body {
     font-family: Arial, sans-serif;
     line-height: 1.6;
     margin-left: 200px;
     margin-right: 200px;
     padding: 0;
     background: #fff;
     color: #333;
 }

 header {
     display: flex;
     justify-content: space-between;
     align-items: center;
     padding: 1rem 2rem;
     border-bottom: 1px solid #ddd;
 }

 header h1 {
     font-size: 1.5rem;
     font-weight: bold;
 }

 nav a {
     margin-left: 1rem;
     text-decoration: none;
     color: #333;
 }

 nav #toggle-dark {
     background: none;
     border: none;
     font: inherit;
     cursor: pointer;
     padding: 0;
     margin-left: 1rem;
     line-height: 1;
     color: inherit;
     vertical-align: middle;
 }

 .container {
     max-width: 900px;
     margin: 2rem auto;
     padding: 0 1rem;
 }

 .intro {
     display: flex;
     align-items: center;
     gap: 2rem;
 }

 .intro img {
     width: 180px;
     border-radius: 10px;
 }

 footer {
     text-align: center;
     padding: 1rem;
     border-top: 1px solid #ddd;
     margin-top: 2rem;
     font-size: 0.9rem;
 }

 h2 {
     margin-top: 2rem;
     border-bottom: 2px solid #eee;
     padding-bottom: 0.3rem;
 }

 .social-icons a {
     display: inline-block;
     margin: 0 10px;
     text-decoration: none;
 }

 .social-icons svg {
     width: 24px;
     height: 24px;
     fill: #333;
     vertical-align: middle;
     transition: fill 0.3s;
 }

 .social-icons svg:hover {
     fill: #0077b5;
 }

 @media (max-width: 900px) {
     body {
         margin-left: 10px;
         margin-right: 10px;
     }

     .container {
         max-width: 100%;
         margin: 1rem auto;
         padding: 0 0.5rem;
     }

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

     .intro img {
         width: 100px;
         margin-bottom: 1rem;
         border-radius: 10px;
     }

     header {
         flex-direction: column;
         align-items: flex-start;
         padding: 1rem 0;
     }

     header h1 {
         width: 100%;
         text-align: center;
         justify-content: center;
         margin: 0 auto;
     }

     nav {
         display: none;
     }

     nav.active {
         display: block;
         position: absolute;
         background: #fff;
         top: 60px;
         left: 0;
         width: 100%;
         z-index: 50;
     }

     .social-icons a {
         margin: 0 5px;
     }
 }

 @media (max-width: 600px) {
     body {
         font-size: 16px;
         margin-left: 0;
         margin-right: 0;
     }

     h1,
     h2 {
         font-size: 1.2rem;
     }
 }


 @media (min-width: 901px) {
     body.dark-mode {
         background: #1d1f21;
         color: #e0e0e0;
     }

     body.dark-mode header {
         border-bottom: 1px solid #333;
     }

     body.dark-mode footer {
         border-top: 1px solid #333;
     }

     body.dark-mode nav a {
         color: #e0e0e0;
     }

     body.dark-mode .intro {
         background: none;
     }

     body.dark-mode .social-icons svg {
         fill: #e0e0e0;
     }

     body.dark-mode .social-icons svg:hover {
         fill: #00aaff;
     }
 }