/* ==========================================================================
   The Bit-Width Compendium — stylesheet
   A field guide to the bitness of processor architectures.
   ========================================================================== */

:root {
  --ink:        #1c1e26;
  --ink-soft:   #3a3f4b;
  --paper:      #f6f3ec;
  --paper-2:    #efeadf;
  --panel:      #ffffff;
  --rule:       #d9d2c3;
  --accent:     #b4441f;   /* oxidized-copper red */
  --accent-2:   #1f6f8b;   /* oscilloscope teal   */
  --accent-3:   #7a5c14;   /* PCB gold            */
  --link:       #1f6f8b;
  --link-hover: #b4441f;
  --code-bg:    #23262f;
  --code-fg:    #e8e6df;
  --shadow:     0 1px 2px rgba(28,30,38,.08), 0 8px 24px rgba(28,30,38,.06);
  --mono: "SFMono-Regular", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, "Liberation Mono", monospace;
  --serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    linear-gradient(180deg, var(--paper) 0%, var(--paper-2) 100%) fixed;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* ---- skip link for accessibility ---- */
.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: var(--paper); padding: .6rem 1rem; z-index: 100;
}
.skip:focus { left: 8px; top: 8px; }

/* ---- masthead ---- */
.masthead {
  border-bottom: 3px double var(--rule);
  background: var(--panel);
}
.masthead .wrap { padding: 1.4rem 0 1.1rem; }
.brand {
  display: flex; align-items: baseline; gap: .8rem; flex-wrap: wrap;
  text-decoration: none; color: inherit;
}
.brand .logo {
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: -.04em;
  font-size: 1.9rem;
  color: var(--paper);
  background: var(--ink);
  padding: .18rem .5rem;
  border-radius: 5px;
  box-shadow: var(--shadow);
}
.brand .logo .hl { color: #ffd15c; }
.brand .titles h1 {
  margin: 0; font-size: 1.5rem; letter-spacing: -.01em; line-height: 1.1;
}
.brand .titles .sub {
  margin: .1rem 0 0; font-family: var(--mono); font-size: .74rem;
  text-transform: uppercase; letter-spacing: .22em; color: var(--accent-3);
}

/* ---- navigation ---- */
nav.primary {
  border-top: 1px solid var(--rule);
  background: var(--paper-2);
  position: sticky; top: 0; z-index: 40;
  box-shadow: 0 1px 0 var(--rule);
}
nav.primary ul {
  list-style: none; margin: 0 auto; padding: 0; max-width: 60rem;
  display: flex; flex-wrap: wrap; gap: .2rem; padding-left: 1.25rem; padding-right: 1.25rem;
}
nav.primary a {
  display: block; padding: .7rem .95rem;
  font-family: var(--mono); font-size: .8rem; text-transform: uppercase;
  letter-spacing: .12em; text-decoration: none; color: var(--ink-soft);
  border-bottom: 3px solid transparent;
}
nav.primary a:hover, nav.primary a[aria-current="page"] {
  color: var(--accent); border-bottom-color: var(--accent);
}

/* ---- layout ---- */
.wrap { max-width: 60rem; margin: 0 auto; padding-left: 1.25rem; padding-right: 1.25rem; }
main { padding: 2.4rem 0 1rem; }
section { margin: 0 0 2.6rem; }

/* ---- hero ---- */
.hero {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 2.2rem 2rem;
  box-shadow: var(--shadow);
  margin-bottom: 2.6rem;
}
.hero .kicker {
  font-family: var(--mono); font-size: .74rem; letter-spacing: .22em;
  text-transform: uppercase; color: var(--accent); margin: 0 0 .6rem;
}
.hero h2 { font-size: 2.15rem; line-height: 1.12; margin: 0 0 .8rem; letter-spacing: -.015em; }
.hero p { margin: 0 0 1rem; font-size: 1.12rem; color: var(--ink-soft); }
.hero .cta { display: flex; gap: .7rem; flex-wrap: wrap; margin-top: 1.3rem; }
.btn {
  font-family: var(--mono); font-size: .82rem; letter-spacing: .04em;
  text-decoration: none; padding: .62rem 1.1rem; border-radius: 6px;
  border: 1px solid var(--ink); color: var(--ink); background: transparent;
}
.btn.primary { background: var(--ink); color: var(--paper); }
.btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ---- typography ---- */
h2.section-title {
  font-size: 1.7rem; letter-spacing: -.01em; margin: 0 0 .3rem;
  padding-bottom: .35rem; border-bottom: 2px solid var(--ink);
  display: inline-block;
}
h3 { font-size: 1.3rem; margin: 1.8rem 0 .5rem; letter-spacing: -.01em; }
h4 { font-size: 1.05rem; margin: 1.3rem 0 .35rem; font-family: var(--sans); }
p { margin: 0 0 1.05rem; }
a { color: var(--link); text-underline-offset: 2px; text-decoration-thickness: 1px; }
a:hover { color: var(--link-hover); }
.lead { font-size: 1.16rem; color: var(--ink-soft); }
.dropcap::first-letter {
  font-family: var(--mono); font-weight: 700; float: left; font-size: 3.4rem;
  line-height: .8; padding: .18rem .5rem .1rem 0; color: var(--accent);
}
small, .muted { color: #6d6656; }
mark { background: #ffe9a8; padding: 0 .18em; }
abbr { text-decoration: underline dotted; cursor: help; }
blockquote {
  margin: 1.4rem 0; padding: .5rem 1.2rem; border-left: 4px solid var(--accent-2);
  background: var(--paper-2); font-style: italic; color: var(--ink-soft);
}

/* ---- code ---- */
code, kbd, samp { font-family: var(--mono); font-size: .86em; }
:not(pre) > code {
  background: var(--paper-2); border: 1px solid var(--rule);
  padding: .06em .38em; border-radius: 4px;
}
pre {
  background: var(--code-bg); color: var(--code-fg);
  padding: 1rem 1.2rem; border-radius: 8px; overflow-x: auto;
  font-family: var(--mono); font-size: .82rem; line-height: 1.55;
  box-shadow: var(--shadow);
}

/* ---- cards / grid ---- */
.grid { display: grid; gap: 1.1rem; }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--panel); border: 1px solid var(--rule); border-radius: 9px;
  padding: 1.2rem 1.25rem; box-shadow: var(--shadow);
}
.card h3 { margin-top: 0; }
.card .tag {
  display: inline-block; font-family: var(--mono); font-size: .68rem;
  text-transform: uppercase; letter-spacing: .12em; color: var(--accent-2);
  border: 1px solid var(--accent-2); border-radius: 20px; padding: .08rem .55rem;
  margin-bottom: .5rem;
}

/* ---- era timeline ---- */
.era {
  display: grid; grid-template-columns: 7.5rem 1fr; gap: 1.2rem;
  padding: 1.3rem 0; border-top: 1px solid var(--rule);
}
.era:first-of-type { border-top: none; }
.era .badge {
  font-family: var(--mono); font-weight: 700; font-size: 1.5rem;
  color: var(--paper); background: var(--accent); border-radius: 8px;
  padding: .7rem .4rem; text-align: center; align-self: start;
  box-shadow: var(--shadow); letter-spacing: -.03em;
}
.era .badge small { display: block; font-size: .6rem; letter-spacing: .1em; opacity: .85; font-weight: 400; }
.era:nth-child(2n) .badge { background: var(--accent-2); }
.era:nth-child(3n) .badge { background: var(--accent-3); }
.era h3 { margin-top: 0; }

/* ---- tables ---- */
.table-scroll { overflow-x: auto; margin: 1.2rem 0; }
table.data {
  border-collapse: collapse; width: 100%; font-family: var(--sans); font-size: .92rem;
  background: var(--panel); box-shadow: var(--shadow); border-radius: 8px; overflow: hidden;
}
table.data th, table.data td { padding: .6rem .8rem; text-align: left; border-bottom: 1px solid var(--rule); }
table.data thead th {
  background: var(--ink); color: var(--paper); font-family: var(--mono);
  font-size: .72rem; text-transform: uppercase; letter-spacing: .1em;
}
table.data tbody tr:nth-child(2n) { background: var(--paper-2); }
table.data caption { caption-side: bottom; font-size: .82rem; color: #6d6656; padding-top: .6rem; text-align: left; }

/* ---- resource / link lists ---- */
.linklist { list-style: none; margin: 0; padding: 0; display: grid; gap: .6rem; }
.linklist li {
  background: var(--panel); border: 1px solid var(--rule); border-radius: 8px;
  padding: .85rem 1rem; box-shadow: var(--shadow);
}
.linklist a.title { font-weight: 700; text-decoration: none; font-size: 1.02rem; }
.linklist a.title::after { content: " ↗"; font-size: .82em; color: var(--accent-3); }
.linklist .host { font-family: var(--mono); font-size: .72rem; color: #6d6656; letter-spacing: .04em; }
.linklist p { margin: .3rem 0 0; font-size: .95rem; color: var(--ink-soft); }

.callout {
  border: 1px solid var(--accent-2); background: #eef6f8; border-radius: 9px;
  padding: 1.1rem 1.25rem; margin: 1.6rem 0;
}
.callout strong { color: var(--accent-2); }

/* ---- footer ---- */
footer.site {
  margin-top: 2rem; border-top: 3px double var(--rule); background: var(--panel);
}
footer.site .wrap { padding: 2rem 1.25rem; display: grid; gap: 1.4rem; grid-template-columns: 2fr 1fr 1fr; }
footer.site h5 { font-family: var(--mono); font-size: .72rem; text-transform: uppercase; letter-spacing: .14em; color: var(--accent-3); margin: 0 0 .6rem; }
footer.site ul { list-style: none; margin: 0; padding: 0; }
footer.site li { margin: 0 0 .35rem; }
footer.site a { text-decoration: none; }
footer .colophon { border-top: 1px solid var(--rule); }
footer .colophon .wrap { grid-template-columns: 1fr; padding-top: 1.2rem; padding-bottom: 1.6rem; font-size: .82rem; color: #6d6656; }

/* ---- responsive ---- */
@media (max-width: 760px) {
  body { font-size: 17px; }
  .grid.cols-2, .grid.cols-3 { grid-template-columns: 1fr; }
  .hero h2 { font-size: 1.7rem; }
  .era { grid-template-columns: 1fr; }
  .era .badge { justify-self: start; min-width: 6rem; }
  footer.site .wrap { grid-template-columns: 1fr; }
  nav.primary ul { flex-wrap: nowrap; overflow-x: auto; }
}