styles.css

@import url('https://fonts.googleapis.com/css2?family=Kanit:ital,wght@0,200;0,300;0,400;0,500;0,600;0,700;1,200;1,300;1,400;1,500;1,600;1,700&display=swap');

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: inherit;
    font-size: inherit;
    font-weight: normal;
}

html {
    font-family: 'Kanit', sans-serif;
    font-size: 62.5%;
    color: inherit;
    width: 100%;
    height: 100%;
}

body {
    background: rgb(49, 49, 49);
    width: 100%;
    height: 100%;
    font-size: 1.7rem;
    color: white;
}

h1 {
    font-size: 1.6em;
    font-weight: 600;
}

h2 {
    font-size: 1.3em;
    font-weight: 500;
}

h6 {
    font-size: 0.85em;
    font-style: italic;
}

.page-wrapper {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    width: 100%;
    background: rgb(201, 201, 201);
    color: rgb(27, 27, 27);
    height: 8vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

main {
    width: 100%;
    flex: 1;
}
    article {
        width: 100%;
        height: 100%;
        display: flex;
    }

    section {
        flex: 1;
        padding: 1em;
        border: 1px solid white;
    }

        .exp-register-form {
            display: flex;
            flex-direction: column;
        }

            .exp-label {
                font-size: .8em;
                color: rgb(182, 182, 182);
            }

            .exp-register-btn {
                
            }

    .show-expenses-container {
        display: flex;
        flex-direction: column;
    }

        .exp-div {
            background: rgb(82, 82, 82);
            padding: 0.25em;
            display: flex;
            flex-direction: column;
            margin: 0.5em 0;
        }

        .exp-div > div:first-child {
            display: flex;
            justify-content: space-between;
        }

footer {
    height: 100%;
    height: 6vh;
}

    footer div {
        height: 100%;
        display: flex;
        align-items: center;
    }