*, *::before, *::after {
    padding: 0;
    margin: 0;
    border: 0;
    box-sizing: border-box;
}
:focus, :active {
    outline: none;
}
a:focus, a:active {
    outline: none;
}
a, a:visited {
    text-decoration: none;
}
a:hover {
    text-decoration: none;
}
ul, ol, li {
    list-style: none;
}
img {
    vertical-align: top;
}
h1, h2, h3, h4, h5, h6 {
    font-weight: inherit;
    font-size: inherit;
}
nav, footer, header, aside {
    display: block;
}
input, button, textarea {
    font-family: inherit;
}
input::-ms-clear {
    display: none;
}
button::-moz-focus-inner {
    padding: 0;
    border: 0;
}
html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, 
pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, 
samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, 
fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, 
canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, 
section, summary, time, mark, audio, video { 
    margin: 0; 
    padding: 0; 
    border: 0; 
    font-size: 100%; 
    font: inherit; 
}
html, body {
    height: 100%;
    line-height: 1;
    font-size: 16px;
    color: #000;
    font-weight: 400;
    font-family: 'Roboto', Arial, sans-serif;
}
strong { font-weight: 700; }

/*====================================*/

body {
    background-color: #ececec;
}

.main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    /*background-color: aqua;*/
    width: 100%;
    margin: 0px auto;
    height: 100%;
}

.form {
    display: flex;
    min-width: 250px;
}

.result {
    margin: 10px auto;
    min-width: 250px;
}

.result span {
    display: inline-block;
    border: 1px solid #000;
    padding: 6px 10px;
    min-height: 30px;
    width: 100%;
    font-weight: 300;
    text-align: center;
}

input,
button {
    padding: 6px 10px;
    margin: 10px auto;
    font-weight: 400;
    border: 1px solid #000;
    font-size: 13px;
}
input {
    justify-self: left;
    width: 100%;
    
}
button {
    justify-self: right;
    width: 40px;
    margin-left: 4px;
}

/* Chrome, Safari, Edge, Opera */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* Firefox */
input[type=number] {
  -moz-appearance: textfield;
}