:root {
      --sage-light: #e8ebe4;
      --sage: #cdd5c6;
      --sage-dark: #a3b18a;
      --sage-darker: #7a8c69;
      --text: #1a1a1a;
      --text-muted: #6b7280;
      --white: #ffffff;
      --radius: 40px;
      --transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
      --elastic: cubic-bezier(0.175, 0.885, 0.32, 1.275);
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html, body {
      height: 100%;
      width: 100%;
      font-family: 'Poppins', sans-serif;
      background: linear-gradient(135deg, var(--white) 0%, var(--sage-light) 100%);
      color: var(--text);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      position: relative;
    }

    /* Background elements with physics */
    .bg-element {
      position: absolute;
      border-radius: 50%;
      opacity: 0.1;
      z-index: -1;
    }

    .bg-element:nth-child(1) {
      width: 200px;
      height: 200px;
      background: var(--sage-dark);
      top: 10%;
      left: 5%;
      animation: float 15s ease-in-out infinite;
    }

    .bg-element:nth-child(2) {
      width: 150px;
      height: 150px;
      background: var(--sage);
      bottom: 15%;
      right: 10%;
      animation: float 12s ease-in-out infinite reverse;
    }

    .bg-element:nth-child(3) {
      width: 100px;
      height: 100px;
      background: var(--sage-darker);
      top: 60%;
      left: 15%;
      animation: float 18s ease-in-out infinite;
    }

    @keyframes float {
      0%, 100% { transform: translate(0, 0) rotate(0deg); }
      25% { transform: translate(10px, -15px) rotate(5deg); }
      50% { transform: translate(-5px, -10px) rotate(-3deg); }
      75% { transform: translate(-10px, 5px) rotate(2deg); }
    }

    /* Main content */
    .content {
      max-width: min(90vw, 800px);
      text-align: center;
      padding: 2rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      opacity: 0;
      transform: translateY(30px);
      animation: contentEntrance 1.2s var(--elastic) 0.3s forwards;
    }

    @keyframes contentEntrance {
      from { opacity: 0; transform: translateY(30px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* 404 number with physics animation */
    .error-code {
      font-size: clamp(6rem, 15vw, 12rem);
      color: var(--sage-dark);
      margin-bottom: 0.5rem;
      font-weight: 700;
      position: relative;
      display: inline-block;
      transform-origin: center;
      animation: numberBounce 1.2s var(--bounce) 0.5s both;
    }

    @keyframes numberBounce {
      0% { transform: scale(0.3) rotate(-10deg); opacity: 0; }
      50% { transform: scale(1.1) rotate(5deg); }
      70% { transform: scale(0.9) rotate(-2deg); }
      100% { transform: scale(1) rotate(0deg); opacity: 1; }
    }

    .error-code::after {
      content: '';
      position: absolute;
      bottom: -10px;
      left: 10%;
      width: 80%;
      height: 8px;
      background: radial-gradient(ellipse at center, rgba(163, 177, 138, 0.4) 0%, rgba(163, 177, 138, 0) 70%);
      border-radius: 50%;
      animation: shadowPulse 3s ease-in-out infinite alternate;
    }

    @keyframes shadowPulse {
      from { transform: scale(0.8); opacity: 0.5; }
      to { transform: scale(1.1); opacity: 0.8; }
    }

    h2 {
      font-size: clamp(1.5rem, 4vw, 2.5rem);
      color: var(--text);
      font-weight: 600;
      margin-bottom: 1.5rem;
      opacity: 0;
      animation: fadeInUp 0.8s ease-out 0.8s forwards;
    }

    p {
      color: var(--text-muted);
      font-size: clamp(1rem, 2.5vw, 1.2rem);
      margin-bottom: 2.5rem;
      line-height: 1.7;
      max-width: 600px;
      opacity: 0;
      animation: fadeInUp 0.8s ease-out 1s forwards;
    }

    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(20px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* Button with physics interaction */
    .button-container {
      position: relative;
      opacity: 0;
      animation: fadeInUp 0.8s ease-out 1.2s forwards;
    }

    a.button {
      display: inline-block;
      padding: 1rem 2.5rem;
      background: var(--sage-dark);
      color: var(--white);
      font-weight: 600;
      text-decoration: none;
      border-radius: var(--radius);
      transition: var(--transition);
      box-shadow: 0 8px 20px rgba(163, 177, 138, 0.4);
      position: relative;
      overflow: hidden;
      transform: translateZ(0);
    }

    a.button::before {
      content: '';
      position: absolute;
      top: 0;
      left: -100%;
      width: 100%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
      transition: left 0.7s ease;
    }

    a.button:hover {
      background: var(--sage-darker);
      transform: translateY(-5px) scale(1.03);
      box-shadow: 0 12px 25px rgba(163, 177, 138, 0.5);
    }

    a.button:hover::before {
      left: 100%;
    }

    a.button:active {
      transform: translateY(-2px) scale(1.01);
      box-shadow: 0 6px 15px rgba(163, 177, 138, 0.4);
    }

    /* Footer */
    footer {
      margin-top: 3rem;
      font-size: 0.85rem;
      color: var(--text-muted);
      opacity: 0;
      animation: fadeIn 0.8s ease-out 1.4s forwards;
    }

    @keyframes fadeIn {
      from { opacity: 0; }
      to { opacity: 1; }
    }

    /* Floating particles */
    .particles-container {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      overflow: hidden;
      z-index: -1;
    }

    .particle {
      position: absolute;
      background: var(--sage);
      border-radius: 50%;
      opacity: 0.15;
      animation: particleFloat linear infinite;
    }

    @keyframes particleFloat {
      from { transform: translateY(100vh) rotate(0deg); }
      to { transform: translateY(-100px) rotate(360deg); }
    }

    /* Current URL display */
    .current-url {
      background: rgba(163, 177, 138, 0.1);
      padding: 0.8rem 1.5rem;
      border-radius: 20px;
      margin: 1rem 0;
      font-family: monospace;
      font-size: 0.9rem;
      border: 1px solid rgba(163, 177, 138, 0.2);
      max-width: 90%;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    /* ========== RESPONSIVE DESIGN ========== */
    @media (max-width: 768px) {
      .content {
        padding: 1.5rem;
      }
      
      .bg-element:nth-child(1) {
        width: 120px;
        height: 120px;
      }

      .bg-element:nth-child(2) {
        width: 80px;
        height: 80px;
      }

      .bg-element:nth-child(3) {
        width: 60px;
        height: 60px;
      }
      
      .current-url {
        font-size: 0.8rem;
        padding: 0.6rem 1rem;
      }
    }

    @media (max-width: 480px) {
      .content {
        padding: 1rem;
      }
      
      a.button {
        padding: 0.9rem 2rem;
      }
    }

    /* High contrast mode support */
    @media (prefers-contrast: high) {
      :root {
        --text: #000000;
        --text-muted: #333333;
        --sage-dark: #5a6d4b;
      }
      
      a.button {
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
      }
    }

    /* Reduced motion support */
    @media (prefers-reduced-motion: reduce) {
      * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
      }
    }