.error-page {
      min-height: 80vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 2rem;
      position: relative;
      overflow: hidden;
    }

    /* Animated background grid */
    .error-bg {
      position: absolute;
      inset: 0;
      background-image:
        linear-gradient(var(--border-color, #e5e5e5) 1px, transparent 1px),
        linear-gradient(90deg, var(--border-color, #e5e5e5) 1px, transparent 1px);
      background-size: 60px 60px;
      opacity: 0.4;
      mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
      -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
    }

    .error-content {
      text-align: center;
      position: relative;
      z-index: 1;
      max-width: 600px;
    }

    .error-code {
      font-size: clamp(6rem, 15vw, 12rem);
      font-weight: 800;
      line-height: 1;
      background: linear-gradient(135deg, var(--primary-color, #825415), #c4841d, var(--primary-color, #825415));
      background-size: 200% 200%;
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      animation: shimmer 3s ease-in-out infinite;
      margin-bottom: 0.5rem;
      letter-spacing: -0.04em;
    }

    @keyframes shimmer {
      0%, 100% { background-position: 0% 50%; }
      50% { background-position: 100% 50%; }
    }

    .error-title {
      font-size: clamp(1.5rem, 3vw, 2rem);
      font-weight: 700;
      color: var(--text-primary, #1a1a1a);
      margin-bottom: 1rem;
    }

    .error-description {
      font-size: 1.0625rem;
      color: var(--text-muted, #6b6b6b);
      line-height: 1.7;
      margin-bottom: 2.5rem;
    }

    .error-actions {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 1rem;
      flex-wrap: wrap;
    }

    .error-actions .btn {
      padding: 0.75rem 1.75rem;
      font-size: 0.9375rem;
      font-weight: 600;
      border-radius: 10px;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      transition: all 0.2s ease;
    }

    .error-actions .btn svg {
      width: 18px;
      height: 18px;
    }

    .error-illustration {
      margin-bottom: 2rem;
    }

    .error-illustration svg {
      width: 180px;
      height: 180px;
      color: var(--primary-color, #825415);
      opacity: 0.15;
    }

    /* Floating particles */
    .error-particle {
      position: absolute;
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: var(--primary-color, #825415);
      opacity: 0.12;
      animation: float-up 6s ease-in-out infinite;
    }

    .error-particle:nth-child(1) { left: 15%; animation-delay: 0s; animation-duration: 7s; }
    .error-particle:nth-child(2) { left: 30%; animation-delay: 1.5s; animation-duration: 5s; width: 4px; height: 4px; }
    .error-particle:nth-child(3) { left: 50%; animation-delay: 3s; animation-duration: 8s; width: 8px; height: 8px; }
    .error-particle:nth-child(4) { left: 70%; animation-delay: 0.5s; animation-duration: 6s; }
    .error-particle:nth-child(5) { left: 85%; animation-delay: 2s; animation-duration: 7.5s; width: 5px; height: 5px; }

    @keyframes float-up {
      0% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
      10% { opacity: 0.12; }
      90% { opacity: 0.12; }
      100% { transform: translateY(-10vh) rotate(360deg); opacity: 0; }
    }

    /* Attempted URL display */
    .error-url {
      display: inline-block;
      margin-bottom: 2rem;
      padding: 0.5rem 1rem;
      background: var(--bg-secondary, #f5f5f5);
      border: 1px solid var(--border-color, #e5e5e5);
      border-radius: 8px;
      font-family: 'SF Mono', 'Fira Code', monospace;
      font-size: 0.8125rem;
      color: var(--text-muted, #6b6b6b);
      max-width: 100%;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      word-break: break-all;
    }

    /* Dark mode */
    [data-theme="dark"] .error-bg {
      opacity: 0.2;
    }

    @media (max-width: 640px) {
      .error-page {
        min-height: 70vh;
        padding: 1.5rem;
      }

      .error-actions {
        flex-direction: column;
      }

      .error-actions .btn {
        width: 100%;
        justify-content: center;
      }
    }