/* roulang page: index */
:root {
      --color-primary: #2B2B28;
      --color-accent: #C8A882;
      --color-bg: #FAF8F5;
      --color-emphasis: #4A6B5F;
      --color-text: #1E1E1C;
      --color-text-soft: #6B6B66;
      --color-card-bg: #FFFFFF;
      --color-card-alt: #F5F3EF;
      --color-border: #E8E5E0;
      --color-utility-bg: #F0EDE8;
      --font-serif: 'Noto Serif SC', Georgia, serif;
      --font-sans: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      --font-mono: 'Inter', 'DM Sans', monospace;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 2px 8px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.06);
      --transition-base: all 0.25s ease;
      --max-width: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--color-bg);
    }
    body {
      font-family: var(--font-sans);
      font-weight: 400;
      line-height: 1.7;
      color: var(--color-text);
      background-color: var(--color-bg);
      -webkit-font-smoothing: antialiased;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }
    /* 顶部信息条 */
    .utility-bar {
      background-color: var(--color-utility-bg);
      color: var(--color-text-soft);
      font-size: 12px;
      font-weight: 400;
      padding: 6px 0;
      border-bottom: 1px solid rgba(0,0,0,0.03);
    }
    .utility-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 10px;
    }
    .utility-left {
      display: flex;
      align-items: center;
      gap: 12px;
      letter-spacing: 0.02em;
    }
    .utility-right {
      display: flex;
      align-items: center;
      gap: 18px;
    }
    .utility-right a {
      color: var(--color-text-soft);
      font-weight: 500;
    }
    .utility-right a:hover {
      color: var(--color-accent);
    }
    /* 主导航 */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: transparent;
      backdrop-filter: blur(0px);
      transition: background 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
    }
    .main-header.scrolled {
      background: rgba(250,248,245,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 16px rgba(0,0,0,0.04);
    }
    .nav-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 72px;
    }
    .logo {
      font-family: var(--font-serif);
      font-size: 26px;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--color-primary);
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .logo-icon {
      width: 36px;
      height: 36px;
      background: linear-gradient(135deg, #2B2B28 0%, #4A4A45 100%);
      mask-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 2L2 22h20L12 2zm0 4.5L18.5 20h-13L12 6.5z"/></svg>');
      mask-size: contain;
      background-color: var(--color-accent);
      display: inline-block;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      font-size: 15px;
      color: var(--color-primary);
    }
    .nav-links a {
      position: relative;
      padding: 8px 0;
      color: var(--color-primary);
    }
    .nav-links a:hover {
      color: var(--color-accent);
    }
    .nav-links a.active {
      color: var(--color-accent);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--color-accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--color-primary);
      transition: 0.2s;
    }
    .hamburger span.short {
      width: 16px;
    }
    @media (max-width: 1024px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: var(--color-bg);
        flex-direction: column;
        justify-content: center;
        align-items: flex-start;
        padding: 40px;
        gap: 28px;
        font-size: 24px;
        z-index: 60;
      }
      .nav-links.mobile-open {
        display: flex;
      }
      .hamburger {
        display: flex;
        z-index: 70;
      }
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-family: var(--font-serif);
      font-weight: 700;
      font-size: 36px;
      letter-spacing: -0.02em;
      margin-bottom: 20px;
      color: var(--color-primary);
    }
    .section-sub {
      color: var(--color-text-soft);
      font-size: 18px;
      max-width: 600px;
    }
    /* Hero */
    .hero {
      min-height: 85vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
    }
    .hero-grid {
      display: flex;
      gap: 60px;
      align-items: center;
    }
    .hero-left {
      flex: 1 1 45%;
    }
    .hero-right {
      flex: 1 1 55%;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 8px 28px rgba(0,0,0,0.06);
    }
    .hero-right img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/4.5;
    }
    .hero h1 {
      font-family: var(--font-serif);
      font-size: 52px;
      font-weight: 700;
      line-height: 1.15;
      color: var(--color-primary);
      margin-bottom: 20px;
    }
    .hero h2 {
      font-size: 22px;
      font-weight: 400;
      color: var(--color-text-soft);
      margin-bottom: 36px;
    }
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 18px;
    }
    .btn-primary {
      background: var(--color-primary);
      color: #FAF8F5;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      display: inline-block;
      transition: 0.25s;
    }
    .btn-primary:hover {
      background: #1E1E1C;
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(0,0,0,0.08);
    }
    .btn-outline {
      border: 1.5px solid var(--color-primary);
      color: var(--color-primary);
      background: transparent;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--color-primary);
      color: #FAF8F5;
    }
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero h1 {
        font-size: 42px;
      }
    }
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
    }
    .highlight-card {
      background: var(--color-card-bg);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: 0.25s;
    }
    .highlight-card.large {
      grid-row: span 2;
    }
    .highlight-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .icon-line {
      font-size: 28px;
      color: var(--color-accent);
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 左右图文 */
    .service-row {
      display: flex;
      gap: 60px;
      align-items: center;
      margin-bottom: 100px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1 1 50%;
      border-radius: 12px;
      overflow: hidden;
    }
    .service-text {
      flex: 1 1 50%;
    }
    @media (max-width: 768px) {
      .service-row, .service-row.reverse {
        flex-direction: column;
        gap: 30px;
        margin-bottom: 70px;
      }
    }
    /* 瀑布流 */
    .masonry {
      columns: 3;
      column-gap: 24px;
    }
    .masonry-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .masonry-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    @media (max-width: 1024px) { .masonry { columns: 2; } }
    @media (max-width: 640px) { .masonry { columns: 1; } }
    /* 流程 */
    .steps {
      display: flex;
      justify-content: center;
      gap: 30px;
      flex-wrap: wrap;
    }
    .step-item {
      text-align: center;
      flex: 1 1 160px;
    }
    /* 对比卡片 */
    .compare-cards {
      display: flex;
      gap: 30px;
      flex-wrap: wrap;
    }
    .compare-card {
      flex: 1;
      background: white;
      padding: 40px;
      border-radius: 16px;
      box-shadow: var(--shadow-card);
    }
    .compare-card.recommended {
      border: 2px solid var(--color-accent);
      background: #FFFBF5;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--color-border);
    }
    .faq-question {
      font-weight: 600;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: #4A4A45;
    }
    /* Footer */
    .footer {
      background: #2B2B28;
      color: #C8A882;
      padding: 60px 0 30px;
    }
    .copyright {
      color: #9B9B93;
      margin-top: 30px;
    }