:root {
  --bg: #eef2f7;
  --panel: #ffffff;
  --ink: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --sidebar: #111827;
  --sidebar-ink: #d1d5db;
  --brand: #2563eb;
  --brand-2: #3b82f6;
  --ok: #059669;
  --warn: #d97706;
  --shadow: 0 10px 28px rgba(17, 24, 39, 0.08);
  --radius: 14px;
  --radius-sm: 10px;
  --max: 1180px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "Cascadia Code", "Consolas", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  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;
  background: #fff;
  border-bottom: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(17, 24, 39, 0.03);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 64px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--brand), #1d4ed8);
}

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

.nav-links {
  display: flex;
  gap: 0.2rem;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 0.4rem 0.75rem;
  border-radius: 8px;
  color: var(--muted);
  font-size: 0.92rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--brand);
  background: #eff6ff;
}

.lang-switch {
  display: inline-flex;
  padding: 0.15rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fafb;
}

.lang-switch button {
  border: 0;
  background: transparent;
  padding: 0.3rem 0.65rem;
  border-radius: 6px;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.82rem;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 42px;
  padding: 0.65rem 1.1rem;
  border-radius: 10px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 0.92rem;
  transition: background .15s ease, transform .15s ease, box-shadow .15s ease;
}

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

.btn-primary {
  color: #fff;
  background: var(--brand);
  box-shadow: 0 8px 18px rgba(37, 99, 235, 0.22);
}

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

.layout-shell {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1rem;
  padding: 1.2rem 0 0;
}

.side-panel {
  background: var(--sidebar);
  color: var(--sidebar-ink);
  border-radius: 16px;
  padding: 1rem 0.85rem;
  min-height: 520px;
  box-shadow: var(--shadow);
}

.side-title {
  color: #fff;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin: 0 0.4rem 0.8rem;
  opacity: 0.7;
}

.side-menu {
  display: grid;
  gap: 0.25rem;
}

.side-menu a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 0.75rem;
  border-radius: 10px;
  color: var(--sidebar-ink);
  font-size: 0.9rem;
}

.side-menu a:hover,
.side-menu a.active {
  background: rgba(255,255,255,0.08);
  color: #fff;
}

.side-menu a span {
  font-family: var(--mono);
  font-size: 0.72rem;
  opacity: 0.6;
}

.hero {
  padding: 0 0 1.2rem;
}

.hero-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 1.4rem;
}

.hero-topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--line);
}

.breadcrumb {
  font-size: 0.84rem;
  color: var(--muted);
  font-family: var(--mono);
}

.breadcrumb b { color: var(--ink); }

.status-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.pill {
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  font-size: 0.74rem;
  font-weight: 700;
  background: #eff6ff;
  color: #1d4ed8;
}

.pill.ok { background: #ecfdf5; color: #047857; }
.pill.warn { background: #fffbeb; color: #b45309; }

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.2rem;
  align-items: start;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 0.85rem;
}

.tag {
  padding: 0.24rem 0.6rem;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 700;
  color: #1d4ed8;
  background: #eff6ff;
  border: 1px solid #dbeafe;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

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

.hero-lead {
  margin: 0 0 1.1rem;
  color: var(--muted);
  font-size: 1rem;
  max-width: 58ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-bottom: 1.1rem;
}

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

.trust-item {
  background: #f9fafb;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.85rem;
}

.trust-item strong {
  display: block;
  font-size: 1rem;
  font-family: var(--mono);
}

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

.admin-card {
  background: #f9fafb;
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
}

.admin-card-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0.9rem;
  background: #fff;
  border-bottom: 1px solid var(--line);
  font-size: 0.84rem;
  font-weight: 700;
}

.admin-card-head span {
  color: var(--muted);
  font-family: var(--mono);
  font-weight: 500;
  font-size: 0.74rem;
}

.admin-card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
}

.admin-table th,
.admin-table td {
  padding: 0.55rem 0.75rem;
  border-top: 1px solid var(--line);
  text-align: left;
}

.admin-table th {
  color: var(--muted);
  font-weight: 600;
  background: #fff;
}

.dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: 0.35rem;
  background: var(--ok);
}

.dot.warn { background: var(--warn); }

.section { padding: 2.2rem 0; }

.section-head { margin-bottom: 1.1rem; }

.section-kicker {
  display: inline-block;
  margin-bottom: 0.35rem;
  color: var(--brand);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: var(--mono);
}

.section-head h2 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.4rem, 2.3vw, 1.9rem);
  letter-spacing: -0.02em;
}

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

.platform-card,
.feature-card,
.recommend-card,
.scene-card,
.faq-item,
.step-card,
.compat-item,
.download-card,
.docs-panel,
.flow-panel,
.preview-panel {
  background: var(--panel);
  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: 0.9rem;
}

.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: 1rem 1.05rem; }

.os-badge,
.badge,
.status,
.step-label,
.feature-index,
.compat-dot {
  display: inline-flex;
  align-items: center;
  padding: 0.18rem 0.55rem;
  border-radius: 6px;
  font-size: 0.74rem;
  font-weight: 800;
  font-family: var(--mono);
}

.os-badge,
.badge,
.step-label,
.feature-index {
  color: #1d4ed8;
  background: #eff6ff;
}

.status {
  color: #047857;
  background: #ecfdf5;
}

.compat-dot {
  color: #374151;
  background: #f3f4f6;
  margin-bottom: 0.65rem;
}

.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: 0.65rem 0 0.4rem;
  font-size: 1.02rem;
}

.meta-list {
  display: grid;
  gap: 0.3rem;
  margin: 0.65rem 0 0.9rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.meta-list li {
  padding-left: 0.85rem;
  position: relative;
}

.meta-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand);
}

.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);
}

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

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

.flow-panel,
.preview-panel { padding: 1.05rem; }

.flow-list { display: grid; gap: 0.8rem; }

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

.flow-num {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #fff;
  font-weight: 800;
  font-size: 0.82rem;
  background: var(--brand);
  font-family: var(--mono);
}

.flow-list h3 {
  margin: 0 0 0.15rem;
  font-size: 0.98rem;
}

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

.preview-panel img {
  width: 100%;
  height: 170px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 0.8rem;
  border: 1px solid var(--line);
}

.code-box {
  margin: 0;
  padding: 0.9rem;
  border-radius: 10px;
  background: #111827;
  color: #e5e7eb;
  font-size: 0.8rem;
  overflow: auto;
  line-height: 1.5;
  font-family: var(--mono);
}

.ability-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.9rem;
}

.ability-row span {
  padding: 0.4rem 0.7rem;
  border-radius: 8px;
  background: #fff;
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.84rem;
  font-family: var(--mono);
}

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

.hint-box {
  margin-top: 0.9rem;
  padding: 0.9rem 1rem;
  border-radius: var(--radius);
  background: #fffbeb;
  border: 1px solid #fde68a;
  color: #92400e;
}

.hint-box strong { display: block; margin-bottom: 0.3rem; }
.hint-box p { margin: 0; }

.page-hero { padding: 1.6rem 0 0.6rem; }

.page-hero h1 {
  margin: 0.3rem 0 0.6rem;
  font-size: clamp(1.6rem, 2.8vw, 2.2rem);
  letter-spacing: -0.02em;
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 64ch;
}

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

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

.cta-band {
  margin: 0.8rem 0 2.4rem;
  padding: 1.8rem;
  border-radius: 16px;
  text-align: center;
  color: #fff;
  background: linear-gradient(135deg, #1d4ed8, #2563eb 55%, #0f172a);
  box-shadow: var(--shadow);
}

.cta-band h2 {
  margin: 0 0 0.4rem;
  font-size: clamp(1.35rem, 2.3vw, 1.85rem);
}

.cta-band p {
  margin: 0 0 1rem;
  opacity: 0.9;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  justify-content: center;
}

.cta-band .btn-primary {
  background: #fff;
  color: #1d4ed8;
  box-shadow: none;
}

.cta-band .btn-secondary {
  color: #fff;
  border-color: rgba(255,255,255,0.35);
  background: transparent;
}

.site-footer {
  padding: 2.2rem 0 1.3rem;
  background: #111827;
  color: #9ca3af;
}

.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;
}

.site-footer p {
  margin: 0;
  font-size: 0.9rem;
}

.site-footer ul { display: grid; gap: 0.35rem; }
.site-footer a:hover { color: #fff; }

.footer-bottom {
  margin-top: 1.4rem;
  padding-top: 0.9rem;
  border-top: 1px solid rgba(156, 163, 175, 0.2);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.84rem;
  font-family: var(--mono);
}

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

.main-wrap { padding-bottom: 0.5rem; }

@media (max-width: 980px) {
  .layout-shell { grid-template-columns: 1fr; }
  .side-panel { display: none; }
  .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; }
  .hero-topbar { flex-direction: column; align-items: flex-start; }
}