/* roulang page: index */
:root {
      --primary-deep: #0D3B2E;
      --accent-cyan: #00E5A1;
      --bg-warm: #F9F9F7;
      --bg-dark: #0A1F1A;
      --text-main: #1A1A1A;
      --text-sub: #5C6B63;
      --text-on-dark: #FFFFFF;
      --text-ondark-sub: #B0CCC2;
      --border-light: #E0E5E2;
      --card-bg: #FFFFFF;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      --max-width: 1200px;
      --section-gap: 120px;
      --btn-transition: all 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      font-weight: 400;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 80px;
      background: transparent;
      backdrop-filter: blur(0px);
      z-index: 1000;
      transition: background 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
      display: flex;
      align-items: center;
    }
    .site-header.scrolled {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: #fff;
      transition: color 0.3s;
      white-space: nowrap;
    }
    .scrolled .logo {
      color: var(--primary-deep);
    }
    .main-nav {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
    }
    .main-nav a {
      font-size: 16px;
      color: rgba(255,255,255,0.9);
      transition: color 0.2s;
    }
    .scrolled .main-nav a {
      color: var(--text-main);
    }
    .main-nav a:hover {
      color: var(--accent-cyan);
    }
    .nav-cta {
      background: var(--accent-cyan);
      color: #0A1F1A !important;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--btn-transition);
      display: inline-block;
    }
    .nav-cta:hover {
      background: #1AFFB5;
      transform: scale(1.03);
      box-shadow: 0 4px 14px rgba(0,229,161,0.4);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: #fff;
      border-radius: 2px;
      transition: 0.3s;
    }
    .scrolled .hamburger span {
      background: var(--primary-deep);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      box-shadow: -4px 0 20px rgba(0,0,0,0.1);
      flex-direction: column;
      padding: 100px 32px 32px;
      gap: 28px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.active {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--text-main);
      border-bottom: 1px solid var(--border-light);
      padding-bottom: 10px;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0D3B2E 0%, #0A1F1A 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 80px;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: -20%;
      right: -10%;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(0,229,161,0.15) 0%, transparent 70%);
      border-radius: 50%;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
      width: 100%;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: #fff;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: #B0CCC2;
      margin-bottom: 36px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A1F1A;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: none;
      font-size: 16px;
      cursor: pointer;
      transition: var(--btn-transition);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #1AFFB5;
      transform: scale(1.03);
      box-shadow: 0 8px 22px rgba(0,229,161,0.45);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-deep);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: var(--btn-transition);
      background: #fff;
    }
    .btn-outline:hover {
      background: var(--primary-deep);
      color: #fff;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      max-height: 380px;
      object-fit: contain;
      border-radius: 24px;
    }
    /* 板块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-title h2 {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-main);
      display: inline-block;
      position: relative;
    }
    .section-title h2::after {
      content: "";
      display: block;
      width: 40px;
      height: 2px;
      background: var(--accent-cyan);
      margin: 16px auto 0;
    }
    /* Features 不对称栅格 */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr;
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 64px;
      height: 64px;
      background: #F4F7F5;
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--accent-cyan);
      font-size: 28px;
    }
    .feature-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .feature-card p {
      color: var(--text-sub);
    }
    /* Versions */
    .versions-grid {
      display: flex;
      gap: 24px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .version-card {
      background: #fff;
      border-radius: var(--radius-card);
      padding: 32px;
      flex: 1;
      min-width: 260px;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
      border: 1px solid transparent;
    }
    .version-card.recommend {
      border-color: var(--accent-cyan);
      box-shadow: 0 8px 28px rgba(0,229,161,0.2);
    }
    .version-card h3 {
      font-size: 24px;
      margin-bottom: 20px;
    }
    .version-list {
      list-style: none;
      margin-bottom: 28px;
    }
    .version-list li {
      padding: 8px 0;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-sub);
    }
    .check-icon {
      color: var(--accent-cyan);
      font-weight: bold;
    }
    /* Scenarios */
    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .scenario-card {
      background: #fff;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .scenario-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .scenario-text {
      padding: 24px;
    }
    /* Stats */
    .stats-section {
      background: var(--bg-dark);
      padding: 80px 0;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 32px;
    }
    .stat-item {
      text-align: center;
      color: #fff;
    }
    .stat-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    .stat-label {
      color: #B0CCC2;
      margin-top: 8px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border: 1px solid var(--border-light);
      border-radius: 8px;
      margin-bottom: 12px;
      background: #fff;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: #fff;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F4F7F5;
      padding: 0 24px;
      color: var(--text-sub);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 18px 24px;
    }
    /* CTA */
    .cta-section {
      background: var(--bg-dark);
      padding: 100px 0;
      text-align: center;
    }
    .cta-section h2 {
      color: #fff;
    }
    .trust-badges {
      margin-top: 24px;
      color: #B0CCC2;
      font-size: 14px;
    }
    /* Footer */
    .footer {
      background: #0A1F1A;
      color: #B0CCC2;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: #fff;
    }
    .footer a {
      color: #B0CCC2;
    }
    .copyright {
      border-top: 1px solid #2C4238;
      padding-top: 20px;
      text-align: center;
      font-size: 13px;
    }
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: 1fr 1fr; }
      .scenarios-grid { grid-template-columns: 1fr 1fr; }
      .hero .container { flex-direction: column; }
      .hero-left h1 { font-size: 38px; }
    }
    @media (max-width: 768px) {
      .main-nav { display: none; }
      .hamburger { display: flex; }
      .mobile-menu { display: flex; }
      .features-grid, .scenarios-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .section-title h2 { font-size: 28px; }
      .hero-left h1 { font-size: 32px; }
      .hero-buttons { flex-direction: column; align-items: flex-start; }
    }