:root {
  --bg: #07111f;
  --bg-2: #0c1a2e;
  --surface: rgba(15, 36, 64, 0.72);
  --ink: #e8f1ff;
  --muted: #93a7c2;
  --line: rgba(120, 170, 230, 0.18);
  --brand: #2dd4bf;
  --brand-2: #38bdf8;
  --gold: #fbbf24;
  --danger: #f87171;
  --shadow: 0 18px 42px rgba(0, 0, 0, 0.35);
  --radius: 18px;
  --radius-sm: 12px;
  --max: 1140px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(900px 480px at 8% -10%, rgba(45, 212, 191, 0.14), transparent 55%),
    radial-gradient(700px 420px at 92% 0%, rgba(56, 189, 248, 0.12), transparent 50%),
    linear-gradient(180deg, #06101c 0%, #07111f 45%, #0a1628 100%);
  line-height: 1.65;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { margin: 0; padding: 0; list-style: none; }
button { font: inherit; }

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(7, 17, 31, 0.82);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 74px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo-mark {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 30% 25%, #ffffff 0%, transparent 28%),
    linear-gradient(160deg, #5eead4, #0ea5e9);
  box-shadow: 0 10px 24px rgba(45, 212, 191, 0.28);
  position: relative;
}

.logo-mark::before {
  content: "";
  width: 16px;
  height: 18px;
  background: #062018;
  clip-path: polygon(50% 0%, 100% 14%, 88% 78%, 50% 100%, 12% 78%, 0% 14%);
}

.logo-mark::after {
  content: "";
  position: absolute;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #5eead4;
  top: 18px;
}

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

.nav-links {
  display: flex;
  gap: 0.3rem;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.94rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ink);
  background: rgba(45, 212, 191, 0.1);
  border: 1px solid rgba(45, 212, 191, 0.28);
}

.lang-switch {
  display: inline-flex;
  padding: 0.2rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255,255,255,0.03);
}

.lang-switch button {
  border: 0;
  background: transparent;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
}

.lang-switch button.active {
  color: #062018;
  background: linear-gradient(135deg, #5eead4, #38bdf8);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 48px;
  padding: 0.75rem 1.25rem;
  border-radius: 14px;
  border: 1px solid transparent;
  font-weight: 700;
  transition: transform .2s ease, box-shadow .2s ease, filter .2s ease;
}

.btn:hover { transform: translateY(-1px); filter: brightness(1.05); }

.btn-primary {
  color: #042f2e;
  background: linear-gradient(135deg, #5eead4, #38bdf8);
  box-shadow: 0 14px 28px rgba(45, 212, 191, 0.25);
}

.btn-secondary {
  color: var(--ink);
  background: rgba(255,255,255,0.03);
  border-color: rgba(148, 197, 255, 0.22);
}

.hero {
  padding: 3.4rem 0 2.2rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 1.6rem;
  align-items: center;
}

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

.tag {
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 700;
  color: #99f6e4;
  background: rgba(45, 212, 191, 0.1);
  border: 1px solid rgba(45, 212, 191, 0.28);
}

.hero h1 {
  margin: 0 0 0.9rem;
  font-size: clamp(2rem, 4vw, 3.15rem);
  line-height: 1.14;
  letter-spacing: -0.03em;
}

.hero h1 em {
  font-style: normal;
  background: linear-gradient(120deg, #5eead4, #38bdf8 55%, #fbbf24);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-lead {
  margin: 0 0 1.4rem;
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 54ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.4rem;
}

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

.trust-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.85rem 0.95rem;
  box-shadow: var(--shadow);
}

.trust-item strong {
  display: block;
  font-size: 1.05rem;
}

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

.shield-stage {
  position: relative;
  min-height: 440px;
  border-radius: 28px;
  padding: 1.25rem;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 18%, rgba(94, 234, 212, 0.18), transparent 40%),
    linear-gradient(160deg, rgba(15, 42, 74, 0.95), rgba(8, 20, 36, 0.98));
  border: 1px solid rgba(94, 234, 212, 0.25);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.08),
    var(--shadow);
}

.shield {
  position: absolute;
  width: 210px;
  height: 240px;
  left: 50%;
  top: 42px;
  transform: translateX(-50%);
  background:
    linear-gradient(160deg, rgba(94, 234, 212, 0.35), rgba(56, 189, 248, 0.2) 45%, rgba(15, 42, 74, 0.9));
  clip-path: polygon(50% 0%, 100% 14%, 88% 78%, 50% 100%, 12% 78%, 0% 14%);
  border: 0;
  box-shadow: 0 0 40px rgba(45, 212, 191, 0.25);
  animation: shield-pulse 4.5s ease-in-out infinite;
}

.shield::before {
  content: "";
  position: absolute;
  inset: 14px 18px 22px;
  background: linear-gradient(160deg, rgba(255,255,255,0.16), rgba(15, 42, 74, 0.55));
  clip-path: polygon(50% 0%, 100% 14%, 88% 78%, 50% 100%, 12% 78%, 0% 14%);
}

.lock {
  position: absolute;
  z-index: 2;
  left: 50%;
  top: 118px;
  transform: translateX(-50%);
  width: 54px;
  height: 54px;
}

.lock-body {
  position: absolute;
  left: 8px;
  top: 20px;
  width: 38px;
  height: 30px;
  border-radius: 8px;
  background: linear-gradient(180deg, #fbbf24, #d97706);
  box-shadow: 0 8px 18px rgba(251, 191, 36, 0.35);
}

.lock-body::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 10px;
  width: 8px;
  height: 10px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: #0f172a;
}

.lock-shackle {
  position: absolute;
  left: 14px;
  top: 4px;
  width: 26px;
  height: 24px;
  border: 5px solid #fde68a;
  border-bottom: 0;
  border-radius: 16px 16px 0 0;
}

.shield-rings {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.shield-rings span {
  position: absolute;
  left: 50%;
  top: 48%;
  border: 1px solid rgba(94, 234, 212, 0.22);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  animation: ring-spin 12s linear infinite;
}

.shield-rings .r1 { width: 220px; height: 220px; }
.shield-rings .r2 { width: 300px; height: 300px; animation-direction: reverse; opacity: 0.7; }
.shield-rings .r3 { width: 380px; height: 380px; opacity: 0.4; }

@keyframes shield-pulse {
  0%, 100% { filter: drop-shadow(0 0 10px rgba(45,212,191,0.25)); }
  50% { filter: drop-shadow(0 0 22px rgba(56,189,248,0.45)); }
}

@keyframes ring-spin {
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

.shield-stage img {
  position: absolute;
  left: 1.25rem;
  right: 1.25rem;
  bottom: 1.25rem;
  width: calc(100% - 2.5rem);
  height: 150px;
  object-fit: cover;
  border-radius: 16px;
  border: 1px solid rgba(148, 197, 255, 0.2);
  z-index: 3;
}

.shield-label {
  position: absolute;
  top: 1.1rem;
  left: 1.25rem;
  z-index: 3;
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #99f6e4;
}

.section { padding: 3.2rem 0; }

.section-head { margin-bottom: 1.4rem; }

.section-kicker {
  display: inline-block;
  margin-bottom: 0.45rem;
  color: var(--brand);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.section-head h2 {
  margin: 0 0 0.45rem;
  font-size: clamp(1.55rem, 2.5vw, 2.15rem);
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 60ch;
}

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

.platform-grid,
.feature-grid,
.recommend-grid,
.scene-grid,
.faq-grid,
.compat-grid {
  display: grid;
  gap: 1rem;
}

.platform-grid,
.feature-grid,
.recommend-grid,
.scene-grid,
.compat-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.faq-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.platform-card,
.feature-card,
.recommend-card,
.scene-card,
.faq-item,
.step-card,
.compat-item,
.docs-panel { padding: 1.15rem 1.2rem; }

.os-badge,
.badge,
.status,
.step-label,
.feature-index,
.compat-dot {
  display: inline-flex;
  align-items: center;
  padding: 0.22rem 0.65rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 800;
}

.os-badge,
.badge,
.step-label,
.feature-index {
  color: #99f6e4;
  background: rgba(45, 212, 191, 0.12);
  border: 1px solid rgba(45, 212, 191, 0.28);
}

.status {
  color: #064e3b;
  background: linear-gradient(135deg, #a7f3d0, #5eead4);
}

.compat-dot {
  color: #0c4a6e;
  background: linear-gradient(135deg, #bae6fd, #38bdf8);
  margin-bottom: 0.7rem;
}

.platform-card h3,
.feature-card h3,
.recommend-card h3,
.scene-card h3,
.faq-item h3,
.step-card h3,
.compat-item h3,
.docs-panel h3,
.download-card h3 {
  margin: 0.7rem 0 0.45rem;
  font-size: 1.08rem;
}

.meta-list {
  display: grid;
  gap: 0.35rem;
  margin: 0.7rem 0 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.meta-list li {
  padding-left: 0.9rem;
  position: relative;
}

.meta-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: linear-gradient(135deg, #5eead4, #38bdf8);
}

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

.feature-card {
  position: relative;
  overflow: hidden;
}

.feature-card::after {
  content: "";
  position: absolute;
  right: 1rem;
  top: 1rem;
  width: 12px;
  height: 14px;
  opacity: 0.35;
  background: linear-gradient(180deg, #5eead4, #38bdf8);
  clip-path: polygon(50% 0%, 100% 14%, 88% 78%, 50% 100%, 12% 78%, 0% 14%);
}

.inline-img {
  margin-top: 1.2rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  width: 100%;
  max-height: 280px;
  object-fit: cover;
}

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

.flow-panel,
.preview-panel { padding: 1.2rem; }

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

.flow-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  align-items: start;
}

.flow-num {
  width: 34px;
  height: 34px;
  border-radius: 11px;
  display: grid;
  place-items: center;
  color: #042f2e;
  font-weight: 800;
  background: linear-gradient(135deg, #5eead4, #38bdf8);
}

.flow-list h3 {
  margin: 0 0 0.2rem;
  font-size: 1rem;
}

.flow-list p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.preview-panel img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 14px;
  margin-bottom: 0.9rem;
  border: 1px solid var(--line);
}

.code-box {
  margin: 0;
  padding: 1rem;
  border-radius: 14px;
  background: #040b14;
  color: #dbeafe;
  font-size: 0.84rem;
  overflow: auto;
  line-height: 1.5;
  border: 1px solid rgba(148, 197, 255, 0.12);
}

.ability-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.ability-row span {
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

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

.hint-box {
  margin-top: 1rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.28);
  color: #fde68a;
}

.hint-box strong { display: block; margin-bottom: 0.35rem; }
.hint-box p { margin: 0; }

.page-hero { padding: 2.6rem 0 1rem; }

.page-hero h1 {
  margin: 0.35rem 0 0.7rem;
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  letter-spacing: -0.02em;
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 62ch;
}

.download-list { display: grid; gap: 1rem; }

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

.cta-band {
  margin: 1rem 0 3rem;
  padding: 2.1rem;
  border-radius: 28px;
  text-align: center;
  color: #042f2e;
  background:
    radial-gradient(circle at 20% 20%, rgba(255,255,255,0.35), transparent 35%),
    linear-gradient(135deg, #5eead4, #38bdf8 55%, #67e8f9);
  box-shadow: 0 24px 48px rgba(45, 212, 191, 0.22);
}

.cta-band h2 {
  margin: 0 0 0.45rem;
  font-size: clamp(1.5rem, 2.5vw, 2rem);
}

.cta-band p {
  margin: 0 0 1.1rem;
  opacity: 0.85;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  justify-content: center;
}

.cta-band .btn-primary {
  background: #0b1220;
  color: #e0f2fe;
  box-shadow: none;
}

.cta-band .btn-secondary {
  color: #0b1220;
  border-color: rgba(15, 23, 42, 0.25);
  background: rgba(255,255,255,0.35);
}

.site-footer {
  padding: 2.5rem 0 1.5rem;
  background: #040b14;
  border-top: 1px solid var(--line);
  color: #93a7c2;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 1.2rem;
}

.site-footer h3,
.site-footer h4 {
  margin: 0 0 0.7rem;
  color: #e8f1ff;
}

.site-footer p {
  margin: 0;
  font-size: 0.92rem;
}

.site-footer ul { display: grid; gap: 0.4rem; }
.site-footer a:hover { color: #fff; }

.footer-bottom {
  margin-top: 1.6rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(148, 163, 184, 0.18);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.88rem;
}

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

@media (max-width: 980px) {
  .hero-grid,
  .how-grid,
  .download-card { grid-template-columns: 1fr; }
  .platform-grid,
  .feature-grid,
  .recommend-grid,
  .scene-grid,
  .compat-grid,
  .steps,
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .nav-links { display: none; }
}

@media (max-width: 640px) {
  .trust-row,
  .platform-grid,
  .feature-grid,
  .recommend-grid,
  .scene-grid,
  .compat-grid,
  .faq-grid,
  .steps,
  .footer-grid { grid-template-columns: 1fr; }
  .shield-stage { min-height: 380px; }
}