/* ═══════════════════════════════════════════════════
   COBSLAB — Global Stylesheet
   Modern & Minimal Design System
   ═══════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;600;700;900&family=Sora:wght@300;400;500;600;700;800&display=swap');

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

:root {
  --bg: #FAFAFA;
  --bg-alt: #FFFFFF;
  --bg-dark: #0A0A0A;
  --bg-dark-alt: #111111;
  --text: #1A1A1A;
  --text-light: #6B6B6B;
  --text-muted: #999;
  --accent: #2563EB;
  --accent-hover: #1D4ED8;
  --accent-light: #DBEAFE;
  --accent-subtle: #EFF6FF;
  --border: #E5E5E5;
  --border-light: #F0F0F0;
  --card-bg: #FFFFFF;
  --gradient-1: linear-gradient(135deg, #2563EB 0%, #7C3AED 100%);
  --gradient-2: linear-gradient(135deg, #0A0A0A 0%, #1E293B 100%);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.08);
  --shadow-accent: 0 4px 20px rgba(37,99,235,0.3);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }

/* ─── NAV ─── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(250,250,250,0.88);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
nav.scrolled { box-shadow: 0 1px 20px rgba(0,0,0,0.06); }
.nav-inner {
  max-width: 1280px; margin: 0 auto;
  padding: 0 2rem;
  display: flex; align-items: center; justify-content: space-between;
  height: 72px;
}
.logo {
  font-family: 'Sora', sans-serif;
  font-weight: 800; font-size: 1.4rem;
  letter-spacing: -0.5px;
  color: var(--text);
}
.logo span { color: var(--accent); }
.nav-links { display: flex; gap: 2.2rem; list-style: none; }
.nav-links a {
  color: var(--text-light);
  font-size: 0.875rem; font-weight: 500;
  transition: color 0.2s;
  letter-spacing: -0.2px;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute; bottom: -4px; left: 0; right: 0;
  height: 2px; background: var(--accent);
  transform: scaleX(0); transition: transform 0.3s;
}
.nav-links a:hover { color: var(--text); }
.nav-links a:hover::after, .nav-links a.active::after { transform: scaleX(1); }
.nav-links a.active { color: var(--accent); }
.nav-cta {
  background: var(--text); color: #fff;
  padding: 0.6rem 1.5rem; border-radius: var(--radius-sm);
  font-size: 0.85rem; font-weight: 500;
  transition: var(--transition);
}
.nav-cta:hover { background: var(--accent); transform: translateY(-1px); }

/* Mobile Nav */
.mobile-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.mobile-toggle span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; transition: 0.3s; }
.mobile-menu {
  display: none; position: fixed; top: 72px; left: 0; right: 0;
  background: rgba(250,250,250,0.98);
  backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 2rem;
}
.mobile-menu.open { display: block; }
.mobile-menu a {
  display: block; padding: 0.75rem 0;
  color: var(--text); font-weight: 500;
  border-bottom: 1px solid var(--border-light);
}

/* ─── BUTTONS ─── */
.btn-primary {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--gradient-1); color: #fff;
  padding: 0.9rem 2rem; border-radius: var(--radius-md);
  font-size: 0.95rem; font-weight: 600;
  transition: var(--transition); border: none; cursor: pointer;
  box-shadow: var(--shadow-accent);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(37,99,235,0.4); }
.btn-secondary {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: transparent; color: var(--text);
  padding: 0.9rem 2rem; border-radius: var(--radius-md);
  font-size: 0.95rem; font-weight: 500;
  border: 1px solid var(--border); transition: var(--transition);
}
.btn-secondary:hover { border-color: var(--text); transform: translateY(-2px); }
.btn-outline {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: transparent; color: var(--accent);
  padding: 0.7rem 1.5rem; border-radius: var(--radius-sm);
  font-size: 0.85rem; font-weight: 600;
  border: 1px solid var(--accent); transition: var(--transition); cursor: pointer;
}
.btn-outline:hover { background: var(--accent); color: #fff; }

/* ─── SECTIONS ─── */
section { padding: 7rem 2rem; }
.section-inner { max-width: 1280px; margin: 0 auto; }
.section-label {
  font-family: 'Sora', sans-serif;
  font-size: 0.72rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 3px;
  color: var(--accent); margin-bottom: 1rem;
}
.section-title {
  font-family: 'Sora', sans-serif;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700; letter-spacing: -1.5px;
  line-height: 1.25; margin-bottom: 1rem;
}
.section-desc { color: var(--text-light); max-width: 560px; font-size: 1.05rem; margin-bottom: 3rem; line-height: 1.8; }
.section-header-center { text-align: center; }
.section-header-center .section-desc { margin-left: auto; margin-right: auto; }

/* ─── PAGE HERO ─── */
.page-hero {
  padding: 10rem 2rem 5rem;
  background: var(--bg-dark); color: #fff;
  position: relative; overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute; top: -40%; right: -15%;
  width: 700px; height: 700px;
  background: radial-gradient(circle, rgba(37,99,235,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.page-hero .section-label { color: rgba(255,255,255,0.35); }
.page-hero .section-desc { color: rgba(255,255,255,0.5); }

/* ─── CARDS ─── */
.card {
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--card-bg);
  transition: var(--transition);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card-accent:hover { border-color: var(--accent); }

/* ─── CLIENT LOGOS ─── */
.logo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}
.logo-item {
  display: flex; align-items: center; justify-content: center;
  gap: 0.75rem;
  padding: 1.25rem 1.5rem;
  background: #fff;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  transition: var(--transition);
  min-height: 80px;
}
.logo-item:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.logo-item img {
  width: 36px; height: 36px;
  object-fit: contain;
  border-radius: 6px;
  flex-shrink: 0;
}
.logo-item .logo-info { text-align: left; }
.logo-item .logo-name { font-weight: 600; font-size: 0.9rem; line-height: 1.3; }
.logo-item .logo-type {
  font-size: 0.65rem; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 1px;
  font-weight: 500;
}

/* ─── GRID LAYOUTS ─── */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

/* ─── FOOTER ─── */
footer {
  background: var(--bg-dark); color: #fff;
  padding: 4rem 2rem 2rem;
}
.footer-inner { max-width: 1280px; margin: 0 auto; }
.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand .logo { color: #fff; margin-bottom: 1rem; }
.footer-brand p { color: rgba(255,255,255,0.4); font-size: 0.85rem; line-height: 1.7; max-width: 300px; }
.footer-col h4 {
  font-family: 'Sora', sans-serif;
  font-size: 0.8rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 1.5px;
  color: rgba(255,255,255,0.3);
  margin-bottom: 1.25rem;
}
.footer-col a {
  display: block; color: rgba(255,255,255,0.6);
  font-size: 0.9rem; margin-bottom: 0.6rem;
  transition: color 0.2s;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 2rem; flex-wrap: wrap; gap: 1rem;
}
.footer-bottom p { color: rgba(255,255,255,0.25); font-size: 0.8rem; }

/* ─── SCROLL ANIMATIONS ─── */
.reveal {
  opacity: 0; transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }

/* ─── RESPONSIVE ─── */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 2rem; }
}
@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-cta { display: none; }
  .mobile-toggle { display: block; }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  section { padding: 5rem 1.25rem; }
  .page-hero { padding: 8rem 1.25rem 3.5rem; }
  .footer-top { grid-template-columns: 1fr; }
  .logo-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: 1fr; }
}