:root {
  --navy: #172033;
  --navy-soft: #33405a;
  --blue: #248bf2;
  --blue-deep: #126fce;
  --sky: #72b9ff;
  --mist: #eaf3ff;
  --mist-strong: #dcecff;
  --surface: #f7faff;
  --white: #ffffff;
  --line: #d8e5f6;
  --muted: #748198;
  --green: #2fa978;
  --orange: #ef9651;
  --shadow-sm: 0 8px 24px rgba(48, 91, 148, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  background: var(--white);
  color: var(--navy);
  font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  font-weight: 400;
  line-height: 1.7;
}

::selection {
  background: #c6e1ff;
  color: var(--navy);
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

a:focus-visible,
summary:focus-visible,
button:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: -64px;
  z-index: 100;
  padding: 8px 16px;
  border-radius: 6px;
  background: var(--navy);
  color: var(--white);
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 clamp(16px, 4vw, 64px);
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  font-size: 16px;
  font-weight: 650;
  white-space: nowrap;
}

.brand-logo {
  width: 30px;
  height: 30px;
  object-fit: contain;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 8px 16px;
  color: var(--muted);
  font-size: 13px;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}

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

.site-nav a[aria-current="page"] {
  color: var(--navy);
  font-weight: 650;
}

.notice-bar {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px clamp(16px, 4vw, 64px);
  background: #fff6ed;
  border-bottom: 1px solid #f3ddc6;
  color: var(--navy-soft);
  font-size: 16px;
}

.notice-bar img {
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  margin-top: 2px;
}

.notice-check {
  color: var(--blue-deep);
  font-weight: 650;
  text-decoration: underline;
}

.page {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 16px 64px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 13px;
}

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

.page-hero {
  margin: 0 0 32px;
  padding: 32px 16px;
  background-color: var(--mist);
  background-image:
    linear-gradient(rgba(36, 139, 242, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(36, 139, 242, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  border-bottom: 1px solid var(--line);
}

.page-hero-inner {
  max-width: 880px;
  margin: 0 auto;
}

.section-kicker {
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--blue-deep);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.signal-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 4px rgba(47, 169, 120, 0.12);
}

.page-hero h1,
.content-block h2 {
  margin: 0;
  color: var(--navy);
  font-size: 40px;
  font-weight: 560;
  line-height: 1.15;
}

.page-lede,
.nav-tip {
  max-width: 42em;
  margin: 16px 0 0;
  color: var(--navy-soft);
}

.content-block {
  margin-top: 32px;
}

.content-block h2 {
  font-size: 24px;
}

.content-block > p {
  margin: 16px 0;
}

.button {
  min-height: 48px;
  padding: 8px 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 650;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.button-primary {
  background: var(--blue);
  color: var(--white);
  border-radius: 6px;
}

.button-primary:hover {
  background: var(--blue-deep);
  transform: translateY(-1px);
}

.button-secondary {
  border-color: var(--line);
  background: var(--white);
  color: var(--navy);
}

.button-secondary:hover {
  border-color: var(--sky);
}

.method-list,
.steps-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.method-list a,
.steps-list > li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 12px 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.method-list a {
  align-items: start;
}

.method-list a:hover .method-title,
.method-list a:hover .method-index {
  color: var(--blue);
}

.method-index,
.step-index {
  color: var(--blue);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12px;
  font-weight: 550;
  padding-top: 4px;
}

.method-title,
.steps-list h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 570;
}

.method-title strong,
.steps-list strong,
.content-block strong,
.faq-list strong {
  color: var(--blue-deep);
  font-weight: 650;
}

.method-list p,
.steps-list p,
.faq-list p {
  margin: 8px 0 0;
  color: var(--navy-soft);
}

.method-list a.is-recommended {
  background: var(--surface);
  margin: 0 -12px;
  padding-left: 12px;
  padding-right: 12px;
  border-radius: 8px;
  border-bottom-color: transparent;
}

.steps-list > li {
  align-items: start;
}

.steps-list .step-body {
  min-width: 0;
}

.steps-list ul {
  margin: 12px 0 0;
  padding-left: 20px;
  color: var(--navy-soft);
}

.steps-list li li {
  display: list-item;
  padding: 4px 0;
  border: 0;
  grid-template-columns: none;
}

.step-figure {
  display: grid;
  gap: 12px;
  margin: 16px 0 0;
  padding: 12px;
  max-width: 420px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.step-figure img {
  display: block;
  width: 100%;
  border-radius: 6px;
}

.steps-list a {
  overflow-wrap: anywhere;
}

.inline-icon {
  width: 20px;
  height: 20px;
  margin: 0 4px;
}

.tip-link,
.item-tips {
  display: inline-flex;
  align-items: flex-start;
  gap: 8px;
  margin-top: 12px;
  color: var(--blue-deep);
  font-size: 16px;
}

.tip-link img,
.item-tips img {
  width: 16px;
  height: 16px;
  margin-top: 4px;
}

.warning-text {
  color: var(--orange);
  font-weight: 650;
}

.faq-list {
  margin-top: 16px;
  border-top: 1px solid var(--line);
}

.faq-list details {
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-size: 18px;
  font-weight: 570;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary i {
  position: relative;
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}

.faq-list summary i::before,
.faq-list summary i::after {
  content: "";
  position: absolute;
  top: 8px;
  left: 3px;
  width: 12px;
  height: 1px;
  background: var(--blue);
}

.faq-list summary i::after {
  transform: rotate(90deg);
}

.faq-list details[open] summary i::after {
  transform: rotate(0);
}

.faq-list details > p,
.faq-list .faq-answer {
  max-width: 42em;
  margin: 0 0 24px;
}

.support-note {
  margin-top: 32px;
  color: var(--muted);
}

.site-footer {
  margin-top: 48px;
  padding: 32px 0 16px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 16px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  color: var(--muted);
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--blue);
}

.footer-copy {
  color: var(--muted);
  font-size: 13px;
}

@media (min-width: 880px) {
  .page,
  .page-hero-inner {
    padding-left: 0;
    padding-right: 0;
  }

  .page-hero {
    margin-left: 0;
    margin-right: 0;
    padding-left: 0;
    padding-right: 0;
  }
}

@media (max-width: 480px) {
  .site-header {
    padding: 8px 16px;
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .site-nav {
    width: 100%;
    justify-content: flex-start;
    gap: 8px 12px;
  }

  .page-hero h1 {
    font-size: 40px;
  }

  .method-list a,
  .steps-list > li {
    grid-template-columns: 36px minmax(0, 1fr);
  }

  .button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .button-primary:hover {
    transform: none;
  }
}