/* roulang page: index */
:root {
      --bg-primary: #0A0F1E;
      --bg-secondary: #0D1424;
      --accent-cyan: #00E5FF;
      --accent-orange: #FF6B35;
      --card-bg: rgba(18, 28, 48, 0.75);
      --card-border: rgba(0, 229, 255, 0.18);
      --text-primary: #EAF0FF;
      --text-secondary: rgba(234, 240, 255, 0.7);
      --text-tertiary: rgba(234, 240, 255, 0.45);
      --green: #2ED573;
      --yellow: #FFA502;
      --glass-bg: rgba(18, 28, 48, 0.65);
      --glass-blur: blur(18px) saturate(140%);
      --radius-lg: 16px;
      --radius-btn: 30px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4), 0 0 0 1px rgba(0,229,255,0.06) inset;
      --shadow-hover: 0 12px 40px rgba(0,0,0,0.5), 0 0 28px rgba(0,229,255,0.15), 0 0 0 1px rgba(0,229,255,0.5) inset;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }

    * {
      box-sizing: border-box;
    }

    body {
      background-color: var(--bg-primary);
      color: var(--text-primary);
      font-family: var(--font-sans);
      line-height: 1.75;
      margin: 0;
      background-image:
        linear-gradient(rgba(0,229,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,229,255,0.03) 1px, transparent 1px);
      background-size: 60px 60px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: var(--accent-cyan);
      text-decoration: none;
      transition: color 0.25s ease;
    }

    a:hover {
      color: var(--accent-orange);
    }

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      font-weight: 700;
      transition: all 0.3s cubic-bezier(0.23, 1, 0.32, 1);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      border: none;
      outline: none;
    }

    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0F1E;
      border-radius: var(--radius-btn);
      padding: 0.8rem 2.2rem;
      font-size: 1rem;
      letter-spacing: 0.02em;
      box-shadow: 0 0 12px rgba(0,229,255,0.25);
    }

    .btn-primary:hover {
      background: #33EAFF;
      box-shadow: 0 0 24px rgba(0,229,255,0.6);
      transform: scale(1.04);
      color: #0A0F1E;
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--accent-orange);
      color: var(--accent-orange);
      border-radius: var(--radius-btn);
      padding: 0.8rem 2.2rem;
    }

    .btn-secondary:hover {
      background: var(--accent-orange);
      color: #0A0F1E;
      box-shadow: 0 0 20px rgba(255,107,53,0.5);
      transform: scale(1.04);
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid rgba(234,240,255,0.25);
      color: var(--text-primary);
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
    }

    .btn-ghost:hover {
      border-color: var(--accent-cyan);
      color: var(--accent-cyan);
    }

    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      transition: all 0.3s cubic-bezier(0.23, 1, 0.32, 1);
    }

    .glass-card:hover {
      border-color: rgba(0,229,255,0.5);
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }

    .section-padding {
      padding: 6rem 0;
    }

    .bg-alternate {
      background-color: var(--bg-secondary);
    }

    .hero-glow {
      position: relative;
      overflow: hidden;
    }

    .hero-glow::before {
      content: '';
      position: absolute;
      top: -20%;
      right: -10%;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle at center, rgba(0,229,255,0.15) 0%, transparent 70%);
      border-radius: 50%;
      filter: blur(80px);
      z-index: 0;
    }

    .hero-glow::after {
      content: '';
      position: absolute;
      bottom: -15%;
      left: -5%;
      width: 550px;
      height: 550px;
      background: radial-gradient(circle at center, rgba(255,107,53,0.14) 0%, transparent 70%);
      border-radius: 50%;
      filter: blur(80px);
      z-index: 0;
    }

    h1 {
      font-size: clamp(2.5rem, 6vw, 3.6rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.15;
    }

    h2 {
      font-size: clamp(2rem, 4.5vw, 2.6rem);
      font-weight: 700;
      letter-spacing: -0.01em;
    }

    h3 {
      font-size: 1.4rem;
      font-weight: 600;
    }

    .subtitle {
      font-size: 1.05rem;
      color: var(--text-secondary);
      font-weight: 400;
      max-width: 700px;
      margin-left: auto;
      margin-right: auto;
    }

    .site-nav {
      background: rgba(10,15,30,0.82);
      backdrop-filter: blur(22px);
      border-bottom: 1px solid rgba(0,229,255,0.1);
      padding: 0.75rem 0;
    }

    .logo-text {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--accent-cyan);
      letter-spacing: -0.01em;
    }

    .nav-link {
      color: var(--text-primary) !important;
      font-weight: 500;
      padding: 0.5rem 1.2rem;
      transition: 0.2s;
    }

    .nav-link:hover {
      color: var(--accent-cyan) !important;
    }

    .active-nav {
      border-bottom: 2px solid var(--accent-cyan);
    }

    .icon-cyan {
      color: var(--accent-cyan);
      font-size: 2.5rem;
      margin-bottom: 1.2rem;
    }

    .stat-number {
      font-size: 2rem;
      font-weight: 700;
      color: var(--accent-orange);
    }

    .progress-step {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
    }

    .step-circle {
      width: 56px;
      height: 56px;
      border: 2px solid var(--accent-cyan);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--accent-cyan);
      margin-bottom: 1rem;
      transition: 0.3s;
    }

    .progress-step:hover .step-circle {
      background: var(--accent-cyan);
      color: #0A0F1E;
    }

    .dashed-connector {
      border-bottom: 2px dashed rgba(0,229,255,0.3);
      width: 100%;
      position: relative;
      top: 28px;
    }

    .accordion-title {
      background: var(--glass-bg);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      color: var(--text-primary);
      font-weight: 600;
      font-size: 1.15rem;
      padding: 1.2rem 1.8rem;
    }

    .accordion-item.is-active .accordion-title {
      border-color: var(--accent-cyan);
      background: rgba(0,229,255,0.08);
    }

    .accordion-content {
      background: transparent;
      border: none;
      color: var(--text-secondary);
      padding: 1rem 1.8rem 1.8rem;
    }

    footer {
      background: #070B17;
      color: var(--text-tertiary);
    }

    @media (max-width: 768px) {
      .section-padding {
        padding: 3.8rem 0;
      }
      .hero-glow::before, .hero-glow::after {
        width: 300px;
        height: 300px;
      }
    }