:root {
  color-scheme: light;
  --bg: #f5f7fa;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --text: #172033;
  --muted: #647084;
  --line: #dde3ec;
  --brand: #1769e0;
  --brand-dark: #0f50af;
  --brand-soft: #eaf2ff;
  --success: #0d7a52;
  --success-soft: #e7f7f0;
  --warning: #8a5500;
  --warning-soft: #fff4db;
  --shadow: 0 16px 50px rgba(31, 45, 68, 0.08);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.75;
}

a {
  color: var(--brand);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--brand-dark);
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(23, 105, 224, 0.35);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--text);
  color: #fff;
  transform: translateY(-160%);
}

.skip-link:focus {
  color: #fff;
  transform: translateY(0);
}

code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(221, 227, 236, 0.85);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1180px, calc(100% - 40px));
  min-height: 64px;
  margin: 0 auto;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 10px;
  background: var(--brand);
  color: #fff;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.topnav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 14px;
}

.topnav a {
  color: var(--muted);
  text-decoration: none;
}

.topnav a:hover {
  color: var(--text);
}

.hero {
  padding: 74px 0 36px;
  background:
    radial-gradient(circle at 15% 0%, rgba(23, 105, 224, 0.12), transparent 34%),
    radial-gradient(circle at 88% 15%, rgba(41, 168, 118, 0.11), transparent 30%);
}

.hero-inner,
.layout {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.3;
}

h1 {
  max-width: 850px;
  margin-bottom: 18px;
  font-size: clamp(34px, 5vw, 58px);
  letter-spacing: -0.045em;
}

.hero-lead {
  max-width: 760px;
  margin: 0 0 28px;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 20px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--brand);
  border-radius: 12px;
  background: var(--brand);
  color: #fff;
  font-weight: 650;
  text-decoration: none;
  touch-action: manipulation;
}

.button:hover {
  background: var(--brand-dark);
  color: #fff;
}

.button.secondary {
  border-color: var(--line);
  background: #fff;
  color: var(--text);
}

.button.secondary:hover {
  border-color: #b8c3d3;
  background: var(--surface-soft);
}

.layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 42px;
  padding: 32px 0 80px;
}

.toc {
  position: sticky;
  top: 92px;
  align-self: start;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.8);
}

.toc-title {
  margin: 0 0 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.toc a {
  display: block;
  padding: 5px 0;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.toc a:hover {
  color: var(--brand);
}

.content {
  min-width: 0;
}

.section {
  margin-bottom: 28px;
  padding: clamp(24px, 4vw, 42px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  scroll-margin-top: 90px;
}

.section h2 {
  margin-bottom: 10px;
  font-size: clamp(25px, 3vw, 34px);
  letter-spacing: -0.025em;
}

.section-intro {
  margin: 0 0 26px;
  color: var(--muted);
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.summary-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface-soft);
}

.summary-card strong {
  display: block;
  margin-bottom: 3px;
}

.summary-card span {
  color: var(--muted);
  font-size: 14px;
}

.update-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 24px 0;
  padding: 0;
  counter-reset: flow-step;
  list-style: none;
}

.update-flow li {
  position: relative;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface-soft);
  counter-increment: flow-step;
}

.update-flow li::before {
  display: block;
  margin-bottom: 5px;
  color: var(--brand);
  content: "0" counter(flow-step);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.update-flow strong {
  display: block;
  margin-bottom: 3px;
  font-size: 15px;
}

.update-flow span {
  color: var(--muted);
  font-size: 13px;
}

.field-list {
  overflow: hidden;
  margin-top: 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
}

.field-row {
  display: grid;
  grid-template-columns: 130px minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  min-height: 62px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
}

.field-row:last-child {
  border-bottom: 0;
}

.field-row span {
  color: var(--muted);
  font-size: 14px;
}

.field-row code {
  min-width: 0;
  overflow-wrap: anywhere;
  color: var(--text);
}

.copy-button {
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #fff;
  color: var(--text);
  cursor: pointer;
}

.copy-button:hover {
  border-color: #abb7c8;
  background: var(--surface-soft);
}

.step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 18px;
  margin: 30px 0 40px;
}

.step:last-child {
  margin-bottom: 0;
}

.step-number {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 14px;
  background: var(--brand-soft);
  color: var(--brand);
  font-weight: 800;
}

.step-body h3 {
  margin-bottom: 7px;
  font-size: 21px;
}

.step-body p {
  margin: 0 0 18px;
  color: var(--muted);
}

.screenshot {
  display: block;
  overflow: hidden;
  border: 1px solid #cfd7e3;
  border-radius: 14px;
  background: #141414;
  box-shadow: 0 12px 28px rgba(20, 29, 45, 0.12);
}

.screenshot img {
  display: block;
  width: 100%;
  height: auto;
}

.caption {
  margin-top: 9px !important;
  color: var(--muted) !important;
  font-size: 13px;
}

.callout {
  margin: 22px 0;
  padding: 16px 18px;
  border-left: 4px solid var(--brand);
  border-radius: 0 12px 12px 0;
  background: var(--brand-soft);
}

.callout.success {
  border-left-color: var(--success);
  background: var(--success-soft);
}

.callout.warning {
  border-left-color: #d78b00;
  background: var(--warning-soft);
  color: var(--warning);
}

.callout strong {
  display: block;
  margin-bottom: 3px;
}

.checklist {
  padding-left: 0;
  list-style: none;
}

.checklist li {
  position: relative;
  margin: 10px 0;
  padding-left: 30px;
}

.checklist li::before {
  position: absolute;
  top: 2px;
  left: 0;
  width: 21px;
  height: 21px;
  border-radius: 50%;
  background: var(--success-soft);
  color: var(--success);
  content: "✓";
  font-size: 13px;
  font-weight: 800;
  line-height: 21px;
  text-align: center;
}

.code-block {
  position: relative;
  overflow-x: auto;
  padding: 18px;
  border-radius: 14px;
  background: #172033;
  color: #f4f7fb;
  font-size: 14px;
  line-height: 1.65;
}

.code-block code {
  white-space: pre;
}

.troubleshooting {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.issue {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface-soft);
}

.issue h3 {
  margin-bottom: 7px;
  font-size: 17px;
}

.issue p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.editor-download {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 24px;
  padding: 22px;
  border: 1px solid #bcd2f4;
  border-radius: 14px;
  background: var(--brand-soft);
}

.editor-download strong,
.editor-download span {
  display: block;
}

.editor-download span {
  margin-top: 4px;
  color: var(--muted);
  font-size: 14px;
}

.editor-download .button {
  flex: none;
}

footer {
  padding: 26px 20px 38px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

@media (max-width: 860px) {
  .topnav {
    display: none;
  }

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

  .toc {
    position: static;
  }

  .summary-grid,
  .troubleshooting,
  .update-flow {
    grid-template-columns: 1fr;
  }

  .editor-download {
    align-items: stretch;
    flex-direction: column;
  }
}

@media (max-width: 600px) {
  .topbar-inner,
  .hero-inner,
  .layout {
    width: min(100% - 24px, 1180px);
  }

  .hero {
    padding-top: 48px;
  }

  .section {
    padding: 22px 18px;
  }

  .step {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .step-number {
    width: 38px;
    height: 38px;
    border-radius: 12px;
  }

  .field-row {
    grid-template-columns: 1fr;
    gap: 3px;
    padding: 14px;
  }

  .copy-button {
    justify-self: start;
    margin-top: 6px;
  }
}

@media print {
  .topbar,
  .toc,
  .hero-actions,
  .copy-button {
    display: none;
  }

  body {
    background: #fff;
  }

  .hero {
    padding: 24px 0;
    background: none;
  }

  .layout {
    display: block;
    padding-top: 0;
  }

  .section {
    break-inside: avoid;
    border: 0;
    box-shadow: none;
  }
}