body {
    font-family: Lato;
    color: #333;
    padding: 20px;
    line-height: 1.5;
    font-size: 18px;
}

h1, h2, h3 {
    font-family: Poppins;
    color: #133a1a;
}

h1 {
    font-size: 26px;
}

h2, h3 {
    font-size: 20px;
}

p {
    margin-bottom: 1em;
}

.container {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.calculator {
    flex: 1 1 60%;
    margin-right: 20px;
}

.density-table {
    flex: 1 1 35%;
    max-width: 300px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

table, th, td {
    border: 1px solid black;
}

    table th {
        background-color: #133a1a;
        color: white;
    }

th, td {
    padding: 8px;
    text-align: left;
}

.form-group {
    margin-bottom: 15px;
}

.result {
    font-weight: bold;
}

.totals-table th, .totals-table td {
    padding: 8px;
    text-align: left;
}

.density-table table {
    width: auto;
}

.density-table td {
    padding: 4px 8px;
}

.buttons {
    margin-top: 20px;
}

    .buttons button {
        padding: 10px 20px;
        font-size: 18px;
        margin-right: 10px;
        background-color: #133a1a;
        color: white;
    }

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

    .header-container .calculator-header,
    .header-container .density-header {
        flex: 1;
    }

.density-header {
    margin-left: 20px;
}

#combinedClass {
    color: red;
}