:root {
  --bg: #F8FAFC;
  --bg-sub: #E2E8F0;
  --accent: #64748B;
  --accent-sub: #0284C7;
  --text: #0F172A;
  --header-h: 64px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4, p { margin: 0; }
h1 { font-size: 29px; font-weight: 700; }
h2 { font-size: 22px; font-weight: 700; }
h3 { font-size: 18px; font-weight: 700; }
p { font-size: 16px; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
section { padding: 50px 0; }
.section-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section-label { display: block; font-size: 13px; font-weight: 700; color: var(--accent-sub); letter-spacing: .08em; margin-bottom: 12px; }
.section-label.case-badge { display: none; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.section-title { margin-bottom: 8px; }
.section-subtitle { font-weight: 400; color: var(--accent); margin-bottom: 32px; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; padding: 0 20px; border-radius: 8px;
  font-size: 16px; font-weight: 700; border: none; cursor: pointer;
  white-space: nowrap;
}
.btn-primary { background: var(--accent-sub); color: #fff; }
.btn-outline { background: transparent; color: var(--text); border: 1px solid var(--accent); }
.btn-sm { min-height: 38px; padding: 0 16px; font-size: 14px; }
.cta-group { display: flex; gap: 12px; flex-wrap: wrap; }

/* icons */
.icon { width: 24px; height: 24px; color: var(--accent-sub); flex-shrink: 0; }

/* header */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: transparent; transition: background-color .2s, border-color .2s;
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled { background: var(--bg); border-bottom-color: var(--bg-sub); }
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: var(--header-h);
}
.logo { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 18px; }
.nav-pc { display: none; align-items: center; gap: 28px; }
.nav-pc a:not(.btn) { font-weight: 600; }
.hamburger {
  display: flex; flex-direction: column; justify-content: center; gap: 5px;
  width: 44px; height: 44px; background: none; border: none; cursor: pointer;
}
.hamburger span { width: 22px; height: 2px; background: var(--text); display: block; margin: 0 auto; }
.mobile-menu {
  display: flex; flex-direction: column; overflow: hidden;
  max-height: 0; background: var(--bg);
  transition: max-height .3s ease;
}
.mobile-menu.is-open { max-height: 260px; border-top: 1px solid var(--bg-sub); }
.mobile-menu a { padding: 14px 24px; font-weight: 600; min-height: 44px; display: flex; align-items: center; }

@media (min-width: 768px) {
  .nav-pc { display: flex; }
  .hamburger { display: none; }
  .mobile-menu { display: none; }
}

/* page top spacer so fixed header doesn't cover content */
main { display: block; padding-top: var(--header-h); }

/* hero */
.hero {
  position: relative; min-height: 560px; display: flex; align-items: center;
  background-size: cover; background-position: center; color: #fff;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(15,23,42,.35), rgba(15,23,42,.55));
}
.hero-inner { position: relative; z-index: 1; max-width: 700px; }
.hero h1 { font-size: 36px; margin-bottom: 16px; }
.hero p { font-size: 16px; margin-bottom: 24px; }
.hero-bg-main { background-image: url('/images/webp/hero.webp'); }
.hero-label-white { color: #fff; }
.hero .btn-outline { color: #fff; border-color: #fff; }
@media (min-width: 768px) {
  .hero h1 { font-size: 56px; }
}
.hero-headline { font-weight: 700; font-size: 20px; margin-bottom: 12px; }

/* reveal animation */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* check list cards */
.check-card {
  display: flex; gap: 16px; align-items: flex-start;
  background: #fff; border-radius: 12px; padding: 24px;
}
.check-card .icon { color: var(--accent-sub); }
.check-card h3 { margin-bottom: 8px; }
.check-card p { color: var(--accent); }
.check-grid { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 768px) { .check-grid { grid-template-columns: repeat(4, 1fr); } }

/* service / case cards */
.card-grid { display: grid; gap: 24px; grid-template-columns: 1fr; }
@media (min-width: 768px) {
  .card-grid { grid-template-columns: repeat(3, 1fr); }
  .card-grid.grid-1col { grid-template-columns: 1fr; }
}

/* grid slider (mobile horizontal scroll-snap), overrides check-grid/card-grid display when combined */
.slider {
  display: flex; gap: 16px; overflow-x: auto; scroll-snap-type: x mandatory;
  -ms-overflow-style: none; scrollbar-width: none; padding-bottom: 4px;
}
.slider::-webkit-scrollbar { display: none; }
.slider > * { flex: 0 0 100%; scroll-snap-align: start; }
.dots { display: flex; justify-content: center; gap: 8px; margin-top: 16px; }
.dots span { width: 8px; height: 8px; border-radius: 50%; background: var(--bg-sub); }
.dots span.is-active { background: var(--accent-sub); }

@media (min-width: 768px) {
  .slider { overflow: visible; }
  .slider > * { flex: 1 1 0; }
  .dots { display: none; }
}

.card {
  border-radius: 12px; overflow: hidden; background: #fff;
  display: block; position: relative;
}
.card-media { position: relative; overflow: hidden; aspect-ratio: 4/3; }
.card-media img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s ease; }
.card:hover .card-media img { transform: scale(1.06); }
.card-overlay {
  position: absolute; inset: 0; background: rgba(15,23,42,.45);
  display: flex; align-items: flex-end; padding: 16px;
  opacity: 0; transition: opacity .3s ease;
}
.card:hover .card-overlay { opacity: 1; }
.card-overlay span {
  color: #fff; font-weight: 700; transform: translateY(12px); transition: transform .3s ease;
}
.card:hover .card-overlay span { transform: translateY(0); }
.card-body { padding: 16px; }
.card-body h3 { margin-bottom: 8px; }
.card-body p { color: var(--accent); font-size: 15px; }
.card-arrow {
  position: absolute; right: 12px; bottom: 12px; width: 36px; height: 36px;
  border-radius: 50%; background: #fff; display: flex; align-items: center; justify-content: center;
  color: var(--accent-sub); z-index: 2;
}
.card.no-link { cursor: default; }

/* materials comparison */
.compare-grid { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 768px) { .compare-grid { grid-template-columns: 1fr 1fr; } }
.compare-card { background: #fff; border-radius: 12px; padding: 24px; border-top: 4px solid var(--bg-sub); }
.compare-card.is-standard { border-top-color: var(--accent-sub); }
.compare-card ul { margin: 12px 0 0; padding-left: 18px; }
.compare-card li { margin-bottom: 8px; }

/* about strengths */
.strength-card { background: #fff; border-radius: 12px; padding: 24px; }
.strength-card .icon { width: 32px; height: 32px; margin-bottom: 12px; }
.strength-card h3 { margin-bottom: 8px; }
.strength-card p { color: var(--accent); }

/* faq */
.faq-item { border-radius: 12px; background: #fff; margin-bottom: 12px; overflow: hidden; }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding: 18px 20px; font-size: 16px; font-weight: 700; min-height: 44px;
  color: var(--text); font-family: inherit;
}
.faq-q .plus { flex-shrink: 0; transition: transform .25s ease; }
.faq-item.is-open .faq-q .plus { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; }
.faq-item.is-open .faq-a { max-height: 400px; }
.faq-a p { padding: 0 20px 18px; color: var(--accent); }

/* contact steps */
.step-grid { display: grid; gap: 16px; grid-template-columns: 1fr; margin: 32px 0; }
@media (min-width: 768px) { .step-grid { grid-template-columns: repeat(5, 1fr); } }
.step-card { background: #fff; border-radius: 12px; padding: 20px 16px; text-align: center; }
.step-card .num { color: var(--accent-sub); font-weight: 700; margin-bottom: 8px; display: block; }
.photo-guide { display: grid; gap: 16px; grid-template-columns: 1fr; margin: 24px 0; }
@media (min-width: 768px) { .photo-guide { grid-template-columns: 1fr 1fr; } }
.photo-guide-card { background: #fff; border-radius: 12px; padding: 24px; display: flex; gap: 16px; align-items: flex-start; }

.consult-cta { background: var(--bg-sub); text-align: center; }
.consult-cta .cta-group { justify-content: center; }

/* sitemap page */
.sitemap-group { margin-bottom: 32px; }
.sitemap-group h2 { margin-bottom: 16px; }
.sitemap-list { display: grid; gap: 12px; grid-template-columns: 1fr; }
@media (min-width: 768px) { .sitemap-list { grid-template-columns: repeat(2, 1fr); } }
.sitemap-list a { background: #fff; border-radius: 12px; padding: 16px 20px; min-height: 44px; display: flex; align-items: center; font-weight: 600; }

.footer-inner .icon{width:20px;height:20px;margin-right:6px;}

/* footer */
.site-footer { background: var(--text); color: var(--bg-sub); padding: 40px 0; }
.footer-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; flex-direction: column; gap: 24px; }
.footer-brand { font-size: 18px; font-weight: 700; color: #fff; margin-bottom: 8px; }
.footer-info p { font-size: 14px; margin-bottom: 4px; color: var(--bg-sub); }
.footer-nav { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-nav a { display: flex; align-items: center; font-size: 14px; min-height: 44px; }

@media (min-width: 768px) {
  h1 { font-size: 40px; }
  h2 { font-size: 30px; }
  h3 { font-size: 20px; }
  .footer-inner { flex-direction: row; justify-content: space-between; align-items: center; }
}