/* ==========================================================================
   TUXUN NETWORK — Zibo Tuxun Network Technology Co., Ltd.
   Dark graphite / deep-green digital infrastructure theme.
   Static, no framework. System fonts only.
   ========================================================================== */

:root {
  --bg: #0a0d0b;
  --bg-elev: #101511;
  --bg-panel: #0d110e;
  --line: rgba(148, 163, 152, 0.16);
  --line-soft: rgba(148, 163, 152, 0.09);
  --text: #e7ece7;
  --soft: #b9c2b8;
  --muted: #8d978d;
  --accent: #3fa97c;
  --accent-bright: #8fe0be;
  --accent-dim: rgba(63, 169, 124, 0.14);
  --accent-line: rgba(63, 169, 124, 0.32);
  --font-sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, "Cascadia Code", "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  color-scheme: dark;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.68;
  color: var(--text);
  background:
    radial-gradient(1100px 520px at 88% -6%, rgba(63, 169, 124, 0.07), transparent 60%),
    radial-gradient(900px 520px at -12% 34%, rgba(63, 169, 124, 0.045), transparent 55%),
    var(--bg);
}

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

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

a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  line-height: 1.18;
  letter-spacing: -0.015em;
  margin: 0;
}

p {
  margin: 0 0 1rem;
}

p:last-child {
  margin-bottom: 0;
}

ul {
  margin: 0;
  padding: 0;
}

::selection {
  background: #2e7d5a;
  color: #fff;
}

:focus-visible {
  outline: 2px solid var(--accent-bright);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3.5rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--bg-elev);
  border: 1px solid var(--accent-line);
  color: var(--accent-bright);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
  text-decoration: none;
}

/* ---------------------------------------------------------------- layout */

.container {
  width: min(1128px, 100% - clamp(2.5rem, 8vw, 6rem));
  margin-inline: auto;
}

.narrow {
  width: min(820px, 100% - clamp(2.5rem, 8vw, 6rem));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

/* ---------------------------------------------------------------- header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 13, 11, 0.86);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--text);
}

.brand:hover {
  text-decoration: none;
}

.brand-name {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  white-space: nowrap;
}

.brand-name em {
  font-style: normal;
  color: var(--accent-bright);
}

.site-nav ul {
  display: flex;
  gap: 0.2rem;
  list-style: none;
}

.site-nav a {
  display: block;
  padding: 0.55rem 0.85rem;
  font-size: 0.86rem;
  letter-spacing: 0.05em;
  color: var(--soft);
  border: 1px solid transparent;
  border-radius: 2px;
}

.site-nav a:hover {
  color: var(--text);
  background: var(--accent-dim);
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  color: var(--accent-bright);
  border-color: var(--accent-line);
  background: var(--accent-dim);
}

.nav-toggle {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 0.5rem 0.9rem;
  cursor: pointer;
}

.nav-toggle:hover {
  border-color: var(--accent-line);
}

@media (max-width: 860px) {
  .nav-toggle {
    display: inline-block;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    background: var(--bg-elev);
    border-bottom: 1px solid var(--line);
  }

  .site-nav.open {
    display: block;
  }

  .site-nav ul {
    flex-direction: column;
    gap: 0;
    padding: 0.6rem clamp(1.25rem, 4vw, 3rem) 1rem;
  }

  .site-nav a {
    padding: 0.85rem 0.4rem;
    border-bottom: 1px solid var(--line-soft);
    border-radius: 0;
  }
}

/* ---------------------------------------------------------------- hero */

.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(4rem, 11vh, 7.5rem) 0 clamp(3.5rem, 9vh, 6.5rem);
  border-bottom: 1px solid var(--line);
}

.hero::before,
.page-head::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(148, 163, 152, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 152, 0.05) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(ellipse 90% 85% at 70% 35%, #000 30%, transparent 78%);
  mask-image: radial-gradient(ellipse 90% 85% at 70% 35%, #000 30%, transparent 78%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.hero h1 {
  font-size: clamp(2.45rem, 5.4vw, 4.15rem);
  line-height: 1.07;
  letter-spacing: -0.022em;
  margin: 1.1rem 0 1.5rem;
}

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

.hero-lede {
  font-size: clamp(1.02rem, 1.35vw, 1.16rem);
  color: var(--soft);
  max-width: 56ch;
}

.hero-brandline {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  margin-top: 1.2rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-bright);
}

.hero-brandline::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--accent);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-top: 2.4rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 2.4rem;
  margin-top: 3.2rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-visual {
  position: relative;
}

@media (max-width: 920px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    max-width: 460px;
  }
}

/* buttons */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.78rem 1.35rem;
  font-size: 0.9rem;
  letter-spacing: 0.03em;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 2px;
  transition: border-color 0.18s ease, background 0.18s ease, color 0.18s ease,
    transform 0.18s ease;
}

.btn:hover {
  border-color: var(--accent);
  color: var(--accent-bright);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn .arr {
  transition: transform 0.18s ease;
}

.btn:hover .arr {
  transform: translateX(3px);
}

.btn-solid {
  background: var(--accent);
  border-color: var(--accent);
  color: #07130d;
  font-weight: 600;
}

.btn-solid:hover {
  background: var(--accent-bright);
  border-color: var(--accent-bright);
  color: #07130d;
}

/* hero network motif */

.net .edge {
  stroke: rgba(143, 224, 190, 0.22);
  stroke-width: 1;
}

.net .edge-flow {
  stroke: rgba(143, 224, 190, 0.4);
  stroke-dasharray: 3 9;
  animation: edgeflow 7s linear infinite;
}

.net .node {
  fill: var(--accent-bright);
  animation: nodepulse 5.5s ease-in-out infinite alternate;
}

.net .node-ring {
  fill: none;
  stroke: rgba(143, 224, 190, 0.35);
  stroke-width: 1;
}

.net .node-dim {
  fill: rgba(143, 224, 190, 0.45);
}

@keyframes edgeflow {
  to {
    stroke-dashoffset: -120;
  }
}

@keyframes nodepulse {
  from {
    opacity: 0.45;
  }
  to {
    opacity: 1;
  }
}

/* ---------------------------------------------------------------- tape */

.tape {
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: rgba(16, 21, 17, 0.55);
}

.tape-track {
  display: flex;
  align-items: center;
  width: max-content;
  padding: 0.85rem 0;
  animation: tape 52s linear infinite;
}

.tape span {
  position: relative;
  padding-inline: 1.9rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}

.tape span::after {
  content: "";
  position: absolute;
  right: -2.5px;
  top: 50%;
  width: 5px;
  height: 5px;
  translate: 0 -50%;
  background: var(--accent);
  border-radius: 50%;
}

@keyframes tape {
  to {
    transform: translateX(-50%);
  }
}

/* ---------------------------------------------------------------- sections */

.section {
  padding: clamp(3.8rem, 8.5vw, 6.75rem) 0;
  border-bottom: 1px solid var(--line);
}

.section:last-of-type {
  border-bottom: none;
}

.section-head {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.4rem 2.2rem;
  align-items: end;
  margin-bottom: clamp(2.2rem, 4.5vw, 3.4rem);
}

.sec-index {
  font-size: clamp(2.7rem, 4vw, 3.5rem);
  font-weight: 700;
  line-height: 1;
  color: rgba(143, 224, 190, 0.22);
  user-select: none;
}

@supports (-webkit-text-stroke: 1px black) {
  .sec-index {
    color: transparent;
    -webkit-text-stroke: 1px rgba(143, 224, 190, 0.4);
  }
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent-bright);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--accent);
  flex: none;
}

.section h2 {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  margin-top: 0.55rem;
}

.section-lede {
  color: var(--soft);
  max-width: 64ch;
  margin-top: 1rem;
  grid-column: 2;
}

@media (max-width: 640px) {
  .section-head {
    grid-template-columns: 1fr;
  }

  .section-lede {
    grid-column: 1;
  }
}

/* module grid (hairline internal grid) */

.mods {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.mods .card {
  background: var(--bg);
}

.card {
  position: relative;
  padding: 1.55rem 1.5rem 1.65rem;
  transition: background 0.18s ease;
}

.card::before {
  content: "";
  position: absolute;
  left: -1px;
  bottom: -1px;
  width: 10px;
  height: 10px;
  border-left: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  transition: border-color 0.18s ease;
}

.card::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 10px;
  height: 10px;
  border-top: 1px solid var(--accent);
  border-right: 1px solid var(--accent);
  opacity: 0;
  transition: opacity 0.18s ease;
}

.card:hover {
  background: var(--bg-elev);
}

.card:hover::after {
  opacity: 1;
}

.card:hover::before {
  border-color: var(--accent-line);
}

.card .idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 1rem;
}

.card h3 {
  font-size: 1.03rem;
  margin-bottom: 0.55rem;
}

.card p {
  font-size: 0.92rem;
  color: var(--soft);
  margin: 0;
}

@media (max-width: 900px) {
  .mods {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .mods {
    grid-template-columns: 1fr;
  }
}

/* generic split layout */

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}

@media (max-width: 860px) {
  .split {
    grid-template-columns: 1fr;
  }
}

/* hairline list */

.list-lines {
  list-style: none;
  border-top: 1px solid var(--line);
}

.list-lines li {
  display: grid;
  grid-template-columns: 1.7rem 1fr;
  gap: 0.9rem;
  padding: 0.8rem 0.2rem;
  border-bottom: 1px solid var(--line);
  font-size: 0.95rem;
  color: var(--soft);
}

.list-lines li::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--accent);
}

.list-lines strong {
  color: var(--text);
  font-weight: 600;
}

/* note / disclaimer panel */

.note {
  border: 1px solid var(--accent-line);
  border-left: 3px solid var(--accent);
  background: rgba(63, 169, 124, 0.06);
  padding: 1.1rem 1.35rem;
  border-radius: 2px;
  font-size: 0.95rem;
  color: var(--soft);
  max-width: 72ch;
}

.note strong {
  color: var(--text);
}

/* fact table */

.facts {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--bg);
}

.facts > div {
  display: grid;
  grid-template-columns: minmax(130px, 190px) 1fr;
  gap: 1rem;
  padding: 0.85rem 1.1rem;
  border-top: 1px solid var(--line);
}

.facts > div:first-child {
  border-top: none;
}

.facts dt {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  padding-top: 0.2rem;
}

.facts dd {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text);
  overflow-wrap: anywhere;
}

@media (max-width: 560px) {
  .facts > div {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }
}

/* brand panel */

.brand-panel {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--accent-line);
  background:
    linear-gradient(155deg, rgba(63, 169, 124, 0.11), rgba(63, 169, 124, 0.02) 55%),
    var(--bg-panel);
  padding: clamp(2rem, 4.5vw, 3.4rem);
}

.brand-word {
  font-size: clamp(2.1rem, 5vw, 3.4rem);
  font-weight: 700;
  letter-spacing: 0.22em;
  line-height: 1.1;
  margin: 0.9rem 0 1.2rem;
}

.brand-tag {
  color: var(--accent-bright);
}

.brand-watermark {
  position: absolute;
  right: -0.5rem;
  bottom: -2.8rem;
  font-family: var(--font-mono);
  font-size: clamp(4rem, 11vw, 8.5rem);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(143, 224, 190, 0.13);
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
}

/* ---------------------------------------------------------------- page head */

.page-head {
  position: relative;
  overflow: hidden;
  padding: clamp(3.4rem, 7vw, 5.5rem) 0 clamp(2.4rem, 5vw, 4rem);
  border-bottom: 1px solid var(--line);
}

.page-head h1 {
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  letter-spacing: -0.02em;
  margin: 1rem 0 1.2rem;
}

.page-lede {
  color: var(--soft);
  font-size: clamp(1rem, 1.3vw, 1.12rem);
  max-width: 62ch;
}

/* ---------------------------------------------------------------- prose */

.prose {
  color: var(--soft);
}

.prose h2 {
  font-size: 1.28rem;
  color: var(--text);
  margin: 2.6rem 0 0.8rem;
}

.prose h2:first-child {
  margin-top: 0;
}

.prose p,
.prose ul {
  max-width: 72ch;
}

.prose ul {
  list-style: none;
  padding-left: 0;
}

.prose ul li {
  position: relative;
  padding-left: 1.4rem;
  margin-bottom: 0.5rem;
}

.prose ul li::before {
  content: "+";
  position: absolute;
  left: 0;
  font-family: var(--font-mono);
  color: var(--accent);
}

.prose strong {
  color: var(--text);
}

/* spec table */

.spec-wrap {
  overflow-x: auto;
}

.spec {
  width: 100%;
  border-collapse: collapse;
}

.spec th {
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
  padding: 0.7rem 0.9rem;
  border-bottom: 1px solid var(--line);
}

.spec td {
  padding: 1.05rem 0.9rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  font-size: 0.95rem;
  color: var(--soft);
}

.spec td:first-child {
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
}

.spec tr:hover td {
  background: rgba(63, 169, 124, 0.04);
}

/* ---------------------------------------------------------------- footer */

.site-footer {
  padding: clamp(3rem, 6vw, 4.8rem) 0 1.6rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 2.5rem;
}

@media (max-width: 820px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.footer-title {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--text);
  margin: 1.1rem 0 0.5rem;
}

.footer-line {
  font-size: 0.9rem;
  color: var(--soft);
  margin: 0 0 0.3rem;
}

.footer-legal {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-top: 1rem;
}

.site-footer h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
  margin-bottom: 1rem;
}

.footer-nav {
  list-style: none;
}

.footer-nav li {
  margin-bottom: 0.55rem;
}

.footer-nav a {
  color: var(--soft);
  font-size: 0.92rem;
}

.footer-nav a:hover {
  color: var(--accent-bright);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.6rem 2rem;
  margin-top: 3rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
  color: var(--muted);
}

/* ---------------------------------------------------------------- 404 */

.nf {
  padding: clamp(6rem, 16vh, 10rem) 0;
  text-align: left;
}

.nf-code {
  font-family: var(--font-mono);
  font-size: clamp(4rem, 10vw, 7rem);
  font-weight: 700;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(143, 224, 190, 0.45);
}

/* ---------------------------------------------------------------- motion */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}