/* Dematigo Publishing — site styles. See docs/spec.md section 6. */

/* Fonts ------------------------------------------------------------------ */

@font-face {
  font-family: "Ubuntu";
  src: url("../fonts/ubuntu-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Ubuntu";
  src: url("../fonts/ubuntu-500.woff2") format("woff2");
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Ubuntu";
  src: url("../fonts/ubuntu-700.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("../fonts/source-serif-4-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("../fonts/source-serif-4-600.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("../fonts/source-serif-4-400-italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

/* Tokens ----------------------------------------------------------------- */

:root {
  --ink: #221B2B;
  --ink-soft: #5C5566;
  --paper: #FFFFFF;
  --violet: #4B2D7F;
  --violet-deep: #2A1846;
  --lilac: #EEE9F6;
  --rule: #DDD6E8;
  --sage: #3F6B4F;
  --on-band: #FFFFFF;

  --font-ui: "Ubuntu", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-ja: "Hiragino Sans", "Yu Gothic", "Noto Sans JP", sans-serif;

  --container: 72rem;
  --measure: 38rem;
  --gutter: clamp(1rem, 4vw, 2.5rem);

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #ECE8F2;
    --ink-soft: #B4ADBF;
    --paper: #16121C;
    --violet: #C4B0EA;
    --violet-deep: #0E0A14;
    --lilac: #241C31;
    --rule: #3A3047;
    --sage: #8FC4A0;
  }
}

/* Base ------------------------------------------------------------------- */

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

html {
  font-size: 106.25%; /* 17px */
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

@media (min-width: 48rem) {
  html {
    font-size: 112.5%; /* 18px */
  }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  font-variant-numeric: oldstyle-nums proportional-nums;
  text-rendering: optimizeLegibility;
}

:lang(ja) {
  font-family: var(--font-body), var(--font-ja);
}

h1,
h2,
h3 {
  font-family: var(--font-ui);
  color: var(--ink);
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 1.4rem + 2.6vw, 2.5rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.6rem;
  font-weight: 500;
  line-height: 1.25;
  margin-top: 3rem;
}

h3 {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.3;
}

p,
ul,
ol,
table {
  margin: 1rem 0 0;
}

strong {
  font-weight: 600;
}

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

a:hover {
  text-decoration-thickness: 2px;
}

a,
.button {
  transition: color 120ms ease, background-color 120ms ease, text-decoration-color 120ms ease;
}

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

img {
  max-width: 100%;
  height: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.meta,
time {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  line-height: 1.4;
  color: var(--ink-soft);
}

.fa-solid,
.fa-brands {
  margin-right: 0.35em;
}

/* Skip link -------------------------------------------------------------- */

.skip-link {
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  z-index: 10;
  padding: 0.5rem 1rem;
  background: var(--paper);
  color: var(--violet);
  font-family: var(--font-ui);
  font-weight: 500;
  transform: translateY(-200%);
}

.skip-link:focus {
  transform: none;
}

/* Layout ----------------------------------------------------------------- */

.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

main {
  padding-block: 3rem 4.5rem;
}

.prose > * {
  max-width: var(--measure);
}

.prose > .wide {
  max-width: none;
}

.lead {
  font-size: 1.15rem;
  margin-top: 1.25rem;
}

/* Header ----------------------------------------------------------------- */

.site-header {
  background: var(--violet-deep);
  color: var(--on-band);
  font-family: var(--font-ui);
  border-bottom: 1px solid var(--rule);
}

.site-header .container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 2rem;
  padding-block: 1rem;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--on-band);
  font-size: 1.25rem;
  font-weight: 500;
  text-decoration: none;
}

.wordmark img {
  display: block;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0.3rem;
  background: #FFFFFF;
  object-fit: contain;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav a {
  display: inline-block;
  padding-block: 0.4rem;
  color: var(--on-band);
  text-decoration: none;
  text-underline-offset: 0.35em;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  text-decoration-line: underline;
  text-decoration-thickness: 2px;
}

.site-header :focus-visible,
.site-footer :focus-visible {
  outline-color: var(--on-band);
}

/* Lesson anatomy panel --------------------------------------------------- */

.anatomy {
  margin-top: 3rem;
  padding: 2rem var(--gutter) 2.25rem;
  margin-inline: calc(var(--gutter) * -1);
  background: var(--lilac);
}

.anatomy h2 {
  margin-top: 0;
}

.anatomy > p {
  max-width: var(--measure);
}

.anatomy ul {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem 2rem;
  margin-top: 1.75rem;
  padding: 0;
  list-style: none;
}

.anatomy li {
  padding-top: 0.75rem;
  border-top: 2px solid var(--violet);
}

.anatomy li p {
  margin-top: 0.4rem;
}

@media (min-width: 36rem) {
  .anatomy ul {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 60rem) {
  .anatomy {
    margin-inline: 0;
    padding-inline: 2.5rem;
  }

  .anatomy ul {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* Tables ----------------------------------------------------------------- */

table {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: lining-nums tabular-nums;
}

th,
td {
  padding: 0.6rem 0.75rem 0.6rem 0;
  border-bottom: 1px solid var(--rule);
  text-align: left;
  vertical-align: top;
}

th {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.3;
}

thead th {
  border-bottom: 2px solid var(--ink);
}

@media (max-width: 30rem) {
  th,
  td {
    font-size: 0.85rem;
    padding-right: 0.4rem;
  }
}

/* Notes and lists -------------------------------------------------------- */

.note {
  padding: 1rem 1.25rem;
  background: var(--lilac);
}

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

.link-list {
  padding: 0;
  list-style: none;
}

.link-list li + li {
  margin-top: 0.4rem;
}

.post-list {
  padding: 0;
  list-style: none;
}

.post-list li {
  padding-block: 1.25rem;
  border-bottom: 1px solid var(--rule);
}

.post-list h2 {
  margin-top: 0;
  font-size: 1.3rem;
}

.post-list p {
  margin-top: 0.4rem;
}

.post-list time {
  display: block;
  margin-top: 0.25rem;
}

.post-header time {
  display: block;
  margin-top: 0.75rem;
}

/* Footer ----------------------------------------------------------------- */

.site-footer {
  background: var(--violet-deep);
  color: var(--on-band);
  font-family: var(--font-ui);
  font-size: 0.85rem;
  border-top: 1px solid var(--rule);
}

.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding-block: 1.75rem;
}

.site-footer p {
  margin: 0;
}

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

.site-footer li + li::before {
  content: "·";
  padding-inline: 0.6rem;
}

.site-footer a {
  display: inline-block;
  padding-block: 0.15rem;
  color: var(--on-band);
}

/* Motion ----------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
  }
}