:root {
  --blue-900: #0a2a5c;
  --blue-700: #1565c0;
  --blue-600: #1e7ae6;
  --blue-500: #2b8cff;
  --blue-100: #e8f3ff;
  --blue-50: #f3f8ff;
  --ink: #1a2332;
  --muted: #5a6a7e;
  --line: #d7e4f4;
  --card: #ffffff;
  --bg: #f6f9fd;
  --accent: #00a8e8;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(21, 101, 192, 0.08);
  --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(--ink);
  background:
    radial-gradient(circle at 12% -10%, rgba(43, 140, 255, 0.18), transparent 42%),
    radial-gradient(circle at 90% 8%, rgba(0, 168, 232, 0.12), transparent 36%),
    linear-gradient(180deg, #eef5ff 0%, var(--bg) 28%, #f8fbff 100%);
  line-height: 1.75;
  min-height: 100vh;
}

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

a {
  color: var(--blue-700);
  text-decoration: none;
}

a:hover {
  color: var(--blue-500);
  text-decoration: underline;
}

.container {
  width: min(100% - 32px, var(--max));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(255, 255, 255, 0.88);
  border-bottom: 1px solid rgba(215, 228, 244, 0.9);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--blue-900);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
}

.brand:hover {
  text-decoration: none;
  color: var(--blue-700);
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 4px 12px rgba(21, 101, 192, 0.2);
}

.nav-toggle {
  display: none;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 10px;
  padding: 8px 12px;
  cursor: pointer;
  color: var(--blue-900);
  font-size: 0.9rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-menu a {
  display: block;
  padding: 8px 12px;
  border-radius: 999px;
  color: var(--ink);
  font-size: 0.95rem;
  text-decoration: none;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: var(--blue-100);
  color: var(--blue-700);
}

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

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 36px;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 14px;
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  line-height: 1.25;
  color: var(--blue-900);
}

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

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--blue-600), var(--accent));
  color: #fff;
  box-shadow: 0 10px 24px rgba(30, 122, 230, 0.28);
}

.btn-primary:hover {
  color: #fff;
}

.btn-ghost {
  background: #fff;
  border-color: var(--line);
  color: var(--blue-700);
}

.hero-visual {
  position: relative;
}

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

.hero-badge {
  position: absolute;
  left: 16px;
  bottom: 16px;
  background: rgba(10, 42, 92, 0.86);
  color: #fff;
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 0.88rem;
}

.section {
  padding: 42px 0;
}

.section-head {
  margin-bottom: 22px;
}

.section-head h2 {
  margin: 0 0 8px;
  font-size: clamp(1.4rem, 2.4vw, 1.9rem);
  color: var(--blue-900);
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 760px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

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

.feature-card img,
.content-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  background: #e9f1fb;
}

.feature-card .body,
.content-card .body,
.info-card .body {
  padding: 16px 18px 18px;
}

.feature-card h3,
.content-card h3,
.info-card h3 {
  margin: 0 0 8px;
  font-size: 1.08rem;
  color: var(--blue-900);
}

.feature-card p,
.content-card p,
.info-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
  align-items: start;
}

.prose {
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 26px;
  box-shadow: var(--shadow);
}

.prose h2,
.prose h3 {
  color: var(--blue-900);
  margin-top: 1.6em;
}

.prose h2:first-child,
.prose h3:first-child {
  margin-top: 0;
}

.prose p {
  margin: 0 0 1em;
  color: #314255;
}

.prose ul,
.prose ol {
  margin: 0 0 1em;
  padding-left: 1.2em;
  color: #314255;
}

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

.shot-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.shot-row figure {
  margin: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

.shot-row figcaption {
  padding: 10px 12px;
  font-size: 0.86rem;
  color: var(--muted);
}

.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 8px;
}

.toc a {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 14px;
  color: var(--blue-700);
  text-decoration: none;
  font-size: 0.92rem;
}

.toc a:hover {
  background: var(--blue-100);
}

.keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.keywords span {
  background: var(--blue-100);
  color: var(--blue-700);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.85rem;
}

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

.page-hero h1 {
  margin: 0 0 10px;
  color: var(--blue-900);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
}

.page-hero p {
  margin: 0;
  color: var(--muted);
  max-width: 720px;
}

.site-footer {
  margin-top: 48px;
  padding: 34px 0 28px;
  background: linear-gradient(180deg, #0d3a78, #0a2a5c);
  color: rgba(255, 255, 255, 0.88);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 24px;
}

.site-footer h3 {
  margin: 0 0 12px;
  color: #fff;
  font-size: 1rem;
}

.site-footer p,
.site-footer li {
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.92rem;
}

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

.site-footer a {
  color: rgba(255, 255, 255, 0.86);
  text-decoration: none;
}

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

.footer-bottom {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.65);
}

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

.error-page .code {
  font-size: clamp(3.5rem, 10vw, 6rem);
  font-weight: 800;
  line-height: 1;
  color: var(--blue-600);
  margin: 0 0 10px;
}

.error-page h1 {
  margin: 0 0 12px;
  color: var(--blue-900);
}

.error-page p {
  margin: 0 0 22px;
  color: var(--muted);
}

.breadcrumb {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 14px;
}

.breadcrumb a {
  color: var(--blue-700);
}

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

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

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

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

  .nav-menu {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 68px;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 8px;
    box-shadow: var(--shadow);
  }

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

  .nav-bar {
    position: relative;
  }

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

  .hero {
    padding-top: 28px;
  }

  .prose {
    padding: 18px 16px;
  }

  .feature-card img,
  .content-card img,
  .shot-row img {
    aspect-ratio: 3 / 4;
  }
}