* {
    color: var(--text-color-1);
    font-family: -apple-system, BlinkMacSystemFont,
        'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell,
        'Open Sans', 'Helvetica Neue', sans-serif;
}

html { scroll-behavior: smooth; }

html, body, p, button, input, textarea, select {
    font-size: var(--base-font-size);
    font-weight: var(--normal-font-weight);
}

body {
    margin: 0;
    line-height: var(--default-line-height);
    background-color: var(--background-color-1);
}

/* HEADINGS */

h1, h2, h3, h4, h5, h6 {
    margin: 0 0 var(--default-spacing) 0;
    color: var(--text-color-0);
    font-weight: var(--semibold-font-weight);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

/* PARAGRAPH */

p { margin: 0 0 var(--default-spacing) 0; }

/* LINK */

a {
    cursor: pointer;
    text-decoration: none;
    color: var(--primary-color-0);
}

a:hover {
    color: var(--primary-color-1);
    border-bottom: var(--thin-thickness) solid currentColor;
}

/* BUTTON */

button,
input[type="button"],
input[type="reset"],
input[type="submit"] {
    border: none;
    cursor: pointer;
    border-radius: var(--default-border-radius);
    color: var(--text-color-on-solid);
    background-color: var(--primary-color-0);
    padding:
        var(--default-spacing)
        calc(var(--default-spacing) + 2 * var(--default-thickness));
    transition: background-color
        var(--default-transition-duration)
        var(--default-transition-function);
}

button:hover,
input[type="button"]:hover,
input[type="reset"]:hover,
input[type="submit"]:hover {
    background-color: var(--primary-color-1);
}

button:active,
input[type="button"]:active,
input[type="reset"]:active,
input[type="submit"]:active,
button:focus,
input[type="button"]:focus,
input[type="reset"]:focus,
input[type="submit"]:focus {
    outline: none;
    box-shadow: 0 0 0 var(--bold-thickness) var(--primary-transparent-1);
}

/* TEXTBOX, TEXTAREA */

textarea,
select,
input[type="text"],
input[type="number"],
input[type="password"],
input[type="date"],
input[type="datetime"],
input[type="datetime-local"],
input[type="email"],
input[type="month"],
input[type="time"],
input[type="url"],
input[type="week"],
input[type="tel"],
input[type="search"] {
    background-color: transparent;
    border-radius: var(--default-border-radius);
    border: var(--default-thickness) solid var(--background-gray-2);
    padding: calc(var(--default-spacing) - var(--default-thickness));
}

textarea:focus,
select:focus,
input[type="text"]:focus,
input[type="number"]:focus,
input[type="password"]:focus,
input[type="date"]:focus,
input[type="datetime"]:focus,
input[type="datetime-local"]:focus,
input[type="email"]:focus,
input[type="month"]:focus,
input[type="time"]:focus,
input[type="url"]:focus,
input[type="week"]:focus,
input[type="tel"]:focus,
input[type="search"]:focus {
    outline: none;
    border: var(--default-thickness) solid var(--primary-color-0);
}

/* OTHER INPUT */

input[type="radio"],
input[type="checkbox"] {
    width: 1.2rem;
    height: 1.2rem;
    border: none;
    vertical-align: middle;
    margin-bottom: var(--default-spacing);
}

input[type="file"]:focus,
input[type="image"]:focus {
    outline: none;
}

/* TABLE */

table { border-collapse: collapse; }

tr, th, td {
    border: var(--thin-thickness) solid var(--background-gray-2);
}

th, td {
    padding: var(--small-spacing) var(--default-spacing);
}

th {
    font-weight: var(--semibold-font-weight);
}

tbody > tr:nth-child(odd) {
    background-color: var(--background-color-2);
}

td[contenteditable="true"] {
    outline: none;
}

td[contenteditable="true"]:empty::before {
    content: attr(placeholder);
    color: var(--text-gray-0);
    cursor: text;
    white-space: nowrap;
}

/* DETAILS & SUMMARY */

details {
    background-color: var(--background-color-2);
    border-radius: var(--default-border-radius);
}

summary {
    border: none;
    cursor: pointer;
    background-color: var(--background-color-2);
    padding: var(--default-spacing);
    border-radius: var(--default-border-radius);
}

summary:focus { outline: none; }

/* OTHERS */

blockquote {
    margin: 0;
    border-left: var(--bold-thickness) solid var(--primary-color-0);
    padding:
        var(--default-spacing)
        calc(2 * var(--default-spacing) - var(--default-thickness));
    background-color: var(--background-color-2);
}

kbd {
    cursor: pointer;
    padding: 0.2rem 0.4rem;
    font-family: Consolas, monospace;
    color: var(--text-reverse-1);
    background-color: var(--background-reverse-1);
    border-radius: var(--default-border-radius);
}

b, strong {
    font-weight: var(--semibold-font-weight);
}

hr {
    border: none;
    border-top: var(--thin-thickness) solid var(--background-gray-2);
}

optgroup, option {
    color: black;
}

input, textarea, button, select, a {
    -webkit-tap-highlight-color: transparent;
}