/* roulang page: index */
:root {
      --primary: #FF4C29;
      --primary-glow: rgba(255, 76, 41, 0.55);
      --primary-soft: rgba(255, 76, 41, 0.18);
      --bg-deep: #0B0E14;
      --bg-card: rgba(176, 184, 196, 0.08);
      --border-light: rgba(255, 255, 255, 0.18);
      --text-white: #FFFFFF;
      --text-silver: #D1D6DC;
      --text-dim: #9AA0AB;
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-img: 14px;
      --shadow-card: 0 10px 30px rgba(0,0,0,0.55);
      --shadow-glow: 0 0 28px rgba(255, 76, 41, 0.65);
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
      --transition-smooth: all 0.28s cubic-bezier(0.2, 0.0, 0, 1.0);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }
    body {
      font-family: var(--font-stack);
      background: var(--bg-deep);
      color: var(--text-white);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: 1240px;
      margin: 0 auto;
      padding: 0 28px;
    }
    /* 玻璃拟态基础 */
    .glass-card {
      background: rgba(11, 14, 20, 0.65);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .glass-card:hover {
      box-shadow: 0 14px 40px rgba(255, 76, 41, 0.25);
      border-color: rgba(255, 76, 41, 0.4);
      transform: translateY(-5px);
    }
    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(8, 10, 15, 0.72);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 14px 0;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 1.9rem;
      font-weight: 800;
      letter-spacing: 1px;
      background: linear-gradient(135deg, #FFFFFF 10%, #FFB3A0 90%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      text-decoration: none;
    }
    .logo span {
      background: linear-gradient(135deg, #FF4C29, #FF7B5C);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-silver);
      text-decoration: none;
      font-weight: 550;
      font-size: 1.05rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .menu-toggle {
      display: none;
      background: transparent;
      border: none;
      color: white;
      font-size: 2rem;
      cursor: pointer;
    }
    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 700;
      padding: 14px 38px;
      border-radius: var(--radius-btn);
      border: none;
      text-decoration: none;
      display: inline-block;
      letter-spacing: 0.6px;
      box-shadow: 0 0 25px var(--primary-glow);
      transition: var(--transition-smooth);
      font-size: 1.1rem;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #FF613B;
      box-shadow: 0 0 38px rgba(255,76,41,0.8);
      transform: scale(1.03);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 650;
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: var(--transition-smooth);
    }
    .btn-outline:hover {
      background: rgba(255,76,41,0.15);
      color: white;
      border-color: white;
    }
    /* hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #0B0E14 0%, #141A24 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 500px;
    }
    .hero-image {
      flex: 1 1 450px;
      border-radius: 36px;
      overflow: hidden;
      box-shadow: 0 0 50px rgba(255,76,41,0.35);
      border: 1px solid rgba(255,255,255,0.18);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: cover;
    }
    h1 {
      font-size: clamp(2.8rem, 6vw, 4.5rem);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.4rem;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-silver);
      margin-bottom: 2.2rem;
      max-width: 550px;
    }
    .section {
      padding: 5.5rem 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 2.8rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      bottom: -12px;
      left: 0;
      width: 65%;
      height: 5px;
      background: var(--primary);
      border-radius: 4px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 2.5rem;
    }
    .pain-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem;
    }
    .card-dark {
      background: rgba(20, 24, 33, 0.8);
      backdrop-filter: blur(12px);
      border-radius: var(--radius-card);
      padding: 2rem;
      border: 1px solid rgba(255,255,255,0.1);
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      text-shadow: 0 0 18px var(--primary-glow);
    }
    .faq-item {
      background: rgba(20, 24, 33, 0.7);
      backdrop-filter: blur(14px);
      border-radius: 16px;
      margin-bottom: 1rem;
      border: 1px solid rgba(255,255,255,0.1);
      overflow: hidden;
    }
    .faq-question {
      padding: 1.2rem 2rem;
      font-weight: 650;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: transparent;
      border: none;
      color: white;
      width: 100%;
      text-align: left;
      font-size: 1.2rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(0,0,0,0.2);
      padding: 0 2rem;
      color: var(--text-silver);
    }
    .faq-item.active .faq-answer {
      max-height: 220px;
      padding: 1.2rem 2rem;
    }
    footer {
      background: #070A0F;
      padding: 3.5rem 0 1.8rem;
      border-top: 1px solid rgba(255,255,255,0.1);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2.5rem;
    }
    @media (max-width: 1023px) {
      .pain-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; flex-direction: column; width: 100%; background: #0B0E14; padding: 1rem; }
      .nav-links.show { display: flex; }
      .menu-toggle { display: block; }
      .hero-grid { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
    }