:root {
  color-scheme: dark;
  --bg: #07100d;
  --bg-soft: #0d1815;
  --panel: #111f1b;
  --panel-2: #172722;
  --text: #eff7f1;
  --muted: #aebdb5;
  --line: rgba(239, 247, 241, 0.14);
  --green: #12c76f;
  --green-soft: rgba(18, 199, 111, 0.16);
  --amber: #d8b56d;
  --coral: #ef6a5c;
  --blue: #71a7ff;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
  --max: 1160px;
  --radius: 8px;
  --fs-xs: 0.84rem;
  --fs-sm: 0.94rem;
  --fs-base: 1rem;
  --fs-md: 1.08rem;
  --fs-lg: 1.18rem;
  --fs-xl: 1.38rem;
  --fs-h2: 2.85rem;
  --fs-hero: 4.6rem;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background:
    linear-gradient(90deg, rgba(18, 199, 111, 0.06) 1px, transparent 1px) 0 0 / 64px 64px,
    linear-gradient(180deg, rgba(216, 181, 109, 0.05) 1px, transparent 1px) 0 0 / 64px 64px,
    radial-gradient(circle at 18% 0%, rgba(18, 199, 111, 0.18), transparent 32rem),
    var(--bg);
  color: var(--text);
}

body.nav-open {
  overflow: hidden;
}

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

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

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 20;
  transform: translateY(-160%);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--text);
  color: var(--bg);
  padding: 0.75rem 1rem;
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(18px);
}

.site-header[data-elevated="true"] {
  border-color: var(--line);
  background: rgba(7, 16, 13, 0.84);
}

.nav {
  width: min(var(--max), calc(100% - 40px));
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
}

.brand {
  display: inline-flex;
  min-width: 0;
  align-items: center;
  gap: 0.78rem;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(18, 199, 111, 0.55);
  border-radius: 50%;
  background: var(--green-soft);
  color: var(--green);
  font-weight: 800;
  box-shadow: inset 0 0 0 6px rgba(7, 16, 13, 0.45);
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.1;
  white-space: nowrap;
}

.brand strong {
  font-size: var(--fs-base);
  letter-spacing: 0;
}

.brand small {
  margin-top: 0.2rem;
  color: var(--muted);
  font-size: var(--fs-xs);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-links a {
  border-radius: 999px;
  color: var(--muted);
  font-size: var(--fs-sm);
  padding: 0.64rem 0.86rem;
  transition:
    background 160ms ease,
    color 160ms ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  background: rgba(255, 255, 255, 0.07);
  color: var(--text);
  outline: none;
}

.nav-toggle {
  display: none;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
}

.nav-toggle span {
  display: block;
  width: 17px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
  transition:
    transform 160ms ease,
    opacity 160ms ease;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.section,
.intro-band,
.contact-section {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  min-height: calc(100vh - 76px);
  display: grid;
  grid-template-columns: minmax(0, 0.98fr) minmax(360px, 0.82fr);
  align-items: center;
  gap: clamp(2.2rem, 5vw, 5rem);
  padding: clamp(4rem, 8vw, 7.5rem) 0 clamp(3rem, 7vw, 6rem);
}

.hero-copy,
.research-console,
.contact-copy,
.wechat-card,
.project-item > div,
.intro-grid > *,
.section-heading > *,
.notes-layout > * {
  min-width: 0;
}

.eyebrow,
.section-kicker,
.project-label {
  margin: 0 0 0.85rem;
  color: var(--green);
  font-size: var(--fs-xs);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 850px;
  margin-bottom: 1.3rem;
  font-size: var(--fs-hero);
  font-weight: 850;
  line-height: 0.98;
  letter-spacing: 0;
  overflow-wrap: normal;
}

h2 {
  font-size: var(--fs-h2);
  line-height: 1.08;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 0.72rem;
  font-size: var(--fs-lg);
  line-height: 1.18;
}

p {
  color: var(--muted);
  line-height: 1.75;
}

.hero-lede {
  max-width: 720px;
  color: #dbe8df;
  font-size: var(--fs-lg);
  line-height: 1.68;
}

.hero-actions,
.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 2rem;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.78rem 1.1rem;
  font-weight: 800;
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    background 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  outline: none;
}

.button.primary {
  border-color: transparent;
  background: var(--green);
  color: #03120a;
}

.button.secondary {
  background: rgba(255, 255, 255, 0.045);
  color: var(--text);
}

.button.secondary:hover,
.button.secondary:focus-visible {
  border-color: rgba(239, 247, 241, 0.34);
}

.research-console {
  overflow: hidden;
  border: 1px solid rgba(239, 247, 241, 0.16);
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), transparent 26%),
    rgba(13, 24, 21, 0.82);
  box-shadow: var(--shadow);
}

.console-bar {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--line);
  padding: 0.82rem 1rem;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: var(--fs-xs);
  text-transform: uppercase;
}

.signal-map {
  padding: clamp(1rem, 3vw, 1.6rem);
}

.signal-node {
  position: relative;
  border: 1px solid rgba(239, 247, 241, 0.13);
  border-left: 3px solid var(--blue);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.045);
  padding: 1rem;
}

.signal-node.large {
  border-left-color: var(--green);
}

.signal-node.accent {
  border-left-color: var(--amber);
}

.signal-node span {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: var(--fs-xs);
  text-transform: uppercase;
}

.signal-node strong {
  display: block;
  font-size: var(--fs-xl);
  line-height: 1.25;
}

.signal-line {
  width: 2px;
  height: clamp(1.2rem, 3vw, 2rem);
  margin-left: 1.1rem;
  background: linear-gradient(var(--green), transparent);
}

.intro-band {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: clamp(3rem, 7vw, 5rem) 0;
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(300px, 0.8fr);
  gap: clamp(1.5rem, 5vw, 5rem);
}

.intro-grid p {
  margin-bottom: 0;
  font-size: var(--fs-md);
}

.section {
  padding: clamp(4.5rem, 9vw, 7rem) 0;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 0.65fr) minmax(0, 1fr);
  align-items: end;
  gap: 2rem;
  margin-bottom: clamp(2rem, 5vw, 3.4rem);
}

.section-heading .eyebrow {
  grid-column: 1 / -1;
  margin-bottom: -0.9rem;
}

.axis-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.axis-card {
  min-height: 255px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 1.25rem;
  background: rgba(255, 255, 255, 0.025);
}

.axis-code {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-bottom: 3rem;
  border: 1px solid rgba(18, 199, 111, 0.45);
  border-radius: 50%;
  color: var(--green);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.8rem;
}

.axis-card:nth-child(2) .axis-code {
  border-color: rgba(216, 181, 109, 0.55);
  color: var(--amber);
}

.axis-card:nth-child(3) .axis-code {
  border-color: rgba(113, 167, 255, 0.55);
  color: var(--blue);
}

.axis-card:nth-child(4) .axis-code {
  border-color: rgba(239, 106, 92, 0.55);
  color: var(--coral);
}

.project-list {
  display: grid;
  gap: 1rem;
}

.project-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.5rem;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.035);
  padding: clamp(1.15rem, 3vw, 1.7rem);
}

.project-item.featured {
  border-color: rgba(18, 199, 111, 0.36);
  background: linear-gradient(90deg, var(--green-soft), rgba(255, 255, 255, 0.035));
}

.project-item h3 {
  font-size: 1.58rem;
  line-height: 1.22;
}

.project-item p:last-child {
  margin-bottom: 0;
}

.text-link {
  white-space: nowrap;
  color: var(--green);
  font-weight: 850;
}

.text-link::after {
  content: " ↗";
}

.project-actions {
  display: grid;
  gap: 0.7rem;
  justify-items: end;
}

.muted-link {
  color: var(--muted);
  font-size: var(--fs-sm);
}

.method-rail {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.method-step {
  min-height: 280px;
  padding: 1.3rem;
  background: rgba(255, 255, 255, 0.03);
}

.method-step + .method-step {
  border-left: 1px solid var(--line);
}

.method-step span {
  display: block;
  margin-bottom: 4.2rem;
  color: var(--amber);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-weight: 800;
}

.notes-section {
  border-top: 1px solid var(--line);
}

.notes-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(260px, 0.65fr);
  gap: clamp(1.5rem, 5vw, 4rem);
}

.topic-list {
  display: grid;
  gap: 0.9rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-list li {
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.9rem;
  color: #dfeae3;
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(320px, 0.72fr);
  align-items: center;
  gap: clamp(1.5rem, 5vw, 5rem);
  border-top: 1px solid var(--line);
  padding: clamp(4rem, 8vw, 6.5rem) 0;
}

.contact-copy h2 {
  margin-bottom: 1rem;
}

.wechat-card {
  margin: 0;
}

.wechat-card img {
  width: 100%;
  border: 1px solid rgba(18, 199, 111, 0.34);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.wechat-card figcaption {
  margin-top: 0.7rem;
  color: var(--muted);
  font-size: var(--fs-sm);
  text-align: right;
}

.site-footer {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  border-top: 1px solid var(--line);
  padding: 1.6rem 0 2.4rem;
  color: var(--muted);
}

.site-footer p {
  margin: 0;
}

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

@media (max-width: 980px) {
  :root {
    --fs-h2: 2.35rem;
    --fs-hero: 3.7rem;
  }

  .hero,
  .intro-grid,
  .section-heading,
  .notes-layout,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 5.5rem;
  }

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

  .method-step:nth-child(3) {
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .method-step:nth-child(4) {
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 720px) {
  :root {
    --fs-xs: 0.82rem;
    --fs-sm: 0.92rem;
    --fs-md: 1rem;
    --fs-lg: 1.04rem;
    --fs-xl: 1.08rem;
    --fs-h2: 1.95rem;
    --fs-hero: 2.38rem;
  }

  .nav,
  .section,
  .intro-band,
  .contact-section,
  .site-footer {
    width: min(calc(100% - 40px), 350px);
  }

  .nav {
    min-height: 68px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    inset: 68px 0 auto 0;
    display: none;
    min-height: calc(100vh - 68px);
    flex-direction: column;
    align-items: stretch;
    border-top: 1px solid var(--line);
    background: rgba(7, 16, 13, 0.98);
    padding: 1rem 20px 2rem;
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-links a {
    border-radius: var(--radius);
    padding: 1rem;
    font-size: var(--fs-md);
  }

  h1 {
    line-height: 1.04;
    overflow-wrap: anywhere;
  }

  .hero-lede,
  .eyebrow {
    overflow-wrap: anywhere;
  }

  .axis-grid,
  .method-rail,
  .project-item {
    grid-template-columns: 1fr;
  }

  .axis-card,
  .method-step {
    min-height: auto;
  }

  .axis-code,
  .method-step span {
    margin-bottom: 1.6rem;
  }

  .method-step + .method-step {
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .project-item .text-link {
    white-space: normal;
  }

  .project-actions {
    justify-items: start;
  }

  .site-footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}