* { margin: 0; padding: 0; box-sizing: border-box; }

  body {
    background: #0e1117;
    color: #c9d1d9;
    font-family: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 14px;
    line-height: 1.7;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 60px 20px;
  }

  .container {
    max-width: 680px;
    width: 100%;
    border: 1px solid #30363d;
    padding: 40px 48px;
    position: relative;
  }

  /* blinking cursor */
  @keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
  }
  .cursor {
    display: inline-block;
    width: 8px;
    height: 15px;
    background: #58a6ff;
    vertical-align: text-bottom;
    animation: blink 1s step-end infinite;
    margin-left: 1px;
  }

  /* fade-in for sections */
  .fade-in {
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.5s ease, transform 0.5s ease;
  }
  .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
  }

  /* header */
  .header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 36px;
    position: relative;
  }
  .header::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 180px;
    right: 80px;
    border-top: 1px dashed #30363d;
  }
  .logo {
    color: #e6edf3;
    text-decoration: underline;
    text-underline-offset: 4px;
    font-weight: 500;
    font-size: 14px;
    position: relative;
    z-index: 1;
    background: #0e1117;
    padding-right: 8px;
  }
  .nav a {
    color: #e6edf3;
    text-decoration: underline;
    text-underline-offset: 4px;
    font-size: 14px;
    position: relative;
    z-index: 1;
    background: #0e1117;
    padding-left: 8px;
  }
  .nav a:hover { color: #58a6ff; }

  /* heading */
  h1 {
    font-size: 16px;
    font-weight: 700;
    color: #e6edf3;
    margin-bottom: 20px;
    letter-spacing: 0.02em;
    min-height: 1.7em;
  }
  h1 .hash {
    color: #484f58;
  }

  .desc {
    margin-bottom: 24px;
    color: #c9d1d9;
    max-width: 560px;
  }

  /* cta */
  .cta-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
  }
  .cta {
    color: #e6edf3;
    text-decoration: underline;
    text-underline-offset: 4px;
    font-weight: 500;
  }
  .cta:hover { color: #58a6ff; }
  .cta-secondary {
    color: #8b949e;
    text-decoration: none;
    font-size: 13px;
  }
  .cta-secondary:hover { color: #c9d1d9; }

  /* divider */
  .divider {
    color: #484f58;
    margin: 28px 0;
    font-size: 14px;
    user-select: none;
  }

  /* flow diagram */
  .diagram {
    border: 1px solid #21262d;
    padding: 28px 24px;
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    overflow-x: auto;
  }
  .diagram-col {
    display: flex;
    flex-direction: column;
    gap: 10px;
    flex-shrink: 0;
  }
  .diagram-box {
    border: 1px solid #30363d;
    padding: 8px 16px;
    font-size: 12px;
    color: #c9d1d9;
    white-space: nowrap;
    text-align: center;
    opacity: 0;
    transform: translateX(-10px);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }
  .diagram-box.visible {
    opacity: 1;
    transform: translateX(0);
  }
  .diagram-center {
    border: 1px dashed #484f58;
    padding: 16px 20px;
    text-align: center;
    flex-shrink: 0;
    opacity: 0;
    transform: scale(0.95);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }
  .diagram-center.visible {
    opacity: 1;
    transform: scale(1);
  }
  .diagram-center .name {
    color: #e6edf3;
    font-weight: 700;
    font-size: 14px;
  }
  .diagram-center .sub {
    color: #8b949e;
    font-size: 12px;
    margin-top: 4px;
  }
  .diagram-arrow {
    color: #484f58;
    font-size: 12px;
    flex-shrink: 0;
    white-space: nowrap;
    opacity: 0;
    transition: opacity 0.3s ease;
  }
  .diagram-arrow.visible { opacity: 1; }
  .diagram-list {
    border: 1px solid #30363d;
    padding: 12px 16px;
    font-size: 12px;
    flex-shrink: 0;
    opacity: 0;
    transform: translateX(10px);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }
  .diagram-list.visible {
    opacity: 1;
    transform: translateX(0);
  }
  .diagram-list .item {
    color: #8b949e;
    white-space: nowrap;
  }
  .diagram-list .item::before {
    content: '~ ';
    color: #484f58;
  }

  /* value props */
  .props {
    margin-bottom: 4px;
  }
  .prop {
    color: #8b949e;
    margin-bottom: 4px;
    opacity: 0;
    transform: translateX(-6px);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }
  .prop.visible {
    opacity: 1;
    transform: translateX(0);
  }
  .prop .action { color: #c9d1d9; }
  .prop .arrow { color: #484f58; }
  .prop .result { color: #8b949e; }

  /* chat demo */
  .chat {
    background: #161b22;
    border: 1px solid #21262d;
    padding: 20px 24px;
    margin-bottom: 32px;
    font-size: 12px;
    line-height: 1.8;
    overflow-x: auto;
  }
  .chat .msg {
    opacity: 0;
    transform: translateY(6px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    margin-bottom: 12px;
  }
  .chat .msg:last-child { margin-bottom: 0; }
  .chat .msg.visible {
    opacity: 1;
    transform: translateY(0);
  }
  .chat .msg-user {
    color: #e6edf3;
    padding-left: 0;
  }
  .chat .msg-user::before {
    content: 'you  ';
    color: #484f58;
    font-size: 11px;
  }
  .chat .msg-bot {
    padding-left: 0;
  }
  .chat .msg-bot::before {
    content: '🦞  ';
    font-size: 11px;
  }
  .chat .msg-bot .thinking {
    color: #484f58;
    font-style: italic;
  }
  .chat .output {
    color: #8b949e;
    padding-left: 28px;
  }
  .chat .highlight {
    color: #3fb950;
  }
  .chat .price {
    color: #58a6ff;
  }
  .chat .alert {
    color: #d29922;
  }
  .chat .dim {
    color: #484f58;
  }
  .chat .msg-notify {
    padding-left: 0;
    border-left: 2px solid #d29922;
    padding-left: 12px;
  }
  .chat .msg-notify::before {
    content: '';
  }

  /* install */
  .install {
    background: #161b22;
    border: 1px solid #21262d;
    padding: 16px 24px;
    margin-bottom: 8px;
    font-size: 12px;
    color: #c9d1d9;
    overflow-x: auto;
    white-space: pre;
    cursor: pointer;
    position: relative;
    transition: border-color 0.2s;
  }
  .install:hover {
    border-color: #30363d;
  }
  .install .comment {
    color: #484f58;
  }
  .install-hint {
    font-size: 11px;
    color: #484f58;
    margin-bottom: 28px;
  }

  /* footer */
  .footer {
    color: #484f58;
    font-size: 12px;
    margin-top: 8px;
    padding-top: 24px;
    border-top: 1px solid #21262d;
  }
  .footer a {
    color: #8b949e;
    text-decoration: underline;
    text-underline-offset: 3px;
  }
  .footer a:hover { color: #c9d1d9; }

  /* faq */
  .faq h2 {
    font-size: 14px;
    font-weight: 700;
    color: #e6edf3;
    margin-bottom: 20px;
  }
  .faq h2 .hash { color: #484f58; }
  .faq-item {
    margin-bottom: 16px;
  }
  .faq-item h3 {
    font-size: 13px;
    font-weight: 500;
    color: #c9d1d9;
    margin-bottom: 4px;
  }
  .faq-item p {
    font-size: 12px;
    color: #8b949e;
    line-height: 1.7;
  }

  a { color: inherit; }

  /* copied toast */
  .toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: #161b22;
    border: 1px solid #30363d;
    color: #e6edf3;
    padding: 8px 20px;
    font-family: inherit;
    font-size: 12px;
    opacity: 0;
    transition: opacity 0.3s, transform 0.3s;
    pointer-events: none;
    z-index: 100;
  }
  .toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }

  /* booking */
  .book form { margin-bottom: 12px; }
  .book fieldset { border: 1px solid #21262d; padding: 12px 16px; margin-bottom: 12px; }
  .book legend { font-size: 12px; color: #8b949e; padding: 0 6px; }
  .fields { display: flex; flex-wrap: wrap; gap: 8px 12px; }
  .field { display: flex; flex-direction: column; flex: 1; min-width: 140px; margin-bottom: 6px; }
  .field label { font-size: 11px; color: #8b949e; }
  .book input, .book select {
    background: #161b22; border: 1px solid #30363d; color: #e6edf3;
    font-family: inherit; font-size: 13px; padding: 6px 10px;
  }
  .book input:focus, .book select:focus { outline: none; border-color: #58a6ff; }
  .book button {
    background: #e6edf3; color: #0e1117; border: 1px solid #e6edf3;
    font-family: inherit; font-size: 13px; font-weight: 500; padding: 6px 14px; cursor: pointer;
  }
  .book button:hover { background: #58a6ff; border-color: #58a6ff; }
  .results { list-style: none; font-size: 12px; margin-bottom: 16px; }
  .results li { display: flex; justify-content: space-between; align-items: center; gap: 8px;
    border-bottom: 1px solid #21262d; padding: 6px 0; }
  .form-msg { font-size: 12px; color: #8b949e; min-height: 1.7em; margin-bottom: 8px; }
  .form-msg.error { color: #f85149; }
  #checkout-link { color: #3fb950; font-weight: 500; }

  /* sections */
  .section h2 {
    font-size: 14px;
    font-weight: 700;
    color: #e6edf3;
    margin-bottom: 16px;
  }
  .section h2 .hash { color: #484f58; }
  .section p { font-size: 12px; color: #8b949e; margin-bottom: 12px; }
  .section p strong { color: #c9d1d9; font-weight: 500; }
  .code-label { font-size: 11px; color: #484f58; margin-bottom: 4px; }

  @media (max-width: 720px) {
    body { padding: 24px 12px; }
    .container { padding: 28px 20px; }
    .diagram { flex-direction: column; align-items: stretch; }
    .diagram-arrow { text-align: center; transform: rotate(90deg); margin: 4px auto; }
    .header::after { display: none; }
  }