:root {
  --bg: #050505;
  --bg-elevated: rgba(10, 10, 10, 0.78);
  --panel: #0d0d0d;
  --line: #232323;
  --line-soft: #171717;
  --text: #f5f5f5;
  --muted: #a1a1aa;
  --muted-2: #71717a;
  --max-width: 920px;
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Apple SD Gothic Neo", "Pretendard", "Inter", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

.shell-inner {
  width: min(calc(100% - 48px), var(--max-width));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--line-soft);
}

.header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.03em;
}

.site-nav {
  display: flex;
  gap: 22px;
}

.site-nav a {
  font-size: 0.95rem;
  color: var(--muted);
  transition: color 0.18s ease;
}

.site-nav a:hover {
  color: var(--text);
}

.site-main {
  min-height: calc(100vh - 145px);
}

.page {
  padding: 56px 0 72px;
}

.page-hero {
  margin-bottom: 42px;
}

.page-hero-compact {
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--muted-2);
  font-size: 0.82rem;
  letter-spacing: 0.16em;
}

.page-title {
  margin: 0;
  font-size: clamp(3rem, 8vw, 5.25rem);
  line-height: 0.98;
  letter-spacing: -0.065em;
  font-weight: 600;
}

.page-subtitle {
  max-width: 720px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  line-height: 1.55;
  letter-spacing: -0.03em;
}

.topic-tabs {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  white-space: nowrap;
  padding-bottom: 16px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
  scrollbar-width: none;
}

.topic-tabs::-webkit-scrollbar {
  display: none;
}

.topic-tab {
  appearance: none;
  border: 0;
  background: none;
  padding: 0;
  color: var(--muted);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  cursor: pointer;
}

.topic-tab.active {
  color: var(--text);
}

.list-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 14px;
}

.toolbar-label,
.toolbar-action {
  font-size: 0.97rem;
  letter-spacing: -0.02em;
}

.toolbar-count {
  font-size: 0.95rem;
  color: var(--muted);
}

.toolbar-action {
  color: var(--muted);
}

.toolbar-action.active {
  color: var(--text);
}

.article-list {
  border-top: 1px solid var(--line-soft);
}

.article-list-tight {
  margin-top: 24px;
}

.article-card {
  border-bottom: 1px solid var(--line);
}

.article-card.is-hidden {
  display: none;
}

.article-link {
  display: block;
  padding: 26px 0 28px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.4;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}

.article-card-title {
  margin: 0 0 14px;
  font-size: clamp(1.45rem, 3vw, 2rem);
  line-height: 1.2;
  letter-spacing: -0.05em;
  font-weight: 500;
}

.article-card-excerpt {
  margin: 0;
  color: var(--muted);
  max-width: 740px;
  font-size: 1rem;
  line-height: 1.65;
  letter-spacing: -0.025em;
}

.article-page {
  padding: 28px 0 80px;
  width: min(calc(100% - 48px), 840px);
  margin: 0 auto;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.95rem;
  letter-spacing: -0.02em;
  margin: 8px 0 26px;
}

.back-link:hover {
  color: var(--text);
}

.article-header {
  margin-bottom: 30px;
}

.article-meta-large {
  margin-bottom: 22px;
}

.article-title {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4.25rem);
  line-height: 1.08;
  letter-spacing: -0.035em;
  font-weight: 600;
  word-break: keep-all;
}

.article-summary {
  margin: 20px 0 0;
  color: var(--text);
  font-size: clamp(1.18rem, 3vw, 1.65rem);
  line-height: 1.42;
  letter-spacing: -0.04em;
  max-width: 760px;
}

.article-divider {
  height: 1px;
  background: var(--line);
  margin: 0 0 34px;
}

.article-cover {
  margin: 0 0 34px;
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid var(--line-soft);
}

.article-cover img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.prose {
  color: #ececec;
  font-size: 1.08rem;
  line-height: 1.8;
  letter-spacing: -0.025em;
}

.prose > *:first-child {
  margin-top: 0;
}

.prose p,
.prose ul,
.prose ol,
.prose blockquote,
.prose pre,
.prose table,
.prose hr {
  margin: 0 0 24px;
}

.prose h2,
.prose h3,
.prose h4 {
  margin: 46px 0 16px;
  line-height: 1.2;
  letter-spacing: -0.045em;
}

.prose h2 { font-size: 2rem; }
.prose h3 { font-size: 1.45rem; }
.prose h4 { font-size: 1.2rem; }

.prose a {
  text-decoration: underline;
  text-underline-offset: 0.18em;
}

.prose ul,
.prose ol {
  padding-left: 1.4rem;
}

.prose li + li {
  margin-top: 0.45rem;
}

.prose blockquote {
  padding-left: 18px;
  border-left: 2px solid var(--line);
  color: var(--muted);
}

.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: #101010;
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  padding: 0.18em 0.42em;
}

.prose pre {
  background: #0d0d0d;
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow-x: auto;
  padding: 20px;
}

.prose pre code {
  background: transparent;
  border: 0;
  padding: 0;
}

.prose img {
  border-radius: 16px;
  border: 1px solid var(--line-soft);
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
}

.article-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 56px;
}

.article-nav-link {
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px 20px;
  min-height: 104px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: linear-gradient(180deg, rgba(255,255,255,0.015), rgba(255,255,255,0));
}

.article-nav-link.next {
  text-align: right;
}

.nav-label {
  color: var(--muted-2);
  font-size: 0.88rem;
  margin-bottom: 12px;
}

.article-nav-link strong {
  font-size: 1rem;
  line-height: 1.45;
  letter-spacing: -0.025em;
}

.site-footer {
  border-top: 1px solid var(--line-soft);
}

.footer-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
}

.footer-inner p {
  margin: 0;
  color: var(--muted-2);
  font-size: 0.88rem;
}

@media (max-width: 720px) {
  .shell-inner,
  .article-page {
    width: min(calc(100% - 40px), var(--max-width));
  }

  .header-inner {
    min-height: 64px;
  }

  .site-nav {
    gap: 14px;
  }

  .site-nav a {
    font-size: 0.9rem;
  }

  .page {
    padding: 40px 0 60px;
  }

  .page-hero {
    margin-bottom: 34px;
  }

  .list-toolbar {
    margin-bottom: 6px;
  }

  .article-link {
    padding: 22px 0 24px;
  }

  .article-meta {
    gap: 12px;
    margin-bottom: 14px;
    font-size: 0.92rem;
  }

  .article-nav {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .shell-inner,
  .article-page {
    width: min(calc(100% - 32px), var(--max-width));
  }

  .header-inner {
    flex-wrap: wrap;
    justify-content: flex-start;
    align-content: center;
    padding: 12px 0;
  }

  .site-nav {
    width: 100%;
    gap: 16px;
  }

  .page-title {
    font-size: 3.45rem;
  }

  .article-title {
    font-size: 2.7rem;
  }

  .article-summary {
    font-size: 1.18rem;
  }
}