:root {
  --paper: #faf8f3;
  --paper-shadow: #efeadf;
  --ink: #16140f;
  --ink-2: #36322b;
  --ink-3: #6c665b;
  --ink-4: #a8a195;
  --rule: #d9d3c5;
  --seal: #bf3a26;
  --seal-deep: #8a2517;
}

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

html,
body {
  background: var(--paper);
  color: var(--ink);
}

body {
  font-family: "EB Garamond", serif;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  line-height: 1.6;
}

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

.page {
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 32px 120px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 96px;
  gap: 24px;
}

.mark {
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-2);
  white-space: nowrap;
}

.mark .dot {
  display: inline-block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--seal);
  margin: 0 8px 3px;
  vertical-align: middle;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: lowercase;
  color: var(--ink-3);
  font-style: italic;
}

.nav a {
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 0.2s, border-color 0.2s;
}

.nav a:hover {
  color: var(--ink);
  border-bottom-color: var(--seal);
}

.post-header {
  margin-bottom: 56px;
}

.eyebrow-label {
  font-size: 11px;
  letter-spacing: 0.42em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.eyebrow-label::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--ink-3);
}

.post-title {
  font-family: "EB Garamond", serif;
  font-weight: 700;
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1.04;
  letter-spacing: -0.015em;
  margin-bottom: 20px;
}

.post-meta {
  display: flex;
  gap: 14px;
  align-items: center;
  font-size: 14px;
  color: var(--ink-3);
  font-style: italic;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.post-meta .sep {
  color: var(--rule);
}

.tldr {
  font-size: 19px;
  line-height: 1.65;
  color: var(--ink-2);
  font-style: italic;
  padding-left: 20px;
  border-left: 1px solid var(--rule);
}

.tldr strong {
  font-style: normal;
  font-weight: 600;
  color: var(--ink);
}

.post-content h2 {
  font-family: "EB Garamond", serif;
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  letter-spacing: -0.01em;
  margin: 48px 0 18px;
  line-height: 1.15;
  color: var(--ink);
}

.post-content h3 {
  font-weight: 600;
  font-size: 1.28rem;
  margin: 32px 0 14px;
  font-style: italic;
  color: var(--ink-2);
}

.post-content h4 {
  font-weight: 600;
  font-size: 1rem;
  margin: 28px 0 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
}

.post-content p {
  font-size: 18px;
  line-height: 1.75;
  color: var(--ink-2);
  margin-bottom: 20px;
}

.post-content em {
  color: var(--ink-2);
}

.post-content strong {
  font-weight: 600;
  color: var(--ink);
}

.post-content ul,
.post-content ol {
  margin: 0 0 20px 26px;
}

.post-content li {
  font-size: 18px;
  line-height: 1.75;
  color: var(--ink-2);
  margin-bottom: 8px;
}

.post-content blockquote {
  margin: 32px 0;
  padding: 2px 0 2px 24px;
  border-left: 1px solid var(--seal);
  font-style: italic;
  color: var(--ink-2);
  font-size: 17px;
  line-height: 1.7;
}

.post-content blockquote strong {
  color: var(--seal-deep);
}

.post-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 16px;
}

.post-content th,
.post-content td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--rule);
  text-align: left;
  color: var(--ink-2);
}

.post-content th {
  font-style: italic;
  color: var(--ink-3);
  font-weight: 500;
}

.rule {
  position: relative;
  height: 40px;
  margin: 48px 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.rule::before,
.rule::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--rule);
}

.rule .glyph {
  font-family: "Noto Serif JP", serif;
  font-weight: 300;
  font-size: 16px;
  color: var(--ink-3);
  margin: 0 20px;
  letter-spacing: 0.5em;
}

.post-footer {
  margin-top: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--rule);
}

.post-footer p {
  font-size: 14px;
  color: var(--ink-3);
  font-style: italic;
  line-height: 1.8;
  margin-bottom: 8px;
}

.post-footer a {
  border-bottom: 1px solid var(--ink-3);
  padding-bottom: 2px;
}

.post-footer a:hover {
  color: var(--seal);
  border-color: var(--seal);
}

.site-footer {
  text-align: center;
  padding: 64px 0 0;
  margin-top: 64px;
  font-style: italic;
  font-size: 13px;
  color: var(--ink-3);
}

.architecture-diagram {
  margin: 32px 0;
  padding: 28px 20px;
  background: var(--paper-shadow);
  border: 1px solid var(--rule);
  text-align: center;
}

.flow-box {
  display: inline-block;
  padding: 12px 18px;
  margin: 8px 6px;
  background: var(--paper);
  border: 1px solid var(--rule);
  font-size: 0.92rem;
  font-style: italic;
  color: var(--ink-2);
}

.arrow {
  display: inline-block;
  margin: 0 6px;
  font-size: 1.2rem;
  color: var(--ink-3);
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin: 28px 0;
}

.metric-card {
  padding: 24px 16px;
  background: var(--paper-shadow);
  border: 1px solid var(--rule);
  text-align: center;
}

.metric-value {
  font-family: "EB Garamond", serif;
  font-size: 2rem;
  font-weight: 700;
  color: var(--seal-deep);
  margin: 8px 0;
}

.metric-label {
  font-size: 11px;
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

.highlight-box {
  padding: 20px 22px;
  margin: 28px 0;
  background: var(--paper-shadow);
  border-left: 1px solid var(--seal);
  font-style: italic;
  color: var(--ink-2);
}

.highlight-box strong {
  font-style: normal;
}

.formula {
  padding: 16px 18px;
  margin: 20px 0;
  background: var(--paper-shadow);
  border: 1px solid var(--rule);
  font-family: "SFMono-Regular", "IBM Plex Mono", Menlo, Consolas, monospace;
  font-size: 0.88rem;
  color: var(--ink-2);
  overflow-x: auto;
}

.chart-container {
  margin: 32px 0;
  padding: 24px 20px;
  background: var(--paper-shadow);
  border: 1px solid var(--rule);
}

.bar-chart {
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
  height: 260px;
  margin: 16px 0;
  padding: 16px;
  border-left: 1px solid var(--ink-3);
  border-bottom: 1px solid var(--ink-3);
}

.bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
  margin: 0 8px;
}

.bar-fill {
  width: 100%;
  background: linear-gradient(180deg, var(--seal) 0%, var(--seal-deep) 100%);
  position: relative;
}

.bar-label {
  margin-top: 10px;
  font-size: 0.85rem;
  font-style: italic;
  color: var(--ink-2);
  text-align: center;
}

.bar-value {
  position: absolute;
  top: -26px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
}

@media (max-width: 640px) {
  .page {
    padding: 40px 20px 88px;
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 64px;
  }
}