:root {
  --blue: #1a6dff;
  --blue-deep: #0d4fcc;
  --blue-soft: #e8f1ff;
  --ink: #152238;
  --muted: #5a6b82;
  --line: #d7e3f5;
  --bg: #f4f8ff;
  --white: #ffffff;
  --wave: linear-gradient(135deg, #1a6dff 0%, #3ec6ff 48%, #6b8cff 100%);
  --shadow: 0 12px 32px rgba(26, 109, 255, 0.12);
  --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(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, rgba(62, 198, 255, 0.18), transparent 60%),
    radial-gradient(900px 420px at 100% 0%, rgba(26, 109, 255, 0.14), transparent 55%),
    var(--bg);
  line-height: 1.75;
}

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

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

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

a:hover {
  color: var(--blue);
  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(244, 248, 255, 0.9);
  border-bottom: 1px solid rgba(215, 227, 245, 0.9);
}

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

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

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

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

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

.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;
}

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

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--line);
  background: var(--white);
  border-radius: 10px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 3.2rem 0 2.4rem;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(62, 198, 255, 0.35), transparent 50%),
    radial-gradient(ellipse at 80% 0%, rgba(107, 140, 255, 0.4), transparent 45%),
    linear-gradient(120deg, #0d4fcc 0%, #1a6dff 48%, #2f8dff 100%);
  z-index: -2;
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 72px;
  background: linear-gradient(to top, var(--bg), transparent);
  z-index: -1;
}

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

.hero-copy {
  color: var(--white);
}

.hero-copy .eyebrow {
  display: inline-block;
  margin: 0 0 0.8rem;
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  opacity: 0.92;
}

.hero-copy h1 {
  margin: 0 0 0.9rem;
  font-size: clamp(1.8rem, 4vw, 2.7rem);
  line-height: 1.25;
  font-weight: 800;
}

.hero-copy p {
  margin: 0 0 1.4rem;
  max-width: 38rem;
  font-size: 1.05rem;
  opacity: 0.95;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  min-height: 46px;
  padding: 0.7rem 1.2rem;
  border-radius: 999px;
  font-weight: 700;
  border: 1px solid transparent;
  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: var(--white);
  color: var(--blue-deep);
  box-shadow: var(--shadow);
}

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

.btn-ghost {
  background: rgba(255, 255, 255, 0.12);
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.4);
}

.btn-ghost:hover {
  color: var(--white);
  background: rgba(255, 255, 255, 0.2);
}

.btn-solid {
  background: var(--wave);
  color: var(--white);
  box-shadow: var(--shadow);
}

.btn-solid:hover {
  color: var(--white);
}

.hero-visual {
  border-radius: 18px;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.28);
  border: 3px solid rgba(255, 255, 255, 0.35);
  background: var(--white);
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  max-height: 520px;
}

.section {
  padding: 2.8rem 0;
}

.section-head {
  margin-bottom: 1.5rem;
}

.section-head h2 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  line-height: 1.3;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 48rem;
}

.prose {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  box-shadow: 0 8px 24px rgba(21, 34, 56, 0.04);
}

.prose p {
  margin: 0 0 1rem;
  color: var(--ink);
}

.prose p:last-child {
  margin-bottom: 0;
}

.prose ul,
.prose ol {
  margin: 0 0 1rem;
  padding-left: 1.2rem;
  color: var(--ink);
}

.prose h2,
.prose h3 {
  margin: 1.4rem 0 0.7rem;
  line-height: 1.35;
}

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

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
}

.feature-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(21, 34, 56, 0.04);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.feature-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.feature-item img {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  max-height: 360px;
  background: #eef4ff;
}

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

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

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

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.4rem;
  align-items: center;
}

.split.reverse .copy {
  order: 2;
}

.split img {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  object-fit: cover;
  object-position: top;
  max-height: 560px;
  background: var(--white);
}

.split .copy h3 {
  margin: 0 0 0.7rem;
  font-size: 1.35rem;
}

.split .copy p {
  margin: 0 0 0.85rem;
  color: var(--muted);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.8rem;
}

.chip {
  display: inline-block;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  background: var(--blue-soft);
  color: var(--blue-deep);
  font-size: 0.86rem;
  font-weight: 700;
}

.guide-list {
  display: grid;
  gap: 0.9rem;
}

.guide-step {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 0.9rem;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
}

.guide-step .num {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--wave);
  color: var(--white);
  font-weight: 800;
}

.guide-step h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}

.guide-step p {
  margin: 0;
  color: var(--muted);
}

.faq details {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  margin-bottom: 0.7rem;
}

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

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

.related {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.related a {
  display: inline-flex;
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  background: var(--white);
  border: 1px solid var(--line);
  color: var(--blue-deep);
  font-weight: 700;
  text-decoration: none;
}

.related a:hover {
  background: var(--blue-soft);
  text-decoration: none;
}

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

.page-banner h1 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
}

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

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

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

.site-footer {
  margin-top: 2rem;
  padding: 2rem 0 2.4rem;
  background: #0d1b33;
  color: #c9d7ef;
}

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

.site-footer h3 {
  margin: 0 0 0.7rem;
  color: var(--white);
  font-size: 1rem;
}

.site-footer p,
.site-footer a {
  color: #c9d7ef;
  font-size: 0.92rem;
}

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

.footer-links {
  display: grid;
  gap: 0.45rem;
}

.copyright {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(201, 215, 239, 0.18);
  font-size: 0.86rem;
  color: #9eb0cd;
}

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

.error-wrap h1 {
  margin: 0 0 0.6rem;
  font-size: clamp(2rem, 6vw, 3.4rem);
  background: var(--wave);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.error-wrap p {
  margin: 0 0 1.2rem;
  color: var(--muted);
}

.toc {
  background: var(--blue-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-bottom: 1.2rem;
}

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

.toc a {
  display: inline-block;
  margin: 0.2rem 0.7rem 0.2rem 0;
  font-weight: 600;
}

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

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

.reveal-delay {
  animation-delay: 0.15s;
}

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

  .split.reverse .copy {
    order: 0;
  }

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

  .hero-visual img,
  .feature-item img {
    max-height: 420px;
  }
}

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

  .nav {
    display: none;
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    left: auto;
    width: min(220px, calc(100vw - 2rem));
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.55rem;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: var(--shadow);
    z-index: 60;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.7rem 0.85rem;
    border-radius: 8px;
  }

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

  .header-inner {
    flex-wrap: nowrap;
  }

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

  .hero {
    padding-top: 2rem;
  }

  .hero-visual {
    max-width: 320px;
    margin-inline: auto;
  }

  .prose {
    padding: 1.1rem;
  }
}