/* =====================================================
   InterLink Homepage — AWS-inspired
   (c) 2026 (주)에이블에스티
===================================================== */

:root {
  --c-navy:        #232F3E;
  --c-navy-2:      #1B2330;
  --c-navy-deep:   #131A24;
  --c-orange:      #FF9900;
  --c-orange-dark: #EC7211;
  --c-blue:        #146EB4;
  --c-text:        #16191F;
  --c-text-mute:   #545B64;
  --c-bg:          #FFFFFF;
  --c-bg-alt:      #FAFAFA;
  --c-bg-alt2:     #F2F4F7;
  --c-line:        #E5E7EB;
  --shadow-sm:     0 1px 2px rgba(0,0,0,.06);
  --shadow:        0 4px 12px rgba(0,0,0,.08);
  --shadow-lg:     0 12px 32px rgba(16,24,40,.12);
  --radius:        8px;
  --radius-lg:     12px;
  --maxw:          1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont,
               "Apple SD Gothic Neo", "Malgun Gothic", "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  font-feature-settings: "ss01", "ss02", "tnum";
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
h1, h2, h3, h4 { letter-spacing: -.02em; }

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ============ TOP BAR ============ */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-navy);
  color: #fff;
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.topbar-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 32px;
  padding: 0 24px;
  height: 60px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  color: #fff;
  white-space: nowrap;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  color: var(--c-orange);
  flex-shrink: 0;
}
.brand-mark svg { width: 100%; height: 100%; display: block; }
.brand-name { letter-spacing: -.3px; line-height: 1; }
.brand-by {
  font-size: 11px;
  font-weight: 400;
  color: rgba(255,255,255,.55);
  margin-left: 2px;
}

.topnav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
}
.topnav a {
  display: inline-block;
  padding: 8px 14px;
  font-size: 14px;
  color: rgba(255,255,255,.85);
  border-radius: 4px;
  transition: color .15s, background .15s;
}
.topnav a:hover {
  color: var(--c-orange);
  background: rgba(255,255,255,.04);
}

.topbar-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

.hamburger {
  display: none;
  background: none;
  border: 0;
  cursor: pointer;
  width: 32px;
  height: 32px;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  transition: transform .2s;
}

/* ============ BUTTONS ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 4px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .1s, background .15s, border-color .15s, color .15s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-lg { padding: 13px 28px; font-size: 15px; }

.btn-primary {
  background: var(--c-orange);
  color: #111;
  border-color: var(--c-orange);
}
.btn-primary:hover { background: var(--c-orange-dark); border-color: var(--c-orange-dark); color: #fff; }

.btn-ghost {
  background: transparent;
  color: rgba(255,255,255,.9);
  border-color: rgba(255,255,255,.25);
}
.btn-ghost:hover { background: rgba(255,255,255,.08); color: #fff; }

.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,.45);
}
.btn-outline:hover { background: rgba(255,255,255,.08); border-color: #fff; }

.btn-outline-light {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,.5);
}
.btn-outline-light:hover { background: rgba(255,255,255,.1); }

/* ============ HERO ============ */
.hero {
  position: relative;
  background: var(--c-navy);
  color: #fff;
  overflow: hidden;
  padding: 100px 0 90px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 85% 20%, rgba(255,153,0,.10), transparent 45%),
    linear-gradient(135deg, #1B2330 0%, #232F3E 100%);
}
.hero-inner {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  text-align: left;
}
.eyebrow {
  display: inline-block;
  margin: 0 0 14px;
  padding: 5px 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--c-orange);
  background: rgba(255,153,0,.1);
  border: 1px solid rgba(255,153,0,.3);
  border-radius: 100px;
}
.eyebrow.center { display: block; text-align: center; max-width: max-content; margin: 0 auto 14px; }
.hero h1 {
  margin: 0 0 24px;
  font-size: 56px;
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -1.5px;
}
.hero h1 .accent { color: var(--c-orange); }
.hero-sub {
  max-width: 680px;
  font-size: 18px;
  color: rgba(255,255,255,.78);
  margin: 0 0 36px;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}
.hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 48px;
}
.hero-chips span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 12.5px;
  font-weight: 500;
  color: rgba(255,255,255,.78);
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.10);
  border-radius: 100px;
  letter-spacing: .01em;
}
.hero-chips span::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--c-orange);
  box-shadow: 0 0 8px rgba(255,153,0,.6);
}
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 56px;
  padding-top: 32px;
  border-top: 1px solid rgba(255,255,255,.12);
  max-width: 720px;
}
.hero-stats > div {
  display: flex;
  flex-direction: column;
}
.hero-stats strong {
  font-size: 32px;
  font-weight: 700;
  color: var(--c-orange);
  line-height: 1.1;
}
.hero-stats span {
  font-size: 13px;
  color: rgba(255,255,255,.65);
  margin-top: 4px;
}

/* ============ SECTION ============ */
.section {
  padding: 90px 0;
  background: var(--c-bg);
}
.section-alt { background: var(--c-bg-alt); }
.section-dark {
  background: var(--c-navy-deep);
  color: #fff;
}

.section-title {
  margin: 0 0 16px;
  font-size: 40px;
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -1px;
  text-align: center;
}
.section-title.light { color: #fff; }
.section-sub {
  max-width: 720px;
  margin: 0 auto 56px;
  font-size: 17px;
  color: var(--c-text-mute);
  text-align: center;
}
.section-sub.light { color: rgba(255,255,255,.7); }

/* ============ CATEGORY GRID ============ */
.cat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.cat-card {
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
  cursor: default;
}
.cat-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(16,24,40,.08);
  border-color: #D1D5DB;
}
.cat-icon {
  width: 52px;
  height: 52px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.cat-card h3 {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -.4px;
}
.cat-desc {
  margin: 0 0 18px;
  font-size: 14px;
  color: var(--c-text-mute);
}
.cat-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
  padding-top: 16px;
}
.cat-list li {
  font-size: 13.5px;
  color: var(--c-text);
  padding: 6px 0;
}
.cat-list li b {
  color: var(--c-blue);
  font-weight: 600;
}

/* ============ SOLUTIONS ============ */
.sol-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.sol-card {
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: 28px 22px;
  position: relative;
  transition: transform .2s, box-shadow .2s;
}
.sol-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}
.sol-card h4 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-navy);
}
.sol-card p {
  margin: 0;
  font-size: 14px;
  color: var(--c-text-mute);
}

/* ============ WHY ============ */
.why-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.why-card {
  background: var(--c-bg-alt2);
  border-radius: var(--radius-lg);
  padding: 32px;
  position: relative;
  overflow: hidden;
}
.why-num {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-orange);
  letter-spacing: .15em;
  margin-bottom: 12px;
}
.why-card h4 {
  margin: 0 0 12px;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -.4px;
}
.why-card p {
  margin: 0;
  font-size: 15px;
  color: var(--c-text-mute);
  line-height: 1.7;
}

/* ============ TECH ============ */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.tech-item {
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: var(--radius);
  padding: 22px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: background .2s, border-color .2s;
}
.tech-item:hover {
  background: rgba(255,153,0,.06);
  border-color: rgba(255,153,0,.3);
}
.tech-item strong {
  color: var(--c-orange);
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  font-weight: 700;
}
.tech-item span {
  color: #fff;
  font-size: 16px;
  font-weight: 600;
}

/* ============ CTA BAND ============ */
.cta-band {
  background: linear-gradient(120deg, var(--c-navy) 0%, var(--c-navy-2) 100%);
  color: #fff;
  padding: 70px 0;
}
.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}
.cta-inner h2 {
  margin: 0 0 8px;
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -.6px;
}
.cta-inner p {
  margin: 0;
  font-size: 16px;
  color: rgba(255,255,255,.8);
}
.cta-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ============ AI SECTION ============ */
.ai-section {
  position: relative;
  background: #0F1622;
  color: #fff;
  overflow: hidden;
}
.ai-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 30%, rgba(107,70,193,.32), transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(20,110,180,.22), transparent 50%),
    linear-gradient(135deg, #0F1622 0%, #1B1530 100%);
  pointer-events: none;
}
.ai-inner { position: relative; }
.ai-head { text-align: center; margin-bottom: 48px; }
.ai-head .section-title { font-size: 36px; }

.ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 1000px;
  margin: 0 auto 40px;
}
.ai-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
  padding: 24px 26px;
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: var(--radius-lg);
  transition: background .2s, border-color .2s, transform .15s;
}
.ai-card:hover {
  background: rgba(107,70,193,.08);
  border-color: rgba(107,70,193,.45);
  transform: translateY(-2px);
}
.ai-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #6B46C1 0%, #146EB4 100%);
  flex-shrink: 0;
}
.ai-card h4 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -.3px;
  color: #fff;
}
.ai-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(255,255,255,.75);
}
.ai-cta {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

@media (max-width: 720px) {
  .ai-grid { grid-template-columns: 1fr; }
  .ai-head .section-title { font-size: 26px; }
}

/* ============ FOOTER ============ */
.footer {
  background: var(--c-navy-deep);
  color: rgba(255,255,255,.7);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding-bottom: 40px;
}
.footer h5 {
  color: #fff;
  font-size: 14px;
  margin: 0 0 16px;
  font-weight: 700;
  letter-spacing: .02em;
}
.footer a {
  display: block;
  color: rgba(255,255,255,.65);
  font-size: 14px;
  padding: 4px 0;
  transition: color .15s;
}
.footer a:hover { color: var(--c-orange); }
.footer .muted { color: rgba(255,255,255,.4); font-size: 13px; }
.footer-co {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(255,255,255,.65);
}
.footer-co strong { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  padding: 20px 0;
  font-size: 13px;
  color: rgba(255,255,255,.5);
}

/* ============ RESPONSIVE ============ */
@media (max-width: 960px) {
  .cat-grid { grid-template-columns: repeat(2, 1fr); }
  .sol-grid { grid-template-columns: repeat(2, 1fr); }
  .tech-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 42px; }
  .section-title { font-size: 32px; }
}

@media (max-width: 720px) {
  .topnav, .topbar-actions { display: none; }
  .hamburger { display: flex; }
  .topbar.is-open .topnav {
    display: flex;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--c-navy);
    padding: 12px 24px;
    border-top: 1px solid rgba(255,255,255,.08);
    gap: 0;
  }
  .topbar.is-open .topnav a {
    padding: 12px 0;
    border-bottom: 1px solid rgba(255,255,255,.06);
  }

  .hero { padding: 60px 0 60px; }
  .hero h1 { font-size: 34px; }
  .hero-sub { font-size: 16px; }
  .hero-stats { gap: 32px; }
  .hero-stats strong { font-size: 26px; }

  .section { padding: 60px 0; }
  .section-title { font-size: 26px; }
  .section-sub { font-size: 15px; margin-bottom: 40px; }

  .cat-grid, .sol-grid, .why-grid, .tech-grid, .footer-grid {
    grid-template-columns: 1fr;
  }

  .cta-inner { flex-direction: column; align-items: flex-start; }
  .cta-inner h2 { font-size: 24px; }
}