/* ==========================================================================
   BIOS design system · 2/5 · base
   Reset, the fresco ground, typography, native form controls, tables,
   layout primitives and a deliberately small set of utilities.
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + 1rem);
  overflow-x: clip;
}
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
body {
  margin: 0;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  background-color: var(--paper);
  color: var(--ink-2);
  font: 400 var(--fs-md)/var(--lh) var(--sans);
  font-kerning: normal;
  font-variant-numeric: proportional-nums;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: clip;
  isolation: isolate;
}
/* The fresco: fixed layers, composited once — scrolling never repaints the paper. */
body::before, body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}
body::before { background: var(--paper) url("../art/paper.webp") center / cover no-repeat; }
body::after { z-index: -1; background: var(--paper-tint); }

figure { margin: 0; }
img, svg, video, canvas { display: block; max-width: 100%; }
img { height: auto; }
svg:not([fill]) { fill: currentColor; }
[hidden], .hidden { display: none !important; }
.overflow-hidden { overflow: hidden !important; }

/* ---------- typography ---------- */
h1, h2, h3, h4, h5, h6 { margin: 0; color: var(--heading); text-wrap: balance; }
h1 { font: 300 var(--fs-h1)/1.04 var(--serif); letter-spacing: -.012em; }
h2 { font: 500 var(--fs-h2)/1.12 var(--serif); letter-spacing: -.005em; }
h3 { font: 500 var(--fs-h3)/1.2 var(--serif); }
h4 { font: 600 var(--fs-md)/1.35 var(--sans); }
h5, h6 { font: 600 var(--fs-sm)/1.4 var(--sans); letter-spacing: .06em; text-transform: uppercase; }
p { margin: 0; text-wrap: pretty; }
p + p { margin-top: .8em; }
small { font-size: var(--fs-sm); }
strong, b { font-weight: 600; color: var(--ink); }
em, i { font-style: italic; }
code, kbd, samp, pre { font-family: var(--mono); font-size: .92em; }
code { padding: .08em .35em; border-radius: var(--radius-sm); background: rgba(74, 48, 28, .07); color: var(--ink); overflow-wrap: anywhere; }
pre { margin: 0; padding: var(--s-4); overflow-x: auto; background: var(--paper-3); border: 1px solid var(--rule); border-radius: var(--radius-sm); }
pre code { padding: 0; background: none; }
hr { border: 0; border-top: 1px solid var(--rule); margin: var(--s-6) 0; }
abbr[title] { text-decoration: none; border-bottom: 1px dotted var(--rule-3); cursor: help; }
ul, ol { margin: 0; padding-left: 1.25em; }
li + li { margin-top: .3em; }
dl, dd { margin: 0; }
blockquote { margin: 0; padding-left: var(--s-4); border-left: 2px solid var(--accent-soft); font-style: italic; }
::selection { background: rgba(207, 152, 68, .35); color: var(--ink); }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { color: var(--ink); }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; border-radius: 2px; }
button:focus-visible, .btn:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible,
summary:focus-visible { outline: none; box-shadow: var(--focus); }

.skip-link {
  position: fixed; left: var(--s-4); top: var(--s-4); z-index: 100;
  padding: .75rem 1rem; background: var(--ink); color: var(--paper-2);
  font: 500 var(--fs-sm)/1 var(--sans); letter-spacing: .06em; text-decoration: none;
  border-radius: var(--radius-sm); transform: translateY(-250%);
}
.skip-link:focus { transform: none; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.sr-only {
  position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap; border: 0;
}

/* ---------- native form controls (every input looks right, class or not) ---------- */
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
label { cursor: default; }
input:not([type]), input[type="text"], input[type="email"], input[type="url"], input[type="tel"], input[type="password"],
input[type="number"], input[type="search"], input[type="date"], input[type="datetime-local"], input[type="time"],
input[type="month"], input[type="week"], input[type="file"], select, textarea {
  display: block;
  width: 100%;
  min-height: 2.75rem;
  margin: 0;
  padding: .62rem .8rem;
  background: var(--paper-4);
  color: var(--ink);
  border: 1px solid var(--field-edge);
  border-radius: min(var(--radius), 8px);
  font: 400 var(--fs-md)/1.4 var(--sans);
  transition: border-color .15s ease, box-shadow .15s ease, background-color .15s ease;
}
textarea { min-height: 7rem; resize: vertical; line-height: var(--lh); }
select {
  appearance: none;
  padding-right: 2.4rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 8'%3E%3Cpath d='M1 1.5 6 6.5 11 1.5' fill='none' stroke='%233d3029' stroke-width='1.4'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right .85rem center; background-size: .75rem;
}
select[multiple] { padding-right: .8rem; background-image: none; min-height: 7rem; }
input::placeholder, textarea::placeholder { color: var(--ink-4); opacity: 1; }
input:hover:not(:disabled), select:hover:not(:disabled), textarea:hover:not(:disabled) { border-color: var(--ink-3); }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--ink); box-shadow: var(--focus); background-color: #fff; }
input:disabled, select:disabled, textarea:disabled { opacity: .6; cursor: not-allowed; }
input[readonly], textarea[readonly] { background: var(--paper-3); }
input[aria-invalid="true"], select[aria-invalid="true"], textarea[aria-invalid="true"] { border-color: var(--bad-ink); background-color: #fff6f3; }
input[type="file"] { padding: .45rem .5rem; cursor: pointer; }
input[type="file"]::file-selector-button {
  margin-right: .8rem; padding: .45rem .9rem; cursor: pointer;
  border: 1px solid var(--rule-3); border-radius: var(--btn-radius); background: var(--paper-2); color: var(--ink);
  font: 500 var(--fs-xs)/1.2 var(--sans); letter-spacing: .1em; text-transform: uppercase;
}
input[type="checkbox"], input[type="radio"] {
  width: 1.15rem; height: 1.15rem; margin: 0; flex: none; accent-color: var(--ink); cursor: pointer; vertical-align: -.2em;
}
input[type="range"] { accent-color: var(--ink); width: 100%; }
input[type="color"] { width: 3rem; height: 2.75rem; padding: .2rem; border: 1px solid var(--field-edge); border-radius: var(--radius-sm); background: var(--paper-4); }
fieldset { margin: 0; padding: 0; border: 0; min-width: 0; }
legend { padding: 0; font: 600 var(--fs-sm)/1.4 var(--sans); color: var(--ink); }
progress, meter { width: 100%; accent-color: var(--ink); }
summary { cursor: pointer; }

/* ---------- tables ---------- */
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
caption { text-align: left; }
th { text-align: left; }

/* ---------- layout ---------- */
.app-main { flex: 1 0 auto; width: 100%; }
.app-main:focus { outline: none; }
.shell { width: 100%; max-width: 76rem; margin-inline: auto; padding-inline: var(--gutter); }
.shell--wide { max-width: 100rem; }
.shell--narrow { max-width: 48rem; }
.shell--prose { max-width: 44rem; }
.page { padding-block: clamp(2rem, 5vw, 3.75rem) clamp(3rem, 7vw, 5.5rem); }
.page > * + * { margin-top: clamp(1.75rem, 3.5vw, 2.75rem); }
.stack > * + * { margin-top: var(--stack, var(--s-4)); }
.stack-sm { --stack: var(--s-2); }
.stack-lg { --stack: var(--s-6); }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--cluster, var(--s-3)); }
.cluster-sm { --cluster: var(--s-2); }
.cluster-lg { --cluster: var(--s-5); }
.split { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--s-3) var(--s-5); }
.split--start { align-items: flex-start; }
.grid { display: grid; gap: var(--grid-gap, var(--s-5)); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 20rem), 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 12.5rem), 1fr)); }
.grid--sidebar { grid-template-columns: minmax(0, 1fr); }
@media (min-width: 60rem) { .grid--sidebar { grid-template-columns: minmax(15rem, 18rem) minmax(0, 1fr); align-items: start; } }
.grid--aside { grid-template-columns: minmax(0, 1fr); }
@media (min-width: 60rem) { .grid--aside { grid-template-columns: minmax(0, 1fr) minmax(16rem, 22rem); align-items: start; } }
.span-full { grid-column: 1 / -1; }

/* ---------- utilities (kept small on purpose) ---------- */
.mono { font-family: var(--mono); }
.serif { font-family: var(--serif); }
.muted { color: var(--ink-3); }
.faint { color: var(--ink-4); }
.small { font-size: var(--fs-sm); }
.xsmall { font-size: var(--fs-xs); }
.nowrap { white-space: nowrap; }
.break { overflow-wrap: anywhere; word-break: break-word; }
.pre-wrap { white-space: pre-wrap; }
.num { text-align: right; font-variant-numeric: tabular-nums; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.upper { text-transform: uppercase; letter-spacing: .08em; }
.w-full { width: 100%; }
.mt-0 { margin-top: 0 !important; } .mt-1 { margin-top: var(--s-1); } .mt-2 { margin-top: var(--s-2); } .mt-3 { margin-top: var(--s-3); }
.mt-4 { margin-top: var(--s-4); } .mt-5 { margin-top: var(--s-5); } .mt-6 { margin-top: var(--s-6); } .mt-7 { margin-top: var(--s-7); }
.ml-auto { margin-left: auto; }
.inline { display: inline; }
.inline-flex { display: inline-flex; align-items: center; gap: var(--s-2); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}
@media print {
  body::before, body::after { display: none; }
  body { background: #fff; color: #000; }
}