gap: 24px; }
  .strength-card { padding-top: 0; padding-bottom: 0; }
  .cert-number { margin-bottom: 16px; }
  .section-contact h2 { font-size: 26px; }
  .section-contact p { font-size: 13px; }
  .section-contact .btn-mail { font-size: 14px; }
  .contact-inner { gap: 24px; }
  .page-head { padding: 38px 0; }
  .page-head h1 { font-size: 28px; }
  .page-head-en { display: block; font-size: 12px; margin-top: 10px; }
  .page-lead { font-size: 13px; }
  .page-head::after { font-size: 110px; bottom: -20px; }
  .area-block-head { padding: 24px; }
  .area-block-head h2 { font-size: 22px; }
  .detail-lead { font-size: 16px; }
  .detail-main .check-list { padding: 12px 16px; }
  .detail-section h2 { font-size: 20px; }
  .about-grid { gap: 30px; }
  .ceo-signature strong { display: block; margin: 12px 0 0; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { padding-bottom: 50px; }
  .mail-dock { right: 16px; bottom: 16px; padding: 12px 16px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}