:root {
    --clr-white: #fff;
    --clr-main: #007bff;
    --clr-font: #333;
    --clr-border: #dcdcdc;
    --box-padding: 2.3em;
    --box-radius: 20px;
}

#footer{
    margin-top: 650px;
}


.container-water {
    width: 95%;
    max-width: 490px;
    height: 505px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.game-container {
    height: 100%;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background-color: var(--clr-white);
    padding: var(--box-padding);
    border-radius: var(--box-radius);
    border: 1px solid var(--clr-border);
    box-shadow: 0 0 10px #b5b3b3;
}

.menu-heading, .rules-heading {
    margin-bottom: 1em;
    font-size: 30px;
    text-align: center;
    font-weight: 900;
    padding: 0 0 15px 0;
    border-bottom: 2px solid var(--clr-border);
}

.menu-list {
    width: 80%;
    margin: auto;
    display: grid;
    grid-template-columns: auto auto;
    gap: 1em;
}

.menu-list .item {
    position: relative;
    user-select: none;
    height: 100px;
    font-size: 21px;
    line-height: 4.4;
    text-align: center;
    font-weight: 700;
    cursor: pointer;
    overflow: hidden;
    color: var(--clr-white);
    border-radius: var(--box-radius);
}

.menu-list .item:not(:last-child)::before {
    content: 'Play';
    position: absolute;
    left: 0;
    top: -100%;
    width: 100%;
    height: 32px;
    font-size: 15px;
    line-height: 2;
    transition: 0.5s;
    letter-spacing: 1px;
    pointer-events: none;
    background: #dcdcdc99;
}

.menu-list .item:hover::before { top: 0; }
.menu-list .item:active { scale: 0.95; }
#easy { background-image: linear-gradient(to bottom right, #037dfb, #0da6ff); }
#medium { background-image: linear-gradient(to bottom right, #a900ff, #00fff3); }
#hard { background-image: linear-gradient(to bottom right, #ff00d4, #ff0000); }
#very-hard { background-image: linear-gradient(to bottom right, #ff00d4, #ff0081); }
#impossible { background-image: linear-gradient(to bottom right, #ff0000, #d800ff); }
.rules-btn { background-image: linear-gradient(to bottom right, #6204f9, #d600fd); }

.level, .rules {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    opacity: 0;
    background: var(--clr-white);
    border-radius: var(--box-radius);
    padding: var(--box-padding);
    border: 1px solid var(--clr-border);
}

.level.active, .rules.active { display: block; }
.level.opacity, .rules.opacity { opacity: 1; }

.level.active.opacity {
    border-color: #1276af;
    background-color: #1276af;
}

.game-option {
    display: flex;
    align-items: center;
    justify-content: space-around;
}

.game-option>.btn {
    padding: 10px 20px;
    font-size: 15px;
    border-radius: 5px;
    color: var(--clr-white);
    letter-spacing: 0.5px;
    cursor: pointer;
    font-weight: 600;
    background-color: var(--clr-main);
}
.btn:active { scale: 0.95; }
.moves {
    color: var(--clr-white);
    font-size: 27px;
    font-weight: 700;
}

.lvl-name {
    margin-top: 0.8em;
    background: var(--clr-main);
    scale: 1.18;
    border-radius: 0 0 25px 25px;
    font-size: 20px;
    font-weight: 800;
    line-height: 44px;
    text-align: center;
    letter-spacing: 3px;
    color: var(--clr-white);
}

.tube-items {
    position: relative;
    margin-top: 1em;
    width: 100%;
    height: 19.8em;
    background: var(--clr-main);
    border-radius: var(--box-radius);
}

.tube {
    position: absolute;
    height: 130px;
    width: 45px;
    border: 2px solid var(--clr-border);
    border-radius: 2px 2px 20px 20px;
    background-position: 0 10px;
    overflow: hidden;
    transition: 1s linear;
    transform: rotate(0deg);
    cursor: pointer;
    scale: 0.9;
    box-shadow: 0 0 2px var(--clr-white);
}

.color {
    position: absolute;
    left: 0;
    height: 30px;
    width: 100%;
    scale: 1.02;
    pointer-events: none;
}

.colorful, .tr-bg {
    position: absolute;
    width: 100%;
    height: 0;
    z-index: 10;
    transition: 1s;
}
.tr-bg { background-color: var(--clr-main); }
.won {
    font-size: 35px;
    color: var(--clr-white);
    font-weight: bold;
    line-height: 1.6;
    text-align: center;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.rules-heading { margin-bottom: 0.6em; }
.rules-text {
    font-size: 17px;
    line-height: 28px;
    color: black;

}

.rules-action-btn {
    margin-top: 15px;
    display: flex;
    align-items: center;
    justify-content: end;
    gap: 1em;
}

.rules-action-btn .btn {
    padding: 8px 15px;
    font-size: 15px;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    color: var(--clr-font);
    border: 1px solid var(--clr-border);
}

.rules-action-btn .btn:hover {
    background-color: var(--clr-border);
}