:root {
  --bg: #f6faf9;
  --surface: #ffffff;
  --surface-strong: #eff8f6;
  --text: #12201d;
  --muted: #62706d;
  --line: #dce8e5;
  --blue: #0877ea;
  --cyan: #12bdd7;
  --green: #18b66a;
  --amber: #f2a93b;
  --ink: #0a1f33;
  --shadow: 0 24px 70px rgba(16, 42, 54, 0.14);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 10% 10%, rgba(18, 189, 215, 0.13), transparent 34rem),
    linear-gradient(180deg, #f7fbfb 0%, #eef7f4 48%, #fbfdfb 100%);
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1180px, calc(100% - 32px));
  margin: 14px auto 0;
  padding: 12px 14px;
  border: 1px solid rgba(220, 232, 229, 0.78);
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 16px 40px rgba(12, 45, 48, 0.08);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav a {
  padding: 10px 14px;
  border-radius: 999px;
  color: #33423f;
  font-size: 14px;
  font-weight: 650;
}

.site-nav a:hover,
.nav-cta {
  background: #e9f7f3;
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 14px;
  background: #e9f7f3;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  border-radius: 1px;
  background: #193632;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.94fr) minmax(420px, 1.06fr);
  align-items: center;
  gap: 44px;
  width: min(1180px, calc(100% - 32px));
  min-height: calc(100vh - 112px);
  margin: 0 auto;
  padding: 86px 0 68px;
}

.release-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  width: fit-content;
  padding: 8px 13px;
  border: 1px solid #cbeee7;
  border-radius: 999px;
  background: #ffffff;
  color: #087263;
  font-size: 14px;
  font-weight: 700;
}

.release-pill::before {
  width: 9px;
  height: 9px;
  border-radius: 999px;
  background: var(--green);
  content: "";
}

.hero h1 {
  max-width: 780px;
  margin: 22px 0 18px;
  color: #0e2521;
  font-size: clamp(44px, 7vw, 82px);
  line-height: 1.02;
  letter-spacing: 0;
}

.hero p {
  max-width: 640px;
  margin: 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.primary-btn,
.secondary-btn,
.download-card a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border-radius: 999px;
  font-weight: 800;
}

.primary-btn,
.download-card a {
  background: linear-gradient(135deg, var(--green), var(--cyan) 54%, var(--blue));
  color: #ffffff;
  box-shadow: 0 14px 34px rgba(8, 119, 234, 0.22);
}

.secondary-btn {
  border: 1px solid var(--line);
  background: #ffffff;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  max-width: 520px;
  margin: 42px 0 0;
}

.hero-stats div {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.74);
}

.hero-stats dt {
  font-size: 26px;
  font-weight: 850;
}

.hero-stats dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.hero-visual {
  position: relative;
}

.app-shell {
  overflow: hidden;
  border: 1px solid rgba(202, 224, 220, 0.9);
  border-radius: 28px;
  background: #ffffff;
  box-shadow: var(--shadow);
}

.window-bar,
.terminal-head {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 50px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
  background: #fbfdfc;
}

.window-bar span,
.terminal-head span {
  width: 11px;
  height: 11px;
  border-radius: 999px;
}

.window-bar span:nth-child(1),
.terminal-head span:nth-child(1) {
  background: #ff6b6b;
}

.window-bar span:nth-child(2),
.terminal-head span:nth-child(2) {
  background: #f2bd4d;
}

.window-bar span:nth-child(3),
.terminal-head span:nth-child(3) {
  background: #27c36a;
}

.window-bar strong,
.terminal-head strong {
  margin-left: 8px;
  color: #6a7774;
  font-size: 13px;
}

.canvas {
  position: relative;
  min-height: 360px;
  background:
    linear-gradient(rgba(18, 32, 29, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 32, 29, 0.045) 1px, transparent 1px),
    #f8fbfa;
  background-size: 28px 28px;
}

.node {
  position: absolute;
  z-index: 2;
  width: 172px;
  padding: 16px;
  border: 1px solid #d7e7e4;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 18px 40px rgba(20, 49, 52, 0.11);
}

.node small {
  display: block;
  color: #778580;
  font-size: 12px;
  font-weight: 750;
}

.node strong {
  display: block;
  margin-top: 9px;
  color: #11231f;
  font-size: 15px;
}

.send {
  top: 55px;
  left: 38px;
}

.serial {
  top: 126px;
  left: 284px;
}

.tcp {
  top: 44px;
  right: 36px;
}

.receive {
  right: 34px;
  bottom: 56px;
}

.links {
  position: absolute;
  inset: 18px;
  width: calc(100% - 36px);
  height: calc(100% - 36px);
}

.links path {
  fill: none;
  stroke: #18b6c9;
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 10 10;
}

.log-dock {
  display: flex;
  gap: 14px;
  align-items: center;
  padding: 16px 18px;
  border-top: 1px solid var(--line);
  background: #0c1f2b;
  color: #d7f8ff;
  font-size: 13px;
}

.log-dock span {
  color: #8dc9d1;
}

.log-dock code {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.section,
.workflow-section {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 84px 0;
}

.section-heading {
  max-width: 720px;
  margin: 0 auto 34px;
  text-align: center;
}

.section-heading span,
.workflow-copy span {
  color: #087263;
  font-size: 13px;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-heading h2,
.workflow-copy h2 {
  margin: 12px 0 14px;
  color: #102520;
  font-size: clamp(32px, 4.5vw, 52px);
  line-height: 1.12;
  letter-spacing: 0;
}

.section-heading p,
.workflow-copy p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.download-card,
.faq-list details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 18px 44px rgba(27, 54, 50, 0.06);
}

.feature-card {
  padding: 24px;
}

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: #eaf8f4;
  color: #087263;
  font-weight: 900;
}

.feature-card h3,
.download-card h3 {
  margin: 18px 0 10px;
  font-size: 20px;
}

.feature-card p,
.download-card p,
.faq-list p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.workflow-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1.1fr);
  gap: 32px;
  align-items: center;
}

.check-list {
  display: grid;
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  display: flex;
  gap: 10px;
  color: #30423e;
  line-height: 1.6;
}

.check-list li::before {
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border-radius: 999px;
  background: #dff7ee;
  color: #0a8a56;
  content: "✓";
  font-size: 14px;
  font-weight: 900;
  line-height: 22px;
  text-align: center;
}

.terminal-panel {
  overflow: hidden;
  border: 1px solid #d5e5e1;
  border-radius: 24px;
  background: #0b1f2b;
  box-shadow: var(--shadow);
}

.terminal-head {
  border-color: rgba(255, 255, 255, 0.08);
  background: #102b38;
}

.terminal-head strong {
  color: #a9c9cf;
}

.terminal-panel pre {
  margin: 0;
  padding: 28px;
  overflow: auto;
  color: #d8f9ff;
  font-size: 15px;
  line-height: 2;
}

.download {
  padding-top: 70px;
}

.download-tabs {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 22px;
}

.tab {
  min-width: 112px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
  color: #33423f;
  cursor: pointer;
  font: inherit;
  font-weight: 800;
}

.tab.is-active {
  border-color: transparent;
  background: #102520;
  color: #ffffff;
}

.download-panels {
  max-width: 760px;
  margin: 0 auto;
}

.download-card {
  display: none;
  padding: 28px;
  text-align: center;
}

.download-card.is-active {
  display: block;
}

.download-card h3 {
  margin-top: 0;
  font-size: 26px;
}

.download-card a {
  margin-top: 22px;
}

.faq-list {
  display: grid;
  gap: 14px;
  max-width: 860px;
  margin: 0 auto;
}

.faq-list details {
  padding: 20px 22px;
}

.faq-list summary {
  cursor: pointer;
  font-size: 18px;
  font-weight: 800;
}

.faq-list p {
  margin-top: 14px;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 34px 0 44px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.footer-brand {
  color: var(--text);
}

.site-footer a {
  color: #087263;
  font-weight: 800;
}

@media (max-width: 980px) {
  .hero,
  .workflow-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 60px;
  }

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .site-header {
    align-items: flex-start;
  }

  .menu-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 66px;
    right: 0;
    left: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #ffffff;
    box-shadow: 0 20px 44px rgba(12, 45, 48, 0.12);
  }

  .site-header.nav-open .site-nav {
    display: flex;
  }

  .site-nav a {
    border-radius: 14px;
  }

  .hero h1 {
    font-size: 42px;
  }

  .hero-stats,
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    margin-inline: -6px;
  }

  .app-shell {
    border-radius: 20px;
  }

  .canvas {
    min-height: 410px;
  }

  .node {
    width: 160px;
  }

  .send {
    top: 34px;
    left: 18px;
  }

  .serial {
    top: 138px;
    left: auto;
    right: 18px;
  }

  .tcp {
    top: 240px;
    right: auto;
    left: 18px;
  }

  .receive {
    right: 18px;
    bottom: 34px;
  }

  .links {
    display: none;
  }

  .download-tabs {
    flex-direction: column;
  }

  .tab {
    width: 100%;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}