/* Kettlebuild: one stylesheet, system fonts, no build step. */

:root {
  color-scheme: light dark;
  --desk: #f1f2ee;
  --grid: #e2e4de;
  --paper: #fdfdfb;
  --fg: #15171c;
  --muted: #535a65;
  --rule: #d3d6dc;
  --link: #0b5cad;
  --link-hover: #073f78;
  --mark: #a34400;
  --mark-soft: #fbeee3;
  --code-bg: #f0f2f4;
  --code-fg: #15171c;
  --code-border: #d3d6dc;
  --inline-code-bg: #eaedf0;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", "DejaVu Sans Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --desk: #0b0d10;
    --grid: #161a1f;
    --paper: #13161b;
    --fg: #e6e8eb;
    --muted: #a3aab5;
    --rule: #2c313a;
    --link: #7cb8ff;
    --link-hover: #b0d3ff;
    --mark: #ffa45c;
    --mark-soft: #2a1f17;
    --code-bg: #0d0f13;
    --code-fg: #e6e8eb;
    --code-border: #2c313a;
    --inline-code-bg: #20252d;
  }
}

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

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

body {
  margin: 0;
  background-color: var(--desk);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 24px 24px;
  color: var(--fg);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  overflow-wrap: break-word;
}

/* ---------- page frame ---------- */

.sheet {
  display: flex;
  flex-direction: column;
  max-width: 48rem;
  min-height: 100vh;
  margin: 0 auto;
  background: var(--paper);
  border-inline: 1px solid var(--rule);
}

.skip {
  position: absolute;
  top: -4rem;
  left: 0.5rem;
  z-index: 10;
  padding: 0.5rem 0.75rem;
  background: var(--fg);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 0.9rem;
}

.skip:focus {
  top: 0.5rem;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--rule);
  font-family: var(--mono);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--fg);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand img {
  display: block;
}

.brand:hover {
  color: var(--fg);
}

.brand:hover span {
  text-decoration: underline;
  text-decoration-color: var(--mark);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.25em;
}

.site-header ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-header nav a {
  display: inline-block;
  padding: 0.3rem 0;
  color: var(--muted);
  font-size: 0.95rem;
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--fg);
  text-decoration: underline;
}

.site-header nav a[aria-current] {
  color: var(--fg);
  text-decoration: underline;
  text-decoration-color: var(--mark);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.3em;
}

main {
  flex: 1;
  min-width: 0;
  padding: 0 1rem 3rem;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 1.25rem 1rem 2rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.85rem;
}

.site-footer p {
  margin: 0;
}

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

.site-footer a:hover {
  color: var(--fg);
}

@media (min-width: 40em) {
  .site-header,
  .site-footer {
    padding-inline: 2.5rem;
  }

  main {
    padding-inline: 2.5rem;
  }
}

/* ---------- type ---------- */

h1,
h2,
h3 {
  font-family: var(--sans);
  line-height: 1.25;
  letter-spacing: -0.015em;
}

h1 {
  margin: 2.25rem 0 0.75rem;
  font-size: clamp(1.7rem, 1.25rem + 2vw, 2.35rem);
}

h2 {
  margin: 2.5rem 0 0.75rem;
  font-size: 1.35rem;
}

h3 {
  margin: 2rem 0 0.5rem;
  font-size: 1.1rem;
}

.prose > h2::before {
  content: "## ";
  content: "## " / "";
  color: var(--mark);
  font-family: var(--mono);
  font-weight: 600;
}

.prose > h3::before {
  content: "### ";
  content: "### " / "";
  color: var(--mark);
  font-family: var(--mono);
  font-weight: 600;
}

p,
ul,
ol,
dl {
  margin: 0 0 1.1rem;
}

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

li {
  margin: 0.3rem 0;
}

li::marker {
  color: var(--muted);
  font-family: var(--mono);
}

strong {
  font-weight: 650;
}

hr {
  margin: 2.5rem 0;
  border: 0;
  border-top: 1px dashed var(--rule);
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--link-hover);
  text-decoration-thickness: 2px;
}

:focus-visible {
  outline: 3px solid var(--mark);
  outline-offset: 2px;
  border-radius: 2px;
}

.lead {
  font-size: 1.15rem;
  line-height: 1.6;
}

.kicker {
  margin: 2.25rem 0 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.85rem;
}

.kicker + h1 {
  margin-top: 0.35rem;
}

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

.kicker a:hover {
  color: var(--fg);
}

/* ---------- code ---------- */

code,
kbd,
samp,
pre {
  font-family: var(--mono);
}

:not(pre) > code {
  padding: 0.1em 0.35em;
  border-radius: 3px;
  background: var(--inline-code-bg);
  font-size: 0.86em;
}

pre {
  max-width: 100%;
  margin: 0;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  border: 1px solid var(--code-border);
  border-left: 3px solid var(--mark);
  border-radius: 0 4px 4px 0;
  background: var(--code-bg);
  color: var(--code-fg);
  font-size: 0.85rem;
  line-height: 1.55;
  white-space: pre;
  tab-size: 4;
}

pre code {
  font-size: inherit;
}

figure {
  margin: 1.6rem 0;
}

figure.code figcaption {
  display: inline-block;
  max-width: 100%;
  padding: 0.2rem 0.75rem;
  border: 1px solid var(--code-border);
  border-bottom: 0;
  border-radius: 4px 4px 0 0;
  background: var(--code-bg);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
}

figure.diagram {
  margin: 2rem 0;
}

figure.diagram img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--rule);
  border-radius: 4px;
}

figure.diagram figcaption {
  margin-top: 0.55rem;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

figure.diagram figcaption b {
  color: var(--fg);
  font-family: var(--mono);
  font-weight: 600;
}

/* ---------- article furniture ---------- */

.meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 1rem;
  margin: 0 0 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px dashed var(--rule);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.85rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.tags li {
  margin: 0;
  padding: 0 0.45rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.6;
}

.note {
  margin: 1.6rem 0;
  padding: 0.8rem 1rem;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--link);
  background: var(--code-bg);
  font-size: 0.97rem;
}

.note p:last-child {
  margin-bottom: 0;
}

.note .label {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.8rem;
  text-transform: lowercase;
}

.checklist {
  padding-left: 0;
  list-style: none;
}

.checklist li {
  position: relative;
  padding-left: 1.9rem;
}

.checklist li::before {
  content: "[ ]";
  content: "[ ]" / "";
  position: absolute;
  left: 0;
  color: var(--mark);
  font-family: var(--mono);
  font-size: 0.9em;
}

.article-end {
  margin-top: 3rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.95rem;
}

.pager {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.pager a {
  display: block;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--rule);
  border-radius: 4px;
  text-decoration: none;
}

.pager a:hover {
  border-color: var(--link);
}

.pager span {
  display: block;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
}

@media (min-width: 40em) {
  .pager {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .pager .next {
    grid-column: 2;
    text-align: right;
  }
}

/* ---------- lists of articles ---------- */

.post-list {
  margin: 1rem 0 2rem;
  padding: 0;
  list-style: none;
}

.post-list > li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.15rem;
  margin: 0;
  padding: 1rem 0;
  border-top: 1px solid var(--rule);
}

.post-list > li:last-child {
  border-bottom: 1px solid var(--rule);
}

.post-list time {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.85rem;
}

.post-list h2,
.post-list h3 {
  margin: 0;
  font-size: 1.12rem;
  letter-spacing: -0.01em;
}

.post-list p {
  margin: 0.2rem 0 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.post-list .tags {
  margin-top: 0.5rem;
}

@media (min-width: 40em) {
  .post-list > li {
    grid-template-columns: 7.5rem minmax(0, 1fr);
    column-gap: 1.25rem;
  }

  .post-list time {
    padding-top: 0.2rem;
  }
}

.rules {
  padding-left: 0;
  list-style: none;
  counter-reset: rule;
}

.rules li {
  position: relative;
  margin: 0.6rem 0;
  padding-left: 2.6rem;
  counter-increment: rule;
}

.rules li::before {
  content: counter(rule, decimal-leading-zero);
  position: absolute;
  top: 0.1rem;
  left: 0;
  color: var(--mark);
  font-family: var(--mono);
  font-size: 0.9rem;
  font-weight: 600;
}

/* ---------- uses / about ---------- */

.tool-list dt {
  margin-top: 1.1rem;
  font-family: var(--mono);
  font-weight: 600;
}

.tool-list dd {
  margin: 0.2rem 0 0;
  padding-left: 1rem;
  border-left: 2px solid var(--rule);
}

.contact {
  padding: 0.9rem 1rem;
  border: 1px dashed var(--rule);
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 0.95rem;
}

.big-code {
  margin: 2.5rem 0 0;
  color: var(--mark);
  font-family: var(--mono);
  font-size: clamp(3rem, 2rem + 6vw, 5rem);
  font-weight: 700;
  line-height: 1;
}

/* ---------- print ---------- */

@media print {
  body {
    background: none;
  }

  .sheet {
    max-width: none;
    border: 0;
  }

  .skip,
  .site-header nav,
  .pager {
    display: none;
  }

  pre {
    white-space: pre-wrap;
  }
}