/* roulang page: index */
:root {
      --sport-red: #E43D2A;
      --dark-rock: #1C1C1E;
      --warm-bg: #F7F5F2;
      --track-yellow: #F5A623;
      --text-primary: #1C1C1E;
      --text-secondary: #5C5C5E;
      --card-bg: #FFFFFF;
      --border-light: rgba(0,0,0,0.08);
      --shadow-sm: 0 2px 12px rgba(28,28,30,0.06);
      --shadow-hover: 0 8px 28px rgba(228,61,42,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --spacing-section: 100px;
      --spacing-card: 24px;
      --font-hero: clamp(2.5rem, 6vw, 3.5rem);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      background-color: var(--warm-bg);
      color: var(--text-primary);
      margin: 0;
      line-height: 1.75;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航栏 */
    .desktop-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--dark-rock);
      z-index: 100;
      display: flex;
      align-items: center;
      box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: white;
    }
    .logo span {
      color: var(--sport-red);
      font-weight: 800;
      margin-right: 4px;
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      color: #f0f0f0;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 0.4rem 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--track-yellow);
      transition: width 0.25s ease;
    }
    .nav-links a:hover {
      color: white;
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--sport-red);
      color: white;
      border: none;
      padding: 0.6rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
      border: 2px solid transparent;
    }
    .btn-primary:hover {
      background: #C83220;
      transform: translateY(-2px);
      box-shadow: 0 6px 18px rgba(228,61,42,0.4);
      color: white;
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--sport-red);
      color: var(--sport-red);
      padding: 0.5rem 1.6rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(228,61,42,0.08);
      color: #C83220;
    }

    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--dark-rock);
      border-top: 1px solid rgba(255,255,255,0.1);
      z-index: 100;
      justify-content: space-around;
      align-items: center;
    }
    .mobile-bottom-nav a {
      color: #aaa;
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      transition: color 0.2s;
    }
    .mobile-bottom-nav a i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }
    .mobile-bottom-nav a.active {
      color: var(--sport-red);
    }

    @media (max-width: 640px) {
      .desktop-nav .nav-links {
        display: none;
      }
      .desktop-nav .nav-container {
        justify-content: center;
      }
      .mobile-bottom-nav {
        display: flex;
      }
      body {
        padding-bottom: 70px;
      }
    }

    /* Hero */
    #hero {
      min-height: 90vh;
      background: radial-gradient(circle at 30% 20%, rgba(228,61,42,0.9), #1C1C1E 90%);
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      margin-top: 0;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.2;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      width: 100%;
      padding: 2rem 20px;
      color: white;
    }
    .hero-title {
      font-size: var(--font-hero);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.2rem;
    }
    .hero-title .red-highlight {
      color: var(--sport-red);
      display: inline;
    }
    .hero-sub {
      font-size: 1.1rem;
      color: #ddd;
      max-width: 600px;
      margin-bottom: 2rem;
    }
    .hero-stats {
      display: flex;
      gap: 2rem;
      margin-top: 2.5rem;
      flex-wrap: wrap;
    }
    .stat-item {
      display: flex;
      flex-direction: column;
    }
    .stat-number {
      font-family: 'DIN Alternate', 'PingFang SC', sans-serif;
      font-weight: 700;
      font-size: 2.2rem;
      color: var(--track-yellow);
      letter-spacing: 1px;
    }

    /* 通用区块 */
    section {
      padding: var(--spacing-section) 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 0.8rem;
      color: var(--dark-rock);
      text-align: center;
    }
    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 3rem auto;
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--spacing-card);
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .card-icon {
      font-size: 2.3rem;
      color: var(--sport-red);
      margin-bottom: 1.2rem;
      background: rgba(228,61,42,0.08);
      width: 56px;
      height: 56px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
    }
    .card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 0.6rem;
    }
    .card p {
      color: var(--text-secondary);
      flex: 1;
    }

    /* 数据优势 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      text-align: center;
    }
    .data-item .big-number {
      font-family: 'DIN Alternate', sans-serif;
      font-weight: 700;
      font-size: 3rem;
      color: var(--track-yellow);
    }

    /* 案例卡片 */
    .case-card img {
      border-radius: 8px;
      aspect-ratio: 16/9;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-card:hover img {
      transform: scale(1.02);
    }
    .tag {
      color: var(--sport-red);
      font-weight: 600;
      font-size: 0.8rem;
    }

    /* 解决方案图文 */
    .solution-row {
      display: flex;
      gap: 2.5rem;
      align-items: center;
      margin-bottom: 3rem;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    .solution-text {
      flex: 1;
    }

    /* FAQ */
    .accordion-item {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: 8px;
      margin-bottom: 12px;
    }
    .accordion-title {
      font-weight: 600;
      padding: 1rem 1.5rem;
      cursor: pointer;
      border-left: 4px solid var(--sport-red);
      transition: 0.2s;
    }
    .accordion-title.active {
      border-left-color: var(--track-yellow);
    }

    /* CTA区块 */
    .cta-dark {
      background: var(--dark-rock);
      color: white;
      border-radius: var(--radius-card);
      padding: 3rem;
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .cta-form input, .cta-form textarea {
      width: 100%;
      margin-bottom: 1rem;
      border-radius: var(--radius-input);
      border: 1px solid #ccc;
      padding: 0.7rem;
    }
    .cta-form input:focus {
      border-color: var(--sport-red);
      outline: none;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .data-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 640px) {
      .grid-3 { grid-template-columns: 1fr; }
      .data-grid { grid-template-columns: 1fr 1fr; }
      .solution-row, .solution-row.reverse { flex-direction: column; }
      .cta-dark { flex-direction: column; }
      .hero-title { font-size: 2rem; }
    }
    footer a {
      color: #ccc;
    }