/* ============================================================
   Swarm Robotics — site styles
   Theme: follows the operating system, with a manual override.
   ============================================================ */

:root {
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --sidebar-w: 264px;
  --measure: 940px;
}

/* ---------- Light theme (default) ---------- */

:root,
[data-theme="light"] {
  --bg:          #ffffff;
  --bg-soft:     #f6f8fa;
  --panel:       #f0f3f6;
  --panel-2:     #e8edf2;
  --line:        #d8dee6;
  --line-soft:   #e6ebf1;
  --text:        #1f2933;
  --text-strong: #0b1117;
  --text-dim:    #5a6773;
  --accent:      #0a66c2;
  --accent-soft: #e3eefb;
  --warn:        #a35c00;
  --warn-soft:   #fdf1de;
  --ok:          #0a7a52;
  --ok-soft:     #e2f4ec;
  --code-bg:     #f5f7f9;
  --fig-bg:      #ffffff;
  --fig-cap:     #4a5565;
  --shadow:      0 1px 2px rgba(16,24,40,.06);
}

/* ---------- Dark theme ---------- */

[data-theme="dark"] {
  --bg:          #0e1116;
  --bg-soft:     #161b22;
  --panel:       #1c2230;
  --panel-2:     #232b3a;
  --line:        #2a3140;
  --line-soft:   #222834;
  --text:        #d7dee8;
  --text-strong: #f0f5fb;
  --text-dim:    #8b97a8;
  --accent:      #4ea3ff;
  --accent-soft: #16304a;
  --warn:        #ffb454;
  --warn-soft:   #33260f;
  --ok:          #5fd39a;
  --ok-soft:     #10301f;
  --code-bg:     #0b0e13;
  --fig-bg:      #f7f9fc;
  --fig-cap:     #4a5565;
  --shadow:      none;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg:          #0e1116;
    --bg-soft:     #161b22;
    --panel:       #1c2230;
    --panel-2:     #232b3a;
    --line:        #2a3140;
    --line-soft:   #222834;
    --text:        #d7dee8;
    --text-strong: #f0f5fb;
    --text-dim:    #8b97a8;
    --accent:      #4ea3ff;
    --accent-soft: #16304a;
    --warn:        #ffb454;
    --warn-soft:   #33260f;
    --ok:          #5fd39a;
    --ok-soft:     #10301f;
    --code-bg:     #0b0e13;
    --fig-bg:      #f7f9fc;
    --fig-cap:     #4a5565;
    --shadow:      none;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
  transition: background .18s ease, color .18s ease;
}

.wrap { display: flex; min-height: 100vh; }

/* ============================================================
   Sidebar
   ============================================================ */

.sidebar {
  width: var(--sidebar-w);
  flex: 0 0 var(--sidebar-w);
  background: var(--bg-soft);
  border-right: 1px solid var(--line);
  padding: 26px 18px 22px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.brand { display: block; text-decoration: none; margin-bottom: 22px; }
.brand-title { display: block; font-size: 17px; font-weight: 650; color: var(--text-strong); letter-spacing: -.01em; }
.brand-sub { display: block; font-size: 11.5px; color: var(--text-dim); text-transform: uppercase; letter-spacing: .09em; margin-top: 3px; }

.nav-list { list-style: none; margin: 0; padding: 0; }
.nav-list li { margin: 1px 0; }
.nav-list a {
  display: block; padding: 7px 11px; border-radius: 6px;
  color: var(--text-dim); text-decoration: none; font-size: 14px;
  border-left: 2px solid transparent;
}
.nav-list a:hover { background: var(--panel); color: var(--text); }
.nav-list a.current {
  background: var(--accent-soft); color: var(--accent);
  border-left-color: var(--accent); font-weight: 550;
}

.sidebar-foot {
  margin-top: auto; padding-top: 16px; border-top: 1px solid var(--line);
  font-size: 11.5px; line-height: 1.5; color: var(--text-dim);
}
.sidebar-foot p { margin: 0 0 12px; }

/* Theme toggle */
.theme-toggle {
  display: flex; align-items: center; gap: 7px;
  width: 100%; padding: 7px 10px;
  background: var(--panel); color: var(--text-dim);
  border: 1px solid var(--line); border-radius: 6px;
  font-family: var(--sans); font-size: 12.5px; cursor: pointer;
  transition: background .15s ease, color .15s ease;
}
.theme-toggle:hover { background: var(--panel-2); color: var(--text); }
.theme-toggle .ico { width: 15px; text-align: center; font-size: 13px; }

.nav-toggle {
  display: none; position: fixed; top: 12px; left: 12px; z-index: 60;
  background: var(--bg-soft); color: var(--text);
  border: 1px solid var(--line); border-radius: 6px;
  padding: 7px 13px; font-size: 13px; font-family: var(--sans); cursor: pointer;
  box-shadow: var(--shadow);
}
.scrim { display: none; }

/* ============================================================
   Content column — centred in the remaining space
   ============================================================ */

.content {
  flex: 1 1 auto;
  min-width: 0;
  max-width: var(--measure);
  margin: 0 auto;
  padding: 40px 48px 80px;
  width: 100%;
}

.page-head { border-bottom: 1px solid var(--line); padding-bottom: 18px; margin-bottom: 0; }
.eyebrow { margin: 0 0 8px; font-size: 11.5px; text-transform: uppercase; letter-spacing: .13em; color: var(--accent); font-weight: 600; }
.page-head h1 { margin: 0; font-size: 33px; line-height: 1.2; letter-spacing: -.02em; font-weight: 660; color: var(--text-strong); }
.subtitle { margin: 11px 0 0; color: var(--text-dim); font-size: 16.5px; max-width: 68ch; }

/* ============================================================
   Sticky tab bar
   ============================================================ */

.tabbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; gap: 4px; flex-wrap: wrap;
  padding: 10px 0 0;
  margin: 0 0 6px;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.tabbar::before {
  content: ""; position: absolute; left: -48px; right: -48px; top: 0; bottom: 0;
  background: var(--bg); z-index: -1; border-bottom: 1px solid var(--line);
}
.tabbtn {
  appearance: none; background: none; border: 0;
  border-bottom: 2px solid transparent;
  padding: 9px 13px 10px; margin-bottom: -1px;
  font-family: var(--sans); font-size: 14px; font-weight: 500;
  color: var(--text-dim); cursor: pointer; white-space: nowrap;
  border-radius: 6px 6px 0 0;
  transition: color .15s ease, background .15s ease;
}
.tabbtn:hover { color: var(--text); background: var(--panel); }
.tabbtn[aria-selected="true"] { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.tabbtn:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }

.tabpanel { padding-top: 20px; }
.tabpanel[hidden] { display: none; }

.tabnav {
  display: flex; justify-content: space-between; gap: 12px;
  margin: 44px 0 0; padding-top: 18px; border-top: 1px solid var(--line);
}
.tabnav button {
  appearance: none; background: var(--panel); color: var(--text);
  border: 1px solid var(--line); border-radius: 7px;
  padding: 9px 15px; font-family: var(--sans); font-size: 13.5px; cursor: pointer;
}
.tabnav button:hover { background: var(--panel-2); border-color: var(--accent); }
.tabnav button:disabled { opacity: .35; cursor: default; }
.tabnav button:disabled:hover { background: var(--panel); border-color: var(--line); }

.tabmark { display: none; }

/* ============================================================
   Prose
   ============================================================ */

.prose h2 {
  margin: 40px 0 14px; font-size: 22px; font-weight: 620;
  letter-spacing: -.01em; padding-bottom: 7px;
  border-bottom: 1px solid var(--line); color: var(--text-strong);
}
.prose > h2:first-child { margin-top: 4px; }
.prose h3 { margin: 30px 0 10px; font-size: 17.5px; font-weight: 620; color: var(--text-strong); }
.prose h4 { margin: 22px 0 8px; font-size: 15px; font-weight: 620; color: var(--text-dim); }

.prose p { margin: 0 0 15px; }
.prose ul, .prose ol { margin: 0 0 16px; padding-left: 22px; }
.prose li { margin: 5px 0; }
.prose a { color: var(--accent); text-decoration: none; border-bottom: 1px solid color-mix(in srgb, var(--accent) 32%, transparent); }
.prose a:hover { border-bottom-color: var(--accent); }
.prose strong { color: var(--text-strong); font-weight: 620; }

.prose code {
  font-family: var(--mono); font-size: 13px;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 4px; padding: 1px 5px;
}
.prose pre {
  background: var(--code-bg); border: 1px solid var(--line);
  border-radius: 8px; padding: 15px 17px; overflow-x: auto;
  margin: 0 0 20px; font-size: 13px; line-height: 1.55;
}
.prose pre code { background: none; border: 0; padding: 0; }

.prose table { width: 100%; border-collapse: collapse; margin: 0 0 22px; font-size: 14.5px; }
.prose th, .prose td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; vertical-align: top; }
.prose th { background: var(--panel); font-weight: 620; color: var(--text-strong); }
.prose tbody tr:nth-child(even) { background: var(--line-soft); }

.prose blockquote { margin: 0 0 20px; padding: 2px 0 2px 16px; border-left: 3px solid var(--line); color: var(--text-dim); }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 36px 0; }

/* ---------- Figures ---------- */

.prose figure {
  margin: 26px 0; background: var(--fig-bg);
  border: 1px solid var(--line); border-radius: 9px; padding: 12px;
  box-shadow: var(--shadow);
}
.prose figure img { width: 100%; display: block; border-radius: 4px; }
.prose figcaption { margin-top: 10px; padding: 0 4px; font-size: 13px; line-height: 1.55; color: var(--fig-cap); }
.prose figcaption b { color: #1d2530; }

/* ---------- Callouts ---------- */

.note, .warn-box, .key {
  border: 1px solid var(--line); border-left: 3px solid var(--accent);
  background: var(--panel); border-radius: 0 7px 7px 0;
  padding: 14px 17px; margin: 0 0 22px; font-size: 14.5px;
}
.note p:last-child, .warn-box p:last-child, .key p:last-child,
.note ol:last-child, .key ol:last-child { margin-bottom: 0; }
.warn-box { border-left-color: var(--warn); background: var(--warn-soft); }
.key { border-left-color: var(--ok); background: var(--ok-soft); }
.note { background: var(--accent-soft); }
.callout-title {
  display: block; font-size: 11.5px; text-transform: uppercase;
  letter-spacing: .11em; font-weight: 660; margin-bottom: 6px; color: var(--accent);
}
.warn-box .callout-title { color: var(--warn); }
.key .callout-title { color: var(--ok); }

/* ---------- Phase cards ---------- */

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; margin: 24px 0 30px; }
.card {
  display: block; background: var(--bg-soft); border: 1px solid var(--line);
  border-radius: 9px; padding: 16px 17px; text-decoration: none; color: inherit;
  transition: border-color .15s ease, transform .15s ease;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card .card-phase { font-size: 11px; text-transform: uppercase; letter-spacing: .12em; color: var(--accent); font-weight: 660; }
.card .card-title { display: block; font-size: 16px; font-weight: 600; margin: 6px 0 5px; color: var(--text-strong); }
.card .card-desc { font-size: 13.5px; color: var(--text-dim); line-height: 1.5; }
.card .card-status { display: inline-block; margin-top: 10px; font-size: 11px; letter-spacing: .06em; text-transform: uppercase; padding: 2px 8px; border-radius: 20px; font-weight: 620; }
.status-done { background: var(--ok-soft); color: var(--ok); }
.status-plan { background: var(--warn-soft); color: var(--warn); }

/* ---------- Image gallery ---------- */

.gallery { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin: 24px 0 30px; }
.shot {
  display: block; background: var(--fig-bg); border: 1px solid var(--line);
  border-radius: 9px; padding: 10px; text-decoration: none; color: inherit;
  box-shadow: var(--shadow); transition: border-color .15s ease, transform .15s ease;
}
.shot:hover { border-color: var(--accent); transform: translateY(-2px); }
.shot img { width: 100%; display: block; border-radius: 4px; }
.shot .shot-cap { display: block; margin-top: 9px; padding: 0 3px; font-size: 12.5px; line-height: 1.45; color: var(--fig-cap); }
.shot .shot-cap b { display: block; color: #1d2530; font-weight: 620; margin-bottom: 2px; }

/* ---------- Video ---------- */

.videos { display: grid; grid-template-columns: repeat(auto-fit, minmax(400px, 1fr)); gap: 20px; margin: 24px 0 30px; }

.clip {
  background: var(--bg-soft); border: 1px solid var(--line);
  border-radius: 10px; padding: 10px; box-shadow: var(--shadow);
}
.clip video {
  width: 100%; display: block; border-radius: 6px;
  background: #0b0e13; aspect-ratio: 1280 / 839;
}
.clip .clip-meta {
  display: flex; flex-wrap: wrap; gap: 6px;
  margin: 11px 3px 6px;
}
.clip .tag {
  font-size: 11px; letter-spacing: .05em; text-transform: uppercase;
  font-weight: 620; padding: 2px 8px; border-radius: 20px;
  background: var(--accent-soft); color: var(--accent);
}
.clip .tag-alt { background: var(--panel); color: var(--text-dim); }
.clip .clip-cap { margin: 0 3px; font-size: 13.5px; line-height: 1.55; color: var(--text-dim); }
.clip .clip-cap b { color: var(--text-strong); }

@media (max-width: 620px) {
  .videos { grid-template-columns: 1fr; }
}

.page-foot { margin-top: 56px; padding-top: 18px; border-top: 1px solid var(--line); color: var(--text-dim); font-size: 13px; }
.page-foot p { margin: 0; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ============================================================
   Mobile
   ============================================================ */

@media (max-width: 900px) {
  /* The button sits on the right so it does not cover the first tab
     once the tab bar is stuck to the top of the viewport. */
  .nav-toggle { display: block; left: auto; right: 12px; }
  .sidebar { position: fixed; left: 0; top: 0; z-index: 50; transform: translateX(-100%); transition: transform .2s ease; }
  .sidebar.open { transform: translateX(0); }
  .scrim.show { display: block; position: fixed; inset: 0; background: rgba(0,0,0,.4); z-index: 45; }
  .content { padding: 60px 18px 60px; max-width: none; }
  .page-head h1 { font-size: 26px; }
  .tabbar { overflow-x: auto; flex-wrap: nowrap; }
  .tabbar::before { left: -18px; right: -18px; }
  .tabbtn { font-size: 13px; padding: 8px 11px 9px; }
}

@media print {
  .sidebar, .nav-toggle, .page-foot, .tabbar, .tabnav, .scrim { display: none; }
  .tabpanel[hidden] { display: block !important; }
  body { background: #fff; color: #000; }
  .content { max-width: none; padding: 0; margin: 0; }
}