:root {
  --bg: #0a0a0b;
  --bg-elevated: #141416;
  --bg-soft: #1a1a1e;
  --text: #f2f2f2;
  --text-muted: #a8a8b0;
  --accent: #c62828;
  --accent-soft: #8b1e1e;
  --line: rgba(255, 255, 255, 0.08);
  --green: #3ddc84;
  --radius: 12px;
  --max: 1120px;
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(198, 40, 40, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 20%, rgba(61, 220, 132, 0.06), transparent 50%),
    linear-gradient(180deg, #0d0d10 0%, var(--bg) 40%, #080809 100%);
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
}

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

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

a:hover {
  color: #6ef0a8;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(10, 10, 11, 0.85);
  border-bottom: 1px solid var(--line);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  object-fit: cover;
}

.brand span {
  font-family: var(--font-display);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  align-items: center;
}

.nav a {
  color: var(--text-muted);
  font-size: 0.92rem;
}

.nav a:hover,
.nav a.active {
  color: var(--text);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  margin: 0;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 1px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Hero */
.hero {
  padding: 3.5rem 0 2.5rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2.5rem;
  align-items: center;
}

.hero-eyebrow {
  display: inline-block;
  color: var(--accent);
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  line-height: 1.25;
  margin: 0 0 1rem;
  font-weight: 700;
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0 0 1.5rem;
  max-width: 36em;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.85rem 1.35rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, #e53935 100%);
  color: #fff;
}

.btn-primary:hover {
  color: #fff;
  background: linear-gradient(135deg, #d32f2f 0%, #ef5350 100%);
}

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: rgba(255, 255, 255, 0.25);
  color: #fff;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.hero-meta strong {
  color: var(--green);
  font-weight: 600;
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  width: min(100%, 320px);
  margin-inline: auto;
  border-radius: 18px;
  border: 1px solid var(--line);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
  animation: floatSoft 5s ease-in-out infinite;
}

.hero-glow {
  position: absolute;
  inset: 15% 20%;
  background: radial-gradient(circle, rgba(198, 40, 40, 0.35), transparent 70%);
  filter: blur(30px);
  z-index: -1;
  animation: pulseGlow 4s ease-in-out infinite;
}

@keyframes floatSoft {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes pulseGlow {
  0%, 100% { opacity: 0.55; }
  50% { opacity: 0.9; }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.reveal {
  animation: fadeUp 0.7s ease both;
}

/* Sections */
.section {
  padding: 3rem 0;
}

.section-alt {
  background: linear-gradient(180deg, transparent, rgba(20, 20, 22, 0.65), transparent);
}

.section-head {
  margin-bottom: 1.75rem;
  max-width: 42rem;
}

.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.5vw, 1.9rem);
  margin: 0 0 0.6rem;
}

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

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

.prose p {
  margin: 0 0 1.1rem;
}

.prose h2,
.prose h3 {
  color: var(--text);
  font-family: var(--font-display);
  margin: 2rem 0 0.85rem;
}

.prose ul,
.prose ol {
  padding-left: 1.25rem;
  margin: 0 0 1.1rem;
}

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

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

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

.feature:hover {
  border-color: rgba(198, 40, 40, 0.45);
  transform: translateY(-2px);
}

.feature h3 {
  margin: 0 0 0.55rem;
  font-size: 1.05rem;
  font-family: var(--font-display);
}

.feature p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

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

.shot {
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.shot:hover {
  transform: translateY(-4px);
  border-color: rgba(61, 220, 132, 0.35);
}

.shot img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
}

.shot figcaption {
  padding: 0.75rem 0.85rem 0.95rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.shot figcaption strong {
  display: block;
  color: var(--text);
  margin-bottom: 0.2rem;
  font-size: 0.92rem;
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
}

.split img {
  border-radius: var(--radius);
  border: 1px solid var(--line);
  width: min(100%, 280px);
  margin-inline: auto;
}

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

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  align-items: start;
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.step h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.step p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.94rem;
}

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

.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

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

.faq summary::after {
  content: "+";
  float: right;
  color: var(--accent);
}

.faq details[open] summary::after {
  content: "−";
}

.faq details p {
  margin: 0.75rem 0 0;
  color: var(--text-muted);
}

.internal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.internal-links a {
  display: inline-block;
  padding: 0.45rem 0.85rem;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.internal-links a:hover {
  color: var(--text);
  border-color: rgba(61, 220, 132, 0.4);
}

.download-banner {
  background:
    linear-gradient(135deg, rgba(198, 40, 40, 0.22), rgba(20, 20, 22, 0.9)),
    var(--bg-elevated);
  border: 1px solid rgba(198, 40, 40, 0.35);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
}

.download-banner h2 {
  margin: 0 0 0.6rem;
  font-family: var(--font-display);
}

.download-banner p {
  margin: 0 auto 1.25rem;
  color: var(--text-muted);
  max-width: 36rem;
}

/* Page header for inner pages */
.page-hero {
  padding: 2.5rem 0 1.5rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2rem;
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin: 0 0 0.6rem;
}

.page-hero p {
  margin: 0;
  color: var(--text-muted);
  max-width: 40rem;
}

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

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

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

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

.error-page h1 {
  font-family: var(--font-display);
  font-size: clamp(3rem, 10vw, 5rem);
  margin: 0 0 0.5rem;
  color: var(--accent);
}

.error-page p {
  color: var(--text-muted);
  margin: 0 0 1.5rem;
}

/* Footer */
.site-footer {
  margin-top: 3rem;
  border-top: 1px solid var(--line);
  background: #070708;
  padding: 2.5rem 0 1.75rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-brand {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
}

.footer-brand img {
  width: 48px;
  height: 48px;
  border-radius: 10px;
}

.footer-brand h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
}

.footer-brand p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-col h4 {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
}

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

.footer-col a:hover {
  color: var(--text);
}

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 1.1rem;
  color: var(--text-muted);
  font-size: 0.82rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
}

/* Mobile */
@media (max-width: 900px) {
  .hero-grid,
  .split,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid {
    grid-template-columns: 1fr 1fr;
  }

  .shot-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero {
    padding-top: 2rem;
  }

  .hero-visual {
    order: -1;
  }

  .hero-visual img {
    width: min(100%, 240px);
  }
}

@media (max-width: 720px) {
  .header-inner {
    position: relative;
    flex-wrap: nowrap;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    display: none;
    position: absolute;
    top: calc(100% + 2px);
    right: 0;
    left: auto;
    width: min(220px, calc(100vw - 2rem));
    flex-direction: column;
    align-items: stretch;
    padding: 0.5rem 0.75rem;
    gap: 0.15rem;
    background: rgba(14, 14, 16, 0.98);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
    z-index: 120;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.7rem 0.45rem;
    border-bottom: 1px solid var(--line);
  }

  .nav a:last-child {
    border-bottom: none;
  }

  .feature-grid,
  .shot-grid {
    grid-template-columns: 1fr;
  }

  .shot img {
    aspect-ratio: 9 / 14;
    max-height: 420px;
    margin-inline: auto;
  }

  .download-banner {
    padding: 1.5rem 1.1rem;
  }
}

/* Ads bar - sticky under header */
.ads-bar {
  position: sticky;
  top: 72px;
  z-index: 90;
  background: rgba(10, 10, 11, 0.94);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  padding: 8px 0 6px;
}

#ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 4px 2px;
  background: transparent;
  margin: 0;
  min-height: 0;
}

#ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 70px;
  box-sizing: border-box;
}

#ads figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#ads img {
  width: 65px;
  height: 65px;
  object-fit: cover;
  border-radius: 18px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
  transition: transform 180ms ease, box-shadow 180ms ease;
  display: block;
  border: none;
  background: linear-gradient(135deg, #fff, #fff);
}

#ads a {
  display: inline-block;
  text-decoration: none;
  border-radius: 15px;
}

#ads img:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.45);
}

#ads figcaption,
#ads .caption {
  height: 15px;
  max-width: 100px;
  margin-top: 4px;
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

@media (max-width: 720px) {
  .ads-bar {
    top: 64px;
  }

  #ads {
    gap: 2px 0;
  }

  #ads > div {
    flex: 0 0 25%;
    width: 25%;
    max-width: 25%;
  }

  #ads img {
    width: 56px;
    height: 56px;
    border-radius: 14px;
  }

  #ads figcaption,
  #ads .caption {
    max-width: 72px;
    font-size: 10px;
  }
}