* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    background-color: green;
    background-image: url('imagens/gramado.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    background-position: left bottom;
    background-attachment: fixed;
    height: 100vh;
}

header {
    max-width: 500px;
    margin: auto;
}

header > img {
    width: 100%;
}

h1, h2 {
    margin-bottom: 10px;
}

main, article#resultado {
    max-width: 500px;
    margin: 30px auto;
    background-color: white;
    padding: 10px;
    border-radius: 10px;
    box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.565);
}

section {
    border: 2px solid green;
    background-color: rgba(0, 128, 0, 0.105);
    margin: 0 0 10px 0;
    padding: 10px;
    border-radius: 10px;
}

ul {
    margin-left: 15px;
    line-height: 1.5em;
}

input[type="number"] {
    padding: 3px 5px;
    margin: 2px;
    text-align: right;
    font-size: 1.2em;
    color: green;
    font-weight: bold;
}

input[type="submit"], button {
    padding: 5px 15px;
    margin: 5px;
    font-size: 1.2em;
    color: white;
    background-color: green;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button {
    padding: 5px 40px;
    display: block;
    margin: auto;
}