:root {
  --primary: #0A84FF;
  --accent: #14B8A6;
  --navy: #0D1B2A;
  --bg: #F2F5F9;
  --bg-elev: #FFFFFF;
  --text: #0F172A;
  --sub: #475569;
  --muted: #94A3B8;
  --line: #E5E7EB;
  --code-bg: #F1F5F9;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Pretendard", "Apple SD Gothic Neo", sans-serif;
  font-size: 17px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
.site-header .inner {
  max-width: 760px; margin: 0 auto;
  padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { font-weight: 700; color: var(--text); font-size: 17px; letter-spacing: -0.01em; }
.brand .dot { color: var(--primary); }
.lang-toggle a {
  display: inline-block; padding: 6px 12px;
  border-radius: 14px;
  font-size: 13px; font-weight: 600;
  color: var(--sub);
}
.lang-toggle a.active { background: var(--primary); color: #fff; }

/* Hero */
.hero {
  max-width: 760px; margin: 0 auto;
  padding: 72px 24px 48px;
  text-align: center;
}
.hero .eyebrow { color: var(--primary); font-size: 13px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; }
.hero h1 { font-size: 44px; line-height: 1.2; font-weight: 800; margin: 16px 0 18px; letter-spacing: -0.02em; }
.hero p { font-size: 19px; color: var(--sub); max-width: 580px; margin: 0 auto; }

/* Post list */
.posts {
  max-width: 760px; margin: 0 auto;
  padding: 0 24px 96px;
}
.post-card {
  display: block;
  padding: 28px 28px;
  margin: 0 0 14px 0;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 18px;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.post-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(10, 132, 255, 0.12);
  border-color: rgba(10, 132, 255, 0.3);
  text-decoration: none;
}
.post-card .num {
  font-size: 12px; font-weight: 700;
  color: var(--primary); letter-spacing: 0.08em;
}
.post-card h2 {
  margin: 8px 0 10px;
  font-size: 22px; line-height: 1.35; font-weight: 700;
  color: var(--text); letter-spacing: -0.01em;
}
.post-card p {
  margin: 0 0 14px;
  color: var(--sub); font-size: 15px; line-height: 1.55;
}
.post-card .tags { display: flex; flex-wrap: wrap; gap: 6px; }
.post-card .tag {
  display: inline-block; padding: 4px 10px;
  font-size: 12px; color: var(--sub);
  background: #F1F5F9; border-radius: 12px;
}

/* Article */
.article {
  max-width: 720px; margin: 0 auto;
  padding: 56px 24px 96px;
}
.article .eyebrow { color: var(--primary); font-size: 13px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; }
.article h1 {
  font-size: 38px; line-height: 1.25; font-weight: 800;
  margin: 14px 0 18px; letter-spacing: -0.02em;
}
.article .meta {
  display: flex; gap: 12px; color: var(--muted); font-size: 13px; margin-bottom: 36px;
}
.article-body h2 {
  margin: 48px 0 16px; font-size: 26px; font-weight: 700; letter-spacing: -0.01em;
}
.article-body h3 { margin: 28px 0 8px; font-size: 19px; font-weight: 700; }
.article-body p { margin: 0 0 18px; }
.article-body ul, .article-body ol { padding-left: 22px; margin: 0 0 18px; }
.article-body li { margin: 6px 0; }
.article-body code {
  font-family: "SF Mono", ui-monospace, monospace;
  background: var(--code-bg); padding: 2px 6px; border-radius: 6px; font-size: 0.92em;
}
.article-body pre {
  background: var(--navy); color: #E2E8F0; padding: 18px 20px; border-radius: 12px;
  overflow-x: auto; font-size: 14px; line-height: 1.55;
}
.article-body pre code { background: transparent; padding: 0; color: inherit; }
.article-body blockquote {
  border-left: 3px solid var(--primary);
  padding: 6px 0 6px 18px; margin: 18px 0; color: var(--sub);
  background: rgba(10, 132, 255, 0.05);
}
.article-body table {
  width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 15px;
}
.article-body th, .article-body td {
  padding: 10px 14px; border: 1px solid var(--line);
  text-align: left; vertical-align: top;
}
.article-body th { background: #F8FAFC; font-weight: 600; }
.article-body hr { border: none; border-top: 1px solid var(--line); margin: 36px 0; }

/* Capture image figure */
.capture {
  margin: 32px auto;
  text-align: center;
}
.capture img {
  display: block;
  margin: 0 auto;
  max-width: 380px;
  width: 100%;
  border-radius: 28px;
  box-shadow: 0 20px 48px rgba(15, 23, 42, 0.12);
}
.capture figcaption {
  margin-top: 14px;
  font-size: 13px;
  color: var(--muted);
}
.capture-missing {
  margin: 28px 0;
  padding: 14px 18px;
  background: #F8FAFC;
  border: 1px dashed var(--line);
  border-radius: 12px;
  color: var(--muted);
  font-size: 13px;
  font-style: italic;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 36px 24px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}
.site-footer a { color: var(--sub); margin: 0 8px; }

/* CTA box */
.cta-box {
  margin: 36px 0;
  padding: 24px 28px;
  background: linear-gradient(135deg, #EFF6FF 0%, #ECFEFF 100%);
  border-radius: 18px;
  text-align: center;
}
.cta-box .cta-title { font-size: 18px; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.cta-box .cta-sub { font-size: 14px; color: var(--sub); margin-bottom: 14px; }
.cta-box .cta-btn {
  display: inline-block; padding: 12px 28px;
  margin: 6px 5px 0;
  background: var(--primary); color: #fff;
  border-radius: 24px; font-weight: 600; font-size: 15px;
}
.cta-box .cta-btn-play { background: var(--accent); }
.cta-box .cta-btn:hover { text-decoration: none; opacity: 0.9; }

/* Language picker (root) */
.picker {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #F2F5F9 0%, #E0F2FE 100%);
  padding: 24px;
}
.picker-card {
  max-width: 520px; width: 100%;
  background: #fff; border-radius: 24px;
  padding: 56px 40px;
  text-align: center;
  box-shadow: 0 24px 64px rgba(15, 23, 42, 0.08);
}
.picker-card .logo { font-size: 28px; font-weight: 800; color: var(--text); margin-bottom: 10px; letter-spacing: -0.02em; }
.picker-card .sub { color: var(--sub); margin-bottom: 32px; font-size: 15px; }
.picker-card .langs {
  display: grid; grid-template-columns: 1fr 1fr; gap: 12px;
}
.picker-card .lang-btn {
  padding: 18px 12px;
  background: var(--bg);
  border-radius: 14px;
  color: var(--text); font-weight: 600; font-size: 16px;
  display: block;
  transition: background 0.15s ease, transform 0.1s ease;
}
.picker-card .lang-btn:hover { background: var(--primary); color: #fff; text-decoration: none; transform: translateY(-1px); }

@media (max-width: 600px) {
  .hero h1 { font-size: 34px; }
  .article h1 { font-size: 30px; }
  .article-body h2 { font-size: 23px; }
  .capture img { max-width: 300px; }
}