:root {
  --ink: #e7f6f2;
  --muted: #93b4ae;
  --line: rgba(98, 214, 196, 0.22);
  --deep: #07141f;
  --panel: #102433;
  --panel-2: #163246;
  --mint: #3ee0c4;
  --mint-mid: #27b39c;
  --mint-deep: #178272;
  --amber: #ffb45c;
  --sky: #6ec8ff;
  --rose: #ff8aa0;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --wrap: 1120px;
  --iso: rotateX(56deg) rotateZ(-45deg);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font);
  line-height: 1.65;
  background-color: var(--deep);
  background-image:
    linear-gradient(30deg, rgba(62, 224, 196, 0.07) 12%, transparent 12.5%, transparent 87%, rgba(62, 224, 196, 0.07) 87.5%),
    linear-gradient(150deg, rgba(62, 224, 196, 0.07) 12%, transparent 12.5%, transparent 87%, rgba(62, 224, 196, 0.07) 87.5%),
    linear-gradient(90deg, rgba(14, 38, 54, 0.55) 2px, transparent 2px),
    radial-gradient(ellipse at 20% 0%, rgba(62, 224, 196, 0.12), transparent 42%),
    radial-gradient(ellipse at 90% 10%, rgba(255, 180, 92, 0.08), transparent 36%);
  background-size: 72px 124px, 72px 124px, 36px 36px, 100% 100%, 100% 100%;
}

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

a {
  color: var(--mint);
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--amber);
}

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 12px;
  top: -56px;
  z-index: 40;
  padding: 0.5rem 0.85rem;
  background: var(--amber);
  color: var(--deep);
  font-weight: 700;
  text-decoration: none;
}

.skip:focus {
  top: 12px;
}

.wrap {
  width: min(var(--wrap), calc(100% - 2rem));
  margin-inline: auto;
}

.topbar {
  border-bottom: 1px solid var(--line);
  background: rgba(7, 20, 31, 0.86);
}

.topbar-inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.55rem 0;
  font-size: 0.82rem;
  color: var(--muted);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid transparent;
  background: rgba(7, 20, 31, 0.72);
  backdrop-filter: blur(10px);
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.28);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
}

.brand img,
.logo-block img {
  width: 40px;
  height: 40px;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: 6px 6px 0 #0b2a28;
}

.brand small,
.logo-block small {
  display: block;
  font-weight: 500;
  font-size: 0.74rem;
  color: var(--muted);
}

.nav-toggle {
  display: none;
  border: 0;
  padding: 0.55rem 0.8rem;
  background: var(--panel-2);
  color: var(--ink);
  font: inherit;
  cursor: pointer;
  box-shadow: 5px 5px 0 #0a1c18;
}

.nav-panel ul {
  display: flex;
  align-items: center;
  gap: 0.35rem 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-panel a {
  color: var(--ink);
  text-decoration: none;
  padding: 0.35rem 0.15rem;
}

.nav-panel a[aria-current="page"] {
  color: var(--mint);
  box-shadow: inset 0 -2px 0 var(--mint);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 0.48rem 0.95rem !important;
  background: var(--mint);
  color: #082018 !important;
  font-weight: 700;
  transform: skewX(-14deg);
  box-shadow: 6px 6px 0 var(--mint-deep);
}

.nav-cta span,
.iso-cta span {
  display: inline-block;
  transform: skewX(14deg);
}

.nav-cta:hover {
  color: #082018 !important;
  background: var(--amber);
  box-shadow: 6px 6px 0 #b8742a;
}

.hero,
.page-hero {
  position: relative;
  padding: 3.2rem 0 2.4rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 460px);
  gap: 2.4rem;
  align-items: center;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 1rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.22rem 0.62rem;
  border: 1px solid var(--line);
  background: rgba(22, 50, 70, 0.8);
  color: var(--mint);
  font-size: 0.78rem;
  transform: skewX(-10deg);
}

.tag.alt {
  color: var(--amber);
}

.hero h1,
.page-hero h1,
.section-head h2,
.detail h2 {
  margin: 0 0 0.7rem;
  line-height: 1.2;
  letter-spacing: 0.01em;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
}

.lead {
  margin: 0 0 1.25rem;
  color: #cfe7e2;
  max-width: 58ch;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin: 1.2rem 0 1.5rem;
}

.iso-cta,
.button,
.button-alt {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0.7rem 1.2rem;
  text-decoration: none;
  font-weight: 700;
}

.iso-cta {
  position: relative;
  background: var(--mint);
  color: #082018;
  transform: skewX(-14deg) rotateX(12deg);
  box-shadow: 8px 8px 0 var(--mint-deep), 14px 14px 0 #0a241f;
}

.iso-cta:hover {
  color: #082018;
  background: #63edd2;
}

.button {
  background: var(--panel-2);
  color: var(--ink);
  transform: skewX(-10deg);
  box-shadow: 6px 6px 0 #0a1d28;
}

.button:hover,
.button-alt:hover {
  color: var(--ink);
}

.button-alt {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
  transform: skewX(-10deg);
}

.button > span,
.button-alt > span {
  transform: skewX(10deg);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.metric {
  padding: 0.85rem 0.9rem;
  background: var(--panel);
  box-shadow: 8px 10px 0 #061018;
}

.metric strong,
.kicker,
.platform .kicker {
  display: block;
  color: var(--mint);
}

.metric span {
  color: var(--muted);
  font-size: 0.86rem;
}

.iso-stage {
  position: relative;
  min-height: 380px;
  perspective: 980px;
}

.iso-floor {
  position: absolute;
  inset: 18% 8% 8%;
  background:
    repeating-linear-gradient(90deg, rgba(62, 224, 196, 0.12) 0 1px, transparent 1px 28px),
    repeating-linear-gradient(0deg, rgba(62, 224, 196, 0.12) 0 1px, transparent 1px 28px),
    linear-gradient(180deg, #163246, #0c2232);
  transform: rotateX(68deg);
  transform-origin: center bottom;
  border: 1px solid var(--line);
}

.node-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.iso-pc {
  position: relative;
  z-index: 2;
  width: min(100%, 360px);
  margin: 1.2rem auto 0;
  transform: rotateY(-16deg) rotateX(8deg);
  transform-style: preserve-3d;
}

.iso-screen {
  background: #0a1a26;
  border: 8px solid #21475c;
  box-shadow:
    16px 18px 0 #071018,
    0 0 0 2px #2d6a7a;
}

.iso-screen img {
  width: 100%;
  aspect-ratio: 880 / 700;
  object-fit: cover;
}

.iso-neck,
.iso-base,
.iso-keys {
  margin: 0 auto;
  background: linear-gradient(180deg, #2a5a6e, #163246);
  box-shadow: 8px 8px 0 #071018;
}

.iso-neck {
  width: 36px;
  height: 22px;
}

.iso-base {
  width: 120px;
  height: 14px;
  transform: skewX(-28deg);
}

.iso-keys {
  width: 190px;
  height: 18px;
  margin-top: 10px;
  transform: skewX(-32deg);
  background:
    repeating-linear-gradient(90deg, #2d6176 0 10px, #1a3d4d 10px 12px),
    #2d6176;
}

.cube {
  --s: 42px;
  position: absolute;
  width: var(--s);
  height: calc(var(--s) * 0.86);
  transform-style: preserve-3d;
  animation: float-cube 6s ease-in-out infinite;
}

.cube span {
  position: absolute;
  width: var(--s);
  height: var(--s);
}

.cube .top {
  background: var(--mint);
  transform: rotateX(90deg) translateZ(calc(var(--s) / 2));
}

.cube .left {
  background: var(--mint-mid);
  transform: rotateY(-90deg) translateZ(calc(var(--s) / 2));
}

.cube .right {
  background: var(--mint-deep);
  transform: rotateY(0deg) translateZ(calc(var(--s) / 2));
}

.cube.amber .top { background: var(--amber); }
.cube.amber .left { background: #e8963a; }
.cube.amber .right { background: #b8742a; }

.cube.sky .top { background: var(--sky); }
.cube.sky .left { background: #3aa0d8; }
.cube.sky .right { background: #2478b0; }

.c1 { top: 18px; left: 8px; animation-delay: 0s; }
.c2 { top: 36px; right: 18px; animation-delay: 0.8s; }
.c3 { bottom: 48px; left: 28px; animation-delay: 1.4s; }
.c4 { bottom: 28px; right: 8px; animation-delay: 2s; }

@keyframes float-cube {
  0%, 100% { transform: translateY(0) rotateX(18deg) rotateY(-24deg); }
  50% { transform: translateY(-8px) rotateX(18deg) rotateY(-16deg); }
}

section {
  padding: 2.6rem 0;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: end;
  margin-bottom: 1.3rem;
}

.section-head p {
  margin: 0;
  max-width: 42ch;
  color: var(--muted);
}

.grid-4,
.grid-3,
.grid-2 {
  display: grid;
  gap: 1rem;
}

.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.seo-card,
.card,
.platform,
.step {
  position: relative;
  padding: 1.1rem 1.05rem 1.15rem;
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  color: inherit;
  text-decoration: none;
  box-shadow: 10px 12px 0 #061018;
}

.seo-card::before,
.card::before,
.platform::before,
.step::before {
  content: "";
  position: absolute;
  inset: auto 10px -8px 0;
  height: 8px;
  background: var(--mint-deep);
  transform: skewX(-38deg);
}

.seo-card:hover,
.card:hover,
.platform:hover {
  transform: translate(-2px, -2px);
}

.seo-card h3,
.card h3,
.platform h3,
.step h3,
.detail h2 {
  margin: 0.2rem 0 0.45rem;
}

.seo-card p,
.card p,
.platform p,
.step p {
  margin: 0;
  color: #c7ddd8;
}

.kicker {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.iso-icon {
  width: 48px;
  height: 42px;
  margin-bottom: 0.55rem;
  color: var(--mint);
}

.detail {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 1.6rem;
  align-items: center;
}

.figure {
  background: var(--panel);
  padding: 0.7rem;
  box-shadow: 14px 16px 0 #061018;
  transform: rotateY(-6deg) rotateX(4deg);
}

.figure img {
  width: 100%;
  aspect-ratio: 880 / 700;
  object-fit: cover;
}

.anno {
  margin: 0 0 0.55rem;
  padding-left: 0.8rem;
  border-left: 3px solid var(--mint);
  color: var(--muted);
}

.iso-module {
  padding-top: 1.4rem;
}

.iso-module .lid {
  height: 14px;
  margin: 0 10px -1px;
  background: var(--mint);
  transform: skewX(-32deg);
}

.iso-module.win .lid { background: var(--sky); }
.iso-module.mac .lid { background: var(--amber); }
.iso-module.lin .lid { background: #9ad07a; }
.iso-module.and .lid { background: var(--rose); }

.faq details {
  margin-bottom: 0.7rem;
  background: var(--panel);
  box-shadow: 8px 8px 0 #061018;
}

.faq summary {
  cursor: pointer;
  padding: 0.9rem 1rem;
  font-weight: 700;
  list-style: none;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  float: right;
  color: var(--mint);
}

.faq details[open] summary::after {
  content: "–";
}

.faq details p {
  margin: 0;
  padding: 0 1rem 1rem;
  color: #c7ddd8;
}

.warn {
  margin: 1.2rem 0;
  padding: 0.85rem 1rem;
  background: rgba(255, 180, 92, 0.1);
  border-left: 4px solid var(--amber);
}

.crumbs {
  color: var(--muted);
}

.crumbs a {
  color: var(--ink);
}

footer {
  padding: 2.4rem 0 1.4rem;
  border-top: 1px solid var(--line);
  background: rgba(7, 20, 31, 0.92);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 1.4rem;
}

.logo-block {
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  margin-bottom: 0.7rem;
}

footer h3 {
  margin: 0 0 0.55rem;
  font-size: 1rem;
}

footer ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

footer li {
  margin-bottom: 0.35rem;
}

footer p {
  color: var(--muted);
}

.legal {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.4rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.86rem;
}

@media (max-width: 980px) {
  .hero,
  .detail,
  .footer-grid,
  .grid-4,
  .metrics {
    grid-template-columns: 1fr 1fr;
  }

  .grid-3 {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav-panel {
    display: none;
    position: absolute;
    left: 1rem;
    right: 1rem;
    top: calc(100% + 6px);
    padding: 0.8rem;
    background: var(--panel);
    box-shadow: 8px 10px 0 #061018;
  }

  .nav-panel.is-open {
    display: block;
  }

  .nav-panel ul {
    flex-direction: column;
    align-items: stretch;
  }

  .hero,
  .detail,
  .footer-grid,
  .grid-4,
  .grid-3,
  .grid-2,
  .metrics {
    grid-template-columns: 1fr;
  }

  .section-head,
  .topbar-inner,
  .legal {
    flex-direction: column;
  }

  .iso-stage {
    min-height: 300px;
  }
}

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

  .cube,
  .iso-cta,
  .seo-card,
  .card,
  .platform,
  .iso-pc,
  .figure {
    animation: none !important;
    transition: none !important;
  }

  .iso-cta,
  .button,
  .button-alt,
  .nav-cta,
  .tag,
  .iso-base,
  .iso-keys {
    transform: none;
  }

  .iso-cta span,
  .button span,
  .button-alt span,
  .nav-cta span {
    transform: none;
  }

  .seo-card:hover,
  .card:hover,
  .platform:hover {
    transform: none;
  }
}