* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    min-height: 100%;
    font-family: Arial, sans-serif;
}

body {
    background: #f5f5f5;
}

#app {
    width: 100%;
    max-width: 390px;
    min-height: 100vh;
    margin: 0 auto;
    background: #ffffff;
}