:root {
  color-scheme: light;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: #1f2329;
  background: #ffffff;
  font-synthesis: none;
  --blue: #3370ff;
  --blue-hover: #245bdb;
  --text-secondary: #646a73;
  --line: #dee0e3;
  --surface: #f5f6f7;
  --danger: #d83931;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 82px;
}

body {
  margin: 0;
  min-width: 320px;
  background: #ffffff;
}

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

[hidden] {
  display: none !important;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.topbar-inner,
.page,
.footer-inner {
  width: min(100% - 40px, 1080px);
  margin-inline: auto;
}

.topbar-inner {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 10px;
  color: #1f2329;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
}

.brand-mark {
  width: 30px;
  height: 30px;
  display: grid;
  flex: 0 0 30px;
  place-items: center;
  border-radius: 6px;
  background: var(--blue);
  color: #ffffff;
  font-size: 17px;
}

.brand-divider {
  width: 1px;
  height: 16px;
  background: var(--line);
}

.brand-product {
  color: var(--text-secondary);
  font-weight: 500;
}

.official-link {
  flex: 0 0 auto;
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
}

.official-link:hover {
  color: var(--blue);
}

.intro {
  padding: 54px 0 42px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 650;
}

h1 {
  margin: 0;
  font-size: 40px;
  line-height: 1.25;
  letter-spacing: 0;
}

.intro-copy {
  max-width: 640px;
  margin: 14px 0 0;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.7;
}

.document-layout {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 64px;
  align-items: start;
}

.step-nav {
  position: sticky;
  top: 92px;
  padding-top: 44px;
}

.step-nav ol {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.step-nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 38px;
  padding: 6px 8px;
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
}

.step-nav a:hover,
.step-nav a:focus-visible {
  background: #f0f4ff;
  color: var(--blue);
}

.step-nav span {
  width: 22px;
  height: 22px;
  display: grid;
  flex: 0 0 22px;
  place-items: center;
  border: 1px solid #bbbfc4;
  border-radius: 50%;
  font-size: 12px;
}

.guide {
  min-width: 0;
}

.step-section {
  padding: 46px 0 50px;
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 26px;
}

.step-number {
  width: 28px;
  height: 28px;
  display: grid;
  flex: 0 0 28px;
  place-items: center;
  margin-top: 1px;
  border-radius: 50%;
  background: var(--blue);
  color: #ffffff;
  font-size: 14px;
  font-weight: 700;
}

h2 {
  margin: 0;
  font-size: 23px;
  line-height: 1.35;
  letter-spacing: 0;
}

.section-heading p {
  margin: 7px 0 0;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

.platform-switch {
  width: fit-content;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3px;
  padding: 3px;
  border-radius: 6px;
  background: var(--surface);
}

.product-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 24px;
  padding: 20px 22px;
  border-left: 3px solid #00b8a9;
  border-radius: 4px;
  background: var(--surface);
}

.product-row strong {
  font-size: 15px;
}

.product-row p {
  margin: 6px 0 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.55;
}

.subsection-label {
  margin: 0 0 10px;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
}

.platform-switch button {
  min-width: 112px;
  height: 36px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--text-secondary);
  font: 600 14px/1 inherit;
  letter-spacing: 0;
  cursor: pointer;
}

.platform-switch button[aria-selected="true"] {
  background: #ffffff;
  color: var(--blue);
  box-shadow: 0 1px 4px rgba(31, 35, 41, 0.12);
}

.platform-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 20px;
  padding: 20px 22px;
  border-left: 3px solid var(--blue);
  border-radius: 4px;
  background: var(--surface);
}

.platform-panel strong {
  font-size: 15px;
}

.platform-panel p {
  margin: 6px 0 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.55;
}

.download-actions {
  display: flex;
  flex: 0 0 auto;
  flex-wrap: wrap;
  gap: 8px;
}

.primary-action,
.secondary-action,
.import-action {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  padding: 9px 16px;
  font-size: 14px;
  font-weight: 650;
  letter-spacing: 0;
  text-decoration: none;
}

.primary-action,
.import-action {
  border: 1px solid var(--blue);
  background: var(--blue);
  color: #ffffff;
}

.primary-action:hover,
.import-action:hover {
  border-color: var(--blue-hover);
  background: var(--blue-hover);
}

.secondary-action {
  border: 1px solid #c9cdd4;
  background: #ffffff;
  color: #1f2329;
}

.update-note {
  margin: 14px 0 0;
  color: var(--text-secondary);
  font-size: 13px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 18px;
}

.field {
  min-width: 0;
}

.field-wide {
  grid-column: 1 / -1;
}

label {
  display: block;
  margin-bottom: 7px;
  font-size: 14px;
  font-weight: 600;
}

input {
  width: 100%;
  height: 44px;
  border: 1px solid #bbbfc4;
  border-radius: 6px;
  padding: 0 12px;
  background: #ffffff;
  color: #1f2329;
  font: inherit;
  letter-spacing: 0;
}

input:hover {
  border-color: #8f959e;
}

input:focus {
  outline: 0;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(51, 112, 255, 0.16);
}

input[aria-invalid="true"] {
  border-color: var(--danger);
}

.error {
  display: block;
  min-height: 24px;
  padding-top: 4px;
  color: var(--danger);
  font-size: 12px;
  line-height: 1.5;
}

.import-action {
  min-width: 168px;
  margin-top: 6px;
  cursor: pointer;
}

.import-action:disabled {
  cursor: wait;
  opacity: 0.6;
}

.status {
  min-height: 24px;
  margin: 10px 0 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(51, 112, 255, 0.22);
  outline-offset: 2px;
}

.finish-section {
  border-bottom: 0;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #fafafa;
}

.footer-inner {
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: var(--text-secondary);
  font-size: 13px;
}

.footer-inner a {
  color: var(--text-secondary);
  text-decoration: none;
}

@media (max-width: 800px) {
  .topbar-inner,
  .page,
  .footer-inner {
    width: min(100% - 28px, 1080px);
  }

  .brand-divider,
  .brand-product {
    display: none;
  }

  .intro {
    padding: 38px 0 30px;
  }

  h1 {
    font-size: 32px;
  }

  .document-layout {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .step-nav {
    position: static;
    padding-top: 20px;
  }

  .step-nav ol {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 4px;
  }

  .step-nav a {
    align-items: flex-start;
    padding: 6px 4px;
    font-size: 12px;
    line-height: 1.4;
  }

  .step-nav span {
    width: 20px;
    height: 20px;
    flex-basis: 20px;
  }

  .step-section {
    padding: 36px 0 40px;
  }

  .platform-panel {
    align-items: stretch;
    flex-direction: column;
  }

  .product-row {
    align-items: stretch;
    flex-direction: column;
  }

  .product-row > .primary-action {
    width: 100%;
  }

  .download-actions,
  .download-actions > * {
    width: 100%;
  }

  .form-grid {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .field-wide {
    grid-column: auto;
  }

  .import-action {
    width: 100%;
  }
}

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