/* LeanSpectrum landing page — geek / maker aesthetic.
   Terminal-green accent, monospace headings, scanline grid background,
   chunky per-OS download buttons. Mobile-first, no JS framework. */

:root {
  --bg:         #0a0c10;
  --bg-grid:    #0e1117;
  --bg-card:    #11151c;
  --bg-card-2:  #161c25;
  --border:     #1f2733;
  --border-hi:  #2c3947;
  --text:       #e6edf3;
  --text-soft:  #8b949e;
  /* WCAG AA contrast: bumped from #5a6370 (3.9:1 against --bg) to
     #7e8895 (5.0:1) so every "dim" surface (captions, table headers,
     dl-meta, footer) clears the 4.5:1 normal-text threshold on both
     --bg and the slightly lighter --bg-card / --bg-card-2 surfaces. */
  --text-dim:   #7e8895;

  --green:      #00ff9c;       /* terminal green */
  --green-dim:  #00b870;
  --amber:      #ffb454;
  --cyan:       #56d4dd;
  --magenta:    #d2a8ff;
  --red:        #ff7b72;

  --win:        #4cc2ff;
  --mac:        #ffffff;
  --linux:      #ffb454;

  --maxw:       1100px;
  --radius:     6px;
  --mono:       "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans:       Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Subtle scan-line / grid background, vignette. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    linear-gradient(rgba(0,255,156,0.012) 50%, transparent 50%),
    radial-gradient(ellipse at top, rgba(0,255,156,0.04) 0%, transparent 60%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-grid) 100%);
  background-size: 100% 3px, 100% 100%, 100% 100%;
}
main, .topbar, footer { position: relative; z-index: 1; }

a { color: var(--green); text-decoration: none; transition: color 0.1s; }
a:hover { color: var(--amber); }

/* Keyboard focus indicator — every interactive surface gets a visible
   2 px amber outline at 2 px offset. Amber clears AA contrast against
   both --bg (8.3:1) and --bg-card. Outline (not box-shadow) is used
   so it survives clipping and inherits browser corner radius. */
:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
  border-radius: var(--radius);
}

/* Skip-to-content link — invisible until keyboard focus brings it
   into view at the top-left, where keyboard users expect bypass
   controls per WCAG 2.4.1. */
.skip-link {
  position: absolute; left: 0; top: -100px;
  background: var(--bg-card); color: var(--green);
  padding: 10px 16px; border: 1px solid var(--green);
  border-radius: var(--radius); font-family: var(--mono);
  font-weight: 500; z-index: 50;
  transition: top 0.15s;
}
.skip-link:focus-visible { top: 8px; left: 8px; outline-offset: 4px; }

code, pre, .mono { font-family: var(--mono); }

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

/* Honour prefers-reduced-motion: suppress decorative animations and
   transitions for vestibular users. The .cursor blink is also gated
   in JS so the setInterval doesn't run at all. */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* Sticky topbar can obscure scrolled-into-view anchor targets; offset
   the scroll position so the section's heading clears the topbar. */
section[id] { scroll-margin-top: 72px; }

/* ============================ topbar ============================ */

.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 24px;
  padding: 12px 24px;
  background: rgba(10,12,16,0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.brand {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1rem;
  color: var(--green);
  letter-spacing: 0;
}
.brand .cursor { color: var(--text-soft); margin-right: 2px; }
.topbar nav {
  display: flex; gap: 18px;
  margin-left: auto;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 0.85rem;
}
.topbar nav a { color: var(--text-soft); }
.topbar nav a:hover { color: var(--green); }
.topbar nav a.ext::after { content: " ↗"; opacity: 0.6; }

.lang {
  background: transparent;
  border: 1px solid var(--border-hi);
  border-radius: var(--radius);
  color: var(--text-soft);
  padding: 5px 11px;
  font-size: 0.78rem;
  cursor: pointer;
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: 0.5px;
}
.lang:hover { color: var(--green); border-color: var(--green-dim); }

@media (max-width: 720px) {
  .topbar { padding: 10px 14px; gap: 12px; }
  .topbar nav { gap: 12px; font-size: 0.78rem; }
}

/* ============================== hero ============================== */

.hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 72px 24px 48px;
  text-align: left;
}
.ascii {
  font-family: var(--mono);
  color: var(--green);
  font-size: clamp(0.55rem, 1.65vw, 0.95rem);
  line-height: 1.15;
  margin: 0 0 28px;
  white-space: pre;
  overflow-x: auto;
  text-shadow: 0 0 12px rgba(0,255,156,0.25);
}
.prompt {
  font-family: var(--mono);
  font-size: clamp(1rem, 2.2vw, 1.3rem);
  margin: 0 0 8px;
  color: var(--text);
}
.prompt .cursor {
  color: var(--green);
  font-weight: 700;
  margin-right: 8px;
}
.cursor.blink-off { opacity: 0.2; }
.text-accent { color: var(--amber); }
.hero .meta {
  margin-top: 28px;
  color: var(--text-dim);
  font-size: 0.85rem;
  font-family: var(--mono);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}
.kbd {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 2px 7px;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--green);
}
.dot { color: var(--text-dim); opacity: 0.5; }

/* ============================== sections ============================== */

section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 56px 24px;
}
section h2 {
  font-family: var(--mono);
  font-size: clamp(1.3rem, 2.6vw, 1.7rem);
  margin: 0 0 16px;
  letter-spacing: -0.01em;
  color: var(--text);
}
section h2 .hash {
  color: var(--green);
  margin-right: 8px;
  opacity: 0.7;
}
section > p,
section > .caption {
  color: var(--text-soft);
  max-width: 780px;
  font-size: 0.97rem;
}
.caption {
  font-size: 0.88rem;
  margin-top: 16px;
  font-family: var(--mono);
  color: var(--text-dim);
}
.caption code {
  color: var(--amber);
  background: var(--bg-card);
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid var(--border);
  font-size: 0.85em;
}

/* ============================ big downloads ============================ */

.download {
  padding-top: 24px;
}
.dl-grid-big {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 28px;
}
.dl-big {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-hi);
  border-radius: var(--radius);
  padding: 22px 22px 22px 22px;
  color: var(--text);
  transition: transform 0.12s, border-color 0.15s, background 0.15s;
  overflow: hidden;
}
.dl-big::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: currentColor;
  opacity: 0.5;
  transition: opacity 0.15s;
}
.dl-big:hover {
  text-decoration: none;
  border-color: currentColor;
  transform: translateY(-2px);
  background: var(--bg-card-2);
}
.dl-big:hover::before { opacity: 1; }
.dl-big.windows { color: var(--win); }
.dl-big.macos   { color: var(--mac); }
.dl-big.linux   { color: var(--linux); }

.dl-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 64px; height: 64px;
  background: var(--bg-card-2);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.dl-big.windows .dl-icon { color: var(--win); }
.dl-big.macos   .dl-icon { color: var(--mac); }
.dl-big.linux   .dl-icon { color: var(--linux); }

.dl-body { min-width: 0; }
.dl-body h3 {
  margin: 0 0 4px;
  font-family: var(--mono);
  font-size: 1.3rem;
  color: var(--text);
}
.dl-meta {
  margin: 0 0 10px;
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 0.78rem;
}
.dl-formats {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}
.fmt {
  background: rgba(0,255,156,0.08);
  border: 1px solid var(--green-dim);
  color: var(--green);
  padding: 3px 8px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
}
.fmt-note {
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 0.78rem;
  padding: 3px 4px;
}
.dl-arrow {
  color: var(--text-soft);
  font-size: 1.6rem;
  transition: transform 0.15s, color 0.15s;
  font-family: var(--mono);
}
.dl-big:hover .dl-arrow {
  color: currentColor;
  transform: translateX(4px);
}

@media (max-width: 980px) {
  .dl-grid-big { grid-template-columns: 1fr; }
}

/* Companion app — smaller card */
.dl-aside {
  margin-top: 36px;
  padding-top: 28px;
  border-top: 1px dashed var(--border);
}
.aside-title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
}
.dl-small {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
  color: var(--text);
  max-width: 540px;
  transition: border-color 0.15s, transform 0.12s;
}
.dl-small:hover {
  text-decoration: none;
  border-color: var(--green-dim);
  transform: translateY(-1px);
}
.dl-small-icon {
  color: var(--green);
  display: flex;
  align-items: center;
}
.dl-small-title {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1rem;
}
.dl-small-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* ============================ pipeline diagram ========================= */

.diagram {
  font-family: var(--mono);
  font-size: clamp(0.6rem, 1.4vw, 0.78rem);
  line-height: 1.3;
  color: var(--text-soft);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin: 28px 0;
  overflow-x: auto;
  white-space: pre;
}
.diagram::-webkit-scrollbar { height: 8px; }
.diagram::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 4px; }

/* ============================= 3 piliers cards ========================= */

.piliers .grid3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 28px;
}
.piliers article {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  position: relative;
}
.piliers article::before {
  content: "";
  position: absolute;
  top: -1px; left: -1px;
  width: 16px; height: 16px;
  border-top: 2px solid var(--green);
  border-left: 2px solid var(--green);
}
.piliers article::after {
  content: "";
  position: absolute;
  bottom: -1px; right: -1px;
  width: 16px; height: 16px;
  border-bottom: 2px solid var(--green);
  border-right: 2px solid var(--green);
}
.card-tag {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--green);
  margin-bottom: 10px;
  letter-spacing: 0.5px;
}
.piliers h3 {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 1.05rem;
  color: var(--text);
}
.piliers article > p {
  color: var(--text-soft);
  font-size: 0.92rem;
  margin: 0 0 16px;
}
.piliers .metric {
  display: block;
  padding: 8px 10px;
  background: var(--bg-card-2);
  border-left: 2px solid var(--amber);
  color: var(--amber);
  font-family: var(--mono);
  font-size: 0.82rem;
}
@media (max-width: 900px) {
  .piliers .grid3 { grid-template-columns: 1fr; }
}

/* ============================== tables ============================== */

.tablewrap { overflow-x: auto; }
table {
  width: 100%;
  margin-top: 24px;
  border-collapse: collapse;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  font-size: 0.95rem;
}
th, td {
  text-align: left;
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
}
th {
  background: var(--bg-card-2);
  font-family: var(--mono);
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr.highlight {
  background: rgba(0,255,156,0.06);
}
tbody tr.highlight strong { color: var(--green); }
td code {
  color: var(--cyan);
  background: var(--bg-card-2);
  padding: 1px 6px;
  border-radius: 3px;
  border: 1px solid var(--border);
  font-size: 0.85em;
}
td strong { color: var(--green); font-weight: 700; }
.badge {
  display: inline-block;
  background: var(--green);
  color: #0a0c10;
  font-family: var(--mono);
  font-size: 0.7rem;
  padding: 1px 6px;
  border-radius: 3px;
  margin-left: 6px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ============================== credits ============================== */

.credits ul {
  margin-top: 24px;
  padding: 0;
  list-style: none;
}
.credits li {
  color: var(--text-soft);
  margin-bottom: 10px;
  font-size: 0.95rem;
  font-family: var(--mono);
}
.credits .kbd {
  display: inline-block;
  min-width: 100px;
  text-align: center;
  margin-right: 8px;
}
.credits a { color: var(--cyan); }
.credits a:hover { color: var(--amber); }

/* ============================== footer ============================== */

footer {
  border-top: 1px solid var(--border);
  margin-top: 56px;
  padding: 32px 24px 48px;
  text-align: center;
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 0.85rem;
}
footer .ascii.small {
  color: var(--text-dim);
  font-size: 0.75rem;
  margin: 0 0 12px;
  text-shadow: none;
}
footer a { color: var(--text-soft); }
footer a:hover { color: var(--green); }