/* roulang page: index */
:root {
      --primary-red: #E63946;
      --deep-black: #1D1D1F;
      --track-gray: #F2F2F4;
      --gold: #F4A261;
      --white: #FFFFFF;
      --soft-red-bg: #FFF5F5;
      --text-primary: #1D1D1F;
      --text-secondary: #4A4A4E;
      --border-light: rgba(0,0,0,0.05);
      --shadow-card: 0px 8px 30px rgba(0,0,0,0.06);
      --shadow-hover: 0px 16px 40px rgba(0,0,0,0.12);
      --radius-lg: 24px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', Roboto, sans-serif;
      --section-gap: 100px;
      --container-max: 1280px;
      --container-padding: 40px;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--track-gray);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, input, textarea {
      font-family: inherit;
      outline: none;
    }

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

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(0,0,0,0.03);
      transition: all 0.3s ease;
    }

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

    .logo {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--deep-black);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--primary-red);
    }

    .nav-links {
      display: flex;
      gap: 2.5rem;
      align-items: center;
      font-weight: 500;
      color: var(--text-secondary);
    }

    .nav-links a {
      font-size: 1rem;
      position: relative;
      padding: 0.5rem 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary-red);
      transition: width 0.2s ease;
    }

    .nav-links a:hover {
      color: var(--primary-red);
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .nav-cta {
      background: var(--primary-red);
      color: white;
      padding: 0.6rem 1.5rem;
      border-radius: 40px;
      font-weight: 600;
      transition: background 0.2s ease, transform 0.2s;
    }
    .nav-cta:hover {
      background: #c5303c;
      color: white;
      transform: translateY(-1px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      width: 28px;
    }
    .hamburger span {
      display: block;
      height: 2px;
      background: var(--deep-black);
      border-radius: 4px;
      transition: 0.3s;
    }

    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(20px);
      border-top: 1px solid rgba(0,0,0,0.05);
      padding: 8px 20px;
      justify-content: space-around;
      align-items: center;
      z-index: 999;
      border-radius: 32px 32px 0 0;
      box-shadow: 0 -4px 20px rgba(0,0,0,0.04);
    }
    .mobile-bottom-nav a {
      font-size: 0.7rem;
      color: var(--text-secondary);
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      font-weight: 500;
    }
    .mobile-bottom-nav .center-cta {
      background: var(--primary-red);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-top: -24px;
      box-shadow: 0 8px 20px rgba(230,57,70,0.3);
      font-size: 1.5rem;
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(175deg, #1D1D1F 0%, #2a2a2d 50%, #1D1D1F 100%);
      color: white;
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-right img {
      border-radius: var(--radius-lg);
      box-shadow: 0 30px 50px rgba(0,0,0,0.5);
      width: 100%;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .hero h1 {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 3.4rem;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      color: white;
    }
    .hero h1 span {
      color: var(--primary-red);
    }
    .hero p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2rem;
      max-width: 90%;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-red);
      color: white;
      padding: 0.9rem 2.2rem;
      border-radius: 40px;
      font-weight: 700;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      border: none;
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-primary:hover {
      background: #c5303c;
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.5);
      color: white;
      padding: 0.9rem 2rem;
      border-radius: 40px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
    }

    /* 板块标题 */
    .section-title {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 2.5rem;
      margin-bottom: 1rem;
      color: var(--deep-black);
    }
    .section-sub {
      color: var(--text-secondary);
      font-size: 1.1rem;
      margin-bottom: 3rem;
    }

    /* 亮点网格 */
    .highlights {
      padding: var(--section-gap) 0;
      background: white;
    }
    .grid-2x3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .stat-card {
      background: var(--track-gray);
      border-radius: var(--radius-lg);
      padding: 2rem 1.8rem;
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
      position: relative;
    }
    .stat-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .stat-badge {
      color: var(--gold);
      font-weight: 700;
      font-size: 0.9rem;
      letter-spacing: 0.5px;
      margin-bottom: 1rem;
    }
    .stat-number {
      font-family: 'DIN Alternate', 'Impact', sans-serif;
      font-weight: 800;
      font-size: 3.8rem;
      color: var(--deep-black);
      line-height: 1;
      margin-bottom: 0.5rem;
    }
    .stat-desc {
      color: var(--text-secondary);
    }

    /* 案例瀑布流 */
    .cases {
      padding: var(--section-gap) 0;
      background: var(--track-gray);
    }
    .waterfall {
      columns: 3;
      column-gap: 24px;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.2s;
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      position: relative;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      display: block;
      transition: transform 0.4s;
      aspect-ratio: 16/10;
      object-fit: cover;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-info {
      padding: 1.2rem;
      font-weight: 600;
    }
    .case-tag {
      color: var(--primary-red);
      font-size: 0.8rem;
      margin-bottom: 4px;
    }

    /* 对比区 */
    .compare {
      padding: var(--section-gap) 0;
      background: white;
    }
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
    .compare-card {
      background: var(--track-gray);
      border-radius: var(--radius-lg);
      padding: 2.5rem;
    }
    .compare-card.highlight {
      background: var(--soft-red-bg);
      border-left: 5px solid var(--primary-red);
    }
    .compare-card h3 {
      font-weight: 700;
      margin-bottom: 1.5rem;
    }
    .compare-list {
      list-style: none;
    }
    .compare-list li {
      margin-bottom: 1rem;
      display: flex;
      align-items: center;
      gap: 0.7rem;
    }
    .check-green {
      color: #2a9d8f;
      font-weight: bold;
    }

    /* FAQ */
    .faq {
      padding: var(--section-gap) 0;
      background: var(--track-gray);
    }
    .accordion {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 1rem;
      overflow: hidden;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .faq-question {
      padding: 1.5rem;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      padding: 0 1.5rem 1.5rem;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active {
      border-left: 4px solid var(--primary-red);
      background: #fafafa;
    }

    /* CTA */
    .cta-section {
      padding: var(--section-gap) 0;
      background: radial-gradient(circle at 30% 30%, #E63946, #1D1D1F);
      color: white;
      text-align: center;
    }
    .cta-form {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      justify-content: center;
      margin-top: 2rem;
    }
    .cta-form input {
      padding: 1rem;
      border-radius: 40px;
      border: none;
      min-width: 220px;
      background: rgba(255,255,255,0.9);
    }
    .btn-gold {
      background: var(--gold);
      color: var(--deep-black);
      font-weight: 700;
      padding: 1rem 2.5rem;
      border-radius: 40px;
      border: none;
      cursor: pointer;
    }

    footer {
      background: var(--deep-black);
      color: rgba(255,255,255,0.7);
      padding: 3rem 0;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 2rem;
    }
    .footer-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: white;
    }

    @media (max-width: 1024px) {
      .grid-2x3 { grid-template-columns: repeat(2,1fr); }
      .waterfall { columns: 2; }
    }
    @media (max-width: 768px) {
      :root { --section-gap: 70px; --container-padding: 24px; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero .container { flex-direction: column; }
      .hero h1 { font-size: 2.4rem; }
      .grid-2x3 { grid-template-columns: 1fr; }
      .waterfall { columns: 1; }
      .compare-grid { grid-template-columns: 1fr; }
      .mobile-bottom-nav { display: flex; }
      .header { top: auto; bottom: auto; position: relative; }
      body { padding-bottom: 80px; }
      .hero { padding-top: 40px; }
    }