:root {
  --bg: #f6f8fb;
  --ink: #172033;
  --muted: #667085;
  --line: #d8e1ec;
  --panel: #ffffff;
  --brand: #6aa30f;
  --brand-dark: #466f05;
  --blue: #2563eb;
  --cyan: #0891b2;
  --amber: #b7791f;
  --red: #c2410c;
  --dark: #101828;
  --shadow: 0 18px 48px rgba(16, 24, 40, .09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.container { width: min(1140px, calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}
.nav {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.brand-logo-link,
.brand-text {
  display: inline-flex;
  align-items: center;
}
.brand-text {
  flex-direction: column;
  align-items: flex-start;
  min-width: 0;
}
.brand-mark {
  width: 48px;
  height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: transparent;
  flex: 0 0 auto;
  overflow: hidden;
}
.brand-mark img {
  display: block;
  width: 48px;
  height: 48px;
  object-fit: cover;
  border-radius: 10px;
}
.brand strong, .brand small { display: block; }
.brand small { color: var(--muted); font-size: 12px; margin-top: 2px; }
.nav-menu {
  display: flex;
  align-items: center;
  gap: 22px;
  color: #475467;
  font-size: 14px;
  white-space: nowrap;
}
.nav-menu a:hover { color: var(--brand-dark); }
.nav-toggle {
  display: none;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 8px;
  padding: 8px 12px;
  color: var(--ink);
}
.global-search-wrap {
  flex: 1 1 260px;
  max-width: 360px;
  min-width: 220px;
}
.global-search-bar {
  position: relative;
  min-height: 38px;
  display: flex;
  align-items: center;
}
.global-search-box {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
}
.global-search-box span {
  flex: 0 0 auto;
  color: var(--brand-dark);
  font-size: 12px;
  font-weight: 900;
}
.global-search-box input {
  width: 100%;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 10px;
  background: #f8fafc;
  color: var(--ink);
  font-size: 13px;
}
.global-search-results {
  position: absolute;
  left: 0;
  top: calc(100% + 8px);
  width: min(520px, 92vw);
  max-height: min(68vh, 520px);
  overflow-y: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
  z-index: 80;
}
.global-search-results[hidden] {
  display: none;
}
.global-search-item {
  display: block;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}
.global-search-item:last-child {
  border-bottom: 0;
}
.global-search-item:hover {
  background: #f4f8ef;
}
.global-search-item strong {
  display: block;
  font-size: 15px;
}
.global-search-item span {
  display: block;
  margin-top: 4px;
  color: var(--brand-dark);
  font-size: 12px;
  font-weight: 900;
}
.global-search-item p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}
.global-search-empty {
  margin: 0;
  padding: 14px 16px;
  color: var(--muted);
}

.hero {
  color: #fff;
  background:
    linear-gradient(135deg, rgba(15, 23, 42, .96), rgba(28, 64, 81, .88)),
    radial-gradient(circle at 84% 20%, rgba(132, 204, 22, .22), transparent 30%);
}
.hero-compact { background: linear-gradient(135deg, #0f172a, #164e63); }
.hero-grid {
  min-height: 620px;
  padding: 78px 0;
  display: grid;
  grid-template-columns: 1.08fr .92fr;
  gap: 34px;
  align-items: center;
}
.hero-compact .hero-grid { min-height: 520px; }
.eyebrow {
  margin: 0 0 12px;
  color: var(--brand-dark);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .08em;
}
.hero .eyebrow { color: #d9f99d; }
h1, h2, h3, p { overflow-wrap: anywhere; }
h1 {
  max-width: 780px;
  margin: 0;
  font-size: 56px;
  line-height: 1.07;
  letter-spacing: 0;
}
.hero-lead {
  max-width: 720px;
  margin: 18px 0 0;
  color: #e6edf6;
  font-size: 19px;
  line-height: 1.75;
}
.hero-actions, .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0 18px;
  font-weight: 800;
  cursor: pointer;
}
.btn-primary { background: #8bc53f; color: #102000; }
.btn-secondary { background: #fff; color: var(--ink); border-color: var(--line); }
.btn-ghost { background: rgba(255, 255, 255, .12); color: #fff; border-color: rgba(255, 255, 255, .35); }
.hero-panel, .demo-board {
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 24px 70px rgba(0, 0, 0, .25);
}
.home-lab {
  overflow: hidden;
}
.lab-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}
.lab-head span {
  color: #d9f99d;
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}
.lab-head strong {
  color: #fff;
  font-size: 18px;
}
.arduino-scene {
  position: relative;
  min-height: 330px;
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(15, 23, 42, .24), rgba(15, 23, 42, .08)),
    radial-gradient(circle at 80% 18%, rgba(34, 211, 238, .2), transparent 32%),
    radial-gradient(circle at 24% 72%, rgba(132, 204, 22, .14), transparent 34%);
  border: 1px solid rgba(255,255,255,.18);
  overflow: hidden;
}
.lab-grid-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.07) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(circle at 50% 50%, #000 35%, transparent 92%);
}
.uno-board-detailed,
.lcd1602-module {
  position: absolute;
  border-radius: 12px;
  box-shadow: 0 24px 54px rgba(0,0,0,.28);
  z-index: 3;
}
.uno-board-detailed {
  left: 22px;
  top: 60px;
  width: 205px;
  height: 218px;
  background:
    linear-gradient(135deg, rgba(20, 184, 166, .35), transparent 48%),
    linear-gradient(180deg, #0f766e, #0f5f72);
  border: 1px solid rgba(209, 250, 229, .28);
}
.uno-label,
.lcd-title {
  position: absolute;
  color: #fff;
  font-weight: 900;
  letter-spacing: .02em;
}
.uno-label { left: 18px; top: 16px; font-size: 17px; }
.usb-port {
  position: absolute;
  left: -12px;
  top: 56px;
  width: 32px;
  height: 56px;
  border-radius: 7px;
  background: linear-gradient(180deg, #dbe4ee, #94a3b8);
  border: 3px solid #e5edf6;
}
.power-jack {
  position: absolute;
  left: 22px;
  bottom: -8px;
  width: 50px;
  height: 26px;
  border-radius: 9px;
  background: #111827;
  border: 4px solid #374151;
}
.chip {
  position: absolute;
  display: grid;
  place-items: center;
  border-radius: 7px;
  background: #07111f;
  color: #dbeafe;
  border: 1px solid rgba(255,255,255,.1);
  font: 800 10px/1 Arial, "Microsoft YaHei", sans-serif;
}
.main-chip { left: 66px; top: 82px; width: 84px; height: 62px; }
.usb-chip { left: 34px; top: 142px; width: 42px; height: 28px; }
.clock-part {
  position: absolute;
  right: 32px;
  top: 154px;
  width: 42px;
  height: 14px;
  border-radius: 999px;
  background: #d9f99d;
  box-shadow: 0 0 16px rgba(217, 249, 157, .45);
}
.header-row {
  position: absolute;
  height: 9px;
  border-radius: 999px;
  background: repeating-linear-gradient(90deg, #0f172a 0 6px, #dbeafe 6px 9px, #0f172a 9px 15px);
}
.header-digital { left: 32px; right: 24px; top: 44px; }
.header-power { left: 150px; top: 86px; width: 9px; height: 116px; background: repeating-linear-gradient(180deg, #0f172a 0 6px, #dbeafe 6px 9px, #0f172a 9px 15px); }
.pin-label {
  position: absolute;
  z-index: 5;
  right: -38px;
  width: 64px;
  min-height: 22px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  background: rgba(255,255,255,.92);
  color: #0f172a;
  font-size: 11px;
  font-weight: 900;
}
.label-5v { top: 78px; }
.label-gnd { top: 107px; }
.label-a4 { top: 136px; }
.label-a5 { top: 165px; }
.lcd1602-module {
  right: 20px;
  top: 56px;
  width: 180px;
  height: 222px;
  background:
    linear-gradient(135deg, rgba(96, 165, 250, .24), transparent 52%),
    linear-gradient(180deg, #1d4ed8, #0f172a);
  border: 1px solid rgba(191, 219, 254, .28);
}
.lcd-title { left: 18px; top: 16px; font-size: 16px; }
.lcd-screen {
  position: absolute;
  left: 24px;
  right: 24px;
  top: 52px;
  height: 74px;
  display: grid;
  align-content: center;
  gap: 7px;
  padding: 10px;
  border-radius: 8px;
  background: linear-gradient(180deg, #a7f3d0, #65a30d);
  border: 4px solid #0f3c2e;
  box-shadow: inset 0 0 18px rgba(15, 23, 42, .3);
  color: #052e16;
}
.lcd-screen i,
.lcd-screen b {
  display: block;
  font: 900 13px/1 ui-monospace, Consolas, monospace;
  letter-spacing: .04em;
}
.i2c-backpack {
  position: absolute;
  left: 46px;
  bottom: 34px;
  width: 84px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 7px;
  background: #08111f;
  color: #dbeafe;
  border: 1px solid rgba(255,255,255,.12);
  font-size: 12px;
  font-weight: 900;
}
.lcd-pin {
  position: absolute;
  z-index: 5;
  left: -30px;
  width: 58px;
  min-height: 22px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  background: rgba(255,255,255,.94);
  color: #0f172a;
  font-size: 11px;
  font-weight: 900;
}
.pin-vcc { top: 72px; }
.pin-gnd { top: 106px; }
.pin-sda { top: 144px; }
.pin-scl { top: 180px; }
.lcd-led {
  position: absolute;
  right: 20px;
  bottom: 20px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #84cc16;
  box-shadow: 0 0 22px rgba(132, 204, 22, .95);
  animation: ledPulse 1.4s ease-in-out infinite;
}
.lab-wires {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  z-index: 2;
}
.wire-path {
  fill: none;
  stroke-width: 6;
  stroke-linecap: round;
  filter: drop-shadow(0 0 5px rgba(255,255,255,.25));
}
.wire-vcc-path { stroke: #fb7185; }
.wire-gnd-path { stroke: #020617; }
.wire-sda-path { stroke: #38bdf8; }
.wire-scl-path { stroke: #facc15; }
.data-pulse {
  fill: #fff;
  filter: drop-shadow(0 0 8px rgba(255,255,255,.9));
}
.pulse-vcc { offset-path: path("M190 148 C250 122 300 94 355 92"); animation: tracePulse 2.8s linear infinite; }
.pulse-sda { offset-path: path("M190 202 C250 214 300 188 355 164"); animation: tracePulse 2.2s linear infinite .3s; }
.pulse-scl { offset-path: path("M190 228 C250 254 306 226 355 198"); animation: tracePulse 2.2s linear infinite .9s; }
.lab-console {
  position: absolute;
  z-index: 6;
  left: 22px;
  right: 20px;
  bottom: 18px;
  min-height: 34px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 0 12px;
  border-radius: 8px;
  background: rgba(2, 6, 23, .68);
  border: 1px solid rgba(148, 163, 184, .22);
  color: #dbeafe;
  font-size: 12px;
}
.lab-console span {
  color: #d9f99d;
  font-weight: 900;
}
.lab-console strong {
  font-size: 12px;
  overflow-wrap: anywhere;
}
.lab-score {
  margin-bottom: 14px;
}
.metric {
  padding: 16px 0;
  border-bottom: 1px solid rgba(255, 255, 255, .18);
}
.metric span, .score-row span, .source-note { color: #dbe7f4; }
.metric strong { display: block; margin-top: 5px; font-size: 24px; }
.score-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 18px 0;
}
.score-row div {
  background: rgba(255, 255, 255, .12);
  border-radius: 8px;
  padding: 16px;
}
.score-row strong { display: block; font-size: 30px; }
.source-note { margin: 0; line-height: 1.65; font-size: 14px; }

.section { padding: 76px 0; }
.section-soft { background: #eef4f8; }
.section-heading { max-width: 780px; margin-bottom: 26px; }
.section-heading h2 {
  margin: 0;
  font-size: 34px;
  line-height: 1.2;
}
.section-heading p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.75;
  margin: 12px 0 0;
}
.doc-search-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 0 0 22px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}
.doc-search-panel strong {
  display: block;
  font-size: 20px;
}
.doc-search-panel p {
  margin: 6px 0 0;
  color: var(--muted);
}
.doc-search-box {
  display: grid;
  gap: 8px;
  min-width: min(420px, 100%);
}
.doc-search-box span {
  color: #475467;
  font-size: 13px;
  font-weight: 800;
}
.doc-search-box input {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 14px;
  color: var(--ink);
  background: #f8fafc;
  font-size: 15px;
}
.doc-card.is-hidden {
  display: none;
}
.no-results-card[hidden] {
  display: none;
}
.notice-grid, .category-grid, .doc-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.notice-card, .category-card, .doc-card, .cta, .code-card, .table-wrap, .faq-list details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}
.notice-card, .category-card, .doc-card { padding: 22px; }
.notice-card h3, .category-card h3, .doc-card h3 {
  margin: 0 0 8px;
  font-size: 20px;
}
.notice-card p, .category-card p, .doc-card p {
  color: #4b5563;
  line-height: 1.7;
  margin: 0;
}
.category-card span {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #e8f4d7;
  color: var(--brand-dark);
  font-weight: 900;
  margin-bottom: 16px;
}
.tag {
  display: inline-flex;
  margin: 0 0 12px;
  padding: 5px 10px;
  border-radius: 999px;
  background: #d9f99d;
  color: #254000;
  font-size: 12px;
  font-weight: 800;
}
.featured-doc .tag,
.alt-doc .tag {
  background: #f5ffd8;
  color: #254000;
  border: 1px solid rgba(37, 64, 0, .18);
}
.featured-doc {
  grid-column: span 2;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  background: #0f172a;
  color: #fff;
}
.featured-doc p { color: #dbe7f4; }
.alt-doc {
  background: linear-gradient(135deg, #164e63, #0f766e);
}
.sku-line {
  margin-top: 10px !important;
  color: #f8fafc !important;
  font-weight: 800;
}
.product-buy-card {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  margin-top: 18px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}
.product-buy-card p {
  margin: 0;
  color: #475467;
  line-height: 1.65;
}
.product-buy-card strong {
  display: block;
  color: var(--ink);
  font-size: 18px;
  margin-bottom: 4px;
}
.sku-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}
.sku-badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  background: #e8f4d7;
  color: var(--brand-dark);
  font-weight: 900;
  font-size: 13px;
}
.image-frame {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 14px;
  margin-bottom: 18px;
}
.image-frame img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 6px;
}
.wiring-table {
  margin-top: 16px;
}
.text-link {
  display: inline-flex;
  margin-top: 16px;
  font-weight: 800;
  color: var(--brand-dark);
}
.text-link:hover { text-decoration: underline; }
.radio-sim {
  display: grid;
  grid-template-columns: .92fr 1.08fr;
  gap: 18px;
  margin: 18px 0;
}
.sim-code-card, .sim-stage {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}
.sim-code-card {
  overflow: hidden;
}
.sim-card-head {
  min-height: 50px;
  padding: 0 14px 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--line);
  font-weight: 800;
}
.inline-copy {
  position: static;
  background: #f8fafc;
  color: var(--ink);
  border-color: var(--line);
}
.sim-code-card pre {
  margin: 0;
  padding: 18px;
  overflow-x: auto;
  background: #0b1020;
}
.sim-code-card code {
  color: #dbeafe;
  font: 14px/1.65 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
}
.run-demo {
  margin: 16px 18px 18px;
}
.download-example {
  margin: 0 18px 18px 0;
}
.sim-stage {
  position: relative;
  min-height: 390px;
  padding: 20px;
  overflow: hidden;
  background:
    linear-gradient(180deg, #ffffff, #f8fbff),
    radial-gradient(circle at 90% 20%, rgba(139, 197, 63, .2), transparent 28%);
}
.sim-device {
  position: absolute;
  border-radius: 10px;
  color: #fff;
  padding: 18px;
  box-shadow: 0 18px 42px rgba(15, 23, 42, .18);
}
.sim-device strong, .sim-device span {
  display: block;
  position: relative;
  z-index: 2;
}
.sim-device span {
  margin-top: 8px;
  color: rgba(255,255,255,.8);
  font-size: 13px;
}
.sim-uno {
  left: 26px;
  top: 54px;
  width: 210px;
  height: 210px;
  background: linear-gradient(135deg, #2563eb, #155a8a);
}
.sim-radio {
  right: 28px;
  top: 66px;
  width: 210px;
  height: 190px;
  background: linear-gradient(135deg, #0f766e, #1d9a8a);
}
.sim-device .pin {
  position: absolute;
  right: -26px;
  width: 54px;
  height: 24px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  background: #111827;
  color: #fff;
  font-style: normal;
  font-size: 12px;
  font-weight: 800;
  z-index: 3;
}
.sim-radio .pin {
  left: -26px;
  right: auto;
}
.pin-5v, .pin-vcc { top: 58px; }
.pin-gnd, .pin-rgnd { top: 94px; }
.pin-a4, .pin-sda { top: 130px; }
.pin-a5, .pin-scl { top: 166px; }
.sim-wire {
  position: absolute;
  left: 238px;
  right: 238px;
  height: 8px;
  border-radius: 999px;
  opacity: .24;
  transform-origin: left center;
  transition: opacity .25s, box-shadow .25s;
}
.sim-vcc { top: 123px; background: #ef4444; }
.sim-gnd { top: 159px; background: #111827; }
.sim-sda { top: 195px; background: #2563eb; }
.sim-scl { top: 231px; background: #f59e0b; }
.radio-led {
  position: absolute;
  right: 22px;
  bottom: 22px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #475569;
  border: 3px solid rgba(255,255,255,.55);
  transition: .2s;
}
.audio-wave {
  position: absolute;
  right: 76px;
  top: 282px;
  display: flex;
  gap: 9px;
  align-items: end;
  height: 46px;
  opacity: .25;
  transition: opacity .25s;
}
.audio-wave span {
  width: 10px;
  height: 20px;
  border-radius: 999px;
  background: #7c3aed;
}
.audio-wave span:nth-child(2) { height: 36px; }
.audio-wave span:nth-child(3) { height: 26px; }
.sim-status {
  position: absolute;
  left: 26px;
  right: 26px;
  bottom: 20px;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  list-style: none;
}
.sim-status li {
  min-height: 44px;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 8px;
  border-radius: 8px;
  background: #eef4f8;
  color: #667085;
  font-size: 13px;
  line-height: 1.35;
}
.sim-status li.done {
  background: #e8f4d7;
  color: var(--brand-dark);
  font-weight: 800;
}
.sim-stage.power-on .sim-vcc,
.sim-stage.power-on .sim-gnd,
.sim-stage.i2c-on .sim-sda,
.sim-stage.i2c-on .sim-scl {
  opacity: 1;
  box-shadow: 0 0 18px currentColor;
}
.sim-stage.tuned .radio-led {
  background: #22c55e;
  box-shadow: 0 0 24px 8px rgba(34, 197, 94, .58);
}
.sim-stage.audio-on .audio-wave {
  opacity: 1;
}
.sim-stage.audio-on .audio-wave span {
  animation: wave-bars .7s infinite ease-in-out alternate;
}
.sim-stage.audio-on .audio-wave span:nth-child(2) { animation-delay: .12s; }
.sim-stage.audio-on .audio-wave span:nth-child(3) { animation-delay: .24s; }
@keyframes wave-bars {
  from { transform: scaleY(.45); }
  to { transform: scaleY(1.15); }
}
.support-grid {
  display: grid;
  grid-template-columns: .9fr 1.1fr;
  gap: 28px;
  align-items: start;
}
.steps { display: grid; gap: 12px; }
.step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 13px;
  align-items: center;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
}
.step strong {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #e8f4d7;
  color: var(--brand-dark);
}
.step span { color: #475467; line-height: 1.65; }
.cta {
  padding: 28px;
  display: flex;
  justify-content: space-between;
  gap: 22px;
  align-items: center;
}
.cta h2 { margin: 0; font-size: 32px; }
.cta p:not(.eyebrow) { color: var(--muted); line-height: 1.7; margin: 10px 0 0; }

.demo-board { display: grid; gap: 18px; }
.board-art {
  height: 260px;
  border-radius: 8px;
  background: linear-gradient(135deg, #0e7490, #0f766e);
  position: relative;
  overflow: hidden;
}
.joystick {
  position: absolute;
  width: 112px;
  height: 112px;
  border-radius: 50%;
  left: 42px;
  top: 74px;
  background: radial-gradient(circle at 34% 24%, #6b7280, #111827 70%);
  box-shadow: 0 16px 36px rgba(0, 0, 0, .28);
}
.led-dot {
  position: absolute;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  right: 92px;
  top: 82px;
  background: #475569;
  border: 3px solid rgba(255,255,255,.55);
  transition: .2s;
}
.led-dot.is-on {
  background: #22c55e;
  box-shadow: 0 0 28px 10px rgba(34, 197, 94, .65);
}
.pin-row {
  position: absolute;
  width: 106px;
  height: 18px;
  left: 94px;
  bottom: 42px;
  background: repeating-linear-gradient(90deg, #111827 0 8px, transparent 8px 15px);
}
.state-card {
  background: rgba(255, 255, 255, .12);
  border-radius: 8px;
  padding: 18px;
}
.state-card p { margin: 0 0 10px; color: #dbe7f4; }
.state-card strong { color: #fff; }
.code-grid {
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 24px;
  align-items: start;
}
.code-grid .state-card {
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.code-grid .state-card p {
  color: #475467;
  line-height: 1.75;
}
.code-grid .state-card strong {
  color: #172033;
}
.code-grid .state-card code {
  color: #0f766e;
  background: #eef8f4;
  border-radius: 5px;
  padding: 2px 5px;
}
.code-card {
  position: relative;
  background: #0b1020;
  border-color: #1f2937;
  overflow: hidden;
}
.code-card pre {
  margin: 0;
  padding: 24px;
  overflow-x: auto;
}
.code-card code {
  color: #dbeafe;
  font: 15px/1.65 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
}
.copy-button {
  position: absolute;
  right: 12px;
  top: 12px;
  border: 1px solid rgba(255,255,255,.22);
  background: rgba(255,255,255,.1);
  color: #fff;
  border-radius: 8px;
  padding: 8px 10px;
  cursor: pointer;
}
.reply-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 22px;
}
.reply-card .copy-button {
  position: static;
  display: inline-flex;
  margin-bottom: 14px;
  background: #0f172a;
  color: #fff;
  border-color: #0f172a;
}
.reply-card p {
  margin: 0;
  color: #334155;
  line-height: 1.9;
  font-size: 16px;
}
.reply-card code {
  display: block;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font: inherit;
  color: inherit;
}
@keyframes ledPulse {
  0%, 100% { opacity: .45; transform: scale(.85); }
  50% { opacity: 1; transform: scale(1.12); }
}
@keyframes tracePulse {
  0% { offset-distance: 0%; opacity: 0; }
  12% { opacity: 1; }
  82% { opacity: 1; }
  100% { offset-distance: 100%; opacity: 0; }
}
@keyframes signalMove {
  0% { transform: translateX(0); opacity: 0; }
  12% { opacity: 1; }
  82% { opacity: 1; }
  100% { transform: translateX(300px); opacity: 0; }
}
.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  min-width: 720px;
}
th, td {
  padding: 15px 16px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  line-height: 1.6;
}
th { background: #f8fafc; }
tr:last-child td { border-bottom: 0; }
.faq-list { display: grid; gap: 12px; background: transparent; border: 0; box-shadow: none; }
.faq-list details { padding: 18px 20px; }
.faq-list summary { cursor: pointer; font-weight: 800; }
.faq-list p { color: var(--muted); line-height: 1.75; margin: 12px 0 0; }

.site-footer {
  background: #0f172a;
  color: #dbe7f4;
  padding: 24px 0;
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.site-footer a:hover { color: #d9f99d; }

@media (max-width: 900px) {
  .container { width: min(100% - 28px, 1140px); }
  .nav {
    min-height: 62px;
    flex-wrap: wrap;
    gap: 10px 12px;
    padding: 8px 0;
  }
  .global-search-wrap {
    order: 3;
    flex-basis: 100%;
    max-width: none;
    min-width: 0;
  }
  .global-search-bar { min-height: 40px; }
  .global-search-box {
    align-items: center;
  }
  .nav-toggle { display: inline-flex; }
  .nav-menu {
    display: none;
    position: absolute;
    left: 14px;
    right: 14px;
    top: 62px;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }
  .nav-menu.is-open { display: flex; }
  .nav-menu a { padding: 13px 12px; border-radius: 8px; }
  .nav-menu a:hover { background: #f2f6fa; }
  .hero-grid, .support-grid, .code-grid {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: 52px 0;
  }
  h1 { font-size: 38px; }
  .hero-lead { font-size: 17px; }
  .notice-grid, .category-grid, .doc-grid { grid-template-columns: 1fr; }
  .doc-search-panel { display: grid; }
  .doc-search-box { min-width: 0; }
  .arduino-scene { min-height: 330px; }
  .uno-board-detailed {
    left: 16px;
    top: 54px;
    width: 178px;
    height: 208px;
  }
  .uno-label { font-size: 14px; }
  .main-chip {
    left: 58px;
    width: 72px;
  }
  .header-power { left: 132px; }
  .pin-label {
    right: -32px;
    width: 58px;
    font-size: 10px;
  }
  .lcd1602-module {
    right: 14px;
    top: 62px;
    width: 154px;
    height: 210px;
  }
  .lcd-title { font-size: 13px; }
  .lcd-screen {
    left: 18px;
    right: 18px;
    height: 66px;
  }
  .lcd-screen i,
  .lcd-screen b { font-size: 11px; }
  .i2c-backpack {
    left: 36px;
    width: 76px;
    font-size: 11px;
  }
  .lcd-pin {
    left: -24px;
    width: 52px;
    font-size: 10px;
  }
  .lab-console {
    display: grid;
    align-content: center;
    min-height: 48px;
    line-height: 1.35;
  }
  .radio-sim { grid-template-columns: 1fr; }
  .sim-stage { min-height: 500px; }
  .sim-uno { left: 18px; top: 42px; width: 178px; }
  .sim-radio { right: 18px; top: 286px; width: 178px; }
  .sim-wire {
    left: 50%;
    right: auto;
    width: 8px;
    height: 110px;
    transform: translateX(-50%);
  }
  .sim-vcc { top: 236px; background: #ef4444; }
  .sim-gnd { top: 246px; left: calc(50% + 16px); background: #111827; }
  .sim-sda { top: 236px; left: calc(50% + 32px); background: #2563eb; }
  .sim-scl { top: 246px; left: calc(50% + 48px); background: #f59e0b; }
  .sim-status { grid-template-columns: 1fr 1fr; }
  .featured-doc { grid-column: auto; display: block; }
  .featured-doc .btn { margin-top: 18px; }
  .cta { display: block; }
  .cta-actions { margin-top: 20px; }
  .score-row { grid-template-columns: 1fr; }
  .section { padding: 54px 0; }
}