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

/* ── Variables ── */
:root {
  --bg: #ffffff;
  --bg-subtle: #fafaf8;
  --border: #ebebeb;
  --text-primary: #111111;
  --text-secondary: #6b6b6b;
  --text-tertiary: #999999;
  --accent: #3182f6;
}

/* ── Base ── */
html {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}
body { min-height: 100vh; display: flex; flex-direction: column; }

/* ── Header ── */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  text-decoration: none;
}
.logo span { color: var(--text-tertiary); font-weight: 400; }

/* ── Nav ── */
.nav { display: flex; align-items: center; gap: 24px; }
.nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
}
.nav a:hover { color: var(--text-primary); }

/* ── Mobile Hamburger ── */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  width: 32px;
  height: 32px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
}
.nav-toggle i {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 1px;
  transition: transform 0.25s, opacity 0.2s;
}
.nav-toggle.active i:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active i:nth-child(2) { opacity: 0; }
.nav-toggle.active i:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  background: var(--bg-subtle);
}
.footer-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.footer-left { display: flex; flex-direction: column; gap: 4px; }
.footer-logo { font-size: 14px; font-weight: 700; color: var(--text-primary); }
.footer-copy { font-size: 12px; color: var(--text-tertiary); }
.footer-links { display: flex; gap: 16px; }
.footer-links a { font-size: 12px; color: var(--text-tertiary); text-decoration: none; }
.footer-links a:hover { color: var(--text-primary); }

/* ── Blog Page Styles ── */
.page-main { flex: 1; max-width: 720px; margin: 0 auto; padding: 48px 24px 80px; width: 100%; }
.breadcrumb { font-size: 13px; color: var(--text-tertiary); margin-bottom: 24px; }
.breadcrumb a { color: var(--text-tertiary); text-decoration: none; }
.breadcrumb a:hover { color: var(--text-primary); }
.page-main h1 { font-size: 28px; font-weight: 700; letter-spacing: -0.5px; margin-bottom: 8px; line-height: 1.4; }
.meta { font-size: 13px; color: var(--text-tertiary); margin-bottom: 40px; }
.updated { font-size: 13px; color: var(--text-tertiary); margin-bottom: 40px; }
.page-main h2 { font-size: 20px; font-weight: 700; margin-top: 40px; margin-bottom: 14px; }
.page-main h3 { font-size: 17px; font-weight: 600; margin-top: 28px; margin-bottom: 10px; }
.page-main p, .page-main li { font-size: 15px; color: var(--text-secondary); line-height: 1.8; }
.page-main p { margin-bottom: 14px; }
.page-main ul, .page-main ol { padding-left: 20px; margin-bottom: 14px; }
.page-main li { margin-bottom: 4px; }
.highlight { color: var(--text-primary); font-weight: 600; }
.cta-box { margin-top: 48px; padding: 28px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg-subtle); text-align: center; }
.cta-box p { margin-bottom: 16px; font-size: 15px; }
.cta-btn { display: inline-block; padding: 12px 32px; background: var(--text-primary); color: #fff; border-radius: 8px; text-decoration: none; font-size: 15px; font-weight: 600; transition: opacity 0.2s; }
.cta-btn:hover { opacity: 0.85; }
.contact-box { margin-top: 24px; padding: 24px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg-subtle); }
.contact-box p { margin-bottom: 8px; }
.contact-box a { color: var(--text-primary); }

/* ── Responsive ── */
@media (max-width: 600px) {
  .nav-toggle { display: flex; }
  .nav {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
  }
  .nav.open { display: flex; }
  .nav a { font-size: 15px; padding: 4px 0; }
  .page-main h1 { font-size: 22px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}