:root {
      --brand: #25d366;
      --brand-dark: #128c4e;
      --step-line: #e2e8f0;
      --step-num-bg: #f8fafc;
      --step-num-border: #e2e8f0;
      --code-bg: #f1f5f9;
      --code-border: #e2e8f0;
      --note-bg: #F5FFEF;
      --note-border: #E2FFD3;
      --note-text: #075e54;
      --tip-bg: #fefce8;
      --tip-border: #fde68a;
      --tip-text: #92400e;
      --thumb-bg: #f8fafc;
      --thumb-border: #e2e8f0;
      --text-main: #0f172a;
      --text-muted: #64748b;
      --radius: 7px;
  }

  body {
      font-family: 'DM Sans', sans-serif;
      color: var(--text-main);
      background: #fff;
      font-size: 15px;
      line-height: 1.7;
  }

  /* ── Page shell ── */
  .guide-wrap {
      max-width: 800px;
      margin: 0 auto;
      padding: 3rem 1.5rem 5rem;
  }

  /* ── Breadcrumb ── */
  .breadcrumb-row {
      font-size: 12.5px;
      color: var(--text-muted);
      margin-bottom: 1.75rem;
  }

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

  .breadcrumb-row a:hover {
      color: var(--text-main);
  }

  .breadcrumb-sep {
      margin: 0 6px;
      opacity: .45;
  }

  /* ── Heading block ── */
  .guide-title {
      font-size: 26px;
      font-weight: 500;
      line-height: 1.3;
      margin-bottom: .5rem;
  }

  .guide-subtitle {
      color: var(--text-muted);
      max-width1: 640px;
      margin-bottom: 1.75rem;
  }

  .guide-subtitle code {
      font-family: 'DM Mono', monospace;
      font-size: 12.5px;
      background: var(--code-bg);
      border: 1px solid var(--code-border);
      border-radius: 5px;
      padding: 1px 6px;
      color: var(--text-main);
  }

  /* ── Callout ── */
  .callout {
      border-radius: var(--radius);
      padding: .75rem 1rem;
      font-size: 13.5px;
      display: flex;
      gap: 10px;
      align-items: flex-start;
      margin-bottom: 1.25rem;
  }

  .callout-info {
      background: var(--note-bg);
      border: 1px solid var(--note-border);
      color: var(--note-text);
  }

  .callout-tip {
      background: var(--tip-bg);
      border: 1px solid var(--tip-border);
      color: var(--tip-text);
  }

  .callout-icon {
      flex-shrink: 0;
      font-size: 15px;
      margin-top: 1px;
  }

  .callout a {
      color: inherit;
  }

  /* ── Steps ── */
  .steps {
      display: flex;
      flex-direction: column;
  }

  .step {
      display: flex;
      gap: 0;
      position: relative;
  }

  .step-gutter {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 44px;
      flex-shrink: 0;
  }

  .step-num {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      background: var(--step-num-bg);
      border: 1.5px solid var(--step-num-border);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 13px;
      font-weight: 500;
      color: var(--text-main);
      flex-shrink: 0;
      z-index: 1;
  }

  .step-connector {
      flex: 1;
      width: 1.5px;
      background: var(--step-line);
      margin: 5px 0;
  }

  .step:last-child .step-connector {
      margin-bottom: 60px;
  }

  .step-body {
      padding: 0 0 2.0rem 1rem;
      flex: 1;
      min-width: 0;
  }

  .step-title {
      font-size: 15.5px;
      font-weight: 500;
      color: var(--text-main);
      margin-bottom: .35rem;
      padding-top: 4px;
  }

  /* ── Step inner layout (text + thumb) ── */
  .step-inner {
      display: flex;
      gap: 1.25rem;
      align-items: flex-start;
  }

  .step-text {
      flex: 1;
      min-width: 0;
      color: var(--text-muted);
      font-size: 14px;
  }

  .step-text p {
      margin: 0;
  }

  /* ── Inline code ── */
  code {
      font-family: 'DM Mono', monospace;
      font-size: 12px;
      background: var(--code-bg);
      border: 1px solid var(--code-border);
      border-radius: 4px;
      padding: 1px 5px;
      color: var(--text-main);
  }

  /* ── Code block ── */
  .code-block {
      margin-top: 0.75rem;
      background: var(--code-bg);
      border: 1px solid var(--code-border);
      border-radius: var(--radius);
      padding: .5rem 1rem;
      font-family: 'DM Mono', monospace;
      font-size: 12.5px;
      color: var(--text-main);
      line-height: 1.65;
      overflow-x: auto;
  }

  .code-block .var {
      color: #2563eb;
  }

  .code-block .comment {
      color: #94a3b8;
  }

  /* ── Inline tip below text ── */
  .step-tip {
      margin-top: .9rem;
  }

  /* ── Badge ── */
  .badge-vip {
      display: inline-block;
      font-size: 10.5px;
      font-weight: 500;
      background: #fef3c7;
      color: #92400e;
      border: 1px solid #fde68a;
      border-radius: 20px;
      padding: 1px 8px;
      margin-left: 5px;
      vertical-align: middle;
      line-height: 1.6;
  }

  /* ── Thumbnail ── */
  .thumb-wrap {
      flex-shrink: 0;
      width: 160px;
      background: var(--thumb-bg);
      border: 1px solid var(--thumb-border);
      border-radius: var(--radius);
      overflow: hidden;
      cursor: zoom-in;
      transition: border-color .15s, box-shadow .15s;
      position: relative;
  }

  .thumb-wrap:hover {
      border-color: #94a3b8;
      box-shadow: 0 4px 14px rgba(0, 0, 0, .08);
  }

  .thumb-wrap img {
      width: 100%;
      display: block;
      max-height: 200px;
      object-fit: cover;
      object-position: top;
  }

  /* Placeholder when no real image */
  .thumb-placeholder {
      height: 150px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 8px;
      color: #94a3b8;
      font-size: 12px;
      text-align: center;
      padding: 1rem;
  }

  .thumb-placeholder svg {
      opacity: .45;
  }

  .thumb-expand {
      position: absolute;
      bottom: 7px;
      right: 7px;
      background: rgba(15, 23, 42, .55);
      color: #fff;
      font-size: 10px;
      border-radius: 5px;
      padding: 2px 7px;
      opacity: 0;
      transition: opacity .15s;
      pointer-events: none;
      display: flex;
      align-items: center;
      gap: 4px;
  }

  .thumb-wrap:hover .thumb-expand {
      opacity: 1;
  }

  /* ── Lightbox ── */
  #lightbox-overlay {
      display: none;
      position: fixed;
      inset: 0;
      background: rgba(15, 23, 42, .75);
      z-index: 1050;
      align-items: center;
      justify-content: center;
      padding: 1.5rem;
  }

  #lightbox-overlay.open {
      display: flex;
  }

  #lightbox-box {
      background: #fff;
      border-radius: 14px;
      padding: 1.25rem;
      max-width: min(90vw, 1200px);
      width: fit-content;
      position: relative;
      max-height: 90vh;
      overflow-y: auto;
  }

  #lightbox-caption {
      font-size: 13.5px;
      font-weight: 500;
      color: var(--text-main);
      margin-bottom: .875rem;
  }

  #lightbox-img {
      max-width: 100%;
      height: auto;
      border-radius: 8px;
      border: 1px solid var(--code-border);
      display: block;
  }

  /* Placeholder for lightbox when no real img */
  #lightbox-placeholder {
      width: 100%;
      border-radius: 8px;
      border: 1px solid var(--code-border);
      background: var(--thumb-bg);
      min-height: 260px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-muted);
      font-size: 13px;
  }

  #lightbox-close {
      position: absolute;
      top: 12px;
      right: 14px;
      background: none;
      border: none;
      font-size: 20px;
      line-height: 1;
      color: var(--text-muted);
      cursor: pointer;
      padding: 0;
  }

  #lightbox-close:hover {
      color: var(--text-main);
  }


  @media (max-width: 576px) {
      .step-inner {
          flex-direction: column-reverse;
          /* image on top, text below */
      }

      .thumb-wrap {
          width: 100%;
          /* full width */
          flex-shrink: 0;
      }

      .thumb-wrap img {
          max-height: 260px;
          /* a bit taller since it has more room */
      }
  }