/* SPDX-License-Identifier: Apache-2.0
 *
 * The palette is not chosen here. It is include/theme.h, transcribed, because
 * a site that describes an operating system should look like the operating
 * system. That includes the rule theme.h enforces:
 *
 *   normal states are calm and dark; only failure is loud.
 *
 * PSOGM purple (--psogm) therefore appears exactly once on this page, in the
 * crash-screen section. If it ever appears anywhere else, delete it there.
 */

:root {
  /* include/theme.h */
  --bg:         #0C0E13;   /* SCH_BG */
  --fg:         #E6E8EC;   /* SCH_FG */
  --dim:        #707784;   /* SCH_DIM */
  --accent:     #7C5CFF;   /* SCH_ACCENT */
  --accent-dim: #2A2440;   /* SCH_ACCENT_DIM */
  --ok:         #4ADE80;   /* SCH_OK */
  --warn:       #FBBF24;   /* SCH_WARN */
  --psogm:      #4B1D9A;   /* PSOGM_BG — failure, and nothing else */

  /* Surfaces lifted off the ground, keeping its blue bias rather than
     sliding toward neutral grey. */
  --surface:    #12151C;
  --surface-2:  #171B24;
  --line:       #212632;

  --sans: "Roboto", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "Cascadia Code",
          Menlo, Consolas, monospace;

  --measure: 66ch;
  --gap:     clamp(1rem, 2.5vw, 1.75rem);
  --section: clamp(4rem, 10vw, 7.5rem);
}

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

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: clamp(1rem, 0.95rem + 0.2vw, 1.0625rem);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---- shared shells ------------------------------------------------- */

.wrap {
  width: min(100% - 2.5rem, 68rem);
  margin-inline: auto;
}

section { padding-block: var(--section); }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.75rem;
}

h1, h2, h3 { text-wrap: balance; line-height: 1.15; margin: 0; }

h2 {
  font-size: clamp(1.75rem, 1.3rem + 2vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.lede {
  max-width: var(--measure);
  color: var(--dim);
  font-size: clamp(1.05rem, 1rem + 0.35vw, 1.2rem);
  margin: 1.25rem 0 0;
}

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

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--fg); }
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

code, .mono { font-family: var(--mono); font-size: 0.9em; }
code { color: var(--fg); background: var(--surface-2); padding: 0.1em 0.4em; border-radius: 3px; }

/* ---- header -------------------------------------------------------- */

header.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.top .wrap {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding-block: 0.85rem;
}
.brand {
  display: flex; align-items: center; gap: 0.6rem;
  font-weight: 700; letter-spacing: -0.01em;
  color: inherit; text-decoration: none;
}
.brand img { width: 26px; height: 26px; display: block; }
.top nav { margin-left: auto; display: flex; gap: 1.5rem; font-size: 0.9rem; }
.top nav a { color: var(--dim); text-decoration: none; }
.top nav a:hover { color: var(--fg); }
@media (max-width: 46rem) { .top nav { display: none; } }

/* ---- hero ---------------------------------------------------------- */

.hero { padding-block: clamp(3.5rem, 9vw, 6.5rem) var(--section); }
.hero .wrap {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
@media (max-width: 56rem) {
  .hero .wrap { grid-template-columns: 1fr; }
}

.hero h1 {
  font-size: clamp(2.75rem, 1.8rem + 4.2vw, 4.75rem);
  font-weight: 700;
  letter-spacing: -0.035em;
}
.hero h1 .mark {
  display: inline-block;
  width: 0.95em;
  height: 0.95em;
  vertical-align: -0.08em;
  margin-right: 0.22em;
}
.hero p { color: var(--dim); font-size: clamp(1.05rem, 1rem + 0.4vw, 1.25rem); margin-top: 1.25rem; }
.hero .cta { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 2rem; }

.btn {
  display: inline-block;
  padding: 0.65rem 1.25rem;
  border-radius: 4px;
  font-size: 0.925rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid var(--line);
  color: var(--fg);
  background: var(--surface);
}
.btn:hover { border-color: var(--accent); color: var(--fg); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #0B0714; font-weight: 700; }
.btn.primary:hover { background: #8F73FF; border-color: #8F73FF; color: #0B0714; }

/* ---- console ------------------------------------------------------- */

.console {
  background: #090B0F;
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 24px 60px -30px #000;
}
.console-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.85rem;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--dim);
  letter-spacing: 0.06em;
}
.console-bar .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--line); }
.console-bar .dot.live { background: var(--ok); }
.console-bar span { margin-left: auto; }

.console pre {
  margin: 0;
  padding: 1rem 1.1rem 1.4rem;
  font-family: var(--mono);
  font-size: clamp(0.72rem, 0.62rem + 0.35vw, 0.82rem);
  line-height: 1.85;
  color: var(--fg);
  overflow-x: auto;
  min-height: 16.5rem;
}
.console .t { color: var(--dim); }
.console .k { color: var(--accent); }
.console .g { color: var(--ok); }
.console .cursor {
  display: inline-block;
  width: 0.55em;
  height: 1.05em;
  background: var(--accent);
  vertical-align: -0.18em;
  animation: blink 1.1s step-end infinite;
}
@keyframes blink { 50% { opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .console .cursor { animation: none; } }

/* ---- origin timeline ----------------------------------------------- */

.origin-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: var(--gap);
  margin-top: 3rem;
}
.step {
  border-left: 2px solid var(--accent-dim);
  padding-left: 1.1rem;
}
.step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 0.4rem; }
.step .when { font-family: var(--mono); font-size: 0.72rem; color: var(--accent); letter-spacing: 0.08em; text-transform: uppercase; display: block; margin-bottom: 0.5rem; }
.step p { color: var(--dim); font-size: 0.925rem; margin: 0; }

/* ---- the stack ----------------------------------------------------- */

.stack { display: flex; flex-direction: column; gap: 3px; margin-top: 3rem; }
.layer {
  display: grid;
  grid-template-columns: 10.5rem 1fr;
  gap: 1.25rem;
  align-items: baseline;
  padding: 0.95rem 1.15rem;
  background: var(--surface);
  border: 1px solid transparent;
  border-radius: 3px;
}
.layer:hover { border-color: var(--accent-dim); background: var(--surface-2); }
.layer .name { font-family: var(--mono); font-size: 0.8rem; color: var(--accent); letter-spacing: 0.04em; }
.layer .what { color: var(--dim); font-size: 0.9rem; }
.layer.seam { background: var(--accent-dim); }
.layer.seam .name { color: var(--fg); }
.layer.seam .what { color: #C9BEEC; }
@media (max-width: 42rem) {
  .layer { grid-template-columns: 1fr; gap: 0.3rem; }
}
.seam-note { margin-top: 1.5rem; color: var(--dim); font-size: 0.9rem; }

/* ---- features ------------------------------------------------------ */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr));
  gap: var(--gap);
  margin-top: 3rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.card h3 { font-size: 1.05rem; font-weight: 700; }
.card p { color: var(--dim); font-size: 0.925rem; margin: 0; max-width: none; }
.card .tag {
  align-self: flex-start;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  border: 1px solid var(--line);
  color: var(--dim);
}
.card .tag.runs   { color: var(--ok);   border-color: color-mix(in srgb, var(--ok) 35%, transparent); }
.card .tag.partial{ color: var(--warn); border-color: color-mix(in srgb, var(--warn) 35%, transparent); }
.card .tag.planned{ color: var(--dim); }

/* ---- numbers ------------------------------------------------------- */

.figures {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
  gap: var(--gap);
  margin-top: 3rem;
}
.figure { border-top: 1px solid var(--line); padding-top: 1rem; }
.figure b {
  display: block;
  font-family: var(--mono);
  font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.25rem);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}
.figure span { color: var(--dim); font-size: 0.85rem; }

/* ---- the crash screen: the one loud thing --------------------------- */

.crash { background: var(--psogm); color: #fff; }
.crash .wrap {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}
@media (max-width: 44rem) { .crash .wrap { grid-template-columns: 1fr; } }
.crash img { width: 100%; max-width: 8rem; height: auto; }
.crash .eyebrow { color: #C3AEEC; }
.crash h2 { color: #fff; }
.crash p { color: #DBCEF5; }
.crash code { background: rgba(0, 0, 0, 0.28); color: #fff; }

/* ---- closing links -------------------------------------------------- */

.links { display: grid; grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr)); gap: var(--gap); margin-top: 2.5rem; }
.link-card {
  display: block;
  padding: 1.2rem;
  border: 1px solid var(--line);
  border-radius: 5px;
  text-decoration: none;
  color: var(--fg);
  background: var(--surface);
}
.link-card:hover { border-color: var(--accent); color: var(--fg); }
.link-card b { display: block; margin-bottom: 0.3rem; }
.link-card span { color: var(--dim); font-size: 0.875rem; }

footer {
  border-top: 1px solid var(--line);
  padding-block: 2.5rem 3.5rem;
  color: var(--dim);
  font-size: 0.85rem;
}
footer .wrap { display: flex; flex-wrap: wrap; gap: 1rem 2rem; align-items: center; }
footer .mono { font-size: 0.78rem; }

/* ---- reveal on scroll ---------------------------------------------- */

.reveal { opacity: 0; transform: translateY(12px); transition: opacity .5s ease, transform .5s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* The SchFS mark, set beside its own card heading. Baseline-aligned rather
   than centred: it sits next to a word, so it follows the word. */
.card h3 .cardmark {
  width: 1.15em;
  height: 1.15em;
  vertical-align: -0.22em;
  margin-right: 0.4em;
}

/* =====================================================================
   The pride mark
   ---------------------------------------------------------------------
   Small, and permanent. It is in the top bar in November the same way it
   is in June, which is the only version of this that means anything --
   support with an end date is marketing.

   Deliberately not bigger than this. The site is about an operating
   system; the flag is a statement, not a subject.
   ===================================================================== */

.pride {
  display: inline-flex;
  align-items: center;
  line-height: 0;
  border-radius: 2px;
  text-decoration: none;
}
.pride img {
  width: 26px;
  height: auto;
  display: block;
  border-radius: 2px;
  /* Sits down slightly against the dark ground so it reads as part of the
     bar rather than as a sticker on top of it; full colour on hover. */
  opacity: 0.85;
  transition: opacity .18s ease, transform .18s ease;
}
.pride:hover img { opacity: 1; transform: translateY(-1px); }
@media (prefers-reduced-motion: reduce) {
  .pride img { transition: none; }
  .pride:hover img { transform: none; }
}

.pride-note {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-basis: 100%;
  color: var(--dim);
  font-size: 0.82rem;
}
.pride-note img { width: 20px; height: auto; border-radius: 2px; flex: none; }

/* =====================================================================
   The documentation reader
   ===================================================================== */

body.reading { display: flex; flex-direction: column; min-height: 100vh; }
body.reading footer { margin-top: auto; }

.docshell {
  width: min(100% - 2.5rem, 84rem);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 15rem minmax(0, 1fr) 13rem;
  gap: clamp(1.5rem, 3vw, 3rem);
  align-items: start;
  padding-block: 2.5rem 4rem;
}
@media (max-width: 72rem) { .docshell { grid-template-columns: 14rem minmax(0, 1fr); } .rail { display: none; } }
@media (max-width: 54rem) { .docshell { grid-template-columns: 1fr; } .sidebar .sticky { position: static; max-height: none; } }

.sticky {
  position: sticky;
  top: 4.5rem;
  max-height: calc(100vh - 6rem);
  overflow-y: auto;
  scrollbar-width: thin;
}

.navgroup {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--dim);
  margin: 1.6rem 0 0.5rem;
}
.navgroup:first-child { margin-top: 0; }

#docnav ul, #toc ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; }
#docnav a, #toc a {
  display: block;
  padding: 0.28rem 0.6rem;
  margin-left: -0.6rem;
  border-radius: 3px;
  color: var(--dim);
  text-decoration: none;
  font-size: 0.875rem;
  line-height: 1.45;
}
#docnav a:hover, #toc a:hover { color: var(--fg); background: var(--surface); }
#docnav a.on {
  color: var(--fg);
  background: var(--accent-dim);
  box-shadow: inset 2px 0 0 var(--accent);
}
#toc .lvl3 a { padding-left: 1.5rem; font-size: 0.8rem; }

/* ---- prose ---------------------------------------------------------- */

.prose { max-width: 46rem; }
.prose .loading { color: var(--dim); font-family: var(--mono); font-size: 0.85rem; }

.prose h1 {
  font-size: clamp(1.9rem, 1.4rem + 2.2vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  margin: 0 0 1.25rem;
}
.prose h2 {
  font-size: clamp(1.3rem, 1.1rem + 1vw, 1.65rem);
  font-weight: 700;
  letter-spacing: -0.015em;
  margin: 2.75rem 0 0.9rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--line);
}
.prose h3 { font-size: 1.1rem; font-weight: 700; margin: 2rem 0 0.6rem; }
.prose h4, .prose h5, .prose h6 { font-size: 0.95rem; font-weight: 700; margin: 1.5rem 0 0.5rem; color: var(--dim); }

.prose p, .prose li { color: #C6CAD3; }
.prose p { margin: 0 0 1.1rem; max-width: none; }
.prose strong { color: var(--fg); }
.prose a { color: var(--accent); }

.prose ul, .prose ol { margin: 0 0 1.2rem; padding-left: 1.35rem; display: flex; flex-direction: column; gap: 0.4rem; }
.prose li { line-height: 1.6; }
.prose li::marker { color: var(--accent); }

.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.25rem 0; }

.prose blockquote {
  margin: 1.4rem 0;
  padding: 0.2rem 0 0.2rem 1.1rem;
  border-left: 2px solid var(--accent);
  color: var(--dim);
}
.prose blockquote p:last-child { margin-bottom: 0; }

.prose pre.code {
  background: #090B0F;
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 0.95rem 1.1rem;
  overflow-x: auto;
  margin: 0 0 1.3rem;
  position: relative;
}
.prose pre.code code {
  font-family: var(--mono);
  font-size: 0.815rem;
  line-height: 1.7;
  color: #CBD1DC;
  background: none;
  padding: 0;
  white-space: pre;
}
.prose pre.code[data-lang]::after {
  content: attr(data-lang);
  position: absolute;
  top: 0.5rem;
  right: 0.7rem;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--dim);
}

.prose :not(pre) > code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--surface-2);
  border: 1px solid var(--line);
  color: #D8DCE4;
  padding: 0.08em 0.36em;
  border-radius: 3px;
}

.tablewrap { overflow-x: auto; margin: 0 0 1.4rem; }
.prose table { border-collapse: collapse; width: 100%; font-size: 0.9rem; }
.prose th, .prose td {
  text-align: left;
  padding: 0.55rem 0.85rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.prose th {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--accent);
  border-bottom-color: var(--accent-dim);
  white-space: nowrap;
}
.prose td { color: #C6CAD3; }
.prose tbody tr:hover td { background: var(--surface); }

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

.top nav a.on { color: var(--fg); }

.readerlink { margin-top: 2rem; }