:root {
  --bg: #ffffff;
  --bg-subtle: #fafafa;
  --bg-soft: #f4f5f7;
  --surface: #ffffff;
  --text: #0a0a0b;
  --text-secondary: #4a4d52;
  --text-tertiary: #6e7178;
  --border: #e8eaed;
  --border-strong: #d6d9de;
  --accent: #0066ff;
  --accent-hover: #0052cc;
  --accent-subtle: #e8f0ff;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 32px rgba(0,0,0,0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; transition: color 0.15s; }
a:hover { color: var(--accent-hover); }

.container { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.container-narrow { max-width: 760px; margin: 0 auto; padding: 0 20px; }

/* === HEADER === */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.brand {
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  letter-spacing: -0.01em;
}
.brand:hover { color: var(--text); }
.brand-icon {
  width: 26px;
  height: 26px;
  display: block;
}
.site-nav { display: flex; gap: 4px; align-items: center; }
.site-nav a {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 8px;
}
.site-nav a:hover {
  color: var(--text);
  background: var(--bg-soft);
}
.site-nav .nav-cta {
  background: var(--text);
  color: white;
  padding: 8px 14px;
  margin-left: 6px;
}
.site-nav .nav-cta:hover {
  background: #1f1f23;
  color: white;
}

/* === HERO === */
.hero { padding: 80px 0 56px; text-align: center; }
.hero-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}
.hero-title {
  font-size: clamp(34px, 6.5vw, 60px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 22px;
}
.hero-sub {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 580px;
  margin: 0 auto 36px;
  line-height: 1.55;
}
.hero-cta-row {
  display: flex; gap: 12px; justify-content: center; align-items: center; flex-wrap: wrap;
}

/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--text);
  color: white;
  font-size: 15px;
  font-weight: 600;
  padding: 13px 24px;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s, transform 0.05s, color 0.15s;
}
.btn:hover { background: #1f1f23; color: white; }
.btn:active { transform: translateY(1px); }
.btn-lg { font-size: 16px; padding: 15px 28px; }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border-strong);
}
.btn-ghost:hover { background: var(--bg-soft); color: var(--text); }
.btn-primary {
  background: var(--accent);
}
.btn-primary:hover { background: var(--accent-hover); color: white; }

/* === SECTIONS === */
.section { padding: 64px 0; }
.section-title {
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 14px;
}
.section-sub {
  font-size: 16px;
  color: var(--text-secondary);
  text-align: center;
  margin: 0 auto 48px;
  max-width: 580px;
}

/* === FEATURES GRID === */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.feature-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}
.feature-icon {
  width: 44px;
  height: 44px;
  background: var(--accent-subtle);
  border-radius: 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  margin-bottom: 18px;
}
.feature-icon svg { width: 22px; height: 22px; }
.feature-title { font-size: 17px; font-weight: 600; margin-bottom: 8px; letter-spacing: -0.01em; }
.feature-desc { font-size: 14px; color: var(--text-secondary); line-height: 1.55; }

/* === STEPS === */
.steps { display: grid; gap: 24px; max-width: 720px; margin: 0 auto; }
.step { display: flex; gap: 18px; align-items: flex-start; }
.step-num {
  flex: none;
  width: 36px;
  height: 36px;
  background: var(--text);
  color: white;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 15px;
}
.step-content h3 { font-size: 17px; font-weight: 600; margin-bottom: 6px; letter-spacing: -0.01em; }
.step-content p { font-size: 15px; color: var(--text-secondary); }

/* === FAQ === */
.faq { max-width: 720px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 20px 0;
}
.faq-item summary {
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  letter-spacing: -0.01em;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 22px;
  color: var(--text-tertiary);
  font-weight: 400;
  flex: none;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item .a {
  margin-top: 12px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
}

/* === CTA BLOCK === */
.cta {
  text-align: center;
  background: var(--bg-soft);
  border-radius: 22px;
  padding: 64px 28px;
  margin: 32px 0;
}
.cta h2 { font-size: clamp(24px, 4vw, 32px); font-weight: 700; letter-spacing: -0.02em; margin-bottom: 12px; }
.cta p { font-size: 16px; color: var(--text-secondary); margin-bottom: 26px; }

/* === ARTICLE / GUIDE === */
.article { padding: 40px 0 80px; }
.article-header { margin-bottom: 36px; }
.article-breadcrumb { font-size: 13px; color: var(--text-tertiary); margin-bottom: 18px; }
.article-breadcrumb a { color: var(--text-secondary); }
.article-title {
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.18;
  margin-bottom: 14px;
}
.article-meta { font-size: 13px; color: var(--text-tertiary); }
.article-body { font-size: 16px; line-height: 1.75; color: #2a2c30; }
.article-body h2 { font-size: 24px; font-weight: 700; letter-spacing: -0.02em; margin: 48px 0 16px; color: var(--text); }
.article-body h3 { font-size: 19px; font-weight: 600; margin: 32px 0 12px; color: var(--text); }
.article-body p { margin-bottom: 18px; }
.article-body ul, .article-body ol { margin: 0 0 22px 22px; }
.article-body li { margin-bottom: 8px; }
.article-body a { color: var(--accent); text-decoration: underline; text-decoration-color: rgba(0,102,255,0.4); text-underline-offset: 3px; }
.article-body blockquote {
  border-left: 3px solid var(--border-strong);
  padding-left: 18px;
  color: var(--text-secondary);
  margin: 22px 0;
}
.article-body code { background: var(--bg-soft); padding: 2px 6px; border-radius: 4px; font-size: 14px; }

.article-cta {
  margin-top: 48px;
  padding: 28px;
  background: var(--bg-soft);
  border-radius: var(--radius-lg);
  text-align: center;
}
.article-cta h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.article-cta p { font-size: 14px; color: var(--text-secondary); margin-bottom: 16px; }

/* === AD SLOTS === */
.ad-slot {
  background: var(--bg-soft);
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius-md);
  padding: 22px;
  text-align: center;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin: 32px 0;
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ad-slot::before { content: "Advertisement"; }

/* === GUIDE LIST === */
.guide-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 18px;
  margin-top: 36px;
}
.guide-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: block;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}
.guide-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
  color: var(--text);
}
.guide-card .tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 3px 9px;
  border-radius: 999px;
  margin-bottom: 12px;
  letter-spacing: 0.04em;
}
.guide-card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; letter-spacing: -0.01em; line-height: 1.35; }
.guide-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.55; }

/* === POLICY === */
.policy { padding: 48px 0 80px; }
.policy h1 { font-size: clamp(28px, 5vw, 38px); font-weight: 700; letter-spacing: -0.025em; margin-bottom: 8px; }
.policy .updated { font-size: 13px; color: var(--text-tertiary); margin-bottom: 32px; }
.policy h2 { font-size: 21px; font-weight: 700; margin: 36px 0 14px; letter-spacing: -0.01em; }
.policy h3 { font-size: 17px; font-weight: 600; margin: 24px 0 10px; }
.policy p, .policy li { font-size: 15px; line-height: 1.75; color: var(--text-secondary); margin-bottom: 12px; }
.policy ul, .policy ol { margin: 0 0 16px 22px; }
.policy strong { color: var(--text); }

/* === FOOTER === */
.site-footer {
  background: var(--bg-subtle);
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  margin-top: 60px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 36px;
}
.footer-brand p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; max-width: 320px; margin-top: 12px; }
.footer-col h4 { font-size: 13px; font-weight: 600; margin-bottom: 12px; color: var(--text); letter-spacing: 0.02em; }
.footer-col a { display: block; color: var(--text-secondary); font-size: 14px; padding: 4px 0; }
.footer-col a:hover { color: var(--text); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-tertiary);
}

@media (max-width: 720px) {
  .hero { padding: 56px 0 40px; }
  .section { padding: 48px 0; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
  .footer-brand { grid-column: 1 / -1; }
  .site-nav a { padding: 8px 10px; font-size: 13px; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
}