/* aiolos site — editorial, high-contrast, cream paper.
   Aesthetic reference: threshold-cryptography diagrams, academic monographs.
   No gradients, no rainbow, no rounded buttons. Just type and paper. */

:root {
  --paper: #f0ece1;
  --paper-dim: #e6e1d2;
  --ink: #141210;
  --ink-dim: #4a4038;
  --rule: #141210;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --serif: "EB Garamond", "Libre Caslon Text", Georgia, serif;
  --measure: 40rem;
}

* { box-sizing: border-box; }

html, body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  padding: 3rem 1.5rem 4rem;
}

main {
  max-width: 64rem;
  margin: 0 auto;
}

article { position: relative; }

/* ── Head ────────────────────────────────────────────────────────────── */

.head {
  max-width: 44rem;
  margin: 2rem auto 4rem;
  text-align: left;
}

.eyebrow {
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  color: var(--ink-dim);
  margin: 0 0 1.5rem;
  font-variant: small-caps;
}

.eyebrow strong {
  font-weight: 600;
  color: var(--ink);
  font-variant: normal;
  letter-spacing: 0;
  font-size: 1.05rem;
}

.eyebrow em {
  font-style: italic;
  font-variant: normal;
}

.eyebrow-sep {
  margin: 0 0.4rem;
  color: var(--ink-dim);
}

h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 3.4rem;
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin: 0 0 1.25rem;
}

.subtitle {
  font-size: 1.2rem;
  line-height: 1.5;
  margin: 0 0 2rem;
}

.subtitle strong { font-weight: 600; font-style: italic; }

.cta {
  margin-top: 1.5rem;
}

.install {
  display: inline-block;
  padding: 1rem 1.3rem;
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
}

.cta-meta {
  font-size: 0.9rem;
  color: var(--ink-dim);
  margin: 0;
}

.cta-meta a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.12em;
}

.sep {
  margin: 0 0.4rem;
  color: var(--ink-dim);
}

/* ── Diagram ─────────────────────────────────────────────────────────── */

.diagram-section {
  margin: 4rem auto 6rem;
  max-width: 62rem;
  text-align: center;
}

.diagram {
  width: 100%;
  height: auto;
  color: var(--ink);
  display: block;
}

.diagram .label {
  font-family: var(--serif);
  font-weight: 700;
  font-variant: small-caps;
  letter-spacing: 0.08em;
  font-size: 14px;
  fill: var(--ink);
}

.diagram .label-sm {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 14px;
  fill: var(--ink);
}

.diagram .annotation {
  font-family: var(--serif);
  font-style: italic;
  font-size: 13px;
  fill: var(--ink-dim);
}

.diagram .annotation-sm {
  font-family: var(--serif);
  font-style: italic;
  font-size: 11px;
  fill: var(--ink-dim);
}

.diagram .mono-sm {
  font-family: var(--mono);
  font-size: 12px;
  fill: var(--ink);
}

.caption {
  font-style: italic;
  color: var(--ink-dim);
  font-size: 0.95rem;
  max-width: var(--measure);
  margin: 1.5rem auto 0;
  text-align: left;
}

.caption em {
  font-weight: 500;
  color: var(--ink);
}

/* ── Prose sections ──────────────────────────────────────────────────── */

.prose {
  max-width: var(--measure);
  margin: 4rem auto;
}

h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.6rem;
  margin: 0 0 1.25rem;
  letter-spacing: 0;
  line-height: 1.25;
}

.diagram-heading {
  max-width: var(--measure);
  margin: 0 auto 2rem;
  text-align: left;
}

p { margin: 0 0 1rem; }

em { font-style: italic; }

.prose a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.15em;
  text-decoration-thickness: 1px;
}

/* ── Code blocks ─────────────────────────────────────────────────────── */

pre {
  font-family: var(--mono);
  font-size: 0.95rem;
  background: var(--paper-dim);
  padding: 1.1rem 1.3rem;
  overflow-x: auto;
  margin: 1rem 0 1.25rem;
  line-height: 1.5;
  border-left: 2px solid var(--ink);
}

pre code {
  background: none;
  padding: 0;
  white-space: pre;
}

code {
  font-family: var(--mono);
  font-size: 0.95em;
  background: var(--paper-dim);
  padding: 0 0.25em;
}

.comment {
  color: var(--ink-dim);
  font-style: italic;
}

.preset {
  font-size: 0.9rem;
}

/* ── Definition list: commands ───────────────────────────────────────── */

dl.commands {
  margin: 1rem 0;
}

dl.commands dt {
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: 500;
  margin-top: 1.25rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--ink);
}

dl.commands dt:first-child { border-top: 0; padding-top: 0; margin-top: 0; }

dl.commands dd {
  margin: 0.35rem 0 0;
  font-size: 1rem;
}

/* ── Principles list ─────────────────────────────────────────────────── */

ul.principles {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

ul.principles li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 1.1rem;
}

ul.principles li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--ink-dim);
}

ul.principles strong { font-weight: 600; }

/* ── "Not to be confused with" table ─────────────────────────────────── */

dl.vs {
  margin: 1rem 0;
}

dl.vs dt {
  font-weight: 500;
  margin-top: 1rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--ink);
}

dl.vs dt:first-child { border-top: 0; padding-top: 0; margin-top: 0; }

dl.vs dt a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

dl.vs dd {
  margin: 0.3rem 0 0;
  font-size: 1rem;
  color: var(--ink-dim);
}

/* ── Foot ────────────────────────────────────────────────────────────── */

.foot {
  max-width: var(--measure);
  margin: 5rem auto 1rem;
  color: var(--ink-dim);
  font-size: 0.9rem;
}

.foot hr {
  border: 0;
  border-top: 1px solid var(--ink);
  margin: 0 0 1rem;
}

.foot p {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.foot a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
}

.foot-right { font-family: var(--mono); font-size: 0.85rem; }

/* ── Sound toggle ────────────────────────────────────────────────────── */

.sound-toggle {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--ink);
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  user-select: none;
  z-index: 10;
}

.sound-toggle:hover { background: var(--paper-dim); }

.sound-toggle[aria-pressed="true"]::before {
  content: "◉ ";
  color: var(--ink);
}

.sound-toggle[aria-pressed="false"]::before {
  content: "◌ ";
  color: var(--ink-dim);
}

/* ── Responsive ──────────────────────────────────────────────────────── */

@media (max-width: 680px) {
  html { font-size: 16px; }
  body { padding: 1.5rem 1rem 3rem; }
  h1 { font-size: 2.3rem; }
  .subtitle { font-size: 1.05rem; }
  .head { margin: 1rem 0 2.5rem; }
  .diagram-section { margin: 2rem 0 3rem; }
  pre { font-size: 0.82rem; padding: 0.9rem 1rem; }
  .install { display: block; }
  .foot p { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
}

/* ── Selection & focus ───────────────────────────────────────────────── */

::selection { background: var(--ink); color: var(--paper); }

a:focus-visible, button:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}