/* Quilzo docs — Material 3 Expressive
 *
 * The tonal palettes are the application's own, copied rather than approximated,
 * so the manual and the product it documents are recognisably one thing. The
 * primary ramp is generated around the mark's #00515f; the neutral is biased
 * toward it rather than being a grey somebody defaulted to.
 *
 * Three ideas from M3 Expressive carry the design:
 *
 *   The shape scale, which deliberately breaks corner symmetry. Chapter cards
 *   and figures are round on three corners and square on the fourth, in the
 *   same direction as the mark — so the shape language of the page and the
 *   logo are the same decision rather than two.
 *
 *   Spring motion. Expressive replaces the old cubic-bezier easings with
 *   spatial springs; linear() approximates one in pure CSS with no library.
 *
 *   Expressive type. A wider range between the smallest and largest sizes than
 *   the 2021 scale used, with tighter tracking at display sizes.
 *
 * Both colour schemes are defined once with light-dark(). One set of tokens,
 * not a light set and a dark override that drifts apart.
 */

:root {
  color-scheme: light dark;

  /* -- tonal palettes, from the application ------------------------------ */
  --primary-10:#002026;  --primary-20:#003741;  --primary-30:#00515f;
  --primary-40:#006c7e;  --primary-60:#00a0b3;  --primary-70:#5eb8c7;
  --primary-80:#93d0dc;  --primary-90:#c2e9f1;  --primary-95:#daf6fb;
  --secondary-30:#304b50; --secondary-80:#b5cace; --secondary-90:#d7e5e8;
  --tertiary-30:#5c3c58;  --tertiary-80:#dbbed6; --tertiary-90:#f0dded;
  --ok-30:#0d5730;   --ok-80:#8fd9ae;   --ok-90:#b9ecce;   --ok-10:#032111;
  --warn-30:#5c4600; --warn-80:#e8c95c; --warn-90:#f6e2a0; --warn-10:#231a00;

  /* -- roles ------------------------------------------------------------- */
  --primary:        light-dark(var(--primary-30), var(--primary-80));
  --on-primary:     light-dark(#ffffff,           var(--primary-20));
  --primary-container:    light-dark(var(--primary-90), var(--primary-20));
  --on-primary-container: light-dark(var(--primary-10), var(--primary-90));

  --surface:        light-dark(#f6fafb, #0d1416);
  --surface-1:      light-dark(#ffffff, #131c1e);
  --surface-2:      light-dark(#eef5f6, #182225);
  --surface-3:      light-dark(#e6eff1, #1d282b);
  --on-surface:     light-dark(#0e1719, #dfe6e7);
  --on-surface-var: light-dark(#465356, #a8b6b9);
  --outline:        light-dark(#6d7b7e, #869497);
  --outline-var:    light-dark(#d3e0e3, #2b3639);

  --ok:        light-dark(var(--ok-30), var(--ok-80));
  --ok-cont:   light-dark(var(--ok-90), var(--ok-10));
  --warn:      light-dark(var(--warn-30), var(--warn-80));
  --warn-cont: light-dark(var(--warn-90), var(--warn-10));
  --note:      light-dark(var(--tertiary-30), var(--tertiary-80));
  --note-cont: light-dark(var(--tertiary-90), #251723);

  /* -- type -------------------------------------------------------------- */
  --font-sans: 'IBM Plex Sans', ui-sans-serif, -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  /* -- M3 Expressive shape scale ---------------------------------------- */
  --shape-xs: 8px;
  --shape-s:  12px;
  --shape-m:  16px;
  --shape-l:  24px;
  --shape-xl: 32px;

  /* -- motion: spatial springs, approximated with linear() --------------- */
  --spring-fast: linear(0, .35 7.5%, .78 16%, .98 22%, 1.07 27%, 1.06 34%, 1 48%, 1);
  --spring-slow: linear(0, .18 5%, .55 12%, .87 19%, 1.04 26%, 1.06 34%, .99 52%, 1);
  --ease-out: cubic-bezier(.2, 0, 0, 1);

  --sidebar-w: 288px;
  --header-h: 64px;
}

:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"]  { color-scheme: dark; }

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
}

body {
  margin: 0;
  background: var(--surface);
  color: var(--on-surface);
  font-family: var(--font-sans);
  font-size: 16.5px;
  line-height: 1.66;
  -webkit-font-smoothing: antialiased;
}

/* ---------------------------------------------------------------- skip -- */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 60;
  background: var(--primary); color: var(--on-primary);
  padding: .75rem 1.25rem; border-radius: 0 0 var(--shape-m) var(--shape-m);
  font-weight: 600;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: var(--shape-xs);
}

/* ------------------------------------------------------------- topbar -- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 1.25rem;
  min-height: var(--header-h);
  padding: 0 clamp(1rem, 3vw, 2rem);
  background: color-mix(in srgb, var(--surface-1) 88%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--outline-var);
}
.brand {
  display: inline-flex; align-items: center; gap: .55rem;
  font-weight: 650; font-size: 1.05rem; letter-spacing: -.01em;
  color: var(--on-surface); text-decoration: none;
}
.brand .mark {
  flex: 0 0 auto; color: var(--primary);
  transition: transform .5s var(--spring-fast);
}
.brand:hover .mark { transform: rotate(-8deg) scale(1.08); }
.brand .dot { display: none; }

.topbar nav { margin-left: auto; display: flex; gap: .4rem; }
.topbar nav a {
  color: var(--on-surface-var); text-decoration: none;
  font-size: .92rem; font-weight: 500;
  padding: .45rem .9rem; border-radius: 999px;
  transition: background .18s var(--ease-out), color .18s var(--ease-out);
}
.topbar nav a:hover { background: var(--surface-3); color: var(--on-surface); }

.nav-toggle {
  display: none; font: inherit; font-size: .9rem; font-weight: 550;
  padding: .5rem 1.1rem; border-radius: 999px;
  border: 1px solid var(--outline-var);
  background: var(--surface-1); color: var(--on-surface); cursor: pointer;
  transition: background .18s var(--ease-out);
}
.nav-toggle:hover { background: var(--surface-3); }

/* --------------------------------------------------------------- hero -- */
.hero {
  padding: clamp(3rem, 8vw, 5.5rem) clamp(1rem, 3vw, 2rem) clamp(2.5rem, 5vw, 4rem);
  max-width: 1180px; margin: 0 auto;
}
.hero-mark {
  display: block; color: var(--primary); margin: 0 0 1.5rem;
  animation: mark-in .9s var(--spring-slow) both;
}
@keyframes mark-in {
  from { opacity: 0; transform: translateY(14px) rotate(-10deg) scale(.85); }
  to   { opacity: 1; transform: none; }
}
.hero h1 {
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  line-height: 1.02; letter-spacing: -.035em; font-weight: 640;
  margin: 0 0 1.1rem; max-width: 16ch; text-wrap: balance;
}
.thesis {
  font-size: clamp(1.08rem, 2.1vw, 1.32rem); line-height: 1.55;
  color: var(--on-surface-var); max-width: 58ch; margin: 0 0 2rem;
}
.hero .meta {
  display: flex; flex-wrap: wrap; gap: .6rem;
  font-family: var(--font-mono); font-size: .82rem;
}
.hero .meta span {
  background: var(--surface-2); border: 1px solid var(--outline-var);
  padding: .4rem .95rem; border-radius: 999px; color: var(--on-surface-var);
}
.hero .meta strong { color: var(--primary); font-weight: 600; }

/* ------------------------------------------------------------- layout -- */
.layout {
  display: grid; grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  max-width: 1180px; margin: 0 auto;
  padding: 0 clamp(1rem, 3vw, 2rem) 6rem;
  align-items: start;
}

.sidebar {
  position: sticky; top: calc(var(--header-h) + 1.5rem);
  max-height: calc(100vh - var(--header-h) - 3rem);
  overflow-y: auto; padding-right: .5rem;
}
.nav-group { margin: 0 0 1.6rem; }
.nav-group h3 {
  font-family: var(--font-mono);
  font-size: .68rem; letter-spacing: .13em; text-transform: uppercase;
  color: var(--on-surface-var); font-weight: 500; margin: 0 0 .55rem;
  padding-left: 1rem;
}
.nav-group ul { list-style: none; margin: 0; padding: 0; }
.nav-group a {
  display: block; padding: .42rem 1rem; border-radius: 999px;
  color: var(--on-surface-var); text-decoration: none;
  font-size: .93rem; line-height: 1.45;
  transition: background .18s var(--ease-out), color .18s var(--ease-out),
              padding-left .28s var(--spring-fast);
}
.nav-group a:hover {
  background: var(--surface-2); color: var(--on-surface); padding-left: 1.3rem;
}
.nav-group a[aria-current="true"] {
  background: var(--primary-container); color: var(--on-primary-container);
  font-weight: 550;
}

/* ------------------------------------------------------------ chapter -- */
/* .chapter is the divider between groups of sections; .doc is a section. */

.main { min-width: 0; }

.chapter {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 620; letter-spacing: -.028em; line-height: 1.15;
  margin: 3rem 0 1.25rem; padding-left: 1rem;
  border-left: 4px solid var(--primary);
  scroll-margin-top: calc(var(--header-h) + 20px);
}
.chapter:first-child { margin-top: 0; }

.doc {
  min-width: 0;
  background: var(--surface-1);
  border: 1px solid var(--outline-var);
  /* The Expressive shape move: round on three corners, square on one, in the
   * same direction the mark's nib points. */
  border-radius: var(--shape-l) var(--shape-l) var(--shape-l) 4px;
  padding: clamp(1.5rem, 3vw, 2.4rem);
  margin: 0 0 1.5rem;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

.doc-head {
  display: flex; flex-wrap: wrap; align-items: baseline;
  justify-content: space-between; gap: .6rem 1rem;
  margin: 0 0 1.2rem; padding-bottom: 1rem;
  border-bottom: 1px solid var(--outline-var);
}
.doc-head h3 {
  font-size: clamp(1.4rem, 2.6vw, 1.85rem); line-height: 1.18;
  letter-spacing: -.02em; font-weight: 620; margin: 0; text-wrap: balance;
}
.hash {
  font-family: var(--font-mono); font-size: .78rem;
  color: var(--on-surface-var); text-decoration: none;
  padding: .28rem .7rem; border-radius: 999px;
  background: var(--surface-2);
  transition: background .18s var(--ease-out), color .18s var(--ease-out);
}
.hash:hover { background: var(--primary-container); color: var(--on-primary-container); }

.doc h4 {
  font-size: 1.05rem; font-weight: 620; letter-spacing: -.005em;
  margin: 2rem 0 .6rem;
}
.doc h4:first-of-type { margin-top: 1rem; }
.doc p { margin: 0 0 1rem; max-width: 68ch; }
.doc ul, .doc ol { max-width: 66ch; padding-left: 1.3rem; margin: 0 0 1rem; }
.doc li { margin: 0 0 .4rem; }
.lead { font-size: 1.08rem; color: var(--on-surface-var); max-width: 62ch; }

a { color: var(--primary); text-underline-offset: 2px; }

code {
  font-family: var(--font-mono); font-size: .87em;
  background: var(--surface-2); padding: .12em .4em;
  border-radius: var(--shape-xs);
  border: 1px solid var(--outline-var);
}
pre.code {
  background: var(--surface-2); border: 1px solid var(--outline-var);
  border-radius: var(--shape-s) var(--shape-s) var(--shape-s) 4px;
  padding: 1rem 1.15rem; overflow-x: auto; margin: 0 0 1.2rem;
}
pre.code code { background: none; border: 0; padding: 0; font-size: .88rem; }

/* ------------------------------------------------------------ figures -- */
.shot { margin: 1.5rem 0; }
.shot img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--outline-var);
  border-radius: var(--shape-m) var(--shape-m) var(--shape-m) 4px;
  background: var(--surface-2);
  transition: transform .4s var(--spring-fast), box-shadow .3s var(--ease-out);
}
.shot img:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 32px -12px color-mix(in srgb, var(--primary) 45%, transparent);
}
.shot figcaption {
  font-size: .87rem; color: var(--on-surface-var);
  margin-top: .7rem; max-width: 62ch;
}

/* ------------------------------------------------------------- notices -- */
.notice {
  border-radius: var(--shape-s) var(--shape-s) var(--shape-s) 4px;
  padding: .95rem 1.15rem; margin: 0 0 1.2rem;
  background: var(--note-cont); color: var(--on-surface);
  border: 1px solid transparent; max-width: 68ch;
}
.notice.warn { background: var(--warn-cont); }
.hint { font-size: .89rem; color: var(--on-surface-var); }

/* -------------------------------------------------------------- tables -- */
.table-wrap { overflow-x: auto; margin: 0 0 1.4rem; }
table { border-collapse: collapse; width: 100%; min-width: 480px; font-size: .93rem; }
thead th {
  text-align: left; font-family: var(--font-mono);
  font-size: .7rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--on-surface-var); font-weight: 500;
  padding: 0 1rem .6rem 0; border-bottom: 1px solid var(--outline-var);
}
tbody th, tbody td {
  text-align: left; font-weight: 400; vertical-align: top;
  padding: .75rem 1rem .75rem 0; border-bottom: 1px solid var(--outline-var);
}
tbody th { font-weight: 550; }
tbody tr:last-child th, tbody tr:last-child td { border-bottom: 0; }

/* ------------------------------------------------------------ responsive */
@media (max-width: 900px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .sidebar {
    position: static; max-height: none; display: none;
    background: var(--surface-1); border: 1px solid var(--outline-var);
    border-radius: var(--shape-l) var(--shape-l) var(--shape-l) 4px;
    padding: 1.25rem; margin-bottom: 1.5rem;
  }
  .sidebar.open { display: block; }
  .nav-toggle { display: inline-block; }
  .topbar nav { display: none; }
}