/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary-coral: #FF6B4A;
      --primary-deep: #E55A3A;
      --secondary-dark: #1E2A2F;
      --bg-warm: #F7F5F0;
      --green-accent: #2E7D32;
      --green-light-bg: #EDF3EC;
      --white-soft: #FFFFFF;
      --text-body: #2C3A40;
      --text-muted: #5F6C72;
      --border-light: rgba(0,0,0,0.05);
      --border-card: rgba(0,0,0,0.08);
      --shadow-card: 0 8px 24px rgba(0,0,0,0.04);
      --shadow-hover: 0 16px 32px rgba(0,0,0,0.08);
      --radius-lg: 24px;
      --radius-md: 18px;
      --radius-sm: 12px;
      --radius-btn: 50px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --font-number: 'Inter', 'Outfit', sans-serif;
      --transition: all 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.6;
      font-size: 16px;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* ----- 导航系统 (沉浸式透明->深色) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 999;
      background: rgba(255,255,255,0.75);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.2);
      transition: background 0.3s, box-shadow 0.3s;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .site-header.scrolled {
      background: rgba(30,42,47,0.92);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.1);
      box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--secondary-dark);
      letter-spacing: -0.3px;
    }
    .scrolled .logo {
      color: white;
    }
    .logo-icon {
      background: var(--primary-coral);
      color: white;
      width: 38px;
      height: 38px;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--secondary-dark);
    }
    .scrolled .nav-links {
      color: rgba(255,255,255,0.9);
    }
    .nav-links a {
      position: relative;
      padding: 6px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--primary-coral);
      border-radius: 3px;
      transition: width 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .menu-toggle {
      display: none;
      background: transparent;
      font-size: 1.6rem;
      color: var(--secondary-dark);
    }
    .scrolled .menu-toggle {
      color: white;
    }

    /* ----- 通用板块 ----- */
    section {
      padding: 80px 0;
      position: relative;
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--secondary-dark);
      letter-spacing: -0.5px;
      margin-bottom: 12px;
    }
    .section-title p {
      color: var(--text-muted);
      font-size: 1.1rem;
      max-width: 600px;
      margin: 0 auto;
    }

    /* 按钮体系 */
    .btn-primary {
      background: var(--primary-coral);
      color: white;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      box-shadow: 0 8px 18px rgba(255, 107, 74, 0.3);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 12px 24px rgba(229, 90, 58, 0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-coral);
      color: var(--primary-coral);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(255,107,74,0.08);
    }
    .btn-light {
      background: white;
      color: var(--secondary-dark);
      border-radius: var(--radius-btn);
    }

    /* Hero 区域 */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(135deg, #FF6B4A 0%, #FFB347 100%);
      color: white;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 3.4rem;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .hero-text p {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 36px;
    }
    .hero-image img {
      border-radius: 80px 20px 80px 20px;
      box-shadow: 0 30px 45px rgba(0,0,0,0.2);
      transform: rotate(1deg);
    }

    /* 卡片系统 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 28px;
    }
    .feature-card {
      background: var(--white-soft);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: 0.25s;
      border-top: 5px solid transparent;
    }
    .feature-card:nth-child(1) { border-top-color: #66BB6A; }
    .feature-card:nth-child(2) { border-top-color: #FF6B4A; }
    .feature-card:nth-child(3) { border-top-color: #FFB347; }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .season-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 30px;
      margin-top: 30px;
    }
    .season-card {
      background: white;
      border-radius: var(--radius-lg);
      display: flex;
      align-items: center;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.2s;
    }
    .season-img {
      width: 45%;
      height: 220px;
      object-fit: cover;
    }
    .season-content {
      padding: 24px;
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .pricing-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 40px 24px;
      text-align: center;
      box-shadow: var(--shadow-card);
    }
    .pricing-card.recommend {
      border: 2px solid var(--primary-coral);
      transform: scale(1.03);
      box-shadow: 0 20px 30px rgba(255,107,74,0.15);
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: #fafaf8;
      padding: 0 24px;
    }
    .footer {
      background: var(--secondary-dark);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .back-to-top {
      position: fixed;
      bottom: 30px;
      right: 30px;
      background: var(--primary-coral);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 8px 18px rgba(0,0,0,0.2);
    }

    @media (max-width: 1024px) {
      .hero-grid, .season-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .card-grid, .pricing-grid { grid-template-columns: 1fr; }
      h1 { font-size: 2.4rem; }
    }