/* ============================================================
   Robotics & Automation — Interactive Concepts
   ============================================================ */

:root {
  --bg: #07090d;
  --bg-2: #0d1117;
  --panel: #11161f;
  --panel-2: #161d29;
  --line: #1f2937;
  --text: #e6edf3;
  --muted: #8b94a3;
  --accent: #5ed3ff;
  --accent-2: #ffb454;
  --accent-3: #b888ff;
  --good: #69e58c;
  --warn: #ff7b7b;
  --grid: rgba(94,211,255,0.07);
  --mono: ui-monospace, "JetBrains Mono", "Fira Code", "SF Mono", Menlo, Consolas, monospace;
  --sans: "Inter", -apple-system, "Segoe UI", Roboto, system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------------- HERO ---------------- */

.hero {
  position: relative;
  padding: 80px 24px 48px;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
  background:
    radial-gradient(ellipse at 80% -10%, rgba(94,211,255,0.18), transparent 60%),
    radial-gradient(ellipse at 0% 20%, rgba(184,136,255,0.12), transparent 50%),
    var(--bg);
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at 50% 30%, #000 30%, transparent 75%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: 1180px;
  margin: 0 auto;
}

.badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--accent);
  border: 1px solid rgba(94,211,255,0.3);
  background: rgba(94,211,255,0.06);
  padding: 6px 12px;
  border-radius: 999px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: clamp(40px, 7vw, 88px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  margin: 18px 0 12px;
  font-weight: 800;
}
.hero h1 .dot { color: var(--accent); }

.tagline {
  font-size: clamp(15px, 1.6vw, 19px);
  color: var(--muted);
  max-width: 720px;
  line-height: 1.55;
  margin: 0 0 28px;
}
.tagline em { color: var(--accent-2); font-style: normal; }

.hero-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin-top: 8px;
}
.hero-nav a {
  font-family: var(--mono);
  font-size: 13px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  background: rgba(255,255,255,0.02);
  transition: all 0.15s;
}
.hero-nav a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(94,211,255,0.06);
  text-decoration: none;
}

/* ---------------- DEMO SECTIONS ---------------- */

main { max-width: 1180px; margin: 0 auto; padding: 24px; }

.demo {
  display: grid;
  grid-template-columns: minmax(320px, 1fr) minmax(360px, 1.1fr);
  gap: 36px;
  align-items: start;
  padding: 56px 0;
  border-top: 1px solid var(--line);
}
.demo:first-child { border-top: 0; }
.demo.flip .demo-text { order: 2; }
.demo.flip .demo-canvas-wrap { order: 1; }

@media (max-width: 880px) {
  .demo, .demo.flip {
    grid-template-columns: 1fr;
  }
  .demo.flip .demo-text { order: 1; }
  .demo.flip .demo-canvas-wrap { order: 2; }
}

.demo-text { padding-top: 8px; }

.kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
  text-transform: uppercase;
}
.demo h2 {
  font-size: clamp(26px, 3vw, 38px);
  line-height: 1.1;
  margin: 10px 0 14px;
  letter-spacing: -0.015em;
}
.demo h2 em { font-style: italic; color: var(--accent-2); }
.demo p {
  color: var(--muted);
  line-height: 1.6;
  font-size: 15px;
  margin: 0 0 18px;
}
.demo p b { color: var(--text); font-weight: 600; }
.demo code, .eq code {
  font-family: var(--mono);
  font-size: 13px;
  background: rgba(94,211,255,0.08);
  border: 1px solid rgba(94,211,255,0.18);
  color: var(--accent);
  padding: 1px 6px;
  border-radius: 4px;
}
.eq {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  margin: 12px 0 18px;
  font-size: 13px;
  line-height: 1.7;
}

/* ---------------- CONTROLS ---------------- */

.controls {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 18px 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.controls.compact { padding: 12px 14px; gap: 6px; }
.controls label {
  display: grid;
  grid-template-columns: 110px 1fr 60px;
  align-items: center;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  gap: 10px;
}
.controls label .val {
  text-align: right;
  color: var(--accent);
  font-weight: 600;
}
.controls input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  height: 4px;
  background: var(--line);
  border-radius: 4px;
  outline: none;
  width: 100%;
}
.controls input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 0 4px rgba(94,211,255,0.18);
}
.controls input[type="range"]::-moz-range-thumb {
  width: 16px; height: 16px; background: var(--accent); border: 0;
  border-radius: 50%; cursor: pointer;
}

.controls .toggle-row { margin-top: 4px; }
.btn {
  font-family: var(--mono);
  font-size: 12.5px;
  background: rgba(94,211,255,0.08);
  border: 1px solid rgba(94,211,255,0.35);
  color: var(--accent);
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  transition: 0.15s;
}
.btn:hover {
  background: rgba(94,211,255,0.18);
  transform: translateY(-1px);
}
.hint {
  font-size: 12px;
  color: var(--muted);
  font-style: italic;
  border-top: 1px dashed var(--line);
  padding-top: 10px;
  margin-top: 4px;
  line-height: 1.5;
}

/* dropdowns (resistor bands) */
.band-sel {
  background: #0d1117;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 4px 8px;
  font-family: var(--mono);
  font-size: 12px;
  width: 100%;
}
.band-sel:focus { outline: none; border-color: var(--accent); }

/* HSV-specific compact block */
.hsv-block {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  margin-bottom: 6px;
}
.hsv-block .hsv-label {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 4px;
}
.dot-r, .dot-g, .dot-b {
  display: inline-block;
  width: 10px; height: 10px; border-radius: 50%;
}
.dot-r { background: #ff5252; }
.dot-g { background: #5ee87d; }
.dot-b { background: #5ea1ff; }

.hsv-block label {
  display: flex;
  align-items: center;
  gap: 4px;
  grid-template-columns: none;
  font-size: 11.5px;
}
.hsv-block label input[type="range"] {
  flex: 1;
  min-width: 60px;
}

/* ---------------- CANVAS WRAPPERS ---------------- */

.demo-canvas-wrap {
  position: relative;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.demo-canvas-wrap canvas,
.demo-canvas-wrap svg {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 8px;
  background: #06080c;
}
.readout {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
  text-align: right;
  padding-right: 4px;
}
.cam-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.cam-grid > div { display: flex; flex-direction: column; gap: 4px; }
.cam-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
  text-transform: uppercase;
}
.cam-grid canvas { width: 100%; height: auto; }

.ros-log {
  background: #05070a;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  height: 130px;
  overflow: hidden;
  display: flex;
  flex-direction: column-reverse;
  gap: 2px;
}
.ros-log .line { color: var(--text); }
.ros-log .line .t { color: var(--accent); }
.ros-log .line .drop { color: var(--warn); }

/* ---------------- FOOTER ---------------- */

footer {
  border-top: 1px solid var(--line);
  background: var(--bg-2);
  margin-top: 40px;
  padding: 36px 24px;
  color: var(--muted);
  font-size: 13px;
}
.foot-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.foot-inner b { color: var(--text); }
.foot-links { display: flex; gap: 18px; }