:root {
  --bg: #fbfbfa;
  --surface: #ffffff;
  --text: #1d1f23;
  --muted: #5d636e;
  --border: #e4e5e8;
  --accent: #2f6fdb;
  --accent-contrast: #ffffff;
  --accent-soft: #e9f0fc;
  --radius: 12px;
  --max: 64rem;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", "Noto Sans JP", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171b;
    --surface: #1c1f24;
    --text: #e6e7ea;
    --muted: #a0a6b1;
    --border: #2d3139;
    --accent: #7aa8f5;
    --accent-contrast: #0f1115;
    --accent-soft: #1f2b40;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.65;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-underline-offset: 0.2em;
}

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0 0 0.5em;
}

h1 {
  font-size: clamp(1.9rem, 4vw + 1rem, 2.75rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.5rem;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1.125rem;
}

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1rem;
}

main.container {
  flex: 1;
  padding-top: 3rem;
  padding-bottom: 4rem;
}

.skip-link {
  position: absolute;
  left: -999px;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  background: var(--surface);
  padding: 0.5rem 1rem;
}

/* Header & footer */

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-top: 1rem;
  padding-bottom: 1rem;
}

.brand {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav,
.footer-links,
.tags,
.post-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--text);
}

.nav a[aria-current="page"] {
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 2px;
}

.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9375rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-top: 1.5rem;
  padding-bottom: 1.5rem;
}

.footer-inner p {
  margin: 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
}

.footer-links a {
  color: var(--muted);
}

/* Hero */

.hero {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 2rem;
  align-items: start;
  margin-bottom: 1rem;
}

.avatar {
  width: 112px;
  height: 112px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--surface);
  box-shadow: 0 0 0 1px var(--border);
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  margin: 0 0 0.5rem;
}

.lead {
  color: var(--muted);
  font-size: 1.1875rem;
  max-width: 44rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.button {
  display: inline-block;
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-contrast);
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--accent);
}

.button.secondary {
  background: transparent;
  color: var(--accent);
}

.button:hover {
  filter: brightness(1.08);
}

@media (max-width: 640px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .avatar {
    width: 88px;
    height: 88px;
  }
}

/* Sections, cards & lists */

.section {
  margin-top: 4rem;
}

.section-heading {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  margin-bottom: 1.25rem;
}

.section-heading h2 {
  margin: 0;
}

.page-header {
  margin-bottom: 2.5rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 18rem), 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.card h2 {
  font-size: 1.3rem;
}

.card p {
  margin: 0 0 0.75rem;
  color: var(--muted);
}

.card ul:not(.tags) {
  margin: 0;
  padding-left: 1.2rem;
}

.card h3 a {
  color: var(--text);
  text-decoration: none;
}

.card h3 a:hover {
  color: var(--accent);
}

.card-links {
  display: flex;
  gap: 1rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1rem;
}

.tags li {
  font-size: 0.8125rem;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

.post-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
}

.post-list li:first-child {
  border-top: 1px solid var(--border);
}

.post-link {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.25rem 1rem;
  text-decoration: none;
}

.post-title {
  color: var(--text);
  font-weight: 600;
}

.post-link:hover .post-title {
  color: var(--accent);
}

.post-link time {
  color: var(--muted);
  font-size: 0.9375rem;
  white-space: nowrap;
}

.post-excerpt {
  margin: 0.35rem 0 0;
  color: var(--muted);
  font-size: 0.9688rem;
}

.callout {
  background: var(--accent-soft);
  border-radius: var(--radius);
  padding: 2rem;
}

.prose {
  max-width: 42rem;
}

.prose h2 {
  margin-top: 2.5rem;
}