:root {
  --bg: #0c0e12;
  --bg-elevated: #151820;
  --bg-card: #1a1e28;
  --border: #2a3140;
  --text: #e8eaed;
  --text-muted: #9aa3b2;
  --accent: #c6f531;
  --accent-dim: #9bc41f;
  --accent-soft: rgba(198, 245, 49, 0.12);
  --link: #d4ff5e;
  --danger: #ff6b6b;
  --radius: 12px;
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
  --max: 1120px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
  background-image:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(198, 245, 49, 0.08), transparent),
    radial-gradient(ellipse 60% 40% at 90% 0%, rgba(80, 120, 255, 0.06), transparent);
}

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

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

ul {
  list-style: none;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(12, 14, 18, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
}

.nav-desktop {
  display: none;
  gap: 0.35rem;
  align-items: center;
}

.nav-desktop a {
  color: var(--text-muted);
  padding: 0.45rem 0.75rem;
  border-radius: 8px;
  font-size: 0.92rem;
}

.nav-desktop a:hover,
.nav-desktop a.active {
  color: var(--accent);
  background: var(--accent-soft);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1.35rem;
  border-radius: 999px;
  font-weight: 650;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, box-shadow 0.2s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-dim));
  color: #10140a;
  box-shadow: 0 8px 24px rgba(198, 245, 49, 0.25);
}

.btn-primary:hover {
  color: #10140a;
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.btn-outline:hover {
  background: var(--accent-soft);
  color: var(--accent);
}

.menu-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

.nav-mobile {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  flex-direction: column;
  padding: 0.5rem 1rem 1rem;
  gap: 0.25rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: rgba(12, 14, 18, 0.98);
  backdrop-filter: blur(12px);
  z-index: 110;
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
}

.nav-mobile.open {
  display: flex;
}

.nav-mobile a {
  color: var(--text-muted);
  padding: 0.75rem 0.25rem;
  border-bottom: 1px solid var(--border);
}

.nav-mobile a:hover {
  color: var(--accent);
}

/* Hero */
.hero {
  padding: 2.5rem 0 2rem;
}

.hero-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.3rem 0.75rem;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 999px;
  font-size: 0.82rem;
  margin-bottom: 1rem;
  border: 1px solid rgba(198, 245, 49, 0.25);
}

.hero h1 {
  font-size: clamp(1.65rem, 4vw, 2.45rem);
  line-height: 1.3;
  margin-bottom: 1rem;
  font-weight: 800;
}

.hero h1 span {
  color: var(--accent);
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 1.5rem;
  max-width: 36em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.hero-meta strong {
  color: var(--text);
}

.hero-visual {
  position: relative;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  max-height: 520px;
  margin-inline: auto;
}

.hero-visual-stack {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.hero-visual-stack img {
  border-radius: 14px;
  border: 1px solid var(--border);
  aspect-ratio: 9 / 16;
  object-fit: cover;
  max-height: 420px;
}

/* Sections */
.section {
  padding: 2.75rem 0;
}

.section-alt {
  background: rgba(255, 255, 255, 0.015);
  border-block: 1px solid var(--border);
}

.section-head {
  margin-bottom: 1.75rem;
  max-width: 46em;
}

.section-head h2 {
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  margin-bottom: 0.65rem;
  line-height: 1.35;
}

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

.prose {
  color: var(--text-muted);
}

.prose p {
  margin-bottom: 1.1rem;
}

.prose h2,
.prose h3 {
  color: var(--text);
  margin: 1.75rem 0 0.85rem;
  line-height: 1.4;
}

.prose h2 {
  font-size: 1.45rem;
}

.prose h3 {
  font-size: 1.2rem;
}

.prose ul,
.prose ol {
  margin: 0 0 1.1rem 1.25rem;
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: 0.45rem;
}

.prose a {
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* Feature / card grids */
.feature-grid {
  display: grid;
  gap: 1.25rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.feature-card:hover {
  border-color: rgba(198, 245, 49, 0.35);
  transform: translateY(-2px);
}

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.shot-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, 1fr);
}

.shot-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.shot-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  max-height: 380px;
}

.shot-card figcaption {
  padding: 0.85rem 1rem 1rem;
}

.shot-card h3 {
  font-size: 1rem;
  margin-bottom: 0.35rem;
}

.shot-card p {
  color: var(--text-muted);
  font-size: 0.88rem;
}

.steps {
  display: grid;
  gap: 1rem;
  counter-reset: step;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem 1.25rem;
}

.step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent);
  color: #10140a;
  display: grid;
  place-items: center;
  font-weight: 800;
}

.step h3 {
  margin-bottom: 0.35rem;
}

.step p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.faq details {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  margin-bottom: 0.75rem;
}

.faq summary {
  cursor: pointer;
  font-weight: 650;
  list-style: none;
}

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

.faq details[open] summary {
  color: var(--accent);
  margin-bottom: 0.65rem;
}

.faq p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.cta-band {
  background: linear-gradient(135deg, rgba(198, 245, 49, 0.14), rgba(26, 30, 40, 0.9));
  border: 1px solid rgba(198, 245, 49, 0.28);
  border-radius: 18px;
  padding: 1.75rem;
  text-align: center;
}

.cta-band h2 {
  margin-bottom: 0.65rem;
}

.cta-band p {
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.tag-cloud a,
.tag-cloud span {
  display: inline-block;
  padding: 0.35rem 0.8rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.tag-cloud a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Page hero for subpages */
.page-hero {
  padding: 2rem 0 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.5rem;
}

.page-hero h1 {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  margin-bottom: 0.5rem;
}

.page-hero p {
  color: var(--text-muted);
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.content-wrap {
  padding-bottom: 3rem;
}

.toc {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem 1.25rem;
  margin-bottom: 1.75rem;
}

.toc h2 {
  font-size: 1rem;
  margin-bottom: 0.65rem;
}

.toc ol {
  margin-left: 1.1rem;
  list-style: decimal;
  color: var(--text-muted);
}

.toc a {
  color: var(--text-muted);
}

.toc a:hover {
  color: var(--accent);
}

.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 3rem 1rem;
}

.error-page h1 {
  font-size: clamp(3rem, 10vw, 5rem);
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.75rem;
}

.error-page p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  max-width: 28em;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  background: #090b0f;
  padding: 2.5rem 0 1.5rem;
  margin-top: 2rem;
}

.footer-grid {
  display: grid;
  gap: 1.75rem;
  margin-bottom: 2rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 0.75rem;
  color: var(--text);
  font-weight: 700;
}

.footer-brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.footer-col h3 {
  font-size: 0.95rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.footer-col a,
.footer-col p {
  display: block;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 0.45rem;
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 1.15rem;
  color: var(--text-muted);
  font-size: 0.82rem;
  text-align: center;
}

.age-note {
  display: inline-block;
  margin-top: 0.75rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

@media (min-width: 768px) {
  .menu-toggle {
    display: none;
  }

  .nav-desktop {
    display: flex;
  }

  .nav-mobile {
    display: none !important;
  }

  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
  }

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

  .shot-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .shot-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .steps {
    grid-template-columns: repeat(4, 1fr);
  }

  .hero-visual-stack {
    grid-template-columns: 1fr 1fr;
  }
}