:root {
     --border-radius: 12px;
     --backdrop-blur: blur(20px);
 }

 .theme-switch {
     position: fixed;
     top: 20px;
     right: 20px;
     z-index: 999;
     display: inline-block;
     width: 60px;
     height: 30px;
     opacity: 0;
     animation: fadeInUp 0.8s ease-out 0.4s forwards;
 }

 .theme-switch input {
     opacity: 0;
     width: 0;
     height: 0;
 }

 .slider {
     position: absolute;
     cursor: pointer;
     background: rgba(255, 255, 255, 0.7);
     border-radius: var(--border-radius);
     backdrop-filter: var(--backdrop-blur);
     border: 1px solid rgba(0, 0, 0, 0.1);
     top: 0;
     left: 0;
     right: 0;
     bottom: 0;
     transition: background-color 0.3s;
     display: flex;
     align-items: center;
     justify-content: space-between;
     padding: 0 5px;
     box-sizing: border-box;
 }

 .slider .icon {
     font-size: 18px;
     user-select: none;
 }

 .slider .sun {
     color: #000;
     /* gold sun */
 }

 .slider .moon {
     color: #f0f0f0;
     /* light moon */
 }

 .theme-switch input:checked+.slider {
     background-color: #444;
     /* dark mode bg */
 }

 .theme-switch input+.slider::before {
     content: "";
     position: absolute;
     height: 22px;
     width: 22px;
     left: 3px;
     bottom: 3px;
     background-color: #cbcccd;
     border-radius: 50%;
     transition: transform 0.3s;
 }

 .theme-switch input:checked+.slider::before {
     transform: translateX(30px);
 }

 #logo {
     transition: opacity 0.3s ease;
 }

 @media (max-width: 768px) {
     #logo {
         width: 400px;
     }

     .logo-container {
         margin-top: 3em;
     }
 }

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

 body {
     font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
     background: linear-gradient(135deg, #0f0f23 0%, #1a1a2e 50%, #16213e 100%);
     min-height: 100vh;
     color: white;
     overflow-x: hidden;
 }

 .container {
     min-height: 100vh;
     display: flex;
     flex-direction: column;
     align-items: center;
     justify-content: center;
     padding: 2rem;
     position: relative;
 }

 .logo-container {
     margin-bottom: 3rem;
     opacity: 0;
     transform: translateY(30px);
     animation: fadeInUp 1s ease-out 0.5s forwards;
 }

 .logo-container svg {
     width: 400px;
     height: auto;
     filter: drop-shadow(0 10px 30px rgba(0, 183, 172, 0.3));
     transition: transform 0.3s ease;
 }

 .logo-container:hover svg {
     transform: scale(1.05);
 }

 .hero-content {
     text-align: center;
     max-width: 600px;
     opacity: 0;
     transform: translateY(30px);
     animation: fadeInUp 1s ease-out 1s forwards;
 }

 .hero-title {
     font-size: 3rem;
     font-weight: 700;
     margin-bottom: 1rem;
     background: linear-gradient(135deg, #00b7ac, #4ecdc4);
     -webkit-background-clip: text;
     -webkit-text-fill-color: transparent;
     background-clip: text;
 }

 .hero-subtitle {
     font-size: 1.25rem;
     color: #a0a0a0;
     margin-bottom: 2.5rem;
     line-height: 1.6;
 }

 .cta-container {
     display: flex;
     gap: 1rem;
     justify-content: center;
     flex-wrap: wrap;
 }

 .btn {
     padding: 1rem 2rem;
     border: none;
     border-radius: 12px;
     font-size: 1.1rem;
     font-weight: 600;
     cursor: pointer;
     transition: all 0.3s ease;
     text-decoration: none;
     display: inline-flex;
     align-items: center;
     gap: 0.5rem;
     position: relative;
     overflow: hidden;
 }

 .btn-primary {
     background: linear-gradient(135deg, #00b7ac, #4ecdc4);
     color: white;
     box-shadow: 0 8px 25px rgba(0, 183, 172, 0.4);
 }

 .btn-primary:hover {
     transform: translateY(-2px);
     box-shadow: 0 12px 35px rgba(0, 183, 172, 0.6);
 }

 .btn-secondary {
     background: rgba(255, 255, 255, 0.1);
     color: white;
     border: 1px solid rgba(255, 255, 255, 0.2);
     backdrop-filter: blur(10px);
 }

 .btn-secondary:hover {
     background: rgba(255, 255, 255, 0.15);
     transform: translateY(-2px);
 }

 footer {
     display: flex;
     gap: 2rem;
     margin-top: 4rem;
     opacity: 0;
     transform: translateY(30px);
     animation: fadeInUp 1s ease-out 1.5s forwards;
     max-width: 80%;
 }

 footer p {
     font-size: 0.9rem;
     color: #a0a0a0;
     line-height: 1.4;
 }

  .link {
     color: #00b7ac;
     text-decoration: none;
 }

   .link:hover {
     color: #00b7ac;
     text-decoration: underline;
 }

 .features {
     display: flex;
     gap: 2rem;
     margin-top: 4rem;
     opacity: 0;
     transform: translateY(30px);
     animation: fadeInUp 1s ease-out 1.5s forwards;
     max-width: 80%;
 }

 .feature {
     text-align: center;
     flex: 1;
     padding: 1.5rem;
     background: rgba(255, 255, 255, 0.05);
     border-radius: 16px;
     backdrop-filter: blur(10px);
     border: 1px solid rgba(255, 255, 255, 0.1);
     transition: transform 0.3s ease;
 }

 .feature:hover {
     transform: translateY(-5px);
 }

 .feature-icon {
     width: 48px;
     height: 48px;
     background: linear-gradient(135deg, #00b7ac, #4ecdc4);
     border-radius: 12px;
     display: flex;
     align-items: center;
     justify-content: center;
     margin: 0 auto 1rem;
     font-size: 1.5rem;
 }

 .feature h3 {
     font-size: 1.1rem;
     margin-bottom: 0.5rem;
     color: #00b7ac;
 }

 .feature p {
     font-size: 0.9rem;
     color: #a0a0a0;
     line-height: 1.4;
 }

 .floating-particles {
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     pointer-events: none;
     overflow: hidden;
 }

 .particle {
     position: absolute;
     width: 4px;
     height: 4px;
     background: #00b7ac;
     border-radius: 50%;
     opacity: 0.6;
     animation: float 15s infinite linear;
 }

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

 @keyframes float {
     0% {
         transform: translateY(100vh) rotate(0deg);
         opacity: 0;
     }

     10% {
         opacity: 0.6;
     }

     90% {
         opacity: 0.6;
     }

     100% {
         transform: translateY(-10vh) rotate(360deg);
         opacity: 0;
     }
 }

 @media (max-width: 768px) {
     .logo-container svg {
         width: 300px;
     }

     .hero-title {
         font-size: 2rem;
     }

     .features {
         flex-direction: column;
         gap: 1rem;
     }

     .cta-container {
         flex-direction: column;
         align-items: center;
     }

     .btn {
         width: 100%;
         max-width: 300px;
         justify-content: center;
     }
 }