:root {
  --uu-blue: #0084ff;
  --uu-blue-deep: #0057c2;
  --uu-cyan: #00d4ff;
  --uu-ink: #0b1b2b;
  --uu-slate: #3a5166;
  --uu-mist: #e8f4ff;
  --uu-paper: #f5f9fc;
  --uu-white: #ffffff;
  --uu-line: rgba(11, 27, 43, 0.08);
  --font-display: "Orbitron", "Sora", sans-serif;
  --font-sans: "Sora", "Noto Sans SC", sans-serif;
  --font-cn: "Noto Sans SC", "Sora", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-cn);
  color: var(--uu-ink);
  background: var(--uu-paper);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

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

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

.container {
  width: min(1120px, calc(100% - 2.5rem));
  margin-inline: auto;
}

/* —— Nav —— */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  transition: background 0.35s var(--ease), backdrop-filter 0.35s var(--ease), box-shadow 0.35s var(--ease);
}

.nav.is-scrolled,
.nav.is-solid {
  background: rgba(245, 249, 252, 0.92);
  backdrop-filter: blur(14px);
  box-shadow: 0 1px 0 var(--uu-line);
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: 0.04em;
  color: var(--uu-ink);
}

.nav__mark {
  width: 2rem;
  height: 2rem;
  border-radius: 0.55rem;
  background: linear-gradient(145deg, var(--uu-cyan), var(--uu-blue));
  display: grid;
  place-items: center;
  color: white;
  font-size: 0.72rem;
  font-weight: 800;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--uu-slate);
}

.nav__links a:hover,
.nav__links a.is-active {
  color: var(--uu-blue);
}

.nav__links a.is-active {
  font-weight: 700;
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: 0.55rem 1.1rem;
  border-radius: 0.55rem;
  background: var(--uu-blue);
  color: white !important;
  font-weight: 600;
  font-size: 0.88rem;
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.nav__cta:hover,
.nav__cta.is-active {
  background: var(--uu-blue-deep);
  color: white !important;
}

.nav__cta:hover {
  transform: translateY(-1px);
}

.nav__toggle {
  display: none;
  width: 2.25rem;
  height: 2.25rem;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.nav__toggle span {
  display: block;
  width: 1.25rem;
  height: 2px;
  margin: 5px auto;
  background: var(--uu-ink);
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse 70% 55% at 50% 40%, rgba(0, 212, 255, 0.26), transparent 60%),
    radial-gradient(ellipse 50% 40% at 50% 70%, rgba(0, 132, 255, 0.14), transparent 55%),
    linear-gradient(165deg, #dff2ff 0%, #f5f9fc 42%, #eaf4ff 100%);
}

.hero > .container {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: center;
  width: min(1120px, calc(100% - 2.5rem));
}

.hero__mesh {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 132, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 132, 255, 0.045) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 65% 55% at 50% 45%, black, transparent 75%);
  pointer-events: none;
}

.hero__visual {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  pointer-events: none;
  opacity: 0.28;
}

.hero__visual svg {
  width: min(72vw, 760px);
  height: auto;
  transform: translateY(6%);
}

.hero__content {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 40rem;
  padding: 6.5rem 0 4rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero__brand {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 4.6rem);
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1;
  color: var(--uu-ink);
  margin-bottom: 1.1rem;
}

.hero__brand span {
  background: linear-gradient(105deg, var(--uu-blue) 10%, var(--uu-cyan) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__title {
  font-family: var(--font-cn);
  font-size: clamp(1.55rem, 3.2vw, 2.15rem);
  font-weight: 900;
  letter-spacing: 0.02em;
  margin-bottom: 0.85rem;
}

.hero__lead {
  font-size: 1.05rem;
  color: var(--uu-slate);
  max-width: 32rem;
  margin: 0 auto 1.75rem;
  text-wrap: balance;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.85rem 1.45rem;
  border-radius: 0.6rem;
  font-family: var(--font-cn);
  font-weight: 700;
  font-size: 0.95rem;
  border: 0;
  cursor: pointer;
  transition: transform 0.25s var(--ease), background 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn--primary {
  background: linear-gradient(120deg, var(--uu-blue), #00a8ff);
  color: white;
  box-shadow: 0 10px 28px rgba(0, 132, 255, 0.28);
}

.btn--primary:hover {
  box-shadow: 0 14px 32px rgba(0, 132, 255, 0.35);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.72);
  color: var(--uu-ink);
  border: 1px solid rgba(0, 132, 255, 0.22);
}

.btn--ghost:hover {
  background: white;
}

.pulse-node {
  transform-origin: center;
  animation: nodePulse 3.2s ease-in-out infinite;
}

.pulse-node:nth-child(2) { animation-delay: 0.4s; }
.pulse-node:nth-child(3) { animation-delay: 0.9s; }
.pulse-node:nth-child(4) { animation-delay: 1.3s; }

@keyframes nodePulse {
  0%, 100% { opacity: 0.55; }
  50% { opacity: 1; }
}

.signal-ring {
  transform-origin: center;
  animation: ringExpand 2.8s ease-out infinite;
}

@keyframes ringExpand {
  0% { opacity: 0.55; transform: scale(0.72); }
  70% { opacity: 0; transform: scale(1.35); }
  100% { opacity: 0; transform: scale(1.35); }
}

.path-flow {
  stroke-dasharray: 8 12;
  animation: dashMove 1.6s linear infinite;
}

@keyframes dashMove {
  to { stroke-dashoffset: -40; }
}

.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

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

/* —— Page shell —— */
.page-hero {
  padding: 8rem 0 2.5rem;
  background:
    radial-gradient(ellipse 70% 80% at 85% 0%, rgba(0, 212, 255, 0.2), transparent 55%),
    linear-gradient(180deg, #dff2ff 0%, var(--uu-paper) 100%);
}

.page-hero .section__title {
  max-width: 28rem;
}

section {
  padding: 4.5rem 0 5.5rem;
}

.section__label {
  font-family: var(--font-display);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--uu-blue);
  margin-bottom: 0.7rem;
}

.section__title {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  font-weight: 900;
  letter-spacing: 0.01em;
  margin-bottom: 0.75rem;
}

.section__desc {
  color: var(--uu-slate);
  max-width: 34rem;
  font-size: 1.05rem;
}

/* Stability */
.stability {
  background: var(--uu-white);
  border-block: 1px solid var(--uu-line);
}

.stability__grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3.5rem;
  align-items: center;
}

.stability__list {
  list-style: none;
  margin-top: 2rem;
  display: grid;
  gap: 1.15rem;
}

.stability__list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.9rem;
  align-items: start;
}

.stability__icon {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 0.55rem;
  background: var(--uu-mist);
  color: var(--uu-blue);
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 800;
}

.stability__list h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.stability__list p {
  color: var(--uu-slate);
  font-size: 0.95rem;
}

.meter {
  position: relative;
  aspect-ratio: 1;
  max-width: 380px;
  margin-inline: auto;
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 50%, rgba(0, 212, 255, 0.12), transparent 55%),
    conic-gradient(from 210deg, var(--uu-cyan), var(--uu-blue) 55%, #cfe9ff 55%, #cfe9ff);
  padding: 1rem;
  animation: meterSpin 12s linear infinite;
}

@keyframes meterSpin {
  to { filter: hue-rotate(12deg); }
}

.meter__inner {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: var(--uu-white);
  display: grid;
  place-items: center;
  text-align: center;
  animation: meterSpin 12s linear infinite reverse;
}

.meter__value {
  font-family: var(--font-display);
  font-size: 3.2rem;
  font-weight: 800;
  color: var(--uu-blue);
  line-height: 1;
}

.meter__unit {
  font-size: 0.95rem;
  color: var(--uu-slate);
  margin-top: 0.35rem;
}

.meter__caption {
  margin-top: 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--uu-ink);
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 0.5rem;
}

.detail-item h3 {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 0.45rem;
}

.detail-item p {
  color: var(--uu-slate);
  font-size: 0.95rem;
}

.detail-item__num {
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--uu-blue);
  margin-bottom: 0.55rem;
}

/* Platforms */
.platforms {
  background: linear-gradient(180deg, var(--uu-paper), #eaf3fb);
}

.platforms__intro {
  margin-bottom: 2.5rem;
}

.platforms__row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem 2.5rem;
}

.platform {
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  padding: 1.35rem 0.25rem 1.25rem;
  text-align: left;
  transition: border-color 0.3s var(--ease);
}

.platform:hover {
  border-color: var(--uu-blue);
}

.platform__name {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: var(--uu-blue);
  margin-bottom: 0.45rem;
}

.platform h3 {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.platform p {
  color: var(--uu-slate);
  font-size: 0.98rem;
}

/* Download */
.download {
  background: var(--uu-ink);
  color: white;
  position: relative;
  overflow: hidden;
  min-height: calc(100svh - 12rem);
  display: flex;
  align-items: center;
}

.download::before {
  content: "";
  position: absolute;
  inset: -20% auto auto -10%;
  width: 55%;
  height: 90%;
  background: radial-gradient(circle, rgba(0, 132, 255, 0.35), transparent 65%);
  pointer-events: none;
}

.download .container {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
  width: min(1120px, calc(100% - 2.5rem));
  padding: 6rem 0 4rem;
}

.download .section__label {
  color: var(--uu-cyan);
}

.download .section__desc {
  color: rgba(255, 255, 255, 0.72);
}

.download__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.5rem;
}

.download__actions .btn--primary {
  background: white;
  color: var(--uu-ink);
  box-shadow: none;
}

.download__actions .btn--ghost {
  background: transparent;
  color: white;
  border-color: rgba(255, 255, 255, 0.28);
}

.download__actions .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.08);
}

.download__qr {
  width: 148px;
  height: 148px;
  background: white;
  border-radius: 0.75rem;
  padding: 0.65rem;
  display: grid;
  place-items: center;
}

.download__qr svg {
  width: 100%;
  height: 100%;
}

.download__qr-note {
  text-align: center;
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.55);
  margin-top: 0.65rem;
}

.download-options {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 2.5rem;
}

.download-option {
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  padding-top: 1.1rem;
}

.download-option h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.download-option p {
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
}

/* Footer */
.footer {
  padding: 2.25rem 0;
  background: #07131f;
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.85rem;
}

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

.footer__brand {
  font-family: var(--font-display);
  color: white;
  letter-spacing: 0.06em;
  font-weight: 700;
}

.footer a:hover {
  color: var(--uu-cyan);
}

@media (max-width: 900px) {
  .nav__links {
    position: fixed;
    inset: 0 0 auto;
    top: 3.75rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(245, 249, 252, 0.97);
    padding: 0.5rem 1.25rem 1rem;
    border-bottom: 1px solid var(--uu-line);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.35s var(--ease), opacity 0.35s var(--ease);
  }

  .nav__links.is-open {
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }

  .nav__links li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--uu-line);
  }

  .nav__toggle {
    display: block;
  }

  .hero__visual {
    opacity: 0.18;
  }

  .hero__visual svg {
    width: 92vw;
  }

  .hero__content {
    max-width: none;
    padding: 6.5rem 0 3.5rem;
  }

  .stability__grid,
  .download .container,
  .detail-grid,
  .download-options {
    grid-template-columns: 1fr;
  }

  .platforms__row {
    grid-template-columns: 1fr;
  }

  .download__side {
    justify-self: start;
  }
}

@media (max-width: 560px) {
  .hero__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }
}