:root {
  --blue-deep: #0a4f8a;
  --blue-mid: #1a7fd4;
  --blue-bright: #3aa0ef;
  --blue-soft: #e8f4fc;
  --blue-mist: #f3f9fd;
  --ink: #1a2332;
  --muted: #5a6a7a;
  --line: #d4e4f0;
  --white: #ffffff;
  --accent: #00b4a0;
  --warning: #e8a317;
  --radius: 12px;
  --shadow: 0 8px 28px rgba(10, 79, 138, 0.08);
  --max: 1120px;
  --font: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --display: "ZCOOL XiaoWei", "Source Han Serif SC", "Noto Serif SC", "Songti SC", serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(58, 160, 239, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(0, 180, 160, 0.12), transparent 50%),
    linear-gradient(180deg, #f7fbfe 0%, #eef6fb 40%, #f8fafc 100%);
  line-height: 1.75;
  min-height: 100vh;
}

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

#ads img,
.site-ads-wrap #ads img {
  max-width: none;
  width: 65px;
  height: 65px;
  object-fit: cover;
  object-position: center;
  aspect-ratio: 1 / 1;
  flex-shrink: 0;
}

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

a:hover {
  color: var(--blue-deep);
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  font-weight: 700;
}

.brand img {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  object-fit: cover;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-text strong {
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.brand-text span {
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 500;
}

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

.nav a {
  color: var(--ink);
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 500;
}

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

.nav-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--white);
  border-radius: 8px;
  padding: 0.45rem 0.7rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--blue-deep);
}

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

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(10, 79, 138, 0.96), rgba(26, 127, 212, 0.88) 55%, rgba(0, 180, 160, 0.75));
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2rem;
  align-items: center;
  color: var(--white);
}

.hero-copy h1 {
  font-family: var(--display);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.2;
  margin: 0 0 0.8rem;
  font-weight: 700;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.25);
}

.hero-copy p {
  margin: 0 0 1.4rem;
  font-size: 1.05rem;
  max-width: 36rem;
  opacity: 0.95;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

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

.btn-primary {
  background: var(--white);
  color: var(--blue-deep);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  color: var(--blue-mid);
}

.btn-ghost {
  background: transparent;
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.55);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  color: var(--white);
}

.hero-visual {
  justify-self: end;
  width: min(100%, 280px);
  border-radius: 22px;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.28);
  border: 3px solid rgba(255, 255, 255, 0.35);
  animation: floaty 5s ease-in-out infinite;
}

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

.section {
  padding: 3rem 0;
}

.section-alt {
  background: rgba(255, 255, 255, 0.65);
  border-block: 1px solid var(--line);
}

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

.section-head .eyebrow {
  display: inline-block;
  color: var(--blue-mid);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}

.section-head h2 {
  font-family: var(--display);
  font-size: clamp(1.55rem, 2.6vw, 2.1rem);
  margin: 0 0 0.55rem;
  color: var(--blue-deep);
  line-height: 1.3;
}

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

.lead {
  font-size: 1.05rem;
  color: var(--ink);
}

.prose p,
.prose li {
  color: var(--ink);
}

.prose h3 {
  margin: 1.8rem 0 0.7rem;
  color: var(--blue-deep);
  font-size: 1.25rem;
}

.prose ul,
.prose ol {
  padding-left: 1.2rem;
}

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

.feature-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 14px 34px rgba(10, 79, 138, 0.12);
}

.feature-card h3 {
  margin: 0.85rem 0 0.45rem;
  font-size: 1.08rem;
  color: var(--blue-deep);
}

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

.feature-card img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  border-radius: 10px;
  background: var(--blue-mist);
}

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

.split.reverse .split-media {
  order: 2;
}

.split-media {
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: var(--white);
}

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

.split-body h3 {
  margin-top: 0;
  color: var(--blue-deep);
  font-size: 1.35rem;
}

.split-body p {
  color: var(--muted);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.tag-list li {
  background: var(--blue-soft);
  color: var(--blue-deep);
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  counter-reset: step;
}

.step {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.2rem;
  position: relative;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  display: inline-flex;
  width: 2rem;
  height: 2rem;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-mid), var(--accent));
  color: var(--white);
  font-weight: 700;
  margin-bottom: 0.7rem;
}

.step h3 {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
  color: var(--blue-deep);
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

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

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

.gallery img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  transition: transform 0.35s ease;
}

.gallery figure:hover img {
  transform: scale(1.04);
}

.gallery figcaption {
  padding: 0.7rem 0.85rem 0.9rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.toc {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.4rem;
  margin: 1.5rem 0 2rem;
  box-shadow: var(--shadow);
}

.toc h2 {
  margin: 0 0 0.7rem;
  font-size: 1.1rem;
  color: var(--blue-deep);
}

.toc ol {
  margin: 0;
  padding-left: 1.2rem;
  columns: 2;
  gap: 2rem;
}

.toc a {
  font-weight: 500;
}

.faq details {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
  margin-bottom: 0.7rem;
}

.faq summary {
  cursor: pointer;
  font-weight: 650;
  color: var(--blue-deep);
}

.faq details p {
  margin: 0.65rem 0 0;
  color: var(--muted);
}

.page-hero {
  padding: 2.4rem 0 1.2rem;
}

.page-hero h1 {
  font-family: var(--display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  margin: 0 0 0.5rem;
  color: var(--blue-deep);
}

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

.breadcrumb {
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: 0.8rem;
}

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

.content-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.6rem 1.7rem;
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
}

.related {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

.related a {
  display: block;
  background: var(--blue-mist);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem;
  color: var(--blue-deep);
  font-weight: 600;
}

.related a span {
  display: block;
  margin-top: 0.35rem;
  color: var(--muted);
  font-weight: 400;
  font-size: 0.88rem;
}

.site-footer {
  background: linear-gradient(180deg, #0d3f6e, #082844);
  color: rgba(255, 255, 255, 0.88);
  padding: 2.5rem 0 1.5rem;
  margin-top: 2rem;
}

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

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

.site-footer p,
.site-footer li {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.92rem;
}

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

.site-footer li + li {
  margin-top: 0.35rem;
}

.site-footer a {
  color: rgba(255, 255, 255, 0.82);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 1rem;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  justify-content: space-between;
}

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

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

.error-page p {
  color: var(--muted);
  max-width: 28rem;
  margin: 0.8rem auto 1.4rem;
}

.cta-band {
  background: linear-gradient(120deg, var(--blue-deep), var(--blue-mid) 55%, var(--accent));
  color: #fff;
  border-radius: 18px;
  padding: 1.8rem 1.6rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
}

.cta-band h2 {
  margin: 0 0 0.35rem;
  font-size: 1.35rem;
}

.cta-band p {
  margin: 0;
  opacity: 0.92;
}

.keywords-box {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: 1rem;
}

.keywords-box span {
  font-size: 0.8rem;
  color: var(--blue-deep);
  background: var(--blue-soft);
  border-radius: 6px;
  padding: 0.2rem 0.55rem;
}

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

  .split.reverse .split-media {
    order: 0;
  }

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

  .toc ol {
    columns: 1;
  }
}

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    display: none;
    position: absolute;
    left: 1rem;
    right: 1rem;
    top: calc(100% + 0.35rem);
    flex-direction: column;
    align-items: stretch;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 0.5rem;
    box-shadow: var(--shadow);
  }

  .nav.open {
    display: flex;
  }

  .header-inner {
    position: relative;
  }

  .hero-inner,
  .feature-grid,
  .steps,
  .gallery,
  .footer-grid,
  .related,
  .split,
  .split.reverse {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 2.2rem 0 2rem;
  }

  .hero-visual {
    justify-self: center;
    width: min(100%, 220px);
  }

  .section {
    padding: 2.2rem 0;
  }

  .content-card {
    padding: 1.2rem;
  }
}