/* roulang page: index */
:root {
      --deep-black: #0B0C0E;
      --card-bg: #16181C;
      --silver-gray: #E5E7EB;
      --text-gray: #9CA3AF;
      --text-muted: #6B7280;
      --race-red: #E11D48;
      --race-red-dark: #BE123C;
      --white: #FFFFFF;
      --border-light: rgba(229, 231, 235, 0.08);
      --border-medium: rgba(229, 231, 235, 0.15);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 40px;
      --shadow-red-glow: 0 0 16px rgba(225, 29, 72, 0.3);
      --transition-base: 0.25s ease;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-mono: 'Inter', 'SF Pro Display', system-ui, sans-serif;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--deep-black);
      color: var(--text-gray);
      line-height: 1.6;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    /* 覆盖Bootstrap默认样式 */
    a {
      color: var(--silver-gray);
      text-decoration: none;
      transition: color var(--transition-base);
    }
    a:hover {
      color: var(--white);
    }
    .btn {
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: all var(--transition-base);
      border: none;
    }
    .btn-primary {
      background: radial-gradient(circle at 30% 30%, var(--race-red), var(--race-red-dark));
      color: var(--white);
      box-shadow: none;
      padding: 0.75rem 2rem;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background: radial-gradient(circle at 30% 30%, #f02d52, var(--race-red));
      box-shadow: var(--shadow-red-glow);
      color: var(--white);
      transform: translateY(-1px);
    }
    .btn-outline-light {
      border: 1px solid var(--border-medium);
      color: var(--silver-gray);
      background: transparent;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-sm);
    }
    .btn-outline-light:hover {
      background: rgba(255,255,255,0.03);
      border-color: var(--race-red);
      color: var(--white);
    }
    .container {
      max-width: 1200px;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 排版重置 */
    h1, h2, h3, h4 {
      font-family: var(--font-sans);
      color: var(--white);
      font-weight: 600;
      letter-spacing: -0.3px;
    }
    .h1-main {
      font-size: 3.5rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    .h2-section {
      font-size: 2rem;
      font-weight: 600;
      letter-spacing: -0.3px;
      margin-bottom: 0.5rem;
    }
    .h3-card {
      font-size: 1.25rem;
      font-weight: 600;
    }
    .text-mono {
      font-family: var(--font-mono);
      font-weight: 700;
    }

    /* 导航胶囊 */
    .navbar-custom {
      position: fixed;
      top: 24px;
      left: 50%;
      transform: translateX(-50%);
      width: auto;
      max-width: 620px;
      background: rgba(11, 12, 14, 0.85);
      backdrop-filter: blur(16px);
      border-radius: var(--radius-lg);
      padding: 0.5rem 1.8rem;
      z-index: 1030;
      border: 1px solid var(--border-light);
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: background 0.3s ease, box-shadow 0.3s ease;
    }
    .navbar-scrolled {
      background: rgba(11, 12, 14, 0.95);
      box-shadow: 0 8px 20px rgba(0,0,0,0.6);
    }
    .nav-logo {
      font-family: var(--font-mono);
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--white);
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      gap: 1.8rem;
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .nav-links a {
      color: var(--text-gray);
      font-size: 0.9rem;
      font-weight: 500;
      position: relative;
      padding-bottom: 4px;
    }
    .nav-links a:hover {
      color: var(--white);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 1px;
      background: var(--race-red);
      transition: width var(--transition-base);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      color: var(--white);
      font-size: 1.5rem;
    }

    /* Hero */
    .hero-section {
      padding: 160px 0 100px;
      position: relative;
      background-color: var(--deep-black);
      background-image: radial-gradient(rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
    }
    .hero-graphic {
      position: relative;
      width: 100%;
      height: 100%;
      min-height: 320px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      border-radius: var(--radius-md);
      mask-image: linear-gradient(to left, transparent, black);
    }
    .cta-link {
      color: var(--silver-gray);
      text-decoration: underline;
      text-underline-offset: 4px;
      margin-left: 1.5rem;
      font-weight: 500;
    }
    .cta-link:hover {
      color: var(--race-red);
      text-decoration-color: var(--race-red);
    }

    /* 痛点卡片 */
    .pain-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 2rem;
      border: none;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      height: 100%;
    }
    .pain-card:hover {
      transform: translateY(-6px);
    }
    .red-line-short {
      width: 40px;
      height: 2px;
      background: var(--race-red);
      margin-bottom: 1.5rem;
      transition: width 0.3s ease;
    }
    .pain-card:hover .red-line-short {
      width: 60px;
    }

    /* 解决方案卡片 */
    .solution-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 2rem 2rem 2rem 2.5rem;
      position: relative;
      overflow: hidden;
      height: 100%;
    }
    .solution-card::before {
      content: '';
      position: absolute;
      left: 20px;
      top: 2rem;
      width: 2px;
      height: 48px;
      background: var(--race-red);
    }
    .solution-bg {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-size: cover;
      background-position: center;
      opacity: 0.08;
      z-index: 0;
    }

    /* 数据展示 */
    .data-number {
      font-family: var(--font-mono);
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--race-red);
      line-height: 1;
    }
    .data-unit {
      font-size: 1.5rem;
      color: var(--silver-gray);
      font-weight: 500;
    }

    /* 证言 */
    .testimonial-quote {
      position: relative;
      padding-left: 2rem;
    }
    .testimonial-quote::before {
      content: "“";
      font-size: 6rem;
      color: var(--race-red);
      opacity: 0.15;
      position: absolute;
      left: -0.5rem;
      top: -2rem;
      font-family: var(--font-mono);
    }

    /* FAQ */
    .accordion-button {
      background: var(--card-bg);
      color: var(--white);
      font-weight: 500;
      border: none;
      box-shadow: none;
      padding: 1.2rem 1.5rem;
    }
    .accordion-button::after {
      filter: brightness(0) invert(1);
    }
    .accordion-button:not(.collapsed) {
      background: var(--card-bg);
      color: var(--white);
      box-shadow: none;
    }
    .accordion-item {
      background: transparent;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .accordion-body {
      color: var(--text-gray);
    }

    /* 最终CTA */
    .cta-final-block {
      background: var(--deep-black);
      border-top: 1px solid var(--race-red);
    }

    /* 页脚 */
    .footer {
      background: var(--deep-black);
      border-top: 1px solid var(--border-light);
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .h1-main { font-size: 2.8rem; }
      .navbar-custom { width: 95%; }
    }
    @media (max-width: 768px) {
      .navbar-custom {
        top: auto;
        bottom: 16px;
        width: 90%;
        padding: 0.5rem 1.5rem;
      }
      .desktop-nav { display: none; }
      .mobile-menu-btn { display: block; }
      .h1-main { font-size: 2.2rem; }
      .hero-graphic { min-height: 200px; opacity: 0.4; }
      .solution-card::before { left: 16px; }
    }
    @media (max-width: 576px) {
      .data-number { font-size: 2.8rem; }
    }

    /* 移动端抽屉菜单 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(11,12,14,0.98);
      backdrop-filter: blur(20px);
      z-index: 1050;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-direction: column;
      gap: 2rem;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-drawer.active {
      transform: translateX(0);
    }
    .mobile-drawer a {
      font-size: 1.5rem;
      color: var(--silver-gray);
    }