:root {
      --bg: #f8f4ed;
      --paper: #fffdf8;
      --ink: #24211d;
      --muted: #665f55;
      --soft: #eee4d6;
      --line: #ded2c3;
      --accent: #b36b2c;
      --accent-2: #315d5c;
      --accent-light: #f4dcc4;
      --shadow: 0 18px 50px rgba(92, 62, 35, 0.12);
      --radius-xl: 28px;
      --radius-lg: 20px;
      --radius-md: 14px;
      --container: 1120px;
      --pad: clamp(18px, 4vw, 36px);
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      margin: 0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
      color: var(--ink);
      background:
        radial-gradient(circle at 12% 8%, rgba(244, 220, 196, 0.95), transparent 28%),
        radial-gradient(circle at 88% 18%, rgba(198, 222, 214, 0.72), transparent 30%),
        linear-gradient(180deg, #faf6ef 0%, var(--bg) 54%, #f7efe4 100%);
      line-height: 1.75;
      overflow-x: hidden;
    }

    a {
      color: inherit;
      text-decoration: none;
    }

    .container {
      width: min(100% - 2 * var(--pad), var(--container));
      margin: 0 auto;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 20;
      background: rgba(248, 244, 237, 0.86);
      backdrop-filter: blur(18px);
      border-bottom: 1px solid rgba(222, 210, 195, 0.7);
    }

    .nav {
      min-height: 70px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: #2a241d;
      white-space: nowrap;
    }

    .brand-mark {
      width: 34px;
      height: 34px;
      border-radius: 12px;
      background: linear-gradient(135deg, var(--accent), #e0a162);
      display: grid;
      place-items: center;
      color: #fffaf3;
      font-size: 18px;
      box-shadow: 0 10px 24px rgba(179, 107, 44, 0.22);
    }

    .nav-links {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 6px;
      flex-wrap: wrap;
    }

    .nav-links a {
      padding: 9px 12px;
      border-radius: 999px;
      color: #51483d;
      font-size: 14px;
      transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
    }

    .nav-links a:hover {
      background: rgba(255, 255, 255, 0.72);
      color: var(--accent);
      transform: translateY(-1px);
    }

    .menu-toggle {
      display: none;
      border: 1px solid var(--line);
      background: var(--paper);
      color: var(--ink);
      border-radius: 999px;
      padding: 9px 12px;
      font: inherit;
      cursor: pointer;
    }

    main {
      position: relative;
    }

    .hero {
      padding: clamp(54px, 8vw, 92px) 0 clamp(34px, 6vw, 64px);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.18fr) minmax(280px, 0.82fr);
      gap: clamp(24px, 5vw, 56px);
      align-items: center;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 7px 12px;
      border: 1px solid rgba(179, 107, 44, 0.24);
      background: rgba(255, 253, 248, 0.72);
      border-radius: 999px;
      color: #7d4a20;
      font-size: 14px;
      font-weight: 700;
      box-shadow: 0 10px 28px rgba(92, 62, 35, 0.07);
    }

    .eyebrow::before {
      content: "";
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background: var(--accent);
      box-shadow: 0 0 0 5px rgba(179, 107, 44, 0.14);
    }

    h1 {
      margin: 18px 0 18px;
      max-width: 820px;
      font-size: clamp(34px, 7vw, 68px);
      line-height: 1.06;
      letter-spacing: -0.055em;
      color: #231f1b;
    }

    .lead {
      max-width: 720px;
      margin: 0;
      font-size: clamp(17px, 2.2vw, 21px);
      color: #5b5147;
    }

    .hero-actions {
      display: flex;
      align-items: center;
      gap: 12px;
      flex-wrap: wrap;
      margin-top: 28px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 46px;
      padding: 12px 18px;
      border-radius: 999px;
      font-weight: 800;
      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
    }

    .btn-primary {
      color: #fffaf3;
      background: #2f5b59;
      box-shadow: 0 14px 28px rgba(49, 93, 92, 0.22);
    }

    .btn-secondary {
      color: #3b3128;
      background: rgba(255, 253, 248, 0.86);
      border: 1px solid rgba(222, 210, 195, 0.9);
    }

    .btn:hover {
      transform: translateY(-2px);
    }

    .btn-primary:hover {
      box-shadow: 0 18px 34px rgba(49, 93, 92, 0.28);
    }

    .decision-card {
      position: relative;
      padding: clamp(20px, 4vw, 30px);
      border-radius: var(--radius-xl);
      background:
        linear-gradient(145deg, rgba(255, 253, 248, 0.94), rgba(255, 248, 237, 0.86));
      border: 1px solid rgba(222, 210, 195, 0.95);
      box-shadow: var(--shadow);
      overflow: hidden;
      animation: floatCard 7s ease-in-out infinite;
    }

    .decision-card::after {
      content: "";
      position: absolute;
      width: 170px;
      height: 170px;
      right: -70px;
      top: -70px;
      border-radius: 50%;
      background: rgba(244, 220, 196, 0.8);
      z-index: 0;
    }

    .decision-card > * {
      position: relative;
      z-index: 1;
    }

    .card-label {
      margin: 0 0 12px;
      color: var(--accent-2);
      font-weight: 900;
      letter-spacing: 0.02em;
    }

    .score-list {
      display: grid;
      gap: 12px;
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .score-list li {
      display: grid;
      grid-template-columns: 34px 1fr;
      gap: 12px;
      align-items: start;
      padding: 14px;
      border-radius: 18px;
      background: rgba(255, 255, 255, 0.68);
      border: 1px solid rgba(222, 210, 195, 0.72);
    }

    .score-list span {
      width: 34px;
      height: 34px;
      border-radius: 12px;
      display: grid;
      place-items: center;
      background: #f1deca;
      color: #804715;
      font-weight: 900;
    }

    .score-list strong {
      display: block;
      margin-bottom: 2px;
      color: #2d2822;
    }

    .score-list p {
      margin: 0;
      color: #665f55;
      font-size: 14px;
      line-height: 1.65;
    }

    .section {
      padding: clamp(42px, 7vw, 76px) 0;
    }

    .section-head {
      display: grid;
      grid-template-columns: minmax(0, 0.85fr) minmax(260px, 0.45fr);
      gap: clamp(18px, 4vw, 36px);
      align-items: end;
      margin-bottom: 24px;
    }

    h2 {
      margin: 0;
      font-size: clamp(26px, 4vw, 42px);
      line-height: 1.16;
      letter-spacing: -0.035em;
      color: #26211d;
    }

    .section-note {
      margin: 0;
      color: var(--muted);
      font-size: 15px;
    }

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

    .rule {
      padding: 20px;
      border-radius: var(--radius-lg);
      background: rgba(255, 253, 248, 0.76);
      border: 1px solid rgba(222, 210, 195, 0.85);
      box-shadow: 0 12px 32px rgba(92, 62, 35, 0.08);
      transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
    }

    .rule:hover {
      transform: translateY(-4px);
      box-shadow: 0 18px 40px rgba(92, 62, 35, 0.13);
      border-color: rgba(179, 107, 44, 0.35);
    }

    .rule b {
      display: block;
      margin-bottom: 8px;
      color: var(--accent);
      font-size: 15px;
    }

    .rule h3 {
      margin: 0 0 8px;
      font-size: 19px;
      line-height: 1.35;
      color: #2a251f;
    }

    .rule p {
      margin: 0;
      color: #645b50;
      font-size: 15px;
    }

    .split-panel {
      display: grid;
      grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
      gap: 18px;
      align-items: stretch;
    }

    .panel {
      padding: clamp(20px, 4vw, 30px);
      border-radius: var(--radius-xl);
      background: rgba(255, 253, 248, 0.8);
      border: 1px solid rgba(222, 210, 195, 0.9);
      box-shadow: 0 12px 36px rgba(92, 62, 35, 0.08);
    }

    .panel h3 {
      margin: 0 0 14px;
      font-size: clamp(21px, 3vw, 28px);
      line-height: 1.25;
    }

    .plain-list {
      margin: 0;
      padding: 0;
      list-style: none;
      display: grid;
      gap: 12px;
    }

    .plain-list li {
      display: flex;
      gap: 10px;
      align-items: flex-start;
      color: #554d44;
    }

    .plain-list li::before {
      content: "";
      flex: 0 0 8px;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      margin-top: 11px;
      background: var(--accent);
    }

    .fault-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 12px;
    }

    .fault {
      padding: 16px;
      border-radius: 18px;
      background: #fbf2e7;
      border: 1px solid #ead8c5;
    }

    .fault strong {
      display: block;
      margin-bottom: 5px;
      color: #2d2822;
    }

    .fault p {
      margin: 0;
      color: #655b51;
      font-size: 14px;
      line-height: 1.65;
    }

    .timeline {
      counter-reset: step;
      display: grid;
      gap: 12px;
    }

    .step {
      counter-increment: step;
      display: grid;
      grid-template-columns: 46px 1fr;
      gap: 14px;
      padding: 18px;
      border-radius: 22px;
      background: rgba(255, 253, 248, 0.78);
      border: 1px solid rgba(222, 210, 195, 0.9);
    }

    .step::before {
      content: counter(step);
      width: 42px;
      height: 42px;
      border-radius: 16px;
      display: grid;
      place-items: center;
      background: #315d5c;
      color: #fffaf3;
      font-weight: 900;
    }

    .step h3 {
      margin: 0 0 4px;
      font-size: 18px;
      color: #27221e;
    }

    .step p {
      margin: 0;
      color: #5f564c;
      font-size: 15px;
    }

    .compare {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 16px;
    }

    .compare-card {
      padding: clamp(20px, 4vw, 28px);
      border-radius: var(--radius-xl);
      background: rgba(255, 253, 248, 0.82);
      border: 1px solid rgba(222, 210, 195, 0.92);
    }

    .compare-card.repair {
      background: linear-gradient(145deg, rgba(255, 253, 248, 0.95), rgba(245, 225, 203, 0.66));
    }

    .compare-card.replace {
      background: linear-gradient(145deg, rgba(255, 253, 248, 0.95), rgba(220, 237, 231, 0.66));
    }

    .compare-card h3 {
      margin: 0 0 12px;
      font-size: 23px;
      color: #29241f;
    }

    .compare-card ul {
      margin: 0;
      padding-left: 20px;
      color: #5e554b;
    }

    .compare-card li + li {
      margin-top: 8px;
    }

    .faq {
      display: grid;
      gap: 12px;
    }

    details {
      border-radius: 20px;
      background: rgba(255, 253, 248, 0.82);
      border: 1px solid rgba(222, 210, 195, 0.9);
      overflow: hidden;
      transition: border-color 0.2s ease, background 0.2s ease;
    }

    details[open] {
      border-color: rgba(179, 107, 44, 0.35);
      background: rgba(255, 253, 248, 0.96);
    }

    summary {
      cursor: pointer;
      padding: 18px 20px;
      font-weight: 850;
      color: #2a251f;
      list-style: none;
      display: flex;
      justify-content: space-between;
      gap: 16px;
      align-items: center;
    }

    summary::-webkit-details-marker {
      display: none;
    }

    summary::after {
      content: "+";
      flex: 0 0 auto;
      width: 28px;
      height: 28px;
      border-radius: 50%;
      display: grid;
      place-items: center;
      background: #f0e1d0;
      color: #7b481c;
      font-weight: 900;
      transition: transform 0.2s ease;
    }

    details[open] summary::after {
      transform: rotate(45deg);
    }

    details p {
      margin: 0;
      padding: 0 20px 20px;
      color: #60574e;
    }

    .closing {
      padding: clamp(26px, 5vw, 40px);
      border-radius: 32px;
      background:
        linear-gradient(135deg, rgba(49, 93, 92, 0.96), rgba(34, 68, 67, 0.96)),
        linear-gradient(180deg, #315d5c, #244443);
      color: #fffaf3;
      display: grid;
      grid-template-columns: minmax(0, 1fr) auto;
      gap: 22px;
      align-items: center;
      box-shadow: 0 20px 52px rgba(49, 93, 92, 0.22);
    }

    .closing h2 {
      color: #fffaf3;
      margin-bottom: 8px;
    }

    .closing p {
      margin: 0;
      color: rgba(255, 250, 243, 0.82);
      max-width: 760px;
    }

    .closing .btn {
      background: #fffaf3;
      color: #244443;
      white-space: nowrap;
    }

    .site-footer {
      margin-top: clamp(34px, 5vw, 56px);
      padding: 26px 0;
      background: #f0e7dc;
      border-top: 1px solid #dccfc0;
      color: #3f382f;
    }

    .footer-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      flex-wrap: wrap;
      font-size: 14px;
    }

    .footer-links {
      display: flex;
      align-items: center;
      gap: 12px;
      flex-wrap: wrap;
    }

    .footer-links a {
      color: #51483d;
    }

    .footer-links a:hover {
      color: var(--accent);
    }

    .reveal {
      opacity: 0;
      transform: translateY(18px);
      transition: opacity 0.65s ease, transform 0.65s ease;
    }

    .reveal.is-visible {
      opacity: 1;
      transform: translateY(0);
    }

    @keyframes floatCard {
      0%, 100% {
        transform: translateY(0);
      }
      50% {
        transform: translateY(-8px);
      }
    }

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

      .decision-card,
      .reveal,
      .btn,
      .rule {
        animation: none;
        transition: none;
      }

      .reveal {
        opacity: 1;
        transform: none;
      }
    }

    @media (max-width: 900px) {
      .hero-grid,
      .section-head,
      .split-panel,
      .compare,
      .closing {
        grid-template-columns: 1fr;
      }

      .closing .btn {
        justify-self: start;
      }

      .rule-strip {
        grid-template-columns: 1fr;
      }

      .hero {
        padding-top: 42px;
      }
    }

    @media (max-width: 720px) {
      .nav {
        min-height: 64px;
      }

      .menu-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
      }

      .nav-links {
        position: absolute;
        left: var(--pad);
        right: var(--pad);
        top: 70px;
        padding: 12px;
        border-radius: 22px;
        background: rgba(255, 253, 248, 0.96);
        border: 1px solid rgba(222, 210, 195, 0.95);
        box-shadow: var(--shadow);
        display: none;
        flex-direction: column;
        align-items: stretch;
      }

      .nav-links.is-open {
        display: flex;
      }

      .nav-links a {
        padding: 12px 14px;
      }

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

      .hero-actions {
        align-items: stretch;
      }

      .btn {
        width: 100%;
      }

      .step {
        grid-template-columns: 40px 1fr;
        padding: 16px;
      }

      .step::before {
        width: 38px;
        height: 38px;
        border-radius: 14px;
      }

      .footer-inner {
        flex-direction: column;
        align-items: flex-start;
      }
    }