/* roulang page: index */
:root {
      --primary: #00E676;
      --primary-dark: #00c853;
      --secondary: #0A0A0A;
      --accent: #FF3D00;
      --gray-bg: #F0F2F5;
      --white: #FFFFFF;
      --text-dark: #1a1a1a;
      --text-gray: #555;
      --text-light: #777;
      --border-light: rgba(255,255,255,0.15);
      --border-dark: rgba(0,0,0,0.06);
      --radius-card: 20px;
      --radius-btn: 50px;
      --shadow-sm: 0 8px 24px rgba(0,0,0,0.04);
      --shadow-md: 0 16px 40px rgba(0,0,0,0.06);
      --shadow-lg: 0 24px 56px rgba(0,0,0,0.08);
      --transition: all 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', sans-serif;
      background-color: var(--gray-bg);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1320px;
      margin: 0 auto;
      padding: 0 32px;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.2;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
      font-weight: 700;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10,10,10,0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      transition: background 0.3s;
    }
    .navbar.scrolled {
      background: rgba(10,10,10,0.96);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--white);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--primary);
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 36px;
    }
    .nav-links a {
      color: #ccc;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 6px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: white;
      background: none;
      border: none;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 280px;
      height: 100vh;
      background: var(--secondary);
      backdrop-filter: blur(30px);
      padding: 32px;
      display: flex;
      flex-direction: column;
      gap: 28px;
      transition: right 0.35s ease;
      z-index: 1001;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.2rem;
      font-weight: 600;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding-bottom: 12px;
    }
    .mobile-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
      margin-bottom: 20px;
    }
    /* Hero */
    .hero {
      padding: 160px 0 100px;
      background: linear-gradient(135deg, #0A0A0A 0%, #1a1a1a 100%);
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: -20%;
      left: -10%;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(0,230,118,0.15) 0%, transparent 70%);
      filter: blur(80px);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1 1 50%;
    }
    .hero-text h1 {
      font-size: clamp(3.2rem, 7vw, 5rem);
      font-weight: 800;
      color: white;
      letter-spacing: -0.02em;
      margin-bottom: 20px;
      position: relative;
    }
    .hero-text h1 .highlight {
      color: var(--primary);
      position: relative;
      z-index: 2;
    }
    .hero-sub {
      font-size: 1.25rem;
      color: #ccc;
      margin-bottom: 36px;
      max-width: 460px;
    }
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .btn-primary {
      background: var(--primary);
      color: #0A0A0A;
      padding: 16px 38px;
      border-radius: var(--radius-btn);
      font-size: 1.1rem;
      box-shadow: 0 6px 18px rgba(0,230,118,0.25);
    }
    .btn-primary:hover {
      background: var(--accent);
      color: white;
      box-shadow: 0 12px 28px rgba(255,61,0,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 16px 38px;
      border-radius: var(--radius-btn);
      font-size: 1.1rem;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: #0A0A0A;
    }
    .hero-visual {
      flex: 1 1 50%;
      position: relative;
    }
    .hero-visual img {
      width: 100%;
      border-radius: 36px;
      mask-image: linear-gradient(to bottom, black 70%, transparent 100%);
      -webkit-mask-image: linear-gradient(to bottom, black 70%, transparent 100%);
    }
    /* 亮点网格 */
    .highlights {
      padding: 90px 0;
      background: var(--white);
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      text-align: center;
    }
    .stat-item i {
      font-size: 2.8rem;
      color: var(--primary);
      margin-bottom: 12px;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--secondary);
      font-feature-settings: "tnum";
    }
    .stat-label {
      color: var(--text-gray);
      margin-top: 8px;
    }
    /* 案例瀑布 */
    .cases {
      padding: 90px 0;
    }
    .section-title {
      font-size: clamp(2rem, 5vw, 2.8rem);
      margin-bottom: 48px;
      font-weight: 700;
    }
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 36px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-lg);
    }
    .case-img {
      height: 260px;
      background-size: cover;
      background-position: center;
    }
    .case-content {
      padding: 28px;
    }
    .case-tags {
      display: flex;
      gap: 10px;
      margin-bottom: 12px;
    }
    .tag {
      background: #0A0A0A;
      color: var(--primary);
      padding: 4px 14px;
      border-radius: 30px;
      font-size: 0.8rem;
      font-weight: 600;
    }
    /* 方案对比 */
    .plans {
      padding: 90px 0;
      background: var(--white);
    }
    .comparison-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .plan-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 40px 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border-dark);
      display: flex;
      flex-direction: column;
    }
    .plan-featured {
      background: #0A0A0A;
      color: white;
      border-top: 5px solid var(--primary);
      transform: scale(1.02);
    }
    .plan-featured .plan-price,
    .plan-featured h3 {
      color: white;
    }
    .plan-price {
      font-size: 2.4rem;
      font-weight: 800;
      margin: 16px 0;
    }
    .feature-list {
      list-style: none;
      margin: 24px 0;
    }
    .feature-list li {
      margin-bottom: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .btn-outline-dark {
      border: 2px solid #0A0A0A;
      background: transparent;
      padding: 14px 24px;
      border-radius: 50px;
      font-weight: 700;
      margin-top: auto;
    }
    .plan-featured .btn-outline-dark {
      border-color: var(--primary);
      color: var(--primary);
    }
    /* FAQ */
    .faq {
      padding: 90px 0;
    }
    .accordion-item {
      background: white;
      border-radius: 16px;
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
    }
    .accordion-btn {
      width: 100%;
      background: none;
      text-align: left;
      padding: 24px 28px;
      font-weight: 700;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      color: var(--text-dark);
    }
    .accordion-btn i {
      color: var(--primary);
    }
    .accordion-content {
      padding: 0 28px 24px;
      display: none;
      color: var(--text-gray);
    }
    .accordion-content.open {
      display: block;
    }
    /* CTA 横幅 */
    .cta-band {
      background: #0A0A0A;
      padding: 80px 0;
      text-align: center;
      position: relative;
    }
    .cta-band h2 {
      color: white;
      font-size: 2.8rem;
      margin-bottom: 28px;
    }
    /* 页脚 */
    .footer {
      background: #0A0A0A;
      color: #ccc;
      padding: 70px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 18px;
    }
    .footer a:hover {
      color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 50px;
      padding-top: 24px;
      text-align: center;
    }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .comparison-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-grid { flex-direction: column; }
      .case-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }