.switch{position:relative;display:inline-block;width:46px;height:26px}.switch input{opacity:0;width:0;height:0}.slider{position:absolute;cursor:pointer;top:0;left:0;right:0;bottom:0;background-color:#3C91E6;-webkit-transition:.4s;transition:.4s}.slider:before{position:absolute;content:"";height:20px;width:20px;left:3px;bottom:3px;background-color:#fff;-webkit-transition:.4s;transition:.4s}input:checked+.slider{background-color:#94b8db}input:focus+.slider{box-shadow:0 0 1px #94b8db}input:checked+.slider:before{-webkit-transform:translateX(20px);-ms-transform:translateX(20px);transform:translateX(20px)}.slider.round{border-radius:26px}.slider.round:before{border-radius:50%}body.light-theme{--text-color: #222;--bkg-color: #fff;--text-link-color: #3C91E6;--text-link-hover-color: #5cacfc;--button-link-background: #D4C5C7}body.dark-theme{--text-color: #eee;--bkg-color: #121212;--text-link-color: #94b8db;--text-link-hover-color: #b5c6d6;--button-link-background: #DAD4EF}body{background:var(--bkg-color);color:var(--text-color);font-family:Arial, Helvetica, sans-serif;max-width:700px;margin:0 auto;padding:10px}a{text-decoration:none;color:var(--text-link-color)}a:hover{color:var(--text-link-hover-color)}.button-link{text-decoration:none;transition:background-color 0.3s}.button-link:hover{background-color:var(--button-link-background)}.header-container{display:flex;align-items:center;justify-content:space-between;margin-bottom:60px;font-size:24px}.footer-container{text-align:center;border-top:1px solid var(--text-color);margin-top:60px}