style.css

*, *::before, *::after {
    box-sizing: border-box;
}

body {
    margin: 0px;
    padding: 0px;
    background-color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-size: 1.1rem;
    background-color: #ECECEC;
}

.wrapper {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-content: center;
    width: 80%;
}

.sort {
    padding: 3px;
    margin-right: 3px;
    color: white;
    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;
    text-align: center;
}

.header {
    background-color: #272C33;
    width: 100%;
    height: 10vh;
    display: flex;
    padding: 10px;
    justify-content: space-between;
    align-items: center;
    color: white;
    font-size: 1em;
}

.logo {
    font-size: 1.2em;
    color: white;
    letter-spacing: 1.5px;
    margin-left: 5px;
    margin-right: 5px;
    cursor: pointer;
}

.logo:hover {
    -webkit-animation: swing 1s ease;
    animation: swing 1s ease;
    -webkit-animation-iteration-count: 1;
    animation-iteration-count: 1;
}

.logo>h3 {
    transition: color .5s;
}

.logo>h3:hover {
    color: #5EA6EE;
}

.firstSectionWrapper {
    display: flex;
    justify-content: center;
}

.speed, .arraySize {
    width: 120px;
    margin-right: 20px;
    font-size: .8em;
}

input[type=number] {
    width: 90%;
    padding: 5px;
    border: 1px solid black;
    border-radius: 3px;
    height: 26px;
    font-size: .7em;
}

label {
    width: 180px;
}

.speedValidation, .arraySizeValidation {
    font-style: normal;
    font-size: .8em;
    color: #F53D3D;
    letter-spacing: .5px;
    padding-top: 5px;
}

.speedInputField, .arraySizeInputField {
    margin-top: 2px;
}

.speedInputField:focus, .arraySizeInputField:focus {
    border: 2px solid #5EA6EE;
    outline: none;
}

button {
    margin: 1rem;
}

.algorithms {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.algorithms .algorithmButton {
    color: white;
    padding: .5rem;
    cursor: pointer;
}

.algorithms .algorithmButton:hover {
    color: #5EA6EE;
}

.algorithms .selected {
    color: white;
    background-color: #5EA6EE;
    border-radius: 5px;
}

.algorithms .selected:hover {
    color: white;
}

.spacer {
    width: 5px;
    height: 100%;
    background-color: white;
    border-bottom-left-radius: 8px;
    border-bottom-right-radius: 8px;
    border-top-left-radius: 8px;
    border-top-right-radius: 8px;
    opacity: .8;
    transition: color 3s;
}

.spacer:hover {
    background-color: #5EA6EE;
}

.btn {
    background-color: #5EA6EE;
    color: white;
    padding: .6em 1em;
    cursor: pointer;
    width: 120px;
    position: relative;
    border-radius: 2px;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-size: .7em;
    border: none;
}

/*#008543 - green*/

.fade {
    opacity: 1;
}

.fade:hover {
    box-shadow: 1px 1px #5EA6EE, 2px 2px #5EA6EE, 3px 3px #5EA6EE;
    -webkit-transform: translateX(-3px);
    transform: translateX(-3px);
}

.fade:active {
    -webkit-transform: rotateZ(-10deg);
    -ms-transform: rotateZ(-10deg);
    transform: rotateZ(-10deg);
    border: none;
}

.fade:focus {
    border: none;
    outline: none;
}

.btn.sortButton {
    border: 1px solid white;
}

.btn.sortButton::before {
    content: '';
    left: 0;
    right: 0;
    bottom: 0;
    height: 4px;
    background-color: #5EA6EE;
    position: absolute;
    transition: transform 300ms ease-in-out;
    transform: scaleX(0);
}

.btn.sortButton:hover::before, .btn.sortButton:focus::before {
    transform: scaleX(1);
}

.btn.sortButton:focus {
    outline: none;
    border: none;
}

.spinner {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 80px;
    height: 80px;
    position: relative;
    z-index: 10;
}

.spinnerSector {
    border-radius: 50%;
    position: absolute;
    width: 100%;
    height: 100%;
    border: 8px solid transparent;
    mix-blend-mode: overlay;
}

.spinnerText {
    font-size: 1em;
    animation: loading-opacity 3s ease-in-out infinite;
}

.spinnerSectorBlue {
    border-top: 8px solid white;
    animation: rotate 2s ease-out infinite;
}

.spinnerSectorRed {
    border-top: 8px solid #5EA6EE;
    animation: rotate 2.5s ease-in infinite;
}

.spinnerSectorGreen {
    border-top: 8px solid #0D4A97;
    animation: rotate 1.5s ease-in-out infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0);
    }
    to {
        transform: rotate(360deg);
    }
}

@media only screen and (min-width: 1700px) {
    .header {
        background-color: #272C33;
        width: 100%;
        height: 10vh;
        display: flex;
        padding: 10px;
        justify-content: space-between;
        align-items: center;
        color: white;
        font-size: 1.1em;
    }
}

@media only screen and (max-width: 1440px) {
    .logo {
        width: 180px;
    }
    .spinner {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 55px;
        height: 55px;
        position: relative;
        z-index: 10;
    }
    .spinnerSector {
        border-radius: 50%;
        position: absolute;
        width: 100%;
        height: 100%;
        mix-blend-mode: overlay;
    }
    .spinnerText {
        font-size: .6em;
        animation: loading-opacity 3s ease-in-out infinite;
    }
}

@media only screen and (max-width: 1300px) {
    .logo {
        width: 180px;
        padding-right: 30px;
    }
    .spinner {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 55px;
        height: 55px;
        position: relative;
        z-index: 10;
    }
    .spinnerSector {
        border-radius: 50%;
        position: absolute;
        width: 100%;
        height: 100%;
        mix-blend-mode: overlay;
    }
    .spinnerText {
        font-size: .6em;
        animation: loading-opacity 3s ease-in-out infinite;
    }
    .spacer {
        margin-right: 20px;
    }
}

@media only screen and (max-width: 1375px) {
    .logo {
        width: 180px;
        padding-right: 30px;
    }
    .spinner {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 55px;
        height: 55px;
        position: relative;
        z-index: 10;
    }
    .spinnerSector {
        border-radius: 50%;
        position: absolute;
        width: 100%;
        height: 100%;
        mix-blend-mode: overlay;
    }
    .spinnerText {
        font-size: .6em;
        animation: loading-opacity 3s ease-in-out infinite;
    }
    .spacer {
        margin-right: 20px;
    }
}

@media only screen and (max-width: 1100px) {
    .logo {
        width: 180px;
        padding-right: 30px;
    }
    .spinner {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 55px;
        height: 55px;
        position: relative;
        z-index: 10;
    }
    .spinnerSector {
        border-radius: 50%;
        position: absolute;
        width: 100%;
        height: 100%;
        mix-blend-mode: overlay;
    }
    .spinnerText {
        font-size: .6em;
        animation: loading-opacity 3s ease-in-out infinite;
    }

    .spacer {
        width: 100%;
        height: 5px;
        background-color: white;
        border-bottom-left-radius: 8px;
        border-bottom-right-radius: 8px;
        border-top-left-radius: 8px;
        border-top-right-radius: 8px;
        opacity: .8;
    }

    .header {
        background-color: #272C33;
        width: 100%;
        height: 80vh;
        display: flex;
        flex-direction: column;
        padding: 10px;
        justify-content: space-between;
        align-items: center;
        color: white;
        font-size: 1em;
    }
}

@media only screen and (max-width: 450px) {
    .logo {
        width: 180px;
        padding-right: 30px;
    }
    .spinner {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 55px;
        height: 55px;
        position: relative;
        z-index: 10;
    }
    .spinnerSector {
        border-radius: 50%;
        position: absolute;
        width: 100%;
        height: 100%;
        mix-blend-mode: overlay;
    }
    .spinnerText {
        font-size: .6em;
        animation: loading-opacity 3s ease-in-out infinite;
    }

    .spacer {
        width: 100%;
        height: 5px;
        background-color: white;
        border-bottom-left-radius: 8px;
        border-bottom-right-radius: 8px;
        border-top-left-radius: 8px;
        border-top-right-radius: 8px;
        opacity: .8;
    }

    .header {
        background-color: #272C33;
        width: 100%;
        height: 80vh;
        display: flex;
        flex-direction: column;
        padding: 10px;
        justify-content: space-between;
        align-items: center;
        color: white;
        font-size: 1em;
    }

    .firstSectionWrapper {
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        align-content: center;
    }

    .algorithms {
        margin: 0;
        padding: 0;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
    }

    .speed, .arraySize {
        width: 120px;
        margin-right: 0px;
        font-size: .8em;
        margin-bottom: 10px;
    }
}

@keyframes loading-opacity {
    0%, 100% {
        opacity: 1;
    }
    25%, 75% {
        opacity: .5;
    }
    50% {
        opacity: .1;
    }
}

@keyframes swing {
    15% {
        -webkit-transform: translateX(5px);
        transform: translateX(5px);
    }
    30% {
        -webkit-transform: translateX(-5px);
        transform: translateX(-5px);
    }
    50% {
        -webkit-transform: translateX(3px);
        transform: translateX(3px);
    }
    65% {
        -webkit-transform: translateX(-3px);
        transform: translateX(-3px);
    }
    80% {
        -webkit-transform: translateX(2px);
        transform: translateX(2px);
    }
    100% {
        -webkit-transform: translateX(0);
        transform: translateX(0);
    }
}