/* SMART-QSO site. One hand-written stylesheet; system fonts; light and dark by prefers-color-scheme. */

:root {
  --bg: #f7f8f6;
  --surface: #ffffff;
  --surface-2: #eef1f4;
  --text: #17202a;
  --muted: #52606d;
  --border: #d5dbe1;
  --accent: #0b5cad;
  --accent-ink: #ffffff;
  --accent-2: #c2410c;
  --note-bg: #fff7e6;
  --note-border: #d9a441;
  --focus: #0b5cad;
  --cell: #1f4f8a;
  --cell-line: #6f98c9;
  --body-front: #dfe5eb;
  --body-side: #c6cfd8;
  --body-bot: #b3bdc8;
  --ants: #8794a1;
  --stroke: #2a3540;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f141a;
    --surface: #161d25;
    --surface-2: #1d2630;
    --text: #e4eaf0;
    --muted: #a3b0bd;
    --border: #324050;
    --accent: #7cb7f5;
    --accent-ink: #0f141a;
    --accent-2: #fb923c;
    --note-bg: #2a2214;
    --note-border: #9a7428;
    --focus: #9ccaff;
    --cell: #3e6fae;
    --cell-line: #8fb4e0;
    --body-front: #3a4654;
    --body-side: #2f3a46;
    --body-bot: #26303a;
    --ants: #56636f;
    --stroke: #c9d3dc;
  }
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-wrap: break-word;
}

a { color: var(--accent); text-underline-offset: 0.15em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; border-radius: 2px; }

code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; font-size: 0.88em; }
code { overflow-wrap: anywhere; }
pre { background: var(--surface-2); border: 1px solid var(--border); padding: 0.75rem 1rem; border-radius: 6px;
      overflow-x: auto; white-space: pre; }
pre code { overflow-wrap: normal; }

h1, h2, h3, h4 { line-height: 1.25; margin: 1.6em 0 0.5em; }
h1 { font-size: clamp(1.9rem, 4vw + 1rem, 2.8rem); margin-top: 1.2em; letter-spacing: -0.01em; }
h2 { font-size: 1.55rem; padding-top: 0.4em; border-top: 1px solid var(--border); }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }

.wrap { max-width: 72rem; margin: 0 auto; padding: 0 1rem; }

.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-ink);
        padding: 0.5rem 1rem; z-index: 10; }
.skip:focus { left: 1rem; top: 0.5rem; }

/* Header */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
                gap: 0.25rem 1.5rem; padding-top: 0.6rem; padding-bottom: 0.6rem; }
.brand { display: inline-flex; align-items: center; gap: 0.5rem; font-weight: 700; font-size: 1.15rem;
         color: var(--text); text-decoration: none; }
.logo { width: 1.8rem; height: 1.8rem; }
.logo-body { fill: var(--body-front); stroke: var(--stroke); stroke-width: 1.5; }
.logo-wing { fill: var(--cell); }
.logo-ant { stroke: var(--accent-2); stroke-width: 2; stroke-linecap: round; }
nav ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.1rem 0.25rem; }
nav a { display: block; padding: 0.35rem 0.6rem; border-radius: 6px; color: var(--text); text-decoration: none; }
nav a:hover { background: var(--surface-2); }
nav a[aria-current="page"] { background: var(--surface-2); color: var(--accent); font-weight: 600;
                             box-shadow: inset 0 -2px 0 var(--accent); }

main { padding-bottom: 3rem; }
.lede { font-size: 1.15rem; max-width: 48rem; }
.muted { color: var(--muted); }
.eyebrow { color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.8rem;
           font-weight: 600; margin: 0; }

/* Citations */
a.src { font-size: 0.78em; white-space: nowrap; color: var(--muted); text-decoration: none;
        border: 1px solid var(--border); border-radius: 999px; padding: 0 0.45em; margin-left: 0.1em;
        background: var(--surface); }
a.src:hover { color: var(--accent); border-color: var(--accent); }
.srcs { margin-bottom: 0; }

/* Hero */
.hero { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); gap: 2rem; align-items: center;
        padding-top: 1.5rem; }
.hero h1 { margin-top: 0.15em; }
.cta { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.btn { display: inline-block; padding: 0.55rem 1.1rem; border-radius: 6px; background: var(--accent);
       color: var(--accent-ink); text-decoration: none; font-weight: 600; }
.btn-2 { background: transparent; color: var(--accent); border: 1px solid var(--accent); }

figure { margin: 1.5rem 0; }
figcaption { color: var(--muted); font-size: 0.92rem; }
.hero-fig, .wide-fig { background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
                       padding: 0.75rem 1rem; margin: 0; }
.wide-fig { margin: 1.5rem 0; }
.wide-fig .sc-illus { max-width: 46rem; display: block; margin: 0 auto; }

/* Illustration */
.sc-illus { width: 100%; height: auto; display: block; }
.sc-illus polygon, .sc-illus line { stroke-linejoin: round; }
.sc-illus .body-front { fill: var(--body-front); stroke: var(--stroke); stroke-width: 1.2; }
.sc-illus .body-side { fill: var(--body-side); stroke: var(--stroke); stroke-width: 1.2; }
.sc-illus .body-bot { fill: var(--body-bot); stroke: var(--stroke); stroke-width: 1.2; }
.sc-illus .ants { fill: var(--ants); stroke: var(--stroke); stroke-width: 0.8; }
.sc-illus .wing { fill: var(--surface-2); stroke: var(--stroke); stroke-width: 1.2; }
.sc-illus .cell { fill: var(--cell); stroke: var(--cell-line); stroke-width: 0.6; }
.sc-illus .rail { stroke: var(--stroke); stroke-width: 2.4; }
.sc-illus .hinge { stroke: var(--stroke); stroke-width: 2; }
.sc-illus .ant { stroke: var(--accent-2); stroke-linecap: round; }
.sc-illus .ant2 { stroke-width: 3; }
.sc-illus .ant7 { stroke-width: 3; }
.sc-illus .brk { stroke: var(--surface); stroke-width: 4; }
.sc-illus .lead { stroke: var(--muted); stroke-width: 1; }
.sc-illus .dot { fill: var(--text); }
.sc-illus .badge { fill: var(--surface); stroke: var(--text); stroke-width: 1.5; }
.sc-illus .badge-t { fill: var(--text); font: 700 17px system-ui, sans-serif; }
.sc-illus .axes text { fill: var(--muted); font: 13px system-ui, sans-serif; }
.fig-legend { list-style: none; padding: 0; margin: 0.5rem 0; display: flex; flex-wrap: wrap; gap: 0.2rem 1.1rem; }
.fig-legend li { display: inline-flex; align-items: center; gap: 0.4rem; color: var(--text); }
.badge-n { display: inline-grid; place-items: center; width: 1.45rem; height: 1.45rem; border-radius: 50%;
           border: 1.5px solid var(--text); font-weight: 700; font-size: 0.8rem; flex: none; }

/* Status / note boxes */
.status { background: var(--note-bg); border: 1px solid var(--note-border); border-left-width: 5px;
          border-radius: 8px; padding: 0.2rem 1.25rem 0.6rem; margin: 2rem 0; }
.status h2 { border-top: 0; padding-top: 0; margin-top: 0.8em; }
.status ul { padding-left: 1.2rem; }
.status li { margin: 0.4rem 0; }
.note { background: var(--surface-2); border-radius: 6px; padding: 0.6rem 0.9rem; }

/* Key numbers */
.stats { display: grid; grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr)); gap: 0.9rem; margin: 1rem 0; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 0.8rem 1rem; }
.stat dt { margin: 0; }
.stat-v { display: block; font-size: 1.7rem; font-weight: 700; line-height: 1.2; color: var(--accent); }
.stat-l { display: block; font-weight: 600; }
.stat dd { margin: 0.3rem 0 0; color: var(--muted); font-size: 0.92rem; }

.cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr)); gap: 1.5rem; }
.cols h3 { margin-top: 0.6em; }

/* Launch chain */
.chain { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
         gap: 0.9rem; counter-reset: step; }
.chain li { background: var(--surface); border: 1px solid var(--border); border-top: 4px solid var(--accent);
            border-radius: 8px; padding: 0.7rem 0.9rem; counter-increment: step; }
.chain h3 { margin: 0.2rem 0 0.3rem; font-size: 1.05rem; }
.chain h3::before { content: counter(step) ". "; color: var(--muted); }
.chain p { margin: 0; font-size: 0.95rem; }

/* Timeline */
.timeline { list-style: none; padding: 0; margin: 1rem 0; border-left: 3px solid var(--border); }
.timeline li { position: relative; padding: 0.1rem 0 0.9rem 1.4rem; }
.timeline li::before { content: ""; position: absolute; left: -0.55rem; top: 0.45rem; width: 0.8rem; height: 0.8rem;
                       border-radius: 50%; background: var(--surface); border: 3px solid var(--accent); }
.timeline h3 { margin: 0 0 0.2rem; font-size: 1.08rem; }
.timeline p { margin: 0; max-width: 48rem; }
.tl-t { font-weight: 700; color: var(--accent); font-size: 0.92rem; font-variant-numeric: tabular-nums; }

.modes li { margin: 0.25rem 0; }

/* Cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr)); gap: 1rem; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 0.3rem 1rem 0.8rem; }
.card h3 { margin-top: 0.7rem; }

/* Tables */
.table-wrap { overflow-x: auto; margin: 1rem 0; border: 1px solid var(--border); border-radius: 8px;
              background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: 0.9rem; line-height: 1.45; }
caption { text-align: left; padding: 0.6rem 0.8rem; font-weight: 600; color: var(--muted); caption-side: top; }
th, td { text-align: left; vertical-align: top; padding: 0.5rem 0.8rem; border-top: 1px solid var(--border); }
thead th { background: var(--surface-2); border-top: 1px solid var(--border); white-space: nowrap; }
tbody th { font-weight: 600; }
table { min-width: 26rem; }
table.wide { min-width: 40rem; }
table.compact { min-width: 0; }
table.margins td:nth-child(4) { font-weight: 600; }
tr.total th, tr.total td { font-weight: 700; }
td, th { overflow-wrap: break-word; hyphens: auto; }
thead th { overflow-wrap: normal; }

details { margin: 1rem 0; background: var(--surface); border: 1px solid var(--border); border-radius: 8px;
          padding: 0.5rem 0.9rem; }
details > summary { cursor: pointer; font-weight: 600; color: var(--accent); }
details[open] > summary { margin-bottom: 0.5rem; }
details .table-wrap { margin: 0.5rem 0; }

.drawing { background: #fff; border: 1px solid var(--border); border-radius: 8px; padding: 0.5rem; }
.drawing img { width: 100%; height: auto; display: block; }
.drawing figcaption { color: #3d4955; padding: 0.4rem 0.3rem 0.1rem; }
.fmt code { white-space: pre-wrap; overflow-wrap: anywhere; }

.doclist li { margin: 0.3rem 0; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--surface); color: var(--muted);
               font-size: 0.9rem; padding: 1rem 0 1.5rem; }

@media (max-width: 760px) {
  body { font-size: 1rem; }
  .hero { grid-template-columns: minmax(0, 1fr); gap: 1rem; padding-top: 0.5rem; }
  h2 { font-size: 1.35rem; }
  .sc-illus .axes { display: none; }
  .header-inner { padding-top: 0.4rem; padding-bottom: 0.4rem; }
  nav a { padding: 0.3rem 0.45rem; }
  .status { padding: 0.1rem 0.9rem 0.5rem; }
}

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}