:root {
    --bg: #140505;
    --surface: #260d0d;
    --accent: #ff6b00;
    --accent2: #ffd700;
    --text: #fff5f0;
    --muted: #c28888;
    --font-display: 'Oswald', sans-serif;
    --font-body: 'Fira Sans', sans-serif;
    --container-width: 1024px;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  * { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
  }

  /* Typography */
  h1, h2, h3, .display-text {
    font-family: var(--font-display);
    text-transform: uppercase;
    font-weight: 700;
    line-height: 1.2;
  }
  a { color: var(--accent2); text-decoration: none; transition: var(--transition); }
  a:hover { color: var(--accent); }
  p { margin-bottom: 1.5rem; color: var(--text); }

  .container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
  }

  /* === HEADER (Standardized for Brand) === */
  header {
    background-color: var(--bg);
    border-bottom: 2px solid var(--accent);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0,0,0,0.5);
  }
  .header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
  }
  .logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
    text-transform: uppercase;
  }
  .menu-toggle {
    display: none;
    background: none;
    border: 1px solid var(--accent);
    color: var(--accent);
    font-size: 1.5rem;
    padding: 5px 10px;
    cursor: pointer;
    border-radius: 4px;
  }
  nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
  }
  nav a {
    color: var(--text);
    font-family: var(--font-display);
    font-size: 1.1rem;
    letter-spacing: 0.5px;
    padding: 5px 0;
    position: relative;
  }
  nav a::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; width: 0; height: 2px;
    background-color: var(--accent);
    transition: var(--transition);
  }
  nav a:hover::after { width: 100%; }

  @media (max-width: 768px) {
    .menu-toggle { display: block; }
    nav {
      position: absolute;
      top: 70px; left: 0; width: 100%;
      background-color: var(--surface);
      border-bottom: 2px solid var(--accent);
      transform: translateY(-150%);
      transition: transform 0.3s ease-in-out;
      z-index: 99;
    }
    nav.active { transform: translateY(0); }
    nav ul {
      flex-direction: column;
      gap: 0;
      padding: 10px 0;
    }
    nav a {
      display: block;
      padding: 15px 20px;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    nav a::after { display: none; }
  }

  /* === HERO BANNER (Racing Kings Specific) === */
  .rk-hero {
    position: relative;
    padding: 60px 20px;
    background: linear-gradient(135deg, #0a0202 0%, var(--surface) 100%);
    border-bottom: 4px solid var(--accent);
    overflow: hidden;
    text-align: center;
  }
  .rk-hero::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image: repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(255, 107, 0, 0.03) 10px, rgba(255, 107, 0, 0.03) 20px);
    pointer-events: none;
  }
  .rk-breadcrumb {
    font-family: var(--font-display);
    color: var(--muted);
    font-size: 0.9rem;
    margin-bottom: 20px;
    letter-spacing: 1px;
    position: relative;
    z-index: 2;
  }
  .rk-hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    color: #fff;
    margin-bottom: 20px;
    text-shadow: 0 4px 20px rgba(255, 107, 0, 0.4);
    font-style: italic;
    position: relative;
    z-index: 2;
  }
  .rk-hero h1 span { color: var(--accent); }
  .rk-meta-chips {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
    position: relative;
    z-index: 2;
  }
  .rk-chip {
    background: rgba(255, 107, 0, 0.15);
    border: 1px solid rgba(255, 107, 0, 0.3);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--accent2);
    display: flex;
    align-items: center;
    gap: 6px;
  }

  /* === MAIN CONTENT AREA === */
  .rk-main {
    padding: 60px 0;
  }

  /* Intro Quote */
  .rk-intro {
    background: linear-gradient(90deg, var(--surface) 0%, transparent 100%);
    border-left: 6px solid var(--accent);
    padding: 2rem;
    margin-bottom: 3rem;
    position: relative;
    font-size: 1.15rem;
    border-radius: 0 8px 8px 0;
  }
  .rk-intro p { margin: 0; color: #fff; }
  .rk-intro::after {
    content: '❝';
    position: absolute;
    top: -10px; right: 20px;
    font-size: 6rem;
    color: var(--muted);
    opacity: 0.1;
    font-family: var(--font-display);
    line-height: 1;
  }

  /* Article Sections */
  .rk-article {
    counter-reset: rk-section;
  }
  .rk-article h2 {
    font-size: 2rem;
    color: var(--accent2);
    margin: 3rem 0 1.5rem 0;
    padding-left: 4rem;
    position: relative;
    font-style: italic;
  }
  .rk-article h2::before {
    counter-increment: rk-section;
    content: "0" counter(rk-section);
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    background: var(--accent);
    color: #000;
    font-size: 1.1rem;
    padding: 4px 8px;
    border-radius: 4px;
    font-style: normal;
    font-weight: 700;
  }
  .rk-article p a {
    text-decoration: underline;
    text-decoration-color: rgba(255,215,0,0.3);
    text-underline-offset: 4px;
    font-weight: 500;
  }
  .rk-article p a:hover {
    text-decoration-color: var(--accent);
    color: var(--accent);
  }

  /* Feature Grid (List Styling) */
  .rk-feature-grid {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin: 2rem 0;
  }
  @media (min-width: 768px) { .rk-feature-grid { grid-template-columns: 1fr 1fr; } }
  .rk-feature-grid li {
    background: var(--surface);
    border: 1px solid rgba(255, 107, 0, 0.2);
    padding: 1.5rem 1.5rem 1.5rem 4rem;
    border-radius: 8px;
    position: relative;
    transition: var(--transition);
  }
  .rk-feature-grid li:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: 0 10px 20px rgba(0,0,0,0.4);
  }
  .rk-feature-grid li::before {
    /* SVG Wrench icon data URI */
    content: '';
    position: absolute;
    left: 1.2rem;
    top: 1.5rem;
    width: 24px;
    height: 24px;
    background-color: var(--accent);
    mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M22.7 19l-9.1-9.1c.9-2.3.4-5-1.5-6.9-2-2-5-2.4-7.4-1.3L9 6 6 9 1.6 4.7C.4 7.1.9 10.1 2.9 12.1c1.9 1.9 4.6 2.4 6.9 1.5l9.1 9.1c.4.4 1 .4 1.4 0l2.4-2.4c.4-.4.4-1 0-1.3z'/%3E%3C/svg%3E") no-repeat center / contain;
    -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M22.7 19l-9.1-9.1c.9-2.3.4-5-1.5-6.9-2-2-5-2.4-7.4-1.3L9 6 6 9 1.6 4.7C.4 7.1.9 10.1 2.9 12.1c1.9 1.9 4.6 2.4 6.9 1.5l9.1 9.1c.4.4 1 .4 1.4 0l2.4-2.4c.4-.4.4-1 0-1.3z'/%3E%3C/svg%3E") no-repeat center / contain;
  }

  /* FAQ Section */
  .rk-faq-wrapper {
    margin-top: 4rem;
    padding-top: 3rem;
    border-top: 2px dashed rgba(194, 136, 136, 0.2);
  }
  .rk-faq-wrapper h2 {
    text-align: center;
    padding-left: 0;
    margin-bottom: 2rem;
  }
  .rk-faq-wrapper h2::before { display: none; }
  details {
    background: var(--surface);
    margin-bottom: 1rem;
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.05);
    overflow: hidden;
  }
  summary {
    padding: 1.2rem 1.5rem;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text);
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  summary::-webkit-details-marker { display: none; }
  summary::after {
    content: '+';
    color: var(--accent);
    font-size: 1.5rem;
    transition: transform 0.3s ease;
  }
  details[open] summary::after { transform: rotate(45deg); color: var(--accent2); }
  details[open] summary { background: rgba(255, 107, 0, 0.1); border-bottom: 1px solid rgba(255, 107, 0, 0.2); }
  details p {
    padding: 1.5rem;
    margin: 0;
    color: var(--muted);
  }

  /* Related Links (Dashboard Panel) */
  .rk-nav-panel {
    margin-top: 4rem;
    background: #0a0202;
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--surface);
  }
  .rk-nav-panel h3 {
    text-align: center;
    color: var(--muted);
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    letter-spacing: 2px;
  }
  .rk-nav-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
  }
  .rk-nav-grid a {
    background: var(--surface);
    color: var(--accent2);
    padding: 12px 24px;
    border-radius: 6px;
    font-family: var(--font-display);
    text-transform: uppercase;
    font-size: 0.9rem;
    border: 1px solid rgba(255, 215, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .rk-nav-grid a::before {
    content: '▸';
    color: var(--accent);
  }
  .rk-nav-grid a:hover {
    background: var(--accent);
    color: #000;
    border-color: var(--accent);
    transform: scale(1.05);
  }
  .rk-nav-grid a:hover::before { color: #000; }

  /* Grand CTA */
  .rk-cta-grand {
    margin-top: 4rem;
    background-color: var(--surface);
    background-image: conic-gradient(rgba(20, 5, 5, 0.8) 90deg, rgba(38, 13, 13, 0.8) 90deg 180deg, rgba(20, 5, 5, 0.8) 180deg 270deg, rgba(38, 13, 13, 0.8) 270deg);
    background-size: 60px 60px;
    padding: 4rem 2rem;
    text-align: center;
    border-radius: 16px;
    border: 2px solid var(--accent);
    box-shadow: 0 15px 30px rgba(0,0,0,0.6);
    position: relative;
  }
  .rk-cta-grand::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to top, var(--surface), transparent);
    border-radius: 14px;
    pointer-events: none;
  }
  .rk-cta-content { position: relative; z-index: 2; }
  .rk-cta-grand h3 {
    font-size: 2.5rem;
    color: #fff;
    margin-bottom: 1rem;
    font-style: italic;
  }
  .rk-cta-grand p { color: var(--accent2); font-size: 1.1rem; margin-bottom: 2rem; }
  .rk-btn-group {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
  }
  .rk-btn {
    display: inline-block;
    padding: 15px 40px;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    text-transform: uppercase;
    border-radius: 4px;
    min-width: 200px;
  }
  .rk-btn-primary {
    background: var(--accent);
    color: #000 !important;
    box-shadow: 0 4px 15px rgba(255, 107, 0, 0.4);
  }
  .rk-btn-primary:hover { background: #fff; box-shadow: 0 6px 20px rgba(255,255,255,0.5); transform: translateY(-3px); }
  .rk-btn-secondary {
    background: transparent;
    color: var(--accent) !important;
    border: 2px solid var(--accent);
  }
  .rk-btn-secondary:hover { background: rgba(255, 107, 0, 0.1); transform: translateY(-3px); }

  /* === FOOTER (Standardized for Brand) === */
  footer {
    background-color: #0a0202;
    border-top: 4px solid var(--surface);
    padding: 60px 0 20px;
    margin-top: 60px;
    font-size: 0.9rem;
  }
  .footer-top { text-align: center; margin-bottom: 40px; }
  .footer-brand {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--accent);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 10px;
  }
  .footer-tagline { color: var(--muted); max-width: 600px; margin: 0 auto; }
  .footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-bottom: 40px;
  }
  @media (min-width: 768px) { .footer-links { grid-template-columns: repeat(4, 1fr); } }
  .footer-links div { display: flex; flex-direction: column; gap: 10px; }
  .footer-links a { color: var(--text); }
  .footer-links a:hover { color: var(--accent); padding-left: 5px; }
  .footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.05);
    color: var(--muted);
  }


/* pipeline image & layout guards */
html, body { overflow-x: clip; }
img { max-width: 100%; height: auto; }
img.site-logo { height: 40px; width: auto; max-width: 240px; object-fit: contain; flex: none; }
header .logo a { display: inline-flex; align-items: center; flex: none; text-decoration: none; }
img.hero-visual { width: 100%; max-width: 560px; height: auto; object-fit: cover; border-radius: 16px; display: block; margin-inline: auto; }
img[class^="strip-"], img[class*=" strip-"] { width: 100%; height: auto; display: block; border-radius: 12px; object-fit: cover; }
/* 合规声明块（zb-disclaimer，全站 footer） */
.zb-disclaimer { margin-top: 18px !important; padding: 14px 0 0 0 !important; border-top: 1px solid rgba(128,128,128,.25) !important; font-size: .72rem !important; line-height: 1.7 !important; opacity: .85 !important; display: block !important; text-align: left !important; width: 100% !important; clear: both !important; }
.zb-disclaimer .zb-18 { display: inline-block !important; padding: 2px 10px !important; border: 1.5px solid currentColor !important; border-radius: 6px !important; font-weight: 800 !important; letter-spacing: 1px !important; margin: 0 0 10px 0 !important; font-size: .78rem !important; }
.zb-disclaimer p { display: block !important; margin: 5px 0 !important; padding: 0 !important; color: inherit !important; font-size: .72rem !important; line-height: 1.7 !important; }
.zb-disclaimer p:last-child { margin-bottom: 0 !important; }