:root {
    --bg: #070b14;
    --bg-secondary: #0d1321;
    --bg-card: #111827;
    --fg: #f1f5f9;
    --fg-muted: #94a3b8;
    --accent: #00a8e8;
    --accent-glow: rgba(0, 168, 232, 0.3);
    --border: #1e293b;
    --gradient-start: #00a8e8;
    --gradient-end: #00d4aa;
  }

  * {
    font-family: 'Noto Sans SC', sans-serif;
  }

  html {
    scroll-behavior: smooth;
  }

  body {
    background: var(--bg);
    color: var(--fg);
    overflow-x: hidden;
  }

  /* 网格背景 */
  .grid-bg {
    position: fixed;
    inset: 0;
    background-image: 
      linear-gradient(rgba(0, 168, 232, 0.03) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0, 168, 232, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none;
    z-index: 0;
  }

  /* 渐变光晕 */
  .hero-glow {
    position: absolute;
    width: 800px;
    height: 800px;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.15;
    pointer-events: none;
  }

  .hero-glow-1 {
    background: var(--accent);
    top: -200px;
    right: -100px;
  }

  .hero-glow-2 {
    background: #00d4aa;
    bottom: -300px;
    left: -200px;
    opacity: 0.1;
  }

  /* 动画关键帧 */
  @keyframes fadeInUp {
    from {
      opacity: 0;
      transform: translateY(40px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  @keyframes drawLine {
    from { stroke-dashoffset: 1000; }
    to { stroke-dashoffset: 0; }
  }

  @keyframes pulse {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 1; }
  }

  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
  }

  .animate-in {
    opacity: 0;
    animation: fadeInUp 0.8s ease forwards;
  }

  .delay-1 { animation-delay: 0.1s; }
  .delay-2 { animation-delay: 0.2s; }
  .delay-3 { animation-delay: 0.3s; }
  .delay-4 { animation-delay: 0.4s; }
  .delay-5 { animation-delay: 0.5s; }

  /* 卡片样式 */
  .feature-card {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(17, 24, 39, 0.6) 100%);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    position: relative;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  }

  .feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0;
    transition: opacity 0.4s;
  }

  .feature-card:hover {
    border-color: rgba(0, 168, 232, 0.3);
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 60px var(--accent-glow);
  }

  .feature-card:hover::before {
    opacity: 1;
  }

  /* 核心功能区 — 精致卡片 */
  #features {
    isolation: isolate;
  }

  #features::before {
    content: '';
    position: absolute;
    inset: 8% 0 auto;
    height: 60%;
    background:
      radial-gradient(ellipse 45% 55% at 15% 35%, rgba(0, 168, 232, 0.1), transparent 70%),
      radial-gradient(ellipse 40% 50% at 85% 65%, rgba(0, 212, 170, 0.07), transparent 70%);
    pointer-events: none;
    z-index: -1;
  }

  .features-label {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    color: var(--accent);
    margin-bottom: 1rem;
  }

  .features-label::before,
  .features-label::after {
    content: '';
    width: 28px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent));
  }

  .features-label::after {
    background: linear-gradient(90deg, var(--accent), transparent);
  }

  .features-card {
    position: relative;
    overflow: hidden;
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border);
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(17, 24, 39, 0.6) 100%);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  }

  .features-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0;
    transition: opacity 0.4s;
  }

  .features-card:hover {
    border-color: rgba(0, 168, 232, 0.3);
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 60px var(--accent-glow);
  }

  .features-card:hover::before {
    opacity: 1;
  }

  .features-card-icon {
    position: relative;
    z-index: 1;
    width: 56px;
    height: 56px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 14px;
    background: linear-gradient(145deg, rgba(0, 168, 232, 0.22), rgba(0, 212, 170, 0.08));
    border: 1px solid rgba(0, 168, 232, 0.2);
    color: var(--accent);
  }

  .features-card:nth-child(even) .features-card-icon {
    background: linear-gradient(145deg, rgba(0, 212, 170, 0.2), rgba(0, 168, 232, 0.08));
    border-color: rgba(0, 212, 170, 0.22);
    color: #00d4aa;
  }

  .features-card h3,
  .features-card p {
    position: relative;
    z-index: 1;
  }

  .reveal-delay-1 { transition-delay: 0.08s; }
  .reveal-delay-2 { transition-delay: 0.16s; }
  .reveal-delay-3 { transition-delay: 0.24s; }
  .reveal-delay-4 { transition-delay: 0.32s; }
  .reveal-delay-5 { transition-delay: 0.4s; }
  .reveal-delay-6 { transition-delay: 0.48s; }

  @media (max-width: 768px) {
    .features-card {
      padding: 1.5rem;
    }
  }

  /* 按钮样式 */
  .btn-primary {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: var(--bg);
    font-weight: 600;
    padding: 16px 40px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .btn-primary::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(255,255,255,0.2) 100%);
    opacity: 0;
    transition: opacity 0.3s;
  }

  .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--accent-glow);
  }

  .btn-primary:hover::after {
    opacity: 1;
  }

  .btn-secondary {
    background: transparent;
    color: var(--fg);
    font-weight: 500;
    padding: 16px 40px;
    border-radius: 12px;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .btn-secondary:hover {
    border-color: var(--accent);
    background: rgba(0, 168, 232, 0.1);
  }

  /* 平台图标 */
  .platform-logo {
    height: 36px;
    opacity: 0.6;
    filter: grayscale(100%) brightness(1.5);
    transition: all 0.3s;
  }

  .platform-item:hover .platform-logo {
    opacity: 1;
    filter: grayscale(0%) brightness(1);
  }

  /* 流程线 */
  .process-line {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), var(--gradient-end));
    opacity: 0.3;
  }

  /* 统计数字 */
  .stat-number {
    font-size: 3.5rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent) 0%, #00d4aa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
  }

  .stat-value {
    display: inline-flex;
    align-items: flex-start;
    gap: 0.1em;
    line-height: 1;
  }

  .stat-suffix {
    font-size:2.2rem;
    font-weight: 800;
    line-height: 1;
    margin-top: 0.5em;
    background: linear-gradient(135deg, var(--accent) 0%, #00d4aa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    opacity: 0.9;
  }

  /* 图纸样式效果 */
  .blueprint-box {
    border: 1px solid rgba(0, 168, 232, 0.2);
    background: linear-gradient(135deg, rgba(0, 168, 232, 0.05) 0%, transparent 100%);
    position: relative;
  }

  .blueprint-box::before {
    content: '';
    position: absolute;
    top: -1px;
    left: -1px;
    right: -1px;
    bottom: -1px;
    border: 1px dashed rgba(0, 168, 232, 0.15);
    border-radius: inherit;
    pointer-events: none;
  }

  /* 滚动显示动画 */
  .reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  }

  .reveal.visible {
    opacity: 1;
    transform: translateY(0);
  }

  /* 标签切换 */
  .tab-btn {
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s;
    color: var(--fg-muted);
    background: transparent;
    border: none;
    cursor: pointer;
  }

  .tab-btn.active {
    background: rgba(0, 168, 232, 0.15);
    color: var(--accent);
  }

  .tab-btn:hover:not(.active) {
    color: var(--fg);
    background: rgba(255, 255, 255, 0.05);
  }

  /* 减少动画偏好 */
  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
    }
  }

  /* 响应式 */
  @media (max-width: 768px) {
    .stat-number {
      font-size: 2.5rem;
    }

    .stat-suffix {
      font-size: 1.25rem;
      margin-top: 0.3em;
    }
    
    .feature-card {
      padding: 24px;
    }
  }