/* Every page: fonts, design tokens, the reset, the reading layout (masthead,
   column and footer) and the edge waves. */

@font-face {
  font-family: "Helvetica";
  src: url("/fonts/helvetica/Helvetica.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Helvetica";
  src: url("/fonts/helvetica/Helvetica-Bold.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: "PP Eiko";
  src: url("/fonts/eiko/PPEiko-Medium.woff2") format("woff2");
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: "Fira Code";
  src: url("/fonts/fira-code/FiraCode-Regular.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}

:root {
  --paper: #f0eee8;
  --ink: #16171b;
  --muted: #666;
  --rule: #c8c5bc;
  --accent: #d91620;
  --link: #7c4147;
  --font-body: Georgia, "Times New Roman", serif;
  --font-display: "PP Eiko", Georgia, serif;
  --font-sans: "Helvetica", Arial, sans-serif;
  --font-code: "Fira Code", ui-monospace, monospace;
  color-scheme: light;
  -webkit-text-size-adjust: 100%;
  tab-size: 4;
}

/* Reset */
*,
::before,
::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border: 0 solid;
}
ol,
ul {
  list-style: none;
}
img,
svg {
  display: block;
  vertical-align: middle;
}
img {
  max-width: 100%;
  height: auto;
}
b,
strong {
  font-weight: bolder;
}
sub,
sup {
  position: relative;
  font-size: 75%;
  line-height: 0;
  vertical-align: baseline;
}
sup {
  top: -0.5em;
}
sub {
  bottom: -0.25em;
}
table {
  border-collapse: collapse;
}
/* Hidden stays hidden, even on an element whose class sets display. */
[hidden] {
  display: none !important;
}

/* Keep the gutter reserved so the centred column never shifts between a page
   that scrolls and one that doesn't. */
html {
  scrollbar-gutter: stable;
}

/* Base */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 25px;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: #ffd987;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--ink);
  font-family: var(--font-display);
  font-size: inherit;
  font-weight: 500;
}
h1 {
  font-size: 36px;
  line-height: 42px;
}
h2 {
  font-size: 24px;
  line-height: 30px;
}
h3 {
  font-size: 20px;
  line-height: 26px;
}
/* The red colon after each heading: <h1>blog<span>:</span></h1> */
:is(h1, h2, h3) > span {
  color: var(--accent);
}

a {
  color: var(--link);
  text-decoration: underline 1px;
  text-underline-offset: 2px;
}
a:hover {
  text-decoration-thickness: 2px;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

code,
pre {
  font-family: var(--font-code);
  font-size: 1em;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

@media (max-width: 599px) {
  h1 {
    font-size: 30px;
    line-height: 36px;
  }
}

/* The reading layout: every page except Home. */
.page {
  display: flex;
  flex-direction: column;
  width: min(720px, calc(100% - 48px));
  min-height: 100svh;
  margin-inline: auto;
  padding-block: 64px 40px;
}

.skip {
  position: absolute;
  top: 16px;
  left: 16px;
  z-index: 1;
  padding: 8px 16px;
  background: var(--paper);
  clip-path: inset(50%);
}
.skip:focus {
  clip-path: none;
}

/* Masthead */
.masthead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--rule);
}

.logo {
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.045em;
  line-height: 34px;
  text-decoration: none;
}
.logo span {
  color: var(--accent);
}

.nav {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 500;
  line-height: 22px;
}
.nav a {
  position: relative;
  color: var(--ink);
  text-decoration: none;
}
/* After the first ericzheng.nz, no underline at rest. On hover a red
   line grows out from the middle, just below the descenders. */
.nav a::after {
  content: "";
  position: absolute;
  top: calc(50% + 11px);
  left: 0;
  width: 100%;
  border-top: 1.5px solid var(--accent);
  transform: scaleX(0);
  transition: transform 250ms ease-out;
}
.nav a:hover::after {
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .nav a::after {
    transition: none;
  }
}
.nav span {
  color: var(--muted);
}

/* Content */
.main {
  display: flex;
  flex: 1;
  flex-direction: column;
  gap: 24px;
  padding-block: 64px;
}
.main :is(p, li, dd, a) {
  overflow-wrap: anywhere;
}

/* Footer */
.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 500;
  line-height: 36px;
}

.profiles {
  display: flex;
  gap: 16px;
}
.profiles a {
  position: relative;
  display: flex;
  align-items: center;
  height: 36px;
}
/* Larger touch targets without moving the 20px icons. */
.profiles a::before {
  content: "";
  position: absolute;
  inset: -4px -6px;
}

@media (max-width: 599px) {
  .page {
    padding-block: 16px 32px;
  }
  .masthead {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-bottom: 12px;
  }
  .nav {
    justify-content: space-between;
    width: 100%;
    gap: 4px;
  }
  .nav a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
  }
  .main {
    padding-top: 40px;
  }
}

@media (max-width: 359px) {
  .nav {
    gap: 2px;
    font-size: 14px;
  }
}

/* The edge waves (js/waves.js): a column of ASCII characters in each side
   gutter. Without JavaScript, or with reduced motion, a still image shows. */
.waves {
  --wave-unread: var(--rule);
  --wave-read: var(--ink);
  --wave-progress: 0%;
  --wave-expansive: 0;
  position: fixed;
  inset: 0 0 0 auto;
  z-index: 0;
  /* Compact gutters stay 24px; the wider desktop treatment is below. */
  width: clamp(14px, calc((100vw - 720px) / 2 - 140px), 220px);
  pointer-events: none;
  user-select: none;
  font-family: var(--font-sans);
}

.waves[data-opening] {
  --wave-unread: color-mix(in srgb, var(--rule) 38%, transparent);
  --wave-read: var(--paper);
}

.waves[data-side="left"] {
  inset: 0 auto 0 0;
  color: #c8c5bc;
  --wave-unread: currentColor;
  --wave-read: currentColor;
}

/* Static fallbacks for no JS, reduced motion or no canvas. */
.waves::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--wave-unread);
  mask: url("/waves/desktop.png") right top / 100% 100% no-repeat;
}

.waves[data-side="left"]::before {
  mask-image: url("/waves/left-desktop.png");
}

/* A page that already fits is fully read, including the reduced-motion fallback. */
.waves[data-scrollable="false"]::before {
  background: var(--wave-read);
}

.waves[data-tracking="true"]::before {
  background: linear-gradient(
    to bottom,
    var(--wave-read) max(0%, calc(var(--wave-progress) - 3%)),
    var(--accent) max(0%, calc(var(--wave-progress) - 3%)),
    var(--accent) min(100%, calc(var(--wave-progress) + 3%)),
    var(--wave-unread) min(100%, calc(var(--wave-progress) + 3%))
  );
}

.waves canvas {
  display: none;
  width: 100%;
  height: 100%;
}

@media (prefers-reduced-motion: no-preference) and (scripting: enabled) {
  /* The still is stretched to the gutter; don't flash it before the canvas starts. */
  .waves:not([data-animate])::before {
    display: none;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .waves[data-animate="true"]::before {
    display: none;
  }
  .waves[data-animate="true"] canvas {
    display: block;
  }
}

@media (max-width: 599px) {
  .waves[data-opening] {
    /* The unexpanded changelog row spans just under 5.625em. */
    max-width: max(0px, calc(50vw - 5.625 * var(--letter-size)));
  }
}

@media (max-width: 1071px) {
  .waves::before {
    mask-image: url("/waves/mobile.png");
  }
  .waves[data-side="left"]::before {
    mask-image: url("/waves/left-mobile.png");
  }
}

@media (min-width: 1200px) {
  .waves {
    --wave-expansive: 1;
    width: min(360px, calc((100vw - 720px) / 2 - 64px));
  }
  .waves[data-opening] {
    /* At most 204px, and always clear of the fully expanded changelog row. */
    max-width: min(
      204px,
      calc(50vw - 6.25 * clamp(2rem, 5.556vw, 5rem) - 16px)
    );
  }
}

@media print, (forced-colors: active) {
  .waves {
    display: none;
  }
}