:root {
  --bg: #e9ecef;
  --ink: #2b3038;
  --muted: #6b7280;
  --line: #cfd4db;
  --panel: #f6f7f9;
  --card: #ffffff;
  --accent: #5b6b7c;
  --accent-2: #6e7f91;
  --ok: #5f8f73;
  --warn: #b0894a;
  --shadow: 0 10px 28px rgba(43, 48, 56, 0.08);
  --radius: 12px;
  --font-display: "Segoe UI Variable", "Bahnschrift", "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(180deg, #eef1f4 0%, var(--bg) 40%, #e6eaee 100%);
  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(246, 247, 249, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.nav {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-weight: 700;
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #f4f6f8;
  background: linear-gradient(145deg, #6a7685, #4d5866);
  box-shadow: var(--shadow);
}

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

.nav-links {
  display: flex;
  gap: 0.15rem;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 0.42rem 0.72rem;
  border-radius: 8px;
  color: var(--muted);
  font-size: 0.94rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
}

.lang-switch {
  display: flex;
  gap: 0.25rem;
  padding: 0.2rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.lang-switch button {
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 0.28rem 0.6rem;
  border-radius: 6px;
}

.lang-switch button.active {
  background: #5a6674;
  color: #fff;
}

.hero {
  padding: 2.2rem 0 2.4rem;
}

.banner {
  border: 1px solid var(--line);
  border-radius: 18px;
  overflow: hidden;
  background:
    linear-gradient(120deg, rgba(90, 102, 116, 0.12), transparent 40%),
    linear-gradient(180deg, #f8f9fb, #eef1f4);
  box-shadow: var(--shadow);
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  min-height: 420px;
}

.banner-copy {
  padding: 2.2rem 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 0.9rem;
}

.tag {
  padding: 0.24rem 0.62rem;
  border-radius: 6px;
  border: 1px solid #c8ced6;
  background: #f0f2f5;
  color: #5a6674;
  font-size: 0.8rem;
  font-weight: 700;
}

.hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 3.6vw, 2.8rem);
  line-height: 1.18;
  letter-spacing: -0.02em;
}

.hero h1 em {
  font-style: normal;
  color: #4d5866;
}

.hero-lead {
  margin: 0.95rem 0 1.25rem;
  color: var(--muted);
  font-size: 1.02rem;
  max-width: 34rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-bottom: 1.2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0.6rem 1.05rem;
  border-radius: 9px;
  border: 1px solid transparent;
  font-weight: 650;
  transition: transform .15s ease, box-shadow .15s ease;
}

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

.btn-primary {
  color: #fff;
  background: linear-gradient(180deg, #6a7685, #525e6c);
  box-shadow: 0 8px 18px rgba(82, 94, 108, 0.22);
}

.btn-secondary {
  color: var(--ink);
  background: #fff;
  border-color: var(--line);
}

.trust-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.65rem;
}

.trust-item {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.75rem 0.8rem;
}

.trust-item strong {
  display: block;
  font-size: 1rem;
}

.trust-item span {
  color: var(--muted);
  font-size: 0.82rem;
}

.banner-visual {
  position: relative;
  min-height: 100%;
  background:
    linear-gradient(160deg, #6a7685 0%, #4d5866 45%, #3d4652 100%);
  display: grid;
  place-items: center;
  padding: 1.4rem;
}

.banner-visual::before {
  content: "";
  position: absolute;
  inset: 12%;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 16px;
}

.banner-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0 48%, rgba(255, 255, 255, 0.05) 50%, transparent 52%),
    linear-gradient(0deg, transparent 0 48%, rgba(255, 255, 255, 0.05) 50%, transparent 52%);
  background-size: 28px 28px;
  opacity: 0.35;
}

.banner-visual img {
  width: min(280px, 80%);
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  position: relative;
  z-index: 1;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.28);
}

.banner-caption {
  position: absolute;
  bottom: 1.4rem;
  left: 1.4rem;
  right: 1.4rem;
  z-index: 1;
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.84rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.section { padding: 3rem 0; }

.section-head {
  margin-bottom: 1.3rem;
  max-width: 42rem;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: #5a6674;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 0.45rem;
}

.section-kicker::before {
  content: "";
  width: 14px;
  height: 2px;
  background: #5a6674;
}

.section-head h2 {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.4vw, 1.95rem);
}

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

.platform-grid,
.feature-grid,
.compat-grid,
.recommend-grid,
.scene-grid,
.faq-grid {
  display: grid;
  gap: 0.9rem;
}

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

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

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

.platform-card,
.feature-card,
.recommend-card,
.step-card,
.scene-card,
.faq-item,
.compat-item,
.docs-panel {
  padding: 1.05rem 1.1rem;
}

.platform-card h3,
.feature-card h3,
.recommend-card h3,
.step-card h3,
.scene-card h3,
.faq-item h3,
.compat-item h3,
.docs-panel h3,
.download-card h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
}

.platform-card p,
.feature-card p,
.recommend-card p,
.step-card p,
.scene-card p,
.faq-item p,
.compat-item p,
.docs-panel p,
.download-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.os-badge,
.badge,
.step-label,
.feature-index,
.compat-dot,
.status {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.os-badge,
.badge {
  color: #5a6674;
  background: #eef1f4;
  border: 1px solid #d5dae1;
  margin-bottom: 0.55rem;
}

.feature-index {
  color: #fff;
  background: linear-gradient(180deg, #6a7685, #525e6c);
  margin-bottom: 0.6rem;
}

.meta-list {
  list-style: none;
  margin: 0.65rem 0 0.95rem;
  padding: 0;
  display: grid;
  gap: 0.3rem;
}

.meta-list li {
  color: var(--muted);
  font-size: 0.9rem;
  padding-left: 0.85rem;
  position: relative;
}

.meta-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 1px;
  background: #7a8796;
}

.how-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}

.flow-panel,
.preview-panel {
  padding: 1.1rem;
}

.flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.8rem;
}

.flow-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.75rem;
  align-items: start;
}

.flow-num {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #fff;
  font-weight: 700;
  background: linear-gradient(180deg, #6a7685, #525e6c);
}

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

.flow-list p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.preview-panel img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 10px;
  border: 1px solid var(--line);
  margin-bottom: 0.8rem;
  filter: saturate(0.75);
}

.code-box {
  margin: 0;
  padding: 0.9rem 1rem;
  border-radius: 10px;
  background: #2b3038;
  color: #d7dde6;
  font-size: 0.82rem;
  overflow: auto;
  line-height: 1.55;
}

.ability-row {
  margin-top: 0.95rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.ability-row span {
  padding: 0.4rem 0.72rem;
  border-radius: 8px;
  background: #fff;
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 0.86rem;
  font-weight: 600;
}

.compat-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  align-items: start;
}

.compat-dot {
  color: #fff;
  background: linear-gradient(180deg, #6a7685, #525e6c);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.9rem;
}

.step-label {
  color: #5a6674;
  background: #eef1f4;
  border: 1px solid #d5dae1;
  margin-bottom: 0.55rem;
}

.hint-box {
  margin-top: 0.95rem;
  padding: 0.95rem 1.05rem;
  border-left: 4px solid var(--warn);
}

.hint-box strong {
  display: block;
  margin-bottom: 0.25rem;
}

.hint-box p {
  margin: 0;
  color: var(--muted);
}

.inline-img {
  margin-top: 1.1rem;
  width: 100%;
  max-height: 270px;
  object-fit: cover;
  border-radius: 12px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  filter: saturate(0.8);
}

.cta-band {
  margin: 0.4rem 0 2.8rem;
  padding: 1.8rem;
  border-radius: 14px;
  border: 1px solid var(--line);
  background:
    linear-gradient(135deg, #f8f9fb, #e9eef3);
  box-shadow: var(--shadow);
  text-align: center;
}

.cta-band h2 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
}

.cta-band p {
  margin: 0 0 1rem;
  color: var(--muted);
}

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

.site-footer {
  background: #2b3038;
  color: #d5dae3;
  padding: 2.4rem 0 1.3rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 1.1rem;
}

.site-footer h3,
.site-footer h4 {
  margin: 0 0 0.65rem;
  color: #fff;
  font-family: var(--font-display);
}

.site-footer p,
.site-footer li {
  color: #9aa3b0;
  font-size: 0.9rem;
}

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.32rem;
}

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

.footer-bottom {
  margin-top: 1.5rem;
  padding-top: 0.95rem;
  border-top: 1px solid rgba(154, 163, 176, 0.25);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.86rem;
  color: #87909d;
}

.page-hero {
  padding: 2.4rem 0 0.9rem;
}

.page-hero h1 {
  margin: 0.35rem 0 0.65rem;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3vw, 2.35rem);
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 42rem;
}

.download-list {
  display: grid;
  gap: 0.85rem;
}

.download-card {
  display: grid;
  grid-template-columns: 1.3fr 1fr auto;
  gap: 0.95rem;
  align-items: center;
  padding: 1.05rem 1.15rem;
}

.status {
  color: var(--ok);
  background: #eaf3ee;
  border: 1px solid #c9ddd2;
  margin-bottom: 0.4rem;
}

.tutorial-layout { display: grid; gap: 0.9rem; }

@media (max-width: 960px) {
  .banner,
  .how-grid,
  .download-card,
  .footer-grid {
    grid-template-columns: 1fr;
  }

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

  .nav-links { display: none; }
  .banner-visual { min-height: 280px; }
}

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

  .cta-band,
  .banner-copy { padding: 1.3rem; }
  .download-card { grid-template-columns: 1fr; }
}