:root {
    --font-family: Roboto, sans-serif;
    --font-size-small: 8pt;
    --font-size-normal: 9pt;
    --font-size-large: 10pt;
    --font-size-huge: 12pt;
    --font-weight-small: normal;
    --font-weight-normal: normal;
    --font-weight-large: bold;
    --font-weight-huge: normal;
    --radius-normal: 5px;
    --margin-normal: 5px;
    --margin-large: 10px;
    --padding-normal: var(--margin-normal);
    --padding-large: var(--margin-large);
    --length-normal: 20px;
    --length-large: 30px;
    --length-huge: 50px;
    --proportion-normal: 75%;
    --width-normal: 2px;
    --line-height-normal: 1.1em;
    --color-void: #2f3640;
    --color-back: #353b48;
    --color-front: white;
    --color-active: #22a6b3;
    --color-disabled: #808e9b;
    --color-focus: #686de0;
    --color-selection: #fbc531;
    --color-hint: #7ed6df;
    --color-backdrop: rgba(47, 54, 64, 0.6);
    --duration-normal: 0.3s;
}

html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    font-family: var(--font-family);
    font-size: var(--font-size-normal);
    font-weight: var(--font-weight-normal);
    background-color: var(--color-void);
    color: var(--color-front);
}

#app {
    position: relative;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    max-width: 400px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

header {
    flex-shrink: 0;
    flex-grow: 0;
    position: relative;
    left: 0;
    width: 100%;
    font-size: var(--font-size-huge);
    font-weight: var(--font-weight-huge);
}

main {
    flex: 1;
    position: relative;
    width: 100%;
}

footer {
    flex-shrink: 0;
    flex-grow: 0;
    position: relative;
    left: 0;
    width: 100%;
    font-family: var(--font-family);
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-small);
    font-style: italic;
}

.btn {
    margin: 0;
    border: none;
    padding: var(--padding-normal);
    box-sizing: border-box;
    font-family: var(--font-family);
    font-size: var(--font-size-normal);
    background-color: var(--color-active);
    color: var(--color-front);
    cursor: pointer;
    transition-property: background-color, color;
    transition-duration: var(--duration-normal);
    transition-timing-function: ease-in-out;
}
.btn:hover {
    background-color: var(--color-focus);
}
.btn:disabled {
    background-color: var(--color-disabled);
    color: var(--color-void);
    cursor: default;
}

.text {
    line-height: var(--line-height-normal);
    border: none;
    padding: var(--padding-normal);
    box-sizing: border-box;
    font-family: var(--font-family);
    font-size: var(--font-size-normal);
    background-color: transparent;
    color: var(--color-front);
    outline: var(--width-normal) solid var(--color-active);
    overflow-y:auto;
    transition-property: outline-color;
    transition-duration: var(--duration-normal);
    transition-timing-function: ease-in-out;
}
.text:hover,
.text:focus {
    outline-color: var(--color-focus);
}
.text>mark {
    display: inline;
    margin: 0;
    padding: 0;
    border: none;
    outline: none;
    background: none;
    color: var(--color-selection);
}

a {
    color: var(--color-selection);
    text-decoration: none;
}

#alert {
    position: absolute;
    top: var(--margin-large);
    left: 50%;
    height: calc(2 * var(--padding-large) + var(--length-normal));
    transform: translateX(-50%);
    padding: var(--padding-large);
    box-sizing: border-box;
    background-color: var(--color-front);
    color: var(--color-void);
    text-align: center;
    pointer-events: none;
    transition-property: opacity;
    transition-duration: var(--duration-normal);
    transition-timing-function: ease-in-out;
}
#alert.hidden {
    opacity: 0;
}
#alert>.message {
    display: inline-block;
    height: 100%;
    line-height: var(--length-normal);
}