/* ------------------------------------------------ */
/* color variables */
/* ------------------------------------------------ */

:root {
    --page-bg: #ffffff;
    --page-text: #000000;
    --nav-bg: #222222;
    --nav-text: #ffffff;
    --surface-bg: #dddddd;
    --surface-text: #000000;
    --border-color: #000000;
    --field-bg: #ffffff;
    --field-text: #000000;
    --link-color: #0000ee;
}

body.dark-mode {
    --page-bg: #1a1a1a;
    --page-text: #ffffff;
    --nav-bg: #111111;
    --nav-text: #ffffff;
    --surface-bg: #2a2a2a;
    --surface-text: #ffffff;
    --border-color: #ffffff;
    --field-bg: #2a2a2a;
    --field-text: #ffffff;
    --link-color: #8ab4ff;
}

/* ------------------------------------------------ */
/* base page styles */
/* ------------------------------------------------ */

body {
    font-family: Arial;
    text-align: center;
    margin: 0;
    background: var(--page-bg);
    color: var(--page-text);
}

h1,
h2,
h3,
p,
label,
span {
    color: var(--page-text);
}

a {
    color: var(--link-color);
}

/* ------------------------------------------------ */
/* nav */
/* ------------------------------------------------ */

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    background: var(--nav-bg);
    padding: 0;
    margin: 0;
    border-bottom: 2px solid var(--border-color);
}

nav ul li a {
    color: var(--nav-text);
    padding: 12px 20px;
    display: block;
    text-decoration: none;
}

nav ul li a:hover {
    background: #555555;
}

/* ------------------------------------------------ */
/* shared form controls */
/* ------------------------------------------------ */

button,
input,
select {
    font: inherit;
    border: 1px solid var(--border-color);
    background: var(--field-bg);
    color: var(--field-text);
    box-sizing: border-box;
}

/* button */
button {
    padding: 10px 20px;
    margin-top: 15px;
    cursor: pointer;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

/* text fields and dropdowns */
input,
select {
    padding: 6px;
}