/* roulang page: index */
:root {
      --primary: #F04E23;
      --primary-hover: #D43D1A;
      --secondary: #1E1E1E;
      --accent: #C7F000;
      --bg-light: #FAFAFA;
      --bg-card: #FFFFFF;
      --text-primary: #1E1E1E;
      --text-secondary: #555555;
      --text-muted: #888888;
      --border-light: #E8E8E8;
      --radius-card: 16px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 16px rgba(0,0,0,0.04), 0 0 0 1px rgba(0,0,0,0.02);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08);
      --transition: 0.25s cubic-bezier(0.25, 0.1, 0.25, 1);
      --container: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    .inter {
      font-family: 'Inter', 'SF Pro Display', sans-serif;
    }
    .container {
      width: 100%;
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      border: none;
      background: none;
      font-family: inherit;
    }
    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.2px;
    }
    h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 800;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 36px;
      line-height: 1.25;
      font-weight: 700;
    }
    h3 {
      font-size: 22px;
      line-height: 1.4;
      font-weight: 600;
    }

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      background: transparent;
      height: 72px;
      display: flex;
      align-items: center;
    }
    #nav.scrolled {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    #nav .nav-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
      height: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: #fff;
      display: flex;
      align-items: center;
      gap: 8px;
      transition: color 0.3s;
      letter-spacing: 1px;
    }
    .logo .dot {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 4px;
      display: inline-block;
      margin-right: 6px;
    }
    #nav.scrolled .logo {
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      transition: color 0.3s;
      font-size: 15px;
    }
    #nav.scrolled .nav-links {
      color: var(--text-secondary);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(240,78,35,0.2);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(240,78,35,0.35);
      color: #fff;
    }
    .btn-outline {
      border: 1.5px solid var(--secondary);
      background: transparent;
      color: var(--secondary);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-outline:hover {
      background: var(--secondary);
      color: #fff;
    }
    .btn-white {
      border: 1.5px solid #fff;
      color: #fff;
    }
    .btn-white:hover {
      background: #fff;
      color: var(--secondary);
    }
    .mobile-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.88);
      backdrop-filter: blur(12px);
      border-top: 1px solid var(--border-light);
      padding: 8px 24px;
      justify-content: space-around;
      align-items: center;
      z-index: 1000;
    }
    @media (max-width: 768px) {
      #nav .nav-links, #nav .btn-primary {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .container { padding: 0 16px; }
    }
    .mobile-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 12px;
      color: var(--text-muted);
      gap: 4px;
      font-weight: 500;
    }
    .mobile-nav a i { font-size: 20px; }
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section { padding: 70px 0; }
    }

    /* Hero */
    #hero {
      position: relative;
      height: 100vh;
      min-height: 650px;
      display: flex;
      align-items: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      overflow: hidden;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 50%, rgba(240,78,35,0.2) 0%, rgba(30,30,30,0.65) 80%);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      color: #fff;
      display: flex;
      flex-direction: column;
      gap: 28px;
      max-width: 650px;
    }
    .hero-data {
      display: flex;
      gap: 32px;
      flex-wrap: wrap;
      margin: 16px 0;
    }
    .hero-data div h3 {
      color: var(--accent);
      font-size: 32px;
      font-weight: 700;
    }
    .cta-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
      margin-top: 12px;
    }

    /* Features 图文交替 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      transition: 0.3s;
    }
    .feature-img img {
      object-fit: cover;
      width: 100%;
      height: auto;
      aspect-ratio: 4/3;
    }
    .feature-text {
      flex: 1;
    }
    @media (max-width: 768px) {
      .feature-row, .feature-row.reverse {
        flex-direction: column;
        gap: 30px;
      }
    }

    /* 课程网格 */
    .programs-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .program-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: var(--transition);
    }
    .program-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .program-img {
      height: 180px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .badge {
      background: rgba(199,240,0,0.2);
      color: var(--secondary);
      border: 1px solid var(--accent);
      padding: 4px 12px;
      border-radius: 30px;
      font-size: 12px;
      font-weight: 600;
    }
    @media (max-width: 1024px) {
      .programs-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .programs-grid { display: flex; overflow-x: auto; scroll-snap-type: x mandatory; gap: 16px; }
      .program-card { min-width: 260px; scroll-snap-align: start; }
    }

    /* 场景拼图 */
    .scenario-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .scenario-item {
      border-radius: 16px;
      height: 320px;
      background-size: cover;
      position: relative;
      overflow: hidden;
    }
    .scenario-mask {
      position: absolute;
      bottom: 0;
      width: 100%;
      padding: 30px;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      color: #fff;
      transition: 0.3s;
    }
    @media (max-width: 768px) {
      .scenario-grid { grid-template-columns: 1fr; }
    }

    /* 成果滚动 */
    .testimonial-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      padding-bottom: 8px;
    }
    .testimonial-card {
      min-width: 320px;
      background: #f5f5f5;
      border-radius: 16px;
      padding: 24px;
      scroll-snap-align: start;
    }
    .progress-bar {
      height: 6px;
      background: #ddd;
      border-radius: 4px;
      margin-top: 6px;
      width: 100%;
    }
    .progress-fill {
      height: 100%;
      width: 0%;
      background: var(--accent);
      border-radius: 4px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--secondary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: #555;
    }
    .faq-item.active .faq-answer { max-height: 200px; padding-top: 12px; }
    .faq-item.active .faq-question { color: var(--primary); }

    #cta {
      background: var(--secondary);
      text-align: center;
      color: #fff;
    }
    #footer {
      background: var(--secondary);
      color: #aaa;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.8fr 1fr 1.2fr 1.5fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }