body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f6fa;
    color: #333;
}

header {
    background-color: #1abc9c;
    color: white;
    padding: 20px;
    text-align: center;
}

header button {
    margin-top: 10px;
}

main {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    padding: 20px;
}

section {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    width: 45%;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

input, select {
    display: block;
    margin: 10px 0;
    padding: 10px;
    width: 100%;
    box-sizing: border-box;
}

button {
    background-color: #1abc9c;
    color: white;
    border: none;
    padding: 10px 20px;
    cursor: pointer;
    border-radius: 5px;
}

button:hover {
    background-color: #16a085;
}

/* Dark mode */
body.dark-mode {
    background-color: #2c3e50;
    color: #ecf0f1;
}

body.dark-mode header {
    background-color: #34495e;
}

body.dark-mode section {
    background-color: #3b4a59;
    box-shadow: 0 2px 5px rgba(0,0,0,0.5);
}

body.dark-mode input,
body.dark-mode select {
    background-color: #4b5d6a;
    color: #ecf0f1;
    border: 1px solid #7f8c8d;
}

body.dark-mode button {
    background-color: #1abc9c;
    color: #ecf0f1;
}