/* One stylesheet for every page of the site.
 *
 * The material is paper, wood and brass: the queue is a tray, a task is an index
 * card, the beat is a clock, and a chain is cards tied together. Objects are
 * drawn with gradients and shadows rather than pictures, so they stay sharp at
 * any size and follow the theme.
 */

:root {
  --paper: #efe9dd;
  --paper-2: #e3dbcb;
  --ink: #23201b;
  --ink-2: #5f584c;
  --line: #cabfa8;
  --wood: #8a6540;
  --wood-dark: #6b4c2e;
  --brass: #b1862f;
  --seal: #8c3b2f;
  --green: #3f6b4a;
  --card: #fbf7ee;
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.65) inset, 0 6px 14px -8px rgba(50, 38, 20, 0.5);
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #16140f;
    --paper-2: #1d1a14;
    --ink: #ece6d8;
    --ink-2: #a89e8b;
    --line: #3a342a;
    --wood: #6a4a2c;
    --wood-dark: #3f2c1a;
    --brass: #d3a952;
    --seal: #b4574a;
    --green: #7fae8b;
    --card: #221f18;
    --shadow: 0 1px 0 rgba(255, 255, 255, 0.06) inset, 0 10px 20px -12px rgba(0, 0, 0, 0.9);
  }
}

html {
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.6 ui-serif, Georgia, "Iowan Old Style", "Times New Roman", serif;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  background-image: radial-gradient(circle at 20% 0%, color-mix(in srgb, var(--paper-2) 70%, transparent), transparent 60%);
}

/* The scrollbar is part of the furniture: a thin brass rail on the page and in
 * every region that scrolls, dim until the pointer is over it. */

@supports selector(::-webkit-scrollbar) {
  html::-webkit-scrollbar { width: 12px; height: 12px; }
  html::-webkit-scrollbar-track { background: transparent; }
  html::-webkit-scrollbar-thumb {
    border-radius: 99px;
    border: 4px solid transparent;
    background-clip: content-box;
    background-color: color-mix(in srgb, var(--brass) 45%, transparent);
  }
  html.at-top::-webkit-scrollbar-thumb { background-color: transparent; }
  .scroll::-webkit-scrollbar { width: 10px; height: 10px; }
  .scroll::-webkit-scrollbar-track { background: transparent; }
  .scroll::-webkit-scrollbar-thumb {
    border-radius: 99px;
    border: 3px solid transparent;
    background-clip: content-box;
    background-color: color-mix(in srgb, var(--ink) 16%, transparent);
  }
  .scroll:hover::-webkit-scrollbar-thumb { background-color: color-mix(in srgb, var(--ink) 34%, transparent); }
}

@supports not selector(::-webkit-scrollbar) {
  html { scrollbar-width: thin; scrollbar-color: color-mix(in srgb, var(--brass) 55%, transparent) transparent; }
  html.at-top { scrollbar-color: transparent transparent; }
  .scroll { scrollbar-width: thin; scrollbar-color: color-mix(in srgb, var(--ink) 24%, transparent) transparent; }
}

::selection { background: color-mix(in srgb, var(--brass) 35%, transparent); }

a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--seal); }

code, pre, kbd { font-family: var(--mono); font-variant-ligatures: no-contextual; }

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px clamp(16px, 4vw, 44px);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  z-index: 20;
  user-select: none;
}

.brand {
  font: 600 15px/1 var(--mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  text-decoration: none;
}

.top nav { display: flex; gap: clamp(8px, 2vw, 20px); font-size: 14px; }
.top nav a { text-decoration: none; color: var(--ink-2); }
.top nav a[aria-current="page"], .top nav a:hover { color: var(--ink); }

main { max-width: 1040px; margin: 0 auto; padding: clamp(24px, 5vw, 64px) clamp(16px, 4vw, 44px) 96px; }

h1 { font-size: clamp(30px, 5vw, 46px); line-height: 1.1; margin: 0 0 12px; font-weight: 600; letter-spacing: -0.01em; }
h2 { font-size: clamp(20px, 3vw, 26px); margin: 56px 0 12px; font-weight: 600; }
h3 { font-size: 17px; margin: 32px 0 8px; font-weight: 600; }
.lede { font-size: 19px; color: var(--ink-2); max-width: 62ch; margin: 0 0 8px; }
p { max-width: 68ch; }

pre.sig, pre.doc-code, pre.term {
  overflow-x: auto;
  background: color-mix(in srgb, var(--card) 92%, var(--paper));
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  font-size: 13px;
  line-height: 1.5;
  box-shadow: var(--shadow);
  scrollbar-width: thin;
}

code { font-size: 0.92em; background: color-mix(in srgb, var(--card) 80%, transparent); padding: 0.1em 0.32em; border-radius: 4px; }
pre code { background: none; padding: 0; }

/* ---- the desk ------------------------------------------------------------ */

.desk {
  position: relative;
  margin: 40px 0 8px;
  padding: clamp(18px, 3vw, 34px);
  border-radius: 18px;
  background:
    linear-gradient(160deg, color-mix(in srgb, var(--wood) 22%, var(--paper)) 0%, var(--paper) 60%),
    var(--paper);
  border: 1px solid var(--line);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.5), 0 30px 60px -40px rgba(60, 40, 16, 0.8);
  user-select: none;
  overflow: hidden;
}

.desk-caption {
  position: absolute;
  right: 16px;
  bottom: 10px;
  font: 11px/1 var(--mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-2);
  opacity: 0.7;
}

.tray {
  position: relative;
  margin: 8px auto 0;
  max-width: 560px;
  min-height: 132px;
  padding: 16px 18px 18px;
  border-radius: 10px 10px 14px 14px;
  background: linear-gradient(175deg, color-mix(in srgb, var(--wood) 70%, #fff) 0%, var(--wood) 22%, var(--wood-dark) 100%);
  box-shadow: 0 12px 0 -6px color-mix(in srgb, var(--wood-dark) 80%, #000), 0 22px 30px -22px rgba(0, 0, 0, 0.7);
  gap: 10px;
  display: flex;
  align-items: flex-end;
}

.tray::before {
  content: "queue";
  position: absolute;
  left: 14px;
  top: -10px;
  font: 10px/1 var(--mono);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--wood-dark) 80%, #000);
  background: color-mix(in srgb, var(--paper) 85%, transparent);
  padding: 3px 6px;
  border-radius: 3px;
}

.card {
  flex: 1 1 0;
  min-width: 0;
  min-height: 84px;
  padding: 10px 10px 12px;
  border-radius: 5px;
  background: linear-gradient(168deg, var(--card), color-mix(in srgb, var(--card) 88%, var(--paper-2)));
  border: 1px solid color-mix(in srgb, var(--line) 90%, transparent);
  box-shadow: var(--shadow), 0 -1px 0 rgba(255, 255, 255, 0.5) inset;
  font-size: 12px;
  line-height: 1.35;
  transform: rotate(var(--tilt, 0deg)) translateY(var(--lift, 0px));
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms;
  cursor: default;
}

.card:hover, .card:focus-visible {
  --lift: -8px;
  --tilt: 0deg;
  box-shadow: 0 18px 26px -18px rgba(50, 38, 20, 0.75), 0 -1px 0 rgba(255, 255, 255, 0.6) inset;
  outline: none;
}

.card .title { display: block; font: 600 12px/1.3 var(--mono); color: var(--ink); }
.card .meta { display: block; color: var(--ink-2); font-size: 11px; margin-top: 4px; }
.card .seal {
  float: right;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, color-mix(in srgb, var(--seal) 70%, #fff), var(--seal) 60%);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
}
.card.ok .seal { background: radial-gradient(circle at 35% 30%, color-mix(in srgb, var(--green) 70%, #fff), var(--green) 60%); }
.card.retry .seal { background: radial-gradient(circle at 35% 30%, color-mix(in srgb, var(--brass) 80%, #fff), var(--brass) 60%); }

.clock {
  width: 84px;
  height: 84px;
  border-radius: 50%;
  margin: 0 auto;
  background:
    radial-gradient(circle at 50% 42%, color-mix(in srgb, var(--card) 92%, #fff) 0 58%, transparent 59%),
    conic-gradient(from -20deg, color-mix(in srgb, var(--brass) 90%, #fff), var(--brass), color-mix(in srgb, var(--brass) 60%, #000), var(--brass));
  box-shadow: 0 6px 12px -8px rgba(0, 0, 0, 0.8), 0 0 0 3px color-mix(in srgb, var(--brass) 35%, transparent);
  position: relative;
}

.clock::before, .clock::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 50%;
  transform-origin: 50% 100%;
  background: var(--ink);
  border-radius: 2px;
}

.clock::before { width: 2px; height: 24px; margin-left: -1px; animation: sweep 6s linear infinite; }
.clock::after { width: 3px; height: 16px; margin-left: -1.5px; background: var(--seal); animation: sweep 72s linear infinite; }

@keyframes sweep { to { transform: rotate(360deg); } }

@media (prefers-reduced-motion: reduce) {
  .clock::before, .clock::after { animation: none; }
  .card { transition: none; }
}

.desk-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 120px;
  align-items: center;
  gap: 18px;
  margin-top: 26px;
}

.chain-line {
  display: flex;
  align-items: center;
  gap: 0;
  min-width: 0;
}

.chain-line .card { flex: 1 1 0; }
.chain-line .link {
  width: 26px;
  height: 2px;
  background: repeating-linear-gradient(90deg, var(--brass) 0 6px, transparent 6px 10px);
  flex: none;
}

/* ---- sections ------------------------------------------------------------ */

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin: 18px 0 0;
}

.tile {
  padding: 16px 18px;
  border-radius: 10px;
  background: linear-gradient(170deg, color-mix(in srgb, var(--card) 96%, var(--paper)), color-mix(in srgb, var(--card) 80%, var(--paper-2)));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.tile h3 { margin: 0 0 6px; font: 600 13px/1.3 var(--mono); letter-spacing: 0.04em; }
.tile p { margin: 0; font-size: 14px; color: var(--ink-2); max-width: none; }

.table { width: 100%; border-collapse: collapse; font-size: 14px; margin: 12px 0 0; }
.table th, .table td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
.table th { font: 600 12px/1.4 var(--mono); text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-2); }

.steps { counter-reset: step; padding: 0; list-style: none; }
.steps > li { counter-increment: step; position: relative; padding-left: 42px; margin: 26px 0; }
.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: -2px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font: 600 12px/1 var(--mono);
  color: var(--card);
  background: radial-gradient(circle at 35% 30%, color-mix(in srgb, var(--brass) 70%, #fff), var(--brass) 65%);
  box-shadow: 0 2px 4px -2px rgba(0, 0, 0, 0.6);
}

/* ---- api ----------------------------------------------------------------- */

.api-entry { margin: 18px 0 22px; }
.api-entry .doc { font-size: 14px; color: var(--ink-2); }
.api-entry .doc p { margin: 6px 0; }
.api h2 { margin-top: 48px; padding-bottom: 6px; border-bottom: 1px solid var(--line); font-family: var(--mono); font-size: 18px; }
.api h3 { font-family: var(--mono); font-size: 13px; text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-2); }
.members { list-style: none; padding: 0; margin: 8px 0 0; font-size: 13px; }
.members li { display: grid; grid-template-columns: minmax(0, 14ch) minmax(0, 1fr); gap: 10px; padding: 4px 0; border-bottom: 1px dotted color-mix(in srgb, var(--line) 70%, transparent); }
.members span { color: var(--ink-2); font-family: var(--mono); font-size: 12px; overflow-wrap: anywhere; }

/* ---- showcase ------------------------------------------------------------ */

.terminal {
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: color-mix(in srgb, var(--card) 90%, var(--paper));
  margin: 20px 0 8px;
}

.terminal .bar {
  display: flex;
  gap: 6px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper-2) 70%, var(--paper));
}

.terminal .bar i { width: 9px; height: 9px; border-radius: 50%; background: color-mix(in srgb, var(--ink) 20%, transparent); }

.terminal pre { margin: 0; border: 0; box-shadow: none; background: none; max-height: 320px; overflow: auto; }
.terminal pre .line { display: block; white-space: pre; }
.terminal pre .prompt { color: var(--ink-2); }
.terminal pre .key { color: var(--seal); }
.terminal pre .val { color: var(--green); }

.actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 12px 0 0; }

button.play {
  font: 600 13px/1 var(--mono);
  letter-spacing: 0.04em;
  padding: 9px 14px;
  border-radius: 6px;
  border: 1px solid color-mix(in srgb, var(--wood) 60%, var(--line));
  background: linear-gradient(180deg, color-mix(in srgb, var(--wood) 62%, #fff), var(--wood));
  color: #fdf8ee;
  cursor: pointer;
  box-shadow: 0 2px 0 color-mix(in srgb, var(--wood-dark) 90%, #000), 0 6px 12px -8px rgba(0, 0, 0, 0.7);
}

button.play:active { transform: translateY(1px); box-shadow: 0 1px 0 color-mix(in srgb, var(--wood-dark) 90%, #000); }

footer {
  border-top: 1px solid var(--line);
  padding: 22px clamp(16px, 4vw, 44px) 40px;
  font-size: 13px;
  color: var(--ink-2);
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: space-between;
}

@media (width <= 860px) {
  .grid-3 { grid-template-columns: minmax(0, 1fr); }
  .desk-row { grid-template-columns: minmax(0, 1fr); }
  .clock { margin: 0; }
  .tray { flex-wrap: wrap; }
  .top { flex-wrap: wrap; }
  .members li { grid-template-columns: minmax(0, 1fr); }
}

/* The figure plate.
 *
 * The diorama is drawn on its own paper inside the frame: the page gives it a
 * mat, a hairline and a plate number, and never recolours what is inside. In the
 * dark theme the mat darkens and the figure stays lit, like a print under a
 * lamp. */
.plate { margin: clamp(20px, 4vw, 36px) 0 6px; }

.plate-frame {
  position: relative;
  padding: clamp(10px, 1.6vw, 18px);
  background: color-mix(in srgb, var(--paper-2) 52%, var(--paper));
  border: 1px solid color-mix(in srgb, var(--line) 88%, var(--ink));
  border-radius: 3px;
  box-shadow: 0 1px 0 color-mix(in srgb, #fff 55%, transparent) inset,
    0 20px 44px -30px rgba(40, 30, 16, 0.7);
}

/* brass corner ticks, the way a plate is pinned down */
.plate-frame::before,
.plate-frame::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border: 1px solid color-mix(in srgb, var(--brass) 70%, transparent);
  pointer-events: none;
}
.plate-frame::before { top: 6px; left: 6px; border-right: 0; border-bottom: 0; }
.plate-frame::after { bottom: 6px; right: 6px; border-left: 0; border-top: 0; }

.plate-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 2px 0 10px;
  font: 600 11px/1 var(--mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.plate-no { color: var(--brass); }
.plate-name { color: var(--ink); }
.plate-hint { margin-left: auto; letter-spacing: 0.04em; text-transform: none; font-weight: 400; }

.plate iframe {
  display: block;
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  height: clamp(430px, 48vw, 620px);
  border: 0;
  border-radius: 2px;
  background: var(--figure-bg);
  outline: 1px solid color-mix(in srgb, var(--ink) 14%, transparent);
  outline-offset: -1px;
}

.plate figcaption {
  margin-top: 10px;
  font-size: 14px;
  color: var(--ink-2);
  max-width: 76ch;
}
.credit { color: color-mix(in srgb, var(--ink-2) 80%, transparent); }
.credit a { color: inherit; text-decoration-color: color-mix(in srgb, var(--brass) 60%, transparent); }
.plate figcaption a { color: var(--ink); text-decoration-color: color-mix(in srgb, var(--brass) 70%, transparent); }

@media (width <= 620px) {
  .plate iframe { height: 88vh; }
  .plate-hint { display: none; }
}

/* A choice the reader made, on top of the system's. The attribute is set in
 * <head> before this file loads, so there is no flash of the wrong paper. */
:root[data-theme="dark"] {
  --paper: #16140f;
  --paper-2: #1d1a14;
  --ink: #ece6d8;
  --ink-2: #a89e8b;
  --line: #3a342a;
  --wood: #6a4a2c;
  --wood-dark: #3f2c1a;
  --brass: #d3a952;
  --seal: #b4574a;
  --green: #7fae8b;
  --card: #221f18;
  --figure-bg: #14120d;
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.06) inset, 0 10px 20px -12px rgba(0, 0, 0, 0.9);
}

:root[data-theme="light"] {
  --paper: #efe9dd;
  --paper-2: #e3dbcb;
  --ink: #23201b;
  --ink-2: #5f584c;
  --line: #cabfa8;
  --wood: #8a6540;
  --wood-dark: #6b4c2e;
  --brass: #b1862f;
  --seal: #8c3b2f;
  --green: #3f6b4a;
  --card: #fbf7ee;
  --figure-bg: #f2efe7;
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.65) inset, 0 6px 14px -8px rgba(50, 38, 20, 0.5);
}

:root { --figure-bg: #f2efe7; }

/* The switch: a sun that turns into a moon, in the same ink as the nav. */
.theme-toggle {
  all: unset;
  cursor: pointer;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--line) 90%, transparent);
  border-radius: 999px;
  color: var(--ink-2);
}
.theme-toggle:hover, .theme-toggle:focus-visible { color: var(--ink); border-color: var(--ink-2); }
.theme-toggle svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.4; stroke-linecap: round; }
.theme-toggle .rays { transition: opacity 0.25s ease, transform 0.25s ease; transform-origin: 10px 10px; }
.theme-toggle[aria-pressed="true"] .rays { opacity: 0; transform: rotate(-40deg) scale(0.6); }
.theme-toggle[aria-pressed="true"] circle { transform-origin: 10px 10px; transform: scale(0.86); }
.to-top, .top { align-items: center; }