:root {
  --bg: #eef5ff;
  --ink: #16324f;
  --muted: #5d7894;
  --blue: #2f7de1;
  --blue-2: #4ea1ff;
  --blue-3: #1f5fad;
  --sky: #9ed0ff;
  --ok: #2f9e7a;
  --panel: #ffffff;
  --line: #cfe0f5;
  --shadow: 0 16px 34px rgba(47, 125, 225, 0.12);
  --radius: 20px;
  --font-display: "Segoe UI Variable", "Trebuchet MS", "PingFang SC", "Microsoft YaHei UI", sans-serif;
  --font-body: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-body);
  background:
    linear-gradient(135deg, rgba(78, 161, 255, 0.08) 25%, transparent 25%) 0 0 / 28px 28px,
    linear-gradient(225deg, rgba(78, 161, 255, 0.08) 25%, transparent 25%) 0 0 / 28px 28px,
    radial-gradient(circle at 12% 0%, rgba(158, 208, 255, 0.45), transparent 30%),
    var(--bg);
  line-height: 1.65;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; cursor: pointer; }

.container {
  width: min(1140px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(238, 245, 255, 0.9);
  border-bottom: 1px solid rgba(207, 224, 245, 0.9);
  backdrop-filter: blur(10px);
}

.nav {
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-display);
  font-weight: 700;
}

.logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  color: #fff;
  background: linear-gradient(145deg, var(--blue-2), var(--blue));
  box-shadow: 6px 8px 0 rgba(47, 125, 225, 0.18);
  font-size: 0.78rem;
}

.logo-text span { color: var(--blue); }

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.05rem;
  color: var(--muted);
}

.nav-links a:hover,
.nav-links a.active { color: var(--blue); font-weight: 700; }

.lang-switch {
  display: flex;
  gap: 0.25rem;
  padding: 0.22rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
}

.lang-switch button {
  border: 0;
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  padding: 0.32rem 0.72rem;
}

.lang-switch button.active {
  background: #e7f1ff;
  color: var(--blue);
}

.hero {
  position: relative;
  padding: 3.6rem 0 2.6rem;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2rem;
  align-items: center;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tag {
  display: inline-flex;
  padding: 0.3rem 0.72rem;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.84rem;
  box-shadow: 3px 4px 0 rgba(47, 125, 225, 0.08);
}

.hero h1 {
  margin: 0 0 0.9rem;
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.2vw, 3.15rem);
  line-height: 1.18;
  max-width: 14ch;
}

.hero h1 em {
  font-style: normal;
  color: var(--blue);
}

.hero-lead {
  margin: 0 0 1.35rem;
  color: var(--muted);
  max-width: 40rem;
  font-size: 1.04rem;
}

.hero-actions,
.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-bottom: 1.35rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.7rem 1.25rem;
  border-radius: 14px;
  border: 1px solid transparent;
  font-family: var(--font-display);
  font-weight: 700;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

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

.btn-primary {
  background: linear-gradient(180deg, var(--blue-2), var(--blue));
  color: #fff;
  box-shadow: 0 10px 0 #1f5fad, 0 16px 28px rgba(47, 125, 225, 0.25);
}

.btn-secondary {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
  box-shadow: 0 8px 0 rgba(47, 125, 225, 0.1);
}

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

.trust-item {
  padding: 0.9rem 1rem;
  border-radius: 16px;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.trust-item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.1rem;
}

.trust-item span {
  color: var(--muted);
  font-size: 0.85rem;
}

.iso-stage {
  position: relative;
  min-height: 420px;
  display: grid;
  place-items: center;
}

.iso-world {
  position: relative;
  width: min(100%, 420px);
  aspect-ratio: 1;
  transform: rotateX(58deg) rotateZ(-40deg);
  transform-style: preserve-3d;
}

.iso-floor {
  position: absolute;
  inset: 12%;
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(78, 161, 255, 0.18) 25%, transparent 25%) 0 0 / 24px 24px,
    linear-gradient(225deg, rgba(78, 161, 255, 0.18) 25%, transparent 25%) 0 0 / 24px 24px,
    #dcecff;
  box-shadow: 0 30px 40px rgba(47, 125, 225, 0.18);
}

.iso-block {
  position: absolute;
  width: 110px;
  height: 110px;
  border-radius: 18px;
  background: linear-gradient(145deg, #7bb8ff, var(--blue));
  box-shadow:
    14px 14px 0 rgba(31, 95, 173, 0.25),
    inset -8px -8px 0 rgba(0, 0, 0, 0.08),
    inset 8px 8px 0 rgba(255, 255, 255, 0.18);
  display: grid;
  place-items: end start;
  padding: 0.7rem;
  color: #fff;
  font-family: var(--font-display);
  font-size: 0.78rem;
  animation: isoFloat 6s ease-in-out infinite;
}

.iso-block:nth-child(2) { top: 18%; left: 22%; animation-delay: 0s; }
.iso-block:nth-child(3) {
  top: 34%;
  right: 16%;
  width: 92px;
  height: 92px;
  background: linear-gradient(145deg, #a8d4ff, #4ea1ff);
  animation-delay: 0.4s;
}
.iso-block:nth-child(4) {
  bottom: 18%;
  left: 30%;
  width: 84px;
  height: 84px;
  background: linear-gradient(145deg, #ffe1b8, #f0a35a);
  animation-delay: 0.8s;
}

.iso-media {
  position: absolute;
  inset: 24% 18% 28% 28%;
  border-radius: 22px;
  overflow: hidden;
  border: 4px solid #fff;
  box-shadow: 12px 16px 0 rgba(47, 125, 225, 0.16);
  transform: translateZ(40px);
  z-index: 2;
}

.iso-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.section { padding: 3.4rem 0; }

.section-head {
  margin-bottom: 1.5rem;
  max-width: 46rem;
}

.section-kicker {
  display: inline-flex;
  margin-bottom: 0.5rem;
  padding: 0.28rem 0.75rem;
  border-radius: 999px;
  background: #e7f1ff;
  color: var(--blue);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.86rem;
}

.section-head h2 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 2.8vw, 2.15rem);
  line-height: 1.25;
}

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

.platform-grid,
.feature-grid,
.recommend-grid,
.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.compat-grid,
.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.platform-card,
.feature-card,
.recommend-card,
.scene-card,
.faq-item,
.step-card,
.compat-item,
.hint-box,
.docs-panel,
.download-card,
.flow-panel,
.preview-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.platform-card,
.feature-card,
.recommend-card,
.scene-card,
.faq-item,
.step-card,
.compat-item,
.hint-box,
.docs-panel,
.flow-panel,
.preview-panel {
  padding: 1.2rem 1.25rem;
}

.platform-card,
.feature-card,
.recommend-card {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.platform-card:hover,
.feature-card:hover,
.recommend-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 36px rgba(47, 125, 225, 0.16);
}

.platform-card h3,
.feature-card h3,
.recommend-card h3,
.scene-card h3,
.faq-item h3,
.step-card h3,
.docs-panel h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.12rem;
}

.platform-card p,
.feature-card p,
.recommend-card p,
.scene-card p,
.faq-item p,
.step-card p,
.compat-item p,
.hint-box p,
.docs-panel p,
.download-card p {
  margin: 0;
  color: var(--muted);
}

.meta-list {
  list-style: none;
  margin: 0.8rem 0 1rem;
  padding: 0;
  display: grid;
  gap: 0.4rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.meta-list li {
  display: flex;
  gap: 0.45rem;
}

.meta-list li::before {
  content: "◆";
  color: var(--blue-2);
  font-size: 0.65rem;
  margin-top: 0.35rem;
}

.os-badge {
  display: inline-flex;
  margin-bottom: 0.7rem;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  background: #e7f1ff;
  color: var(--blue);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.8rem;
}

.feature-index {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  margin-bottom: 0.75rem;
  background: linear-gradient(145deg, #dcecff, #b9d8ff);
  color: var(--blue);
  font-family: var(--font-display);
  font-weight: 700;
  box-shadow: 4px 5px 0 rgba(47, 125, 225, 0.12);
}

.how-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.flow-list li {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 0.8rem;
}

.flow-num {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(145deg, var(--blue-2), var(--blue));
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  box-shadow: 4px 6px 0 rgba(31, 95, 173, 0.2);
}

.flow-list h3 {
  margin: 0 0 0.25rem;
  font-size: 1.02rem;
  font-family: var(--font-display);
}

.flow-list p {
  margin: 0;
  color: var(--muted);
}

.preview-panel img {
  border-radius: 16px;
  border: 1px solid var(--line);
  margin-bottom: 0.85rem;
}

.code-box {
  margin: 0;
  padding: 0.95rem 1rem;
  border-radius: 14px;
  background: #16324f;
  color: #d7ecff;
  font-size: 0.84rem;
  overflow-x: auto;
  line-height: 1.55;
}

.ability-row {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.ability-row span {
  display: block;
  padding: 0.85rem 0.95rem;
  border-radius: 14px;
  background: #fff;
  border: 1px dashed #b9d4f2;
  color: var(--muted);
  font-size: 0.9rem;
}

.compat-item {
  display: grid;
  grid-template-columns: 50px 1fr;
  gap: 0.85rem;
  align-items: start;
}

.compat-dot {
  width: 50px;
  height: 50px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  background: #e7f1ff;
  color: var(--blue);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.74rem;
  box-shadow: 4px 5px 0 rgba(47, 125, 225, 0.1);
}

.recommend-card .badge {
  display: inline-flex;
  margin-bottom: 0.65rem;
  padding: 0.22rem 0.65rem;
  border-radius: 999px;
  background: #e8f8f1;
  color: var(--ok);
  font-size: 0.8rem;
  font-weight: 700;
}

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

.step-label {
  display: inline-block;
  margin-bottom: 0.55rem;
  color: var(--blue);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.86rem;
}

.hint-box {
  border-color: #f0d3a8;
  background: #fff9f0;
}

.hint-box strong {
  display: block;
  margin-bottom: 0.4rem;
  color: #c47b1a;
  font-family: var(--font-display);
}

.scene-card { min-height: 150px; }

.cta-band {
  margin: 0.5rem 0 3rem;
  padding: 2.3rem;
  border-radius: 28px;
  text-align: center;
  background: linear-gradient(135deg, #2f7de1, #4ea1ff 55%, #7bb8ff);
  color: #fff;
  box-shadow: 0 18px 36px rgba(47, 125, 225, 0.28);
}

.cta-band h2 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.8vw, 2.05rem);
}

.cta-band p {
  margin: 0 auto 1.2rem;
  max-width: 34rem;
  color: rgba(255, 255, 255, 0.92);
}

.cta-band .btn-primary {
  background: #fff;
  color: var(--blue);
  box-shadow: 0 8px 0 rgba(20, 70, 140, 0.18);
}

.cta-band .btn-secondary {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.45);
  color: #fff;
  box-shadow: none;
}

.cta-actions { justify-content: center; margin-bottom: 0; }

.site-footer {
  background: #16324f;
  color: #d7e6f7;
  padding: 2.8rem 0 1.3rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.35fr repeat(4, 1fr);
  gap: 1.1rem;
  margin-bottom: 1.5rem;
}

.site-footer h3,
.site-footer h4 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  color: #fff;
}

.site-footer p,
.site-footer li,
.site-footer a { color: #a9c0d8; }

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}

.site-footer a:hover { color: #fff; }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: #8eabc6;
  font-size: 0.9rem;
}

.page-hero {
  padding: 2.9rem 0 1rem;
}

.page-hero h1 {
  margin: 0 0 0.7rem;
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3.2vw, 2.45rem);
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 46rem;
}

.download-list {
  display: grid;
  gap: 0.9rem;
}

.download-card {
  display: grid;
  grid-template-columns: 1.25fr 1fr auto;
  gap: 1rem;
  align-items: center;
  padding: 1.2rem 1.3rem;
}

.download-card h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--ok);
  font-weight: 700;
  font-size: 0.88rem;
}

.status::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ok);
}

.inline-img {
  border-radius: 18px;
  border: 1px solid var(--line);
  margin: 1rem 0;
  box-shadow: var(--shadow);
}

.tutorial-layout { display: grid; gap: 1rem; }

@keyframes isoFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@media (max-width: 980px) {
  .hero-grid,
  .how-grid,
  .download-card,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .iso-world { transform: rotateX(56deg) rotateZ(-36deg) scale(0.92); }

  .platform-grid,
  .feature-grid,
  .recommend-grid,
  .scene-grid,
  .steps,
  .ability-row {
    grid-template-columns: 1fr 1fr;
  }

  .nav-links { display: none; }
}

@media (max-width: 640px) {
  .platform-grid,
  .feature-grid,
  .recommend-grid,
  .scene-grid,
  .steps,
  .ability-row,
  .compat-grid,
  .faq-grid,
  .trust-row {
    grid-template-columns: 1fr;
  }

  .cta-band { padding: 1.5rem; }
  .iso-stage { min-height: 320px; }
}