/* roulang page: index */
:root {
      --primary: #0B2B40;
      --primary-dark: #0A1F2E;
      --accent-coral: #FF6B4A;
      --accent-coral-dark: #E55A3A;
      --accent-teal: #7EC8C8;
      --bg-light: #F5F7FA;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --text-on-dark: #F1F5F9;
      --white: #FFFFFF;
      --border-light: #CBD5E1;
      --shadow-card: 0 4px 20px rgba(11,43,64,0.06);
      --shadow-card-hover: 0 12px 32px rgba(11,43,64,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --radius-pill: 999px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
      --transition-smooth: 0.2s cubic-bezier(0.2, 0.0, 0, 1.0);
    }

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

    body {
      font-family: var(--font-sans);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.7;
      color: var(--text-main);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

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

    a {
      color: inherit;
      text-decoration: none;
      transition: color var(--transition-smooth);
    }

    button, input, textarea, select {
      font-family: inherit;
      font-size: inherit;
      line-height: inherit;
      outline: none;
      border: none;
      background: none;
    }

    button {
      cursor: pointer;
      transition: all var(--transition-smooth);
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    @media (max-width: 640px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 数字专用字体 */
    .number-font {
      font-family: var(--font-number);
      font-weight: 800;
    }

    /* 标题风格 */
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.25;
    }

    h1 {
      font-size: 48px;
      letter-spacing: -0.015em;
      line-height: 1.1;
      font-weight: 800;
    }

    h2 {
      font-size: 32px;
      letter-spacing: -0.005em;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
      line-height: 1.4;
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 26px;
      }
    }

    .section-padding {
      padding-top: 120px;
      padding-bottom: 120px;
    }

    @media (max-width: 1024px) {
      .section-padding {
        padding-top: 80px;
        padding-bottom: 80px;
      }
    }

    @media (max-width: 768px) {
      .section-padding {
        padding-top: 64px;
        padding-bottom: 64px;
      }
    }

    /* 导航栏 */
    .navbar {
      background-color: var(--white);
      position: sticky;
      top: 0;
      z-index: 50;
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
      backdrop-filter: blur(8px);
      background-color: rgba(255,255,255,0.95);
    }

    /* 卡片系统 */
    .card-custom {
      background-color: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 32px;
      transition: all var(--transition-smooth);
      border: none;
    }

    .card-custom:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    /* 按钮系统 */
    .btn-primary {
      background-color: var(--accent-coral);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      box-shadow: 0 2px 0 rgba(0,0,0,0.08);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all var(--transition-smooth);
    }
    .btn-primary:hover {
      background-color: var(--accent-coral-dark);
      box-shadow: 0 2px 0 rgba(0,0,0,0.12), inset 0 1px 2px rgba(0,0,0,0.1);
    }
    .btn-primary:active {
      transform: translateY(1px);
      box-shadow: none;
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      transition: all var(--transition-smooth);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-outline:hover {
      background-color: var(--primary);
      color: white;
    }

    .btn-ghost {
      border: 2px solid rgba(255,255,255,0.7);
      color: white;
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      transition: all var(--transition-smooth);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.1);
    }

    /* 表单输入 */
    .input-custom {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-btn);
      padding: 14px 16px;
      width: 100%;
      color: var(--text-main);
      transition: all var(--transition-smooth);
    }
    .input-custom::placeholder {
      color: #94A3B8;
    }
    .input-custom:focus {
      border-color: var(--accent-coral);
      box-shadow: 0 0 0 3px rgba(255,107,74,0.2);
    }

    /* 搜索框 */
    .search-box {
      background: white;
      border-radius: var(--radius-pill);
      border: 1px solid var(--border-light);
      padding: 12px 20px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-muted);
      transition: all var(--transition-smooth);
    }
    .search-box input {
      flex:1;
      border: none;
      background: transparent;
      font-size: 15px;
    }
    .search-box:focus-within {
      border-color: var(--accent-coral);
      box-shadow: 0 0 0 3px rgba(255,107,74,0.2);
    }

    /* 标签 */
    .tag {
      background-color: rgba(126,200,200,0.2);
      color: var(--primary);
      border-radius: 6px;
      padding: 4px 12px;
      font-size: 13px;
      font-weight: 500;
      display: inline-block;
    }

    /* 数据数字强视觉 */
    .data-number {
      font-family: var(--font-number);
      font-size: 40px;
      font-weight: 800;
      color: var(--accent-coral);
      line-height: 1.2;
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid #E2E8F0;
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-weight: 600;
      font-size: 18px;
      gap: 16px;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--primary);
      transition: all 0.3s ease;
      flex-shrink: 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-muted);
      padding-right: 40px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-icon {
      color: var(--accent-coral);
      transform: rotate(45deg);
    }

    /* Hero 背景装饰 */
    .hero-bg {
      background: linear-gradient(135deg, #0B2B40 0%, #0A1F2E 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-bg::before {
      content: "";
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(126,200,200,0.15) 0%, transparent 60%);
      pointer-events: none;
    }
    .wave-decoration {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 80px;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 80" preserveAspectRatio="none"><path fill="%23F5F7FA" d="M0,40 C240,80 480,0 720,40 C960,80 1200,0 1440,40 L1440,80 L0,80 Z"/></svg>') no-repeat bottom center;
      background-size: cover;
    }

    @media (max-width: 768px) {
      .navbar .nav-links {
        display: none;
      }
    }