/* LUMEN — tech official site
   Dial: variance 7 · motion 6 · density 4
   Palette: ink + copper + teal signal (no purple stack) */

:root {
  --ink: #070b10;
  --ink-2: #0e141c;
  --ink-3: #16202c;
  --snow: #e9eef4;
  --mist: #8b97a8;
  --copper: #d4a574;
  --copper-bright: #f2c892;
  --teal: #3d9b8f;
  --teal-soft: rgba(61, 155, 143, 0.18);
  --line: rgba(233, 238, 244, 0.1);
  --line-strong: rgba(233, 238, 244, 0.18);
  --radius: 18px;
  --shell: min(1120px, calc(100% - 2.5rem));
  --font-display: "Syne", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --header-h: 72px;
  color-scheme: dark;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-weight: 400;
  color: var(--snow);
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(212, 165, 116, 0.12), transparent 55%),
    radial-gradient(900px 500px at 0% 20%, rgba(61, 155, 143, 0.1), transparent 50%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 40%, var(--ink) 100%);
  line-height: 1.65;
  overflow-x: hidden;
}

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

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

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--copper);
  color: var(--ink);
  border-radius: 999px;
}

.skip-link:focus {
  top: 1rem;
}

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 50;
  opacity: 0.035;
  mix-blend-mode: soft-light;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.shell {
  width: var(--shell);
  margin-inline: auto;
}

.eyebrow {
  margin: 0 0 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--copper);
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.85rem, 3.6vw, 2.75rem);
  max-width: 16ch;
}

h3 {
  font-size: 1.25rem;
}

p {
  margin: 0;
}

/* Header */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  height: var(--header-h);
  transition: background 0.35s ease, border-color 0.35s ease, backdrop-filter 0.35s ease;
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  background: rgba(7, 11, 16, 0.72);
  border-bottom-color: var(--line);
  backdrop-filter: blur(16px);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.55rem;
}

.brand-mark {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, var(--copper-bright), var(--copper) 55%, #8a5a2b);
  box-shadow: 0 0 18px rgba(212, 165, 116, 0.55);
  transform: translateY(0.05rem);
}

.brand-word {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: 0.08em;
}

.brand-zh {
  font-size: 0.85rem;
  color: var(--mist);
}

.nav {
  display: none;
  align-items: center;
  gap: 1.6rem;
  font-size: 0.92rem;
  color: var(--mist);
}

.nav a:hover,
.nav a:focus-visible {
  color: var(--snow);
}

.nav-cta {
  padding: 0.55rem 0.95rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--snow) !important;
  transition: border-color 0.25s ease, background 0.25s ease;
}

.nav-cta:hover,
.nav-cta:focus-visible {
  border-color: var(--copper);
  background: rgba(212, 165, 116, 0.08);
}

.nav-toggle {
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  background: transparent;
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 0.35rem;
  cursor: pointer;
}

.nav-toggle span {
  width: 1rem;
  height: 1.5px;
  background: var(--snow);
  transition: transform 0.25s ease;
}

.nav-toggle[aria-expanded="true"] span:first-child {
  transform: translateY(3.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:last-child {
  transform: translateY(-3.5px) rotate(-45deg);
}

.mobile-nav {
  display: grid;
  gap: 0.25rem;
  padding: 0.75rem 1.25rem 1.25rem;
  background: rgba(7, 11, 16, 0.94);
  border-bottom: 1px solid var(--line);
}

.mobile-nav[hidden] {
  display: none;
}

.mobile-nav a {
  padding: 0.85rem 0.5rem;
  border-bottom: 1px solid var(--line);
  color: var(--mist);
}

.mobile-nav a:last-child {
  border-bottom: 0;
  color: var(--copper-bright);
}

@media (min-width: 860px) {
  .nav {
    display: flex;
  }

  .nav-toggle,
  .mobile-nav {
    display: none !important;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.25s ease, background 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.btn:focus-visible,
.nav a:focus-visible,
.brand:focus-visible,
input:focus-visible,
textarea:focus-visible,
.nav-toggle:focus-visible {
  outline: 2px solid var(--copper-bright);
  outline-offset: 3px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--copper-bright), var(--copper));
  color: #1a120a;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(212, 165, 116, 0.22);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 34px rgba(212, 165, 116, 0.32);
}

.btn-ghost {
  border-color: var(--line-strong);
  color: var(--snow);
  background: rgba(255, 255, 255, 0.02);
}

.btn-ghost:hover {
  border-color: var(--teal);
  background: var(--teal-soft);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  padding: calc(var(--header-h) + 2.5rem) 0 2rem;
  display: grid;
  align-content: end;
  gap: 3rem;
  overflow: hidden;
}

.hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-veil {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(7, 11, 16, 0.88) 0%, rgba(7, 11, 16, 0.55) 42%, rgba(7, 11, 16, 0.2) 100%),
    linear-gradient(180deg, transparent 50%, rgba(7, 11, 16, 0.85) 100%);
}

.hero-copy,
.hero-meta {
  position: relative;
  z-index: 2;
}

.hero-title {
  display: grid;
  gap: 0.35rem;
  margin-bottom: 1.25rem;
}

.hero-brand {
  font-family: var(--font-display);
  font-size: clamp(3.4rem, 10vw, 6.5rem);
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 0.95;
  background: linear-gradient(120deg, var(--snow) 20%, var(--copper-bright) 70%, var(--teal) 120%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-line {
  font-size: clamp(1.55rem, 3.8vw, 2.4rem);
  font-weight: 500;
  max-width: 14ch;
}

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

.hero-lead {
  max-width: 36ch;
  color: var(--mist);
  font-size: 1.05rem;
  margin-bottom: 1.75rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

.hero-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}

.meta-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--mist);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
}

.meta-value {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
}

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

/* Sections */
.section {
  padding: clamp(4.5rem, 10vw, 7.5rem) 0;
}

.section-head {
  margin-bottom: clamp(2rem, 5vw, 3.25rem);
}

.section-lead {
  margin-top: 1rem;
  max-width: 38ch;
  color: var(--mist);
}

.capability-grid {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 900px) {
  .capability-grid {
    grid-template-columns: 1.35fr 1fr;
    align-items: stretch;
  }
}

.capability-feature {
  padding: clamp(1.5rem, 3vw, 2.4rem);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  background:
    linear-gradient(160deg, rgba(212, 165, 116, 0.08), transparent 45%),
    linear-gradient(180deg, rgba(22, 32, 44, 0.9), rgba(14, 20, 28, 0.9));
  min-height: 100%;
}

.feature-kicker {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--teal);
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.capability-feature h3 {
  margin-bottom: 0.9rem;
  font-size: clamp(1.5rem, 2.5vw, 2rem);
}

.capability-feature > p {
  color: var(--mist);
  max-width: 42ch;
  margin-bottom: 1.5rem;
}

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

.feature-list li {
  position: relative;
  padding-left: 1.2rem;
  color: var(--snow);
}

.feature-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--copper);
  box-shadow: 0 0 10px rgba(212, 165, 116, 0.6);
}

.capability-stack {
  display: grid;
  gap: 1rem;
}

.stack-item {
  padding: 1.35rem 1.4rem;
  border-left: 2px solid transparent;
  border-image: linear-gradient(180deg, var(--copper), var(--teal)) 1;
  background: rgba(255, 255, 255, 0.02);
}

.stack-item h3 {
  margin-bottom: 0.45rem;
}

.stack-item p {
  color: var(--mist);
  font-size: 0.95rem;
}

/* Method */
.method {
  background:
    linear-gradient(180deg, transparent, rgba(61, 155, 143, 0.05), transparent);
}

.method-rail {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  counter-reset: none;
}

@media (min-width: 860px) {
  .method-rail {
    grid-template-columns: repeat(3, 1fr);
    gap: 0;
  }

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

.method-step {
  padding: 1.5rem 1.25rem;
}

.step-index {
  display: block;
  font-family: var(--font-mono);
  color: var(--copper);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  margin-bottom: 1rem;
}

.method-step h3 {
  margin-bottom: 0.6rem;
}

.method-step p {
  color: var(--mist);
  max-width: 28ch;
}

/* Signal */
.signal-layout {
  display: grid;
  gap: 2rem;
}

@media (min-width: 900px) {
  .signal-layout {
    grid-template-columns: 1fr 1.05fr;
    align-items: center;
    gap: 3rem;
  }
}

.signal-copy blockquote {
  margin: 1.4rem 0 1rem;
  padding: 0;
  border: 0;
  font-size: clamp(1.2rem, 2.2vw, 1.55rem);
  line-height: 1.55;
  color: var(--snow);
  max-width: 22ch;
}

.quote-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--mist);
  letter-spacing: 0.04em;
}

.signal-panel {
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  background: linear-gradient(180deg, rgba(22, 32, 44, 0.95), rgba(7, 11, 16, 0.95));
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.35);
}

.panel-top {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.02);
}

.dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: #3a4554;
}

.dot:nth-child(1) { background: #c97b63; }
.dot:nth-child(2) { background: #d4a574; }
.dot:nth-child(3) { background: #3d9b8f; }

.panel-title {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.panel-body {
  padding: 1.25rem;
}

.wave {
  height: 140px;
  border-radius: 12px;
  background:
    radial-gradient(circle at 20% 50%, rgba(212, 165, 116, 0.25), transparent 35%),
    radial-gradient(circle at 70% 40%, rgba(61, 155, 143, 0.22), transparent 40%),
    linear-gradient(180deg, #101820, #0a1016);
  position: relative;
  overflow: hidden;
}

.wave::before,
.wave::after {
  content: "";
  position: absolute;
  left: -10%;
  right: -10%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--copper), var(--teal), transparent);
  opacity: 0.75;
  animation: sweep 4.8s ease-in-out infinite;
}

.wave::before {
  top: 42%;
}

.wave::after {
  top: 62%;
  animation-delay: -1.8s;
  opacity: 0.45;
}

@keyframes sweep {
  0%,
  100% {
    transform: translateX(-8%) scaleX(0.9);
    opacity: 0.35;
  }
  50% {
    transform: translateX(8%) scaleX(1.05);
    opacity: 0.9;
  }
}

.panel-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin-top: 1rem;
}

.panel-stats span {
  display: block;
  font-size: 0.72rem;
  color: var(--mist);
  margin-bottom: 0.3rem;
}

.panel-stats strong {
  font-family: var(--font-display);
  font-size: 1.2rem;
}

/* Contact */
.contact-card {
  display: grid;
  gap: 2rem;
  padding: clamp(1.5rem, 4vw, 2.75rem);
  border-radius: calc(var(--radius) + 8px);
  border: 1px solid var(--line-strong);
  background:
    radial-gradient(600px 240px at 100% 0%, rgba(212, 165, 116, 0.16), transparent 55%),
    linear-gradient(160deg, rgba(22, 32, 44, 0.95), rgba(7, 11, 16, 0.98));
}

@media (min-width: 900px) {
  .contact-card {
    grid-template-columns: 0.95fr 1.05fr;
    align-items: start;
  }
}

.contact-card > div p:last-child {
  margin-top: 1rem;
  color: var(--mist);
  max-width: 34ch;
}

.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}

.contact-form label {
  display: grid;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--mist);
}

.contact-form .full {
  grid-column: 1 / -1;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.25);
  padding: 0.85rem 0.95rem;
  resize: vertical;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.contact-form input:hover,
.contact-form textarea:hover {
  border-color: var(--line-strong);
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: #5f6b7a;
}

.form-note {
  grid-column: 1 / -1;
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--teal);
}

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

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.75rem 0 2.25rem;
}

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

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  color: var(--mist);
  font-size: 0.9rem;
}

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

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

/* Reveal */
[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

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

  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .wave::before,
  .wave::after,
  .btn,
  .site-header {
    animation: none !important;
    transition: none !important;
  }
}