:root {
  --brand: #2f9bff;
  --brand-dark: #1a7fd9;
  --brand-soft: #e8f5ff;
  --ink: #1a2332;
  --muted: #5a6a7e;
  --line: #d7e6f4;
  --bg: #f4f8fc;
  --card: #ffffff;
  --warn: #e8913a;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(30, 90, 150, 0.08);
  --max: 1120px;
  --font-display: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: "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-body);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #d9efff 0%, transparent 55%),
    radial-gradient(900px 420px at 100% 0%, #cfe8ff 0%, transparent 50%),
    linear-gradient(180deg, #eef6fc 0%, var(--bg) 28%, #f7fbfe 100%);
  line-height: 1.75;
  min-height: 100vh;
}

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

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

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

a:hover {
  text-decoration: underline;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.88);
  border-bottom: 1px solid rgba(215, 230, 244, 0.9);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 68px;
  position: relative;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 2px #fff, 0 0 0 3px var(--brand);
}

.brand span {
  font-size: 1.05rem;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1rem;
  align-items: center;
}

.nav a {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  padding: 0.25rem 0;
}

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

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 10px;
  cursor: pointer;
  color: var(--ink);
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.menu-toggle .menu-icon {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  position: relative;
  transition: background 0.2s ease;
}

.menu-toggle .menu-icon::before,
.menu-toggle .menu-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform 0.2s ease, top 0.2s ease;
}

.menu-toggle .menu-icon::before {
  top: -6px;
}

.menu-toggle .menu-icon::after {
  top: 6px;
}

.menu-toggle[aria-expanded="true"] .menu-icon {
  background: transparent;
}

.menu-toggle[aria-expanded="true"] .menu-icon::before {
  top: 0;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-icon::after {
  top: 0;
  transform: rotate(-45deg);
}

.hero {
  padding: 3.2rem 0 2.2rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2rem;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--brand-dark);
  background: var(--brand-soft);
  border: 1px solid #c7e4ff;
  border-radius: 999px;
  padding: 0.28rem 0.8rem;
  font-size: 0.86rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.hero h1 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.2vw, 2.55rem);
  line-height: 1.25;
  letter-spacing: 0.01em;
}

.hero-lead {
  margin: 0 0 1.4rem;
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 38rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  border-radius: 999px;
  padding: 0.72rem 1.25rem;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid transparent;
  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(--brand), var(--brand-dark));
  color: #fff;
  box-shadow: 0 10px 22px rgba(47, 155, 255, 0.28);
}

.btn-secondary {
  background: #fff;
  color: var(--brand-dark);
  border-color: #b7dbff;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1.2rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  width: 100%;
  border-radius: 22px;
  box-shadow: var(--shadow);
  border: 1px solid #dff0ff;
  background: #fff;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: auto -8% -8% auto;
  width: 42%;
  height: 42%;
  background: radial-gradient(circle, rgba(47, 155, 255, 0.25), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.section {
  padding: 2.4rem 0;
}

.section-head {
  margin-bottom: 1.4rem;
}

.section-head h2 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  line-height: 1.3;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 46rem;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.35rem;
}

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

.feature-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 34px rgba(30, 90, 150, 0.12);
}

.feature-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top center;
  background: #edf5fc;
}

.feature-card .body {
  padding: 1rem 1.05rem 1.15rem;
}

.feature-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
}

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

.split {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 1.25rem;
  align-items: stretch;
}

.split.reverse {
  grid-template-columns: 1.05fr 0.95fr;
}

.split .shot {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #fff;
  box-shadow: var(--shadow);
}

.split .shot img {
  width: 100%;
  height: 100%;
  max-height: 620px;
  object-fit: cover;
  object-position: top center;
}

.content-block h2,
.content-block h3 {
  margin-top: 0;
}

.content-block p {
  color: var(--ink);
}

.content-block ul,
.content-block ol {
  padding-left: 1.2rem;
  color: var(--muted);
}

.content-block li {
  margin-bottom: 0.45rem;
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1rem 0 0;
}

.chip {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-dark);
  border: 1px solid #c9e5ff;
  font-size: 0.86rem;
  font-weight: 650;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.9rem;
}

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

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

.gallery figcaption {
  padding: 0.7rem 0.8rem 0.85rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.prose {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: clamp(1.2rem, 3vw, 2rem);
}

.prose h1 {
  margin-top: 0;
  font-size: clamp(1.55rem, 2.8vw, 2.1rem);
}

.prose h2 {
  margin-top: 1.8rem;
  font-size: 1.28rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--line);
}

.prose h3 {
  margin-top: 1.3rem;
  font-size: 1.08rem;
}

.prose p,
.prose li {
  color: #334155;
}

.toc {
  background: var(--brand-soft);
  border: 1px solid #c7e4ff;
  border-radius: 12px;
  padding: 1rem 1.1rem;
  margin: 1.2rem 0 1.6rem;
}

.toc strong {
  display: block;
  margin-bottom: 0.45rem;
}

.toc a {
  display: inline-block;
  margin: 0.2rem 0.7rem 0.2rem 0;
}

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.85rem 1rem;
  margin-bottom: 0.7rem;
}

.faq summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--ink);
}

.faq p {
  margin: 0.7rem 0 0.2rem;
  color: var(--muted);
}

.cta-band {
  margin: 1.5rem 0 0.5rem;
  padding: 1.5rem;
  border-radius: 16px;
  background: linear-gradient(135deg, #1f8ef0, #4eb3ff 55%, #79c8ff);
  color: #fff;
  box-shadow: 0 14px 30px rgba(31, 142, 240, 0.25);
}

.cta-band h2 {
  margin: 0 0 0.55rem;
  color: #fff;
}

.cta-band p {
  margin: 0 0 1rem;
  color: rgba(255, 255, 255, 0.92);
}

.cta-band .btn-secondary {
  border-color: transparent;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  color: var(--muted);
  font-size: 0.9rem;
  margin: 1.2rem 0 0.8rem;
}

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

.site-footer {
  margin-top: 3rem;
  padding: 2.2rem 0 2.6rem;
  background: #132033;
  color: #c9d7e8;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 1.5rem;
}

.site-footer a {
  color: #d7ebff;
}

.site-footer h3 {
  margin: 0 0 0.7rem;
  color: #fff;
  font-size: 1rem;
}

.site-footer p,
.site-footer li {
  color: #a9bdd4;
  font-size: 0.92rem;
}

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

.site-footer li {
  margin-bottom: 0.4rem;
}

.footer-bottom {
  margin-top: 1.6rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.86rem;
  color: #8fa5bf;
}

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

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

.error-page h1 {
  margin: 0.6rem 0 0.8rem;
}

.related-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.8rem;
}

.related-links a {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  text-decoration: none;
  color: var(--ink);
  font-weight: 650;
}

.related-links a span {
  display: block;
  margin-top: 0.25rem;
  color: var(--muted);
  font-weight: 400;
  font-size: 0.88rem;
}

.related-links a:hover {
  border-color: #9ccfff;
  box-shadow: var(--shadow);
}

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

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

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

  .split .shot img {
    max-height: 520px;
  }
}

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

  .nav {
    display: none;
    position: absolute;
    top: calc(100% + 1px);
    left: 0;
    right: 0;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.55rem 0.85rem 0.85rem;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: var(--shadow);
    z-index: 60;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.7rem 0.35rem;
    border-bottom: 1px solid var(--line);
  }

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

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

  .hero {
    padding-top: 1.8rem;
  }

  .feature-grid,
  .gallery,
  .related-links {
    grid-template-columns: 1fr 1fr;
  }

  .feature-card img,
  .gallery img {
    aspect-ratio: 3 / 4;
  }
}

@media (max-width: 480px) {
  .feature-grid,
  .gallery,
  .related-links {
    grid-template-columns: 1fr;
  }

  .container {
    width: min(100% - 1.25rem, var(--max));
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-grid,
.feature-card,
.split,
.panel {
  animation: rise-in 0.55s ease both;
}