/* WeMQTT marketing site — cool zinc + signal green */

:root {
  --ink: #12151a;
  --ink-soft: #3a414c;
  --muted: #6b7380;
  --line: #d8dee6;
  --surface: #ffffff;
  --canvas: #eef1f5;
  --canvas-deep: #e4e9f0;
  --green: #2e9b57;
  --green-deep: #247a45;
  --green-soft: rgba(46, 155, 87, 0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 18px 50px rgba(18, 21, 26, 0.08);
  --font-sans: "Avenir Next", "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "SF Mono", "Menlo", "Consolas", "JetBrains Mono", ui-monospace,
    monospace;
  --max: 1120px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 85% -10%, rgba(46, 155, 87, 0.09), transparent 55%),
    radial-gradient(900px 420px at -10% 20%, rgba(18, 21, 26, 0.04), transparent 50%),
    var(--canvas);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

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

.container {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

/* Nav */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(14px);
  background: rgba(238, 241, 245, 0.82);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(255, 255, 255, 0.88);
}

.nav {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  font-size: 1.05rem;
}

.brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.nav-links a:hover {
  color: var(--ink);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.7);
}

.lang-btn {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.28rem 0.55rem;
  border-radius: 999px;
  cursor: pointer;
  line-height: 1;
}

.lang-btn:hover {
  color: var(--ink);
}

.lang-btn.is-active {
  background: var(--ink);
  color: #fff;
}

html[lang="zh-Hans"] .section-title {
  white-space: normal;
}

html[lang="zh-Hans"] .hero-copy h1 {
  max-width: 12em;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  background: var(--ink);
  color: #fff !important;
  font-size: 0.88rem;
  font-weight: 600;
  transition: transform 0.15s ease, background 0.15s ease;
}

.nav-cta:hover {
  background: #000;
}

.nav-cta:active {
  transform: scale(0.98);
}

.nav-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 8px;
  width: 40px;
  height: 40px;
  cursor: pointer;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.78rem 1.2rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
  cursor: pointer;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--green);
  color: #fff;
}

.btn-primary:hover {
  background: var(--green-deep);
}

.btn-secondary {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}

.btn-secondary:hover {
  border-color: var(--ink-soft);
  background: rgba(255, 255, 255, 0.7);
}

/* Hero */

.hero {
  padding: 1.75rem 0 2.5rem;
  display: grid;
  align-items: start;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 3rem;
  align-items: center;
}

.hero-copy h1 {
  margin: 0;
  font-size: clamp(2.35rem, 4.4vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -0.045em;
  font-weight: 750;
  max-width: 11ch;
}

.hero-copy h1 .accent {
  color: var(--green);
}

.hero-lead {
  margin: 1.1rem 0 0;
  color: var(--ink-soft);
  font-size: 1.05rem;
  max-width: 34ch;
}

.hero-actions {
  margin-top: 1.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-meta {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1.25rem;
  color: var(--muted);
  font-size: 0.86rem;
}

.hero-meta span {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 4px var(--green-soft);
}

/* Product stage */

.product-stage {
  position: relative;
  border-radius: calc(var(--radius) + 4px);
  background: linear-gradient(160deg, #1a1f27 0%, #12151a 55%, #0e1116 100%);
  color: #e8edf4;
  box-shadow: var(--shadow);
  overflow: hidden;
  min-height: 380px;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.product-stage::before {
  content: "";
  position: absolute;
  inset: auto -20% -30% 20%;
  height: 60%;
  background: radial-gradient(circle, rgba(46, 155, 87, 0.28), transparent 65%);
  pointer-events: none;
}

.stage-top {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: rgba(232, 237, 244, 0.55);
}

.stage-pill {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #3d4450;
}

.stage-pill.live {
  background: var(--green);
}

.stage-body {
  display: grid;
  grid-template-columns: 140px 1fr;
  min-height: 320px;
}

.stage-side {
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  padding: 0.85rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
}

.stage-side .label {
  color: rgba(232, 237, 244, 0.4);
  margin-bottom: 0.55rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.62rem;
}

.topic-row {
  padding: 0.45rem 0.5rem;
  border-radius: 6px;
  margin-bottom: 0.25rem;
  color: rgba(232, 237, 244, 0.72);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topic-row.active {
  background: rgba(46, 155, 87, 0.16);
  color: #d8f5e3;
}

.stage-main {
  padding: 1rem 1.1rem 1.2rem;
}

.msg {
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.8rem;
  margin-bottom: 0.55rem;
  background: rgba(255, 255, 255, 0.03);
  animation: rise-in 0.7s ease both;
}

.msg:nth-child(2) {
  animation-delay: 0.18s;
}

.msg:nth-child(3) {
  animation-delay: 0.34s;
}

.msg-head {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: rgba(232, 237, 244, 0.5);
  margin-bottom: 0.35rem;
}

.msg-topic {
  color: #9be4b4;
}

.msg-body {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: rgba(232, 237, 244, 0.88);
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .msg {
    animation: none;
  }
}

/* Sections */

.section {
  padding: 4.5rem 0;
}

.section-tight {
  padding: 3.25rem 0;
}

.section-title {
  margin: 0;
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  letter-spacing: -0.035em;
  line-height: 1.15;
  max-width: none;
  white-space: nowrap;
}

.section-lead {
  margin: 0.85rem 0 0;
  color: var(--ink-soft);
  max-width: 48ch;
}

/* Feature mosaic */

.feature-mosaic {
  margin-top: 2.25rem;
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  grid-template-rows: auto auto;
  gap: 1rem;
}

.feature {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.4rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.feature:hover {
  border-color: #b8c2d0;
  transform: translateY(-2px);
}

.feature-wide {
  grid-row: span 2;
  background:
    linear-gradient(165deg, rgba(46, 155, 87, 0.08), transparent 42%),
    var(--surface);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 280px;
}

.feature h3 {
  margin: 0;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.feature p {
  margin: 0.55rem 0 0;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.feature-code {
  margin-top: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--ink-soft);
  background: var(--canvas-deep);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1rem;
}

.feature-code .g {
  color: var(--green-deep);
}

/* Strip */

.strip {
  background: var(--ink);
  color: #edf1f6;
  border-radius: calc(var(--radius) + 4px);
  padding: 2rem 1.75rem;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 1.5rem;
  align-items: center;
}

.strip h2 {
  margin: 0;
  font-size: clamp(1.45rem, 2.5vw, 1.9rem);
  letter-spacing: -0.03em;
  line-height: 1.2;
  max-width: 16ch;
}

.strip p {
  margin: 0.7rem 0 0;
  color: rgba(237, 241, 246, 0.72);
  max-width: 42ch;
}

.strip-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

.strip-list li {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 0.75rem;
  align-items: baseline;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.95rem;
}

.strip-list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.strip-list strong {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #9be4b4;
  font-weight: 600;
}

.strip-list span {
  color: rgba(237, 241, 246, 0.78);
}

/* Requirements */

.req-grid {
  margin-top: 1.75rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.req {
  padding: 1.2rem 1.25rem;
  border-top: 2px solid var(--ink);
}

.req h3 {
  margin: 0;
  font-size: 1rem;
  letter-spacing: -0.02em;
}

.req p {
  margin: 0.45rem 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

/* CTA band */

.cta-band {
  text-align: left;
  padding: 3.5rem 0 4.5rem;
}

.cta-card {
  background: linear-gradient(135deg, #f7faf8, #ffffff 45%, #eef5f0);
  border: 1px solid #cfe3d6;
  border-radius: calc(var(--radius) + 4px);
  padding: 2.25rem 2rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
}

.cta-card h2 {
  margin: 0;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  letter-spacing: -0.03em;
}

.cta-card p {
  margin: 0.45rem 0 0;
  color: var(--ink-soft);
}

/* Legal pages */

.legal {
  padding: 3rem 0 4.5rem;
}

.legal h1 {
  margin: 0;
  font-size: clamp(1.9rem, 3vw, 2.5rem);
  letter-spacing: -0.035em;
}

.legal .updated {
  margin: 0.6rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.legal-body {
  margin-top: 2rem;
  max-width: 68ch;
}

.legal-body h2 {
  margin: 2rem 0 0.6rem;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.legal-body p,
.legal-body li {
  color: var(--ink-soft);
}

.legal-body ul {
  padding-left: 1.2rem;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.75rem 0 2.25rem;
  background: rgba(255, 255, 255, 0.45);
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.25rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: var(--ink);
}

.footer-copy {
  color: var(--muted);
  font-size: 0.85rem;
}

/* Reveal */

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* Responsive */

@media (max-width: 900px) {
  .section-title {
    white-space: normal;
  }

  .hero-grid,
  .feature-mosaic,
  .strip,
  .stage-body,
  .req-grid {
    grid-template-columns: 1fr;
  }

  .feature-wide {
    grid-row: auto;
    min-height: 0;
  }

  .hero {
    padding: 1.25rem 0 2rem;
  }

  .hero-copy h1 {
    max-width: none;
  }

  .nav-links {
    display: none;
  }

  .nav-links.open {
    display: flex;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.75rem 1.25rem 1rem;
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid var(--line);
  }

  .nav-links.open a,
  .nav-links.open .lang-switch {
    padding: 0.7rem 0;
    border-bottom: 1px solid var(--line);
  }

  .nav-links.open .lang-switch {
    width: fit-content;
  }

  .nav-links.open .nav-cta {
    margin-top: 0.65rem;
    justify-content: center;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
}