* {
    box-sizing: border-box;
}

body {
    margin:0px;
}

.main-container {
    background:rgb(183, 233, 183);
    width:100vw;
    height:100vh;
    display:flex;
    flex-direction: column;
    padding:20px;
    gap:20px;
}

.upper {
    height:25%;
    display:flex;
    gap: 20px;
}

.upper-item {
    background:lightseagreen;
    width:100%;
    height:100%;
}

.left {
    height:75%;
    display:flex;
    gap:20px;
}

.left-box {
    background: purple;
    width:50%;
    display:flex;
    justify-content: center;
    align-items: center;
}

.center-box {
    background: yellowgreen;
    width:25%;
    height: 30%;
}

.lower {
    width:50%;
    display:flex;
    flex-direction:column;
    gap:20px;
}

.lower-item {
    background: yellow;
    height:25%;
}