:root {
      --bg: #f4f8fb;
      --bg-soft: #eef5f8;
      --card: rgba(255, 255, 255, 0.86);
      --card-solid: #ffffff;
      --text: #17232d;
      --muted: #5f7180;
      --line: rgba(116, 145, 160, 0.24);
      --primary: #2d6f87;
      --primary-dark: #174c63;
      --accent: #8fbecd;
      --ice: #dceff5;
      --warm: #f8fbfc;
      --shadow: 0 22px 60px rgba(43, 86, 105, 0.12);
      --shadow-soft: 0 14px 34px rgba(43, 86, 105, 0.08);
      --radius-lg: 28px;
      --radius-md: 18px;
      --radius-sm: 12px;
      --container: 1160px;
      --pad: 20px;
    }

    * {
      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(--text);
      background:
        radial-gradient(circle at 12% 8%, rgba(210, 236, 243, 0.9) 0, rgba(210, 236, 243, 0.28) 28%, transparent 46%),
        radial-gradient(circle at 86% 18%, rgba(232, 246, 249, 0.9) 0, rgba(232, 246, 249, 0.3) 30%, transparent 52%),
        linear-gradient(180deg, #f7fbfd 0%, var(--bg) 48%, #f8faf8 100%);
      line-height: 1.7;
      overflow-x: hidden;
    }

    body::before {
      content: "";
      position: fixed;
      inset: 0;
      pointer-events: none;
      background-image:
        linear-gradient(120deg, rgba(255, 255, 255, 0.36) 0 1px, transparent 1px 100%),
        linear-gradient(0deg, rgba(95, 140, 157, 0.05) 0 1px, transparent 1px 100%);
      background-size: 86px 86px, 42px 42px;
      mask-image: linear-gradient(to bottom, rgba(0,0,0,0.8), rgba(0,0,0,0.18));
      z-index: -1;
    }

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

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button {
      font: inherit;
    }

    .container {
      width: min(100% - 40px, var(--container));
      margin: 0 auto;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(246, 250, 252, 0.78);
      backdrop-filter: blur(18px);
      border-bottom: 1px solid rgba(122, 154, 168, 0.2);
    }

    .nav {
      min-height: 72px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 20px;
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      letter-spacing: 0.04em;
      color: var(--primary-dark);
      white-space: nowrap;
    }

    .logo-mark {
      width: 42px;
      height: 42px;
      display: grid;
      place-items: center;
      border-radius: 15px;
      color: #123849;
      background:
        linear-gradient(145deg, rgba(255,255,255,0.96), rgba(210,232,238,0.86));
      border: 1px solid rgba(128, 168, 184, 0.36);
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.9), 0 10px 22px rgba(49, 96, 114, 0.12);
      font-size: 22px;
    }

    .brand-text {
      display: flex;
      flex-direction: column;
      line-height: 1.25;
    }

    .brand-text span:first-child {
      font-size: 16px;
    }

    .brand-text span:last-child {
      font-size: 12px;
      color: var(--muted);
      font-weight: 600;
    }

    .nav-links {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 8px;
    }

    .nav-links a {
      padding: 10px 12px;
      border-radius: 999px;
      color: #294353;
      font-size: 14px;
      font-weight: 650;
      transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
    }

    .nav-links a:hover {
      background: rgba(215, 235, 241, 0.86);
      color: var(--primary-dark);
      transform: translateY(-1px);
    }

    .nav-cta {
      margin-left: 6px;
      padding: 10px 16px;
      border-radius: 999px;
      background: #173f52;
      color: #ffffff;
      font-size: 14px;
      font-weight: 750;
      box-shadow: 0 10px 24px rgba(23, 63, 82, 0.18);
    }

    .menu-toggle {
      display: none;
      width: 42px;
      height: 42px;
      border: 1px solid var(--line);
      border-radius: 13px;
      background: rgba(255,255,255,0.76);
      color: var(--primary-dark);
      cursor: pointer;
    }

    .menu-toggle span {
      width: 18px;
      height: 2px;
      display: block;
      margin: 4px auto;
      background: currentColor;
      border-radius: 999px;
      transition: transform 0.2s ease, opacity 0.2s ease;
    }

    .hero {
      padding: 72px 0 42px;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
      gap: 34px;
      align-items: center;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 13px;
      border: 1px solid rgba(112, 153, 169, 0.28);
      border-radius: 999px;
      background: rgba(255, 255, 255, 0.66);
      color: var(--primary-dark);
      font-size: 13px;
      font-weight: 750;
      box-shadow: 0 8px 20px rgba(55, 101, 118, 0.06);
    }

    .eyebrow::before {
      content: "";
      width: 8px;
      height: 8px;
      border-radius: 99px;
      background: var(--accent);
      box-shadow: 0 0 0 5px rgba(143, 190, 205, 0.2);
    }

    h1 {
      margin: 18px 0 16px;
      max-width: 760px;
      font-size: clamp(34px, 7vw, 62px);
      line-height: 1.08;
      letter-spacing: -0.05em;
      color: #102533;
    }

    .hero-lead {
      max-width: 700px;
      margin: 0;
      color: #4e6371;
      font-size: clamp(16px, 2.4vw, 19px);
    }

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 46px;
      padding: 12px 20px;
      border-radius: 999px;
      border: 1px solid transparent;
      font-weight: 780;
      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
      cursor: pointer;
    }

    .btn-primary {
      background: linear-gradient(135deg, #174c63, #2f758d);
      color: #ffffff;
      box-shadow: 0 16px 34px rgba(31, 88, 110, 0.22);
    }

    .btn-secondary {
      background: rgba(255, 255, 255, 0.72);
      color: var(--primary-dark);
      border-color: rgba(109, 151, 166, 0.3);
    }

    .btn:hover {
      transform: translateY(-2px);
      box-shadow: 0 18px 36px rgba(31, 88, 110, 0.16);
    }

    .hero-note {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 24px;
    }

    .hero-note span {
      padding: 7px 11px;
      border-radius: 999px;
      background: rgba(255,255,255,0.62);
      color: #46616f;
      border: 1px solid rgba(122, 154, 168, 0.22);
      font-size: 13px;
      font-weight: 650;
    }

    .diagnosis-card {
      position: relative;
      padding: 26px;
      border-radius: var(--radius-lg);
      background:
        linear-gradient(160deg, rgba(255,255,255,0.92), rgba(234,246,250,0.72)),
        linear-gradient(45deg, rgba(255,255,255,0.58), transparent);
      border: 1px solid rgba(123, 163, 178, 0.28);
      box-shadow: var(--shadow);
      overflow: hidden;
    }

    .diagnosis-card::before {
      content: "";
      position: absolute;
      width: 210px;
      height: 210px;
      right: -62px;
      top: -78px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(177, 219, 230, 0.75), rgba(177, 219, 230, 0.06) 64%, transparent 70%);
      animation: breathe 6s ease-in-out infinite;
    }

    .risk-panel {
      position: relative;
      display: grid;
      gap: 14px;
    }

    .risk-top {
      display: flex;
      justify-content: space-between;
      gap: 16px;
      align-items: flex-start;
      padding-bottom: 16px;
      border-bottom: 1px solid var(--line);
    }

    .risk-top strong {
      display: block;
      font-size: 22px;
      color: #163448;
      line-height: 1.25;
    }

    .risk-top small {
      display: block;
      margin-top: 6px;
      color: var(--muted);
      font-weight: 600;
    }

    .frost-icon {
      width: 58px;
      height: 58px;
      flex: 0 0 auto;
      display: grid;
      place-items: center;
      border-radius: 19px;
      background: #e6f4f8;
      color: var(--primary-dark);
      font-size: 28px;
      border: 1px solid rgba(110, 156, 172, 0.22);
    }

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

    .check-list li {
      display: flex;
      gap: 11px;
      align-items: flex-start;
      padding: 12px 13px;
      border-radius: 16px;
      background: rgba(255,255,255,0.66);
      border: 1px solid rgba(116, 145, 160, 0.16);
      color: #344d5c;
      font-size: 14px;
    }

    .check-list li::before {
      content: "✓";
      width: 22px;
      height: 22px;
      flex: 0 0 auto;
      display: grid;
      place-items: center;
      border-radius: 50%;
      background: #d9eef4;
      color: #1d637c;
      font-size: 13px;
      font-weight: 900;
      margin-top: 1px;
    }

    .section {
      padding: 42px 0;
    }

    .section-head {
      display: flex;
      justify-content: space-between;
      align-items: flex-end;
      gap: 24px;
      margin-bottom: 22px;
    }

    .section-kicker {
      margin: 0 0 7px;
      color: var(--primary);
      font-weight: 850;
      font-size: 13px;
      letter-spacing: 0.08em;
      text-transform: uppercase;
    }

    h2 {
      margin: 0;
      color: #132c3c;
      font-size: clamp(26px, 4vw, 40px);
      line-height: 1.18;
      letter-spacing: -0.035em;
    }

    .section-desc {
      max-width: 450px;
      margin: 0;
      color: var(--muted);
      font-size: 15px;
    }

    .service-strip {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 16px;
    }

    .service-card {
      padding: 22px;
      border-radius: 24px;
      background: rgba(255,255,255,0.76);
      border: 1px solid rgba(126, 160, 174, 0.24);
      box-shadow: var(--shadow-soft);
      transition: transform 0.22s ease, border-color 0.22s ease, background 0.22s ease;
    }

    .service-card:hover {
      transform: translateY(-5px);
      border-color: rgba(48, 116, 141, 0.34);
      background: rgba(255,255,255,0.94);
    }

    .service-card .num {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 38px;
      height: 38px;
      margin-bottom: 14px;
      border-radius: 14px;
      background: #e5f3f7;
      color: var(--primary-dark);
      font-weight: 900;
    }

    h3 {
      margin: 0 0 8px;
      color: #183448;
      font-size: 18px;
      line-height: 1.35;
    }

    .service-card p,
    .solution-copy p,
    .guarantee-card p,
    .contact-card p {
      margin: 0;
      color: #5c6f7b;
      font-size: 14px;
    }

    .solution-wrap {
      display: grid;
      grid-template-columns: minmax(0, 0.88fr) minmax(0, 1.12fr);
      gap: 18px;
      align-items: stretch;
    }

    .solution-copy {
      padding: 26px;
      border-radius: var(--radius-lg);
      background: linear-gradient(180deg, rgba(236, 247, 250, 0.88), rgba(255,255,255,0.86));
      border: 1px solid rgba(121, 161, 175, 0.24);
      box-shadow: var(--shadow-soft);
    }

    .timeline {
      display: grid;
      gap: 12px;
      padding: 0;
      margin: 18px 0 0;
      list-style: none;
    }

    .timeline li {
      position: relative;
      padding: 14px 14px 14px 44px;
      border-radius: 18px;
      background: rgba(255,255,255,0.66);
      border: 1px solid rgba(116, 145, 160, 0.18);
    }

    .timeline li::before {
      content: attr(data-step);
      position: absolute;
      left: 13px;
      top: 14px;
      width: 22px;
      height: 22px;
      display: grid;
      place-items: center;
      border-radius: 50%;
      background: var(--primary-dark);
      color: #ffffff;
      font-size: 12px;
      font-weight: 900;
    }

    .timeline strong {
      display: block;
      color: #19364a;
      font-size: 15px;
      margin-bottom: 3px;
    }

    .timeline span {
      display: block;
      color: #637683;
      font-size: 13px;
    }

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

    .photo-card {
      overflow: hidden;
      border-radius: 22px;
      background: #e7f2f6;
      border: 1px solid rgba(122, 154, 168, 0.26);
      box-shadow: var(--shadow-soft);
    }

    .photo-card img {
      width: 100%;
      aspect-ratio: 4 / 3;
      object-fit: cover;
      transition: transform 0.5s ease;
    }

    .photo-card:hover img {
      transform: scale(1.04);
    }

    .guarantee-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 18px;
      align-items: stretch;
    }

    .guarantee-card {
      padding: 24px;
      border-radius: var(--radius-lg);
      background: rgba(255,255,255,0.78);
      border: 1px solid rgba(126, 160, 174, 0.24);
      box-shadow: var(--shadow-soft);
    }

    .policy-list {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 12px;
      margin: 18px 0 0;
      padding: 0;
      list-style: none;
    }

    .policy-list li {
      padding: 13px;
      border-radius: 16px;
      background: rgba(236, 247, 250, 0.72);
      color: #405a68;
      font-size: 13px;
      border: 1px solid rgba(116, 145, 160, 0.16);
    }

    .policy-list strong {
      display: block;
      margin-bottom: 3px;
      color: #18384c;
      font-size: 14px;
    }

    .cold-quote {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      min-height: 100%;
      padding: 28px;
      border-radius: var(--radius-lg);
      background:
        linear-gradient(145deg, rgba(227, 243, 248, 0.95), rgba(255,255,255,0.74)),
        radial-gradient(circle at 20% 10%, rgba(255,255,255,0.9), transparent 46%);
      border: 1px solid rgba(113, 151, 166, 0.26);
      box-shadow: var(--shadow-soft);
    }

    .cold-quote p {
      margin: 0;
      color: #294a5b;
      font-size: 18px;
      line-height: 1.75;
      font-weight: 650;
    }

    .cold-quote span {
      display: block;
      margin-top: 18px;
      color: var(--muted);
      font-size: 13px;
    }

    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 18px;
      align-items: stretch;
    }

    .contact-card {
      padding: 24px;
      border-radius: var(--radius-lg);
      background: rgba(255,255,255,0.82);
      border: 1px solid rgba(126, 160, 174, 0.24);
      box-shadow: var(--shadow-soft);
    }

    .contact-items {
      display: grid;
      gap: 12px;
      margin-top: 18px;
    }

    .contact-item {
      padding: 14px;
      border-radius: 17px;
      background: #eef7fa;
      border: 1px solid rgba(116, 145, 160, 0.16);
    }

    .contact-item strong {
      display: block;
      color: #18384c;
      margin-bottom: 3px;
    }

    .contact-item span,
    .contact-item a {
      color: #526b79;
      font-size: 14px;
    }

    .map-link {
      display: inline-flex;
      margin-top: 16px;
      color: #ffffff;
      background: #174c63;
      padding: 11px 16px;
      border-radius: 999px;
      font-weight: 780;
      box-shadow: 0 14px 28px rgba(23, 76, 99, 0.18);
    }

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

    .faq-item {
      border-radius: 20px;
      overflow: hidden;
      background: rgba(255,255,255,0.82);
      border: 1px solid rgba(126, 160, 174, 0.24);
      box-shadow: 0 8px 22px rgba(43, 86, 105, 0.06);
    }

    .faq-button {
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
      padding: 18px 20px;
      border: 0;
      background: transparent;
      color: #17364a;
      text-align: left;
      font-weight: 800;
      cursor: pointer;
    }

    .faq-button::after {
      content: "+";
      flex: 0 0 auto;
      width: 28px;
      height: 28px;
      display: grid;
      place-items: center;
      border-radius: 50%;
      background: #e5f3f7;
      color: var(--primary-dark);
      font-weight: 900;
      transition: transform 0.2s ease;
    }

    .faq-item.active .faq-button::after {
      transform: rotate(45deg);
    }

    .faq-panel {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.28s ease;
    }

    .faq-panel p {
      margin: 0;
      padding: 0 20px 18px;
      color: #5d707d;
      font-size: 14px;
    }

    .closing {
      padding: 8px 0 48px;
    }

    .closing-box {
      display: grid;
      grid-template-columns: minmax(0, 1fr) auto;
      gap: 22px;
      align-items: center;
      padding: 26px;
      border-radius: 30px;
      background: linear-gradient(135deg, #e9f6fa, #ffffff);
      border: 1px solid rgba(126, 160, 174, 0.26);
      box-shadow: var(--shadow);
    }

    .closing-box h2 {
      font-size: clamp(24px, 3.2vw, 34px);
    }

    .closing-box p {
      margin: 8px 0 0;
      color: var(--muted);
    }

    .site-footer {
      background: #e7f1f5;
      border-top: 1px solid rgba(111, 145, 160, 0.26);
      color: #203746;
    }

    .footer-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 18px;
      padding: 22px 0;
    }

    .footer-links {
      display: flex;
      flex-wrap: wrap;
      gap: 10px 16px;
      justify-content: flex-end;
    }

    .footer-links a {
      color: #2f5568;
      font-size: 13px;
      font-weight: 700;
    }

    .copyright {
      margin: 0;
      color: #526b79;
      font-size: 13px;
    }

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

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

    @keyframes breathe {
      0%, 100% {
        transform: scale(1);
        opacity: 0.72;
      }
      50% {
        transform: scale(1.08);
        opacity: 0.42;
      }
    }

    @media (max-width: 920px) {
      .menu-toggle {
        display: block;
      }

      .nav-links {
        position: absolute;
        left: 20px;
        right: 20px;
        top: 72px;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 6px;
        padding: 14px;
        border-radius: 20px;
        background: rgba(255,255,255,0.96);
        border: 1px solid rgba(122, 154, 168, 0.24);
        box-shadow: var(--shadow-soft);
      }

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

      .nav-links a,
      .nav-cta {
        width: 100%;
        margin: 0;
        text-align: center;
      }

      .hero {
        padding-top: 46px;
      }

      .hero-grid,
      .solution-wrap,
      .guarantee-grid,
      .contact-grid,
      .closing-box {
        grid-template-columns: 1fr;
      }

      .section-head {
        display: block;
      }

      .section-desc {
        margin-top: 10px;
      }

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

      .closing-box .btn {
        width: 100%;
      }
    }

    @media (max-width: 620px) {
      .container {
        width: min(100% - 28px, var(--container));
      }

      .hero-actions .btn {
        width: 100%;
      }

      .photo-grid,
      .policy-list {
        grid-template-columns: 1fr;
      }

      .diagnosis-card,
      .solution-copy,
      .guarantee-card,
      .cold-quote,
      .contact-card,
      .closing-box {
        border-radius: 22px;
        padding: 20px;
      }

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

      .footer-links {
        justify-content: flex-start;
      }
    }