style.css

/* Document Root */
:root {
    /* Background Color */
    --background-color: rgb(185, 185, 185);

    /* Score Color */
    --score-color: rgb(55, 55, 55);

    /* Main Grid/Block Color */
    --grid-color: rgb(55, 55, 55);
    --block-color: rgb(115, 115, 115);

    /* Other Grid/Block Color */
    --won-color: rgb(0, 255, 0);
    --lost-color: rgb(255, 0, 0);
    --incorrect-color: rgb(185, 0, 0);
    --correct-color: rgb(185, 185, 185);

    /* Button Color */
    --button-color: rgb(125, 125, 125);
    --button-hover-color: rgb(145, 145, 145);
    --border-color: rgb(85, 85, 85);

    /* Font Color */
    --font-color: rgb(0, 0, 0);
}

/* Body */
body {
    background-color: var(--background-color);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    font-family: "Oswald";
}

/* Heading One */
h1 {
    color: var(--font-color);
    font-size: 30px;
    text-align: center;
}

/* Heading Two */
h2 {
    color: var(--font-color);
    font-size: 20px;
    text-align: center;
}

/* Grid */
div.grid {
    margin: 15px auto;
    width: 650px;
    height: 650px;
    display: grid;
    background: var(--grid-color);
    grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
    grid-template-rows: 1fr 1fr 1fr 1fr 1fr;
    gap: 10px;
    padding: 10px;
}

/* Grid - Won Color */
.grid.won .block {
    background: var(--won-color);
}

/* Grid - Lost Color*/
.grid.lost .block {
    background: var(--lost-color);
}

/* Block */
.block {
    width: 100%;
    height: 100%;
    border-radius: 5px;
    cursor: pointer;
    background: var(--block-color);
}

/* Block Show - Block Correct */
.block.show, .block.correct{
    background: var(--correct-color);
}

/* Block Incorrect */
.block.incorrect{
    background: var(--incorrect-color);
}

/* Grid Lost - Show Block */
.grid.lost .show.block {
    background: var(--won-color);
}

/* Grid Lost - Block*/
.grid.lost .block {
    background: var(--lost-color);
}

/* Grid Lost - Block Clicked Incorrect*/
.grid.lost .block.clicked.incorrect {
    background: var(--incorrect-color);
}

/* Grid Lost - Block Clicked Correct */
.grid.lost .block.clicked.correct {
    background: var(--correct-color);
}

/* Start Button - Base */
.start-button {
    display: block;
    padding: 15px 50px;
    cursor: pointer;
    font-size: 15px;
    text-align: center;
    text-decoration: none;
    transition-duration: 0.1s;
    border: 2px solid var(--border-color);
    background: var(--button-color);
}

/* Start Button - Hover */
.start-button:hover {
    background: var(--button-hover-color);
}