:root {
  --bg: #050814;
  --bg-raise: #0b1222;
  --ink: #e7eef8;
  --muted: #93a0b8;
  --faint: #6d7c96;
  --line: rgba(148, 196, 228, 0.16);
  --cyan: #67e8f9;
  --blue: #60a5fa;
  --header: 76px;
  --max: 1120px;
  --serif: "Noto Serif SC", "Songti SC", "STSong", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --en: "Outfit", "Avenir Next", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    radial-gradient(900px 520px at 80% 8%, rgba(56, 132, 255, 0.16), transparent 60%),
    radial-gradient(700px 480px at 8% 30%, rgba(99, 102, 241, 0.12), transparent 55%),
    var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(125, 211, 252, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(125, 211, 252, 0.045) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(circle at 50% 20%, #000 0%, transparent 75%);
  z-index: 0;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button, input, textarea { font: inherit; color: inherit; }
::selection { background: rgba(103, 232, 249, 0.28); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0;
  z-index: 50;
  background: linear-gradient(90deg, #22d3ee, #818cf8);
}

.pointer-glow {
  position: fixed;
  width: 520px;
  height: 520px;
  margin: -260px 0 0 -260px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 1;
  background: radial-gradient(circle, rgba(56, 160, 255, 0.14), transparent 68%);
}

.site-header,
main,
.site-footer { position: relative; z-index: 2; }

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header);
  display: flex;
  align-items: center;
  z-index: 30;
  backdrop-filter: blur(18px);
  background: rgba(5, 8, 20, 0.55);
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: rgba(5, 8, 20, 0.82);
  border-bottom-color: var(--line);
}
.header-inner,
.wrap {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.brand img { width: 42px; height: 42px; flex: none; }
.brand-name {
  display: block;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.18em;
  line-height: 1.2;
}
.brand-legal {
  display: block;
  margin-top: 3px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.02em;
  line-height: 1.2;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav a {
  font-family: var(--en);
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.nav a:hover { color: var(--ink); }
.nav-contact {
  border: 1px solid rgba(103, 232, 249, 0.45);
  color: var(--ink) !important;
  padding: 8px 14px;
  border-radius: 999px;
}
.nav-contact:hover { background: rgba(103, 232, 249, 0.1); }

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border-radius: 999px;
  border: 1px solid rgba(232, 238, 248, 0.45);
  background: rgba(8, 16, 32, 0.55);
  color: var(--ink);
  place-items: center;
  cursor: pointer;
  flex: none;
}
.nav-toggle i {
  display: block;
  width: 18px;
  height: 2px;
  background: #e8eef8;
  border-radius: 2px;
  box-shadow: 0 -6px 0 #e8eef8, 0 6px 0 #e8eef8;
  transition: background 0.2s ease, box-shadow 0.2s ease;
}
.nav-toggle[aria-expanded="true"] i {
  background: transparent;
  box-shadow: none;
  position: relative;
}
.nav-toggle[aria-expanded="true"] i::before,
.nav-toggle[aria-expanded="true"] i::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 18px;
  height: 2px;
  background: #e8eef8;
  border-radius: 2px;
}
.nav-toggle[aria-expanded="true"] i::before { transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] i::after { transform: rotate(-45deg); }

.hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: center;
  overflow: hidden;
}
.hero-mark {
  position: absolute;
  right: max(12px, calc(50% - 720px));
  top: 52%;
  width: min(540px, 42vw);
  transform: translateY(-50%);
  pointer-events: none;
}
.hero-mark svg { width: 100%; height: auto; overflow: visible; }
.hero-inner { padding: 140px 0 88px; position: relative; }
.kicker {
  margin: 0 0 18px;
  color: var(--cyan);
  font-size: 13px;
  letter-spacing: 0.16em;
}
h1 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(64px, 8vw, 112px);
  line-height: 0.96;
  letter-spacing: 0.04em;
}
.tagline {
  margin: 28px 0 0;
  font-family: var(--serif);
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 500;
  line-height: 1.3;
}
.tagline em {
  font-style: normal;
  color: var(--cyan);
}
.lede {
  max-width: 460px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 16px;
}
.hero-actions {
  display: flex;
  gap: 14px;
  margin-top: 36px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(90deg, #22d3ee, #60a5fa);
  color: #041018;
  font-weight: 700;
}
.btn-ghost {
  border-color: var(--line);
  background: rgba(8, 14, 28, 0.4);
}
.btn-primary:hover { filter: brightness(1.05); }
.btn-ghost:hover { border-color: rgba(103, 232, 249, 0.5); }

.walls { transform-origin: 200px 200px; animation: spin 96s linear infinite; }
.thread {
  fill: none;
  stroke: rgba(125, 243, 255, 0.45);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.thread-hot {
  fill: none;
  stroke: #f4fdff;
  stroke-width: 2.3;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 70 1000;
  filter: url(#softGlow);
  animation: run 6.4s linear infinite;
}
.core-halo {
  transform-origin: 200px 200px;
  animation: halo 3.4s ease-in-out infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes run { to { stroke-dashoffset: -1000; } }
@keyframes halo {
  0%, 100% { transform: scale(0.9); opacity: 0.55; }
  50% { transform: scale(1.18); opacity: 1; }
}

section { scroll-margin-top: 92px; }
.band { padding: 108px 0; }
.section-label {
  margin: 0 0 14px;
  font-family: var(--en);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
}
h2 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.25;
  letter-spacing: 0.02em;
}

.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  margin-top: 48px;
  align-items: start;
}
.about-copy p { margin: 0; color: var(--muted); font-size: 17px; }
.about-copy p + p { margin-top: 18px; }
.points { list-style: none; margin: 0; padding: 0; display: grid; gap: 18px; }
.points li {
  padding-top: 16px;
  border-top: 1px solid var(--line);
}
.points strong {
  display: block;
  font-family: var(--en);
  font-weight: 500;
  letter-spacing: 0.14em;
  font-size: 13px;
  color: var(--cyan);
}
.points span { display: block; margin-top: 6px; color: var(--ink); }

.cap-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 16px;
  margin-top: 48px;
}
.card {
  position: relative;
  overflow: hidden;
  padding: 32px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 24, 44, 0.86), rgba(7, 12, 24, 0.92));
  min-height: 230px;
}
.card:first-child { grid-row: span 2; min-height: 476px; }
.card-index {
  font-family: var(--en);
  color: var(--faint);
  letter-spacing: 0.16em;
  font-size: 13px;
}
.card h3 {
  margin: 28px 0 12px;
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 600;
}
.card p { margin: 0; color: var(--muted); max-width: 36em; }
.card:hover { border-color: rgba(103, 232, 249, 0.45); }
.card-mark {
  position: absolute;
  right: -30px;
  bottom: -40px;
  width: 220px;
  opacity: 0.85;
  pointer-events: none;
}

.steps {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
  margin-top: 56px;
}
.steps::before {
  content: "";
  position: absolute;
  top: 15px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(103, 232, 249, 0.7), transparent);
}
.step-no {
  position: relative;
  display: inline-grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #07101d;
  border: 1px solid rgba(103, 232, 249, 0.7);
  color: var(--cyan);
  font-family: var(--en);
  font-size: 12px;
}
.step h3 {
  margin: 22px 0 8px;
  font-size: 20px;
  font-family: var(--serif);
  font-weight: 600;
}
.step p { margin: 0; color: var(--muted); }

.contact-form-wrap { min-width: 0; }
.contact-panel {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  padding: 40px;
  border: 1px solid var(--line);
  background: rgba(8, 14, 28, 0.72);
}
.contact-panel h2 { font-size: clamp(32px, 4vw, 46px); }
.contact-note { color: var(--muted); margin: 16px 0 28px; }
.meta { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.meta span {
  display: block;
  color: var(--faint);
  font-family: var(--en);
  font-size: 12px;
  letter-spacing: 0.14em;
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.field { display: grid; gap: 8px; }
.field-wide { grid-column: 1 / -1; }
.field span { font-size: 13px; color: var(--muted); }
.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: rgba(4, 8, 18, 0.65);
  border-radius: 12px;
  padding: 12px 14px;
  outline: none;
}
.field textarea { min-height: 140px; resize: vertical; }
.field input:focus,
.field textarea:focus { border-color: rgba(103, 232, 249, 0.7); }
.field input[aria-invalid="true"],
.field textarea[aria-invalid="true"] { border-color: #fb7185; }
.error { min-height: 1.2em; margin: 0; color: #fda4af; font-size: 12px; }
.form-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 8px;
}
.fine {
  margin: 0;
  color: var(--faint);
  font-size: 12px;
  line-height: 1.6;
}
.form-success {
  min-height: 280px;
  display: grid;
  align-content: center;
  gap: 12px;
}
.form-success h3 {
  margin: 0;
  font-family: var(--serif);
  font-size: 36px;
  font-weight: 600;
}
.form-success p { margin: 0; color: var(--muted); max-width: 36em; }
.form-success[hidden],
.contact-form[hidden] { display: none; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 36px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  color: var(--muted);
  font-size: 13px;
}
.footer-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
}
.footer-meta p { margin: 0; }
.footer-meta a:hover { color: var(--cyan); }
.footer-brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.footer-brand img { width: 36px; height: 36px; }
.footer-brand strong { display: block; letter-spacing: 0.14em; font-size: 14px; }
.footer-brand span { display: block; color: var(--muted); font-weight: 400; letter-spacing: 0; font-size: 12px; }

.reveal {
  opacity: 0;
  transform: translateY(16px);
  animation: rise 0.8s ease forwards;
}
.reveal-delay { animation-delay: 0.12s; }
@keyframes rise {
  to { opacity: 1; transform: none; }
}

@media (max-width: 980px) {
  .brand-legal { display: none; }
  .about-grid,
  .cap-grid,
  .contact-panel,
  .steps { grid-template-columns: 1fr; }
  .card:first-child { grid-row: auto; min-height: 0; }
  .steps::before { display: none; }
  .hero {
    display: flex;
    flex-direction: column;
    min-height: auto;
  }
  .hero-inner { order: 1; }
  .hero-mark {
    order: 2;
    position: relative;
    top: auto;
    right: auto;
    width: min(420px, 78vw);
    transform: none;
    opacity: 1;
    margin: 0 auto 56px;
  }
  .lede { max-width: 36em; }
}

@media (max-width: 760px) {
  .header-inner, .wrap { width: min(var(--max), calc(100% - 32px)); }
  .nav-toggle { display: grid; }
  .nav {
    display: none;
    position: absolute;
    top: var(--header);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
    padding: 8px 24px 22px;
    background: rgba(5, 8, 20, 0.96);
    border-bottom: 1px solid var(--line);
  }
  .nav.is-open { display: flex; }
  h1 { font-size: 56px; letter-spacing: 0.02em; }
  .hero-inner { padding-top: 108px; padding-bottom: 12px; }
  .tagline { font-size: 28px; }
  .hero-mark { width: min(300px, 76vw); margin-bottom: 36px; }
  .hero-actions, .form-foot, .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-meta { align-items: flex-start; }
  .form-grid { grid-template-columns: 1fr; }
  .band { padding: 80px 0; }
  .contact-panel { padding: 24px; }
  .pointer-glow { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .walls, .thread-hot, .core-halo, .reveal { animation: none; }
  .reveal { opacity: 1; transform: none; }
  .btn { transition: none; }
}