:root {
  --bg: #ffffff;
  --bg-dark: #0b0d12;
  --bg-soft: #f6f7f9;
  --bg-accent: #0f1219;
  --fg: #1a1d24;
  --fg-soft: #555a66;
  --fg-mute: #8a8f99;
  --fg-on-dark: #e8eaef;
  --fg-on-dark-soft: #a5aab5;
  --accent: #4f8cff;
  --accent-deep: #2563eb;
  --accent-glow: rgba(79, 140, 255, 0.18);
  --border: #e5e7eb;
  --border-dark: #1c1f27;
  --max-w: 880px;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow: 0 8px 24px rgba(0,0,0,0.06);
  --shadow-lg: 0 24px 64px rgba(0,0,0,0.08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI',
               'Helvetica Neue', Arial, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'ss05', 'ss06';
  word-break: keep-all;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-deep); }

/* ============ NAV ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 32px;
  background: rgba(255,255,255,0.86);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  font-size: 15px;
}

.brand-mark {
  color: var(--accent);
  font-size: 18px;
  transform: rotate(45deg);
  display: inline-block;
}

.brand-name { letter-spacing: 0.18em; }
.brand-ai { color: var(--accent); }

.nav-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--fg);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ============ HERO ============ */
.hero {
  min-height: 78vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 80px 24px 60px;
  background:
    radial-gradient(ellipse at 50% 20%, var(--accent-glow), transparent 60%),
    linear-gradient(180deg, #fafbfd 0%, #ffffff 100%);
  border-bottom: 1px solid var(--border);
}

.hero-eyebrow {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.32em;
  color: var(--accent);
  margin-bottom: 28px;
}

.hero-title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
}

.accent { color: var(--accent); }

.hero-sub {
  font-size: clamp(16px, 2vw, 19px);
  color: var(--fg-soft);
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-cta { margin-top: 16px; }

.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
}

.btn-ghost {
  background: transparent;
  color: var(--fg-soft);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* ============ SECTION ============ */
.section {
  padding: 110px 24px;
  border-bottom: 1px solid var(--border);
}

.section > * { max-width: var(--max-w); margin-left: auto; margin-right: auto; }

.section-dark {
  background: var(--bg-dark);
  color: var(--fg-on-dark);
  border-color: var(--border-dark);
}

.section-dark .section-body,
.section-dark .section-foot {
  color: var(--fg-on-dark-soft);
}

.section-dark strong { color: #fff; }

.section-eyebrow {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.32em;
  color: var(--accent);
  margin-bottom: 24px;
  text-align: center;
}

.section-title {
  font-size: clamp(28px, 4.5vw, 44px);
  font-weight: 800;
  letter-spacing: -0.018em;
  line-height: 1.25;
  margin-bottom: 32px;
  text-align: center;
}

.section-body {
  font-size: 17px;
  color: var(--fg-soft);
  line-height: 1.8;
  margin-bottom: 8px;
  max-width: 640px;
  text-align: center;
}

.section-lede {
  font-size: 19px;
  line-height: 1.7;
  color: var(--fg);
  margin-bottom: 56px;
  font-weight: 500;
  max-width: 640px;
  text-align: center;
}

.section-foot {
  margin-top: 36px;
  font-size: 14px;
  color: var(--fg-mute);
  font-style: italic;
  text-align: center;
}

/* ============ BIG NUMBER ============ */
.big-number {
  margin: 36px auto 28px;
  text-align: center;
}

.big-number .num {
  display: block;
  font-size: clamp(56px, 12vw, 132px);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.04em;
  color: #fff;
  font-feature-settings: 'tnum';
}

.big-number .num-cap {
  display: block;
  margin-top: 16px;
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--fg-on-dark-soft);
  text-transform: uppercase;
}

/* ============ QUOTE ============ */
.quote-card {
  margin: 24px auto 36px;
  padding: 40px 36px 36px;
  background: var(--bg-soft);
  border-radius: var(--radius-lg);
  position: relative;
}

.quote-mark {
  font-size: 80px;
  line-height: 0.6;
  color: var(--accent);
  font-family: Georgia, serif;
  margin-bottom: 16px;
  font-weight: 700;
}

.quote-text {
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 600;
  color: var(--fg);
  line-height: 1.5;
}

/* ============ PROBLEM GRID ============ */
.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 36px auto 12px;
}

.problem-grid-2 { grid-template-columns: repeat(2, 1fr); }

@media (max-width: 720px) {
  .problem-grid,
  .problem-grid-2 { grid-template-columns: 1fr; }
}

.problem-card {
  padding: 32px 28px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.2s;
  text-align: left;
}

.problem-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.section-dark .problem-card {
  background: rgba(255,255,255,0.04);
  border-color: var(--border-dark);
}

.problem-num {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 14px;
}

.problem-card h3 {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--fg);
}

.problem-card p {
  font-size: 14.5px;
  color: var(--fg-soft);
  line-height: 1.7;
}

.section-dark .problem-card h3 { color: #fff; }
.section-dark .problem-card p { color: var(--fg-on-dark-soft); }

/* ============ COST TABLE ============ */
.cost-table {
  width: 100%;
  margin: 28px auto 8px;
  border-collapse: collapse;
  font-size: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.cost-table th,
.cost-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.cost-table th {
  background: var(--bg-soft);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--fg-soft);
  text-transform: uppercase;
}

.cost-table td:nth-child(2),
.cost-table td:nth-child(3) {
  font-feature-settings: 'tnum';
  font-variant-numeric: tabular-nums;
  color: var(--fg-soft);
}

.cost-table tbody tr:last-child td { border-bottom: none; }

.row-highlight td {
  background: linear-gradient(90deg, var(--accent-glow), transparent);
  color: var(--fg) !important;
  font-weight: 700;
}

.row-highlight td:first-child {
  border-left: 3px solid var(--accent);
}

/* ============ SECTION ACCENT (Solution) ============ */
.section-accent {
  background:
    radial-gradient(ellipse at 80% 20%, var(--accent-glow), transparent 50%),
    linear-gradient(180deg, #f8fafe 0%, #ffffff 100%);
  border-color: var(--border);
}

.section-accent .section-title {
  background: linear-gradient(135deg, var(--accent-deep) 0%, #06b6d4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin: 16px auto 36px;
}

@media (max-width: 720px) {
  .metric-grid { grid-template-columns: 1fr; }
}

.metric {
  padding: 36px 28px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: left;
  transition: all 0.2s;
}

.metric:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.metric-num {
  font-size: clamp(52px, 7vw, 76px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--accent-deep);
  font-feature-settings: 'tnum';
  margin-bottom: 14px;
}

.metric-x {
  font-size: 0.4em;
  font-weight: 700;
  color: var(--fg-mute);
  margin-left: 4px;
}

.metric-label {
  font-size: 15px;
  font-weight: 700;
  color: var(--fg);
  margin-bottom: 8px;
  line-height: 1.4;
}

.metric-foot {
  font-size: 13px;
  color: var(--fg-mute);
  font-style: italic;
}

.accent-foot {
  font-size: 16px;
  font-weight: 600;
  font-style: normal;
  color: var(--accent);
  text-align: center;
  margin-top: 16px;
}

/* ============ CTA ============ */
.section-cta {
  background: var(--bg-soft);
  text-align: center;
}

.section-cta .section-title { margin-bottom: 56px; }

.cta-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

@media (max-width: 720px) {
  .cta-grid { grid-template-columns: 1fr; }
}

.cta-card {
  display: block;
  padding: 44px 32px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: left;
  transition: all 0.25s;
  color: var(--fg);
}

.cta-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  color: var(--fg);
}

.cta-card-primary {
  background: linear-gradient(135deg, var(--bg-dark) 0%, #1a1d28 100%);
  color: var(--fg-on-dark);
  border-color: var(--bg-dark);
}

.cta-card-primary:hover { color: var(--fg-on-dark); }

.cta-card-primary p { color: var(--fg-on-dark-soft); }

.cta-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  margin-bottom: 24px;
}

.cta-card h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: -0.01em;
}

.cta-card p {
  font-size: 15px;
  color: var(--fg-soft);
  line-height: 1.7;
  margin-bottom: 24px;
}

.cta-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.02em;
}

.cta-card-primary .cta-link { color: var(--accent); }

/* ============ FOOTER ============ */
.footer {
  background: var(--bg-dark);
  color: var(--fg-on-dark);
  padding: 64px 24px 40px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 24px;
  font-size: 16px;
}

.footer-info {
  font-size: 14px;
  color: var(--fg-on-dark-soft);
  line-height: 1.9;
  max-width: 600px;
  margin: 0 auto 36px;
}

.footer-contact { margin-top: 12px; }
.footer-contact a { color: var(--accent); }

.footer-fine {
  font-size: 12px;
  color: #555a66;
  letter-spacing: 0.04em;
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--border-dark);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 600px) {
  .nav { padding: 14px 20px; }
  .section { padding: 80px 20px; }
  .hero { padding: 60px 20px 50px; }
  .quote-card { padding: 32px 24px; }
  .cost-table th, .cost-table td { padding: 12px 14px; font-size: 14px; }
  .cost-table th:first-child, .cost-table td:first-child { font-size: 13px; }
}