:root {
  --c-bg: #f4f7fb;
  --c-surface: #ffffff;
  --c-ink: #1a2332;
  --c-muted: #5a6a7e;
  --c-line: #d8e2ef;
  --c-brand: #1e7fd6;
  --c-brand-deep: #0f5fa8;
  --c-brand-soft: #e8f3fc;
  --c-accent: #00a8c4;
  --shadow: 0 10px 30px rgba(15, 55, 100, 0.08);
  --radius: 14px;
  --max: 1120px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #d9eefc 0%, transparent 55%),
    radial-gradient(900px 420px at 100% 0%, #d7f4f4 0%, transparent 50%),
    var(--c-bg);
  line-height: 1.75;
  font-size: 16px;
}

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

#ads img {
  max-width: 65px;
  width: 65px;
  height: 65px;
  object-fit: contain;
}

a {
  color: var(--c-brand-deep);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(100% - 32px, var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--c-line);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--c-ink);
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
}

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

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  align-items: center;
}

.nav a {
  color: var(--c-muted);
  font-size: 0.95rem;
  text-decoration: none;
  padding: 6px 2px;
}

.nav a:hover,
.nav a.active {
  color: var(--c-brand-deep);
}

.menu-toggle {
  display: none;
  border: 1px solid var(--c-line);
  background: var(--c-surface);
  border-radius: 10px;
  padding: 8px 12px;
  cursor: pointer;
  color: var(--c-ink);
}

.hero {
  padding: 48px 0 28px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 28px;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 14px;
  font-size: clamp(1.7rem, 3.2vw, 2.45rem);
  line-height: 1.25;
  letter-spacing: 0.02em;
}

.hero-copy .lead {
  color: var(--c-muted);
  font-size: 1.05rem;
  margin: 0 0 22px;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--c-brand), var(--c-accent));
  color: #fff;
  box-shadow: 0 10px 22px rgba(30, 127, 214, 0.28);
}

.btn-secondary {
  background: var(--c-surface);
  color: var(--c-brand-deep);
  border-color: var(--c-line);
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  width: min(100%, 360px);
  margin-inline: auto;
  border-radius: 22px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.8);
}

.section {
  padding: 34px 0;
}

.section-head {
  margin-bottom: 18px;
}

.section-head h2 {
  margin: 0 0 8px;
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
}

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

.panel {
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}

.prose p {
  margin: 0 0 1em;
}

.prose h2,
.prose h3 {
  scroll-margin-top: 90px;
}

.prose h3 {
  margin: 1.4em 0 0.55em;
  font-size: 1.2rem;
}

.prose ul,
.prose ol {
  padding-left: 1.2em;
  margin: 0 0 1em;
}

.prose li {
  margin-bottom: 0.35em;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feature-card {
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.feature-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  background: #eef3f8;
}

.feature-card .body {
  padding: 14px 14px 16px;
}

.feature-card h3 {
  margin: 0 0 6px;
  font-size: 1.05rem;
}

.feature-card p {
  margin: 0;
  color: var(--c-muted);
  font-size: 0.94rem;
}

.shot-row {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 18px;
  align-items: start;
  margin: 18px 0;
}

.shot-row img {
  width: 100%;
  border-radius: 16px;
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow);
}

.steps {
  counter-reset: step;
  display: grid;
  gap: 12px;
}

.step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 12px;
  align-items: start;
  background: var(--c-brand-soft);
  border-radius: 12px;
  padding: 14px;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--c-brand);
  color: #fff;
  font-weight: 700;
}

.toc {
  background: linear-gradient(180deg, #f8fbff, #ffffff);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 22px;
}

.toc strong {
  display: block;
  margin-bottom: 8px;
}

.toc a {
  display: inline-block;
  margin: 4px 10px 4px 0;
  font-size: 0.95rem;
}

.faq details {
  border: 1px solid var(--c-line);
  border-radius: 12px;
  background: var(--c-surface);
  padding: 12px 14px;
  margin-bottom: 10px;
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
}

.faq p {
  margin: 10px 0 0;
  color: var(--c-muted);
}

.internal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  display: inline-flex;
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--c-brand-soft);
  color: var(--c-brand-deep);
  text-decoration: none;
  font-size: 0.92rem;
}

.chip:hover {
  text-decoration: none;
  background: #d7ebfa;
}

.site-footer {
  margin-top: 40px;
  padding: 28px 0 36px;
  border-top: 1px solid var(--c-line);
  background: #0f2740;
  color: #d7e4f2;
}

.site-footer a {
  color: #9fd0ff;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 20px;
}

.footer-grid h3 {
  margin: 0 0 10px;
  font-size: 1rem;
  color: #fff;
}

.footer-grid p,
.footer-grid li {
  color: #b7c7d8;
  font-size: 0.92rem;
}

.footer-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-grid li {
  margin-bottom: 6px;
}

.copyright {
  margin-top: 22px;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.86rem;
  color: #8ea3ba;
}

.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 48px 0;
}

.error-page h1 {
  font-size: clamp(2rem, 6vw, 3.5rem);
  margin: 0 0 10px;
}

.error-page p {
  color: var(--c-muted);
  margin: 0 0 20px;
}

.page-hero {
  padding: 36px 0 10px;
}

.page-hero h1 {
  margin: 0 0 8px;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
}

.page-hero p {
  margin: 0;
  color: var(--c-muted);
}

.legal .panel {
  padding: 26px clamp(16px, 3vw, 34px);
}

@media (max-width: 960px) {
  .hero-grid,
  .feature-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

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

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

  .shot-row img {
    width: min(240px, 100%);
    margin-inline: auto;
  }
}

@media (max-width: 720px) {
  .menu-toggle {
    display: inline-flex;
  }

  .nav-wrap {
    position: relative;
    flex-wrap: nowrap;
  }

  .nav {
    display: none;
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    right: 0;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 12px;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--c-line);
    border-radius: 12px;
    box-shadow: var(--shadow);
    z-index: 60;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 10px 8px;
    border-bottom: 1px solid var(--c-line);
  }

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

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

  .hero {
    padding-top: 28px;
  }

  .hero-visual img {
    width: min(100%, 280px);
  }
}