body{background-color:skyblue}.btn-back-to-top{left:95%;position:fixed;top:90%}.header-button{background-color:#1d4ed8;border-radius:.5rem;color:#fff;font-size:.875rem;font-weight:500;margin-bottom:.5rem;margin-right:.5rem;outline:none;padding:.625rem 1.25rem;transition:background-color .3s}.header-button:hover{background-color:#1e40af}.header-button:focus{box-shadow:0 0 0 .25rem rgba(59,130,246,.5);outline:none}.header-button.dark{background-color:#2563eb}.header-button.dark:hover{background-color:#1e3a8a}.header-button.dark:focus{box-shadow:0 0 0 .25rem rgba(37,99,235,.8)}