:root {
  /* hsl (fallback color) */
  --bg-dark: hsl(216 100% 2%);
  --bg: hsl(205 100% 4%);
  --bg-light: hsl(199 100% 7%);
  --txt: hsl(200 100% 91%);
  --txt-m: hsl(199 70% 65%);
  --highlight: hsl(195 100% 28%);
  --border: hsl(194 100% 16%);
  --border-muted: hsl(197 100% 10%);
  --primary: hsl(199 70% 65%);
  --secondary: hsl(22 68% 68%);
  --danger: hsl(9 53% 66%);
  --warning: hsl(51 35% 50%);
  --success: hsl(149 34% 54%);
  --info: hsl(217 59% 67%);
  /* oklch */
  --bg-dark: oklch(0.1 0.05 230);
  --bg: oklch(0.15 0.05 230);
  --bg-light: oklch(0.2 0.05 230);
  --txt: oklch(0.96 0.1 230);
  --txt-m: oklch(0.76 0.1 230);
  --highlight: oklch(0.5 0.1 230);
  --border: oklch(0.4 0.1 230);
  --border-muted: oklch(0.3 0.1 230);
  --primary: oklch(0.76 0.1 230);
  --secondary: oklch(0.76 0.1 50);
  --danger: oklch(0.7 0.1 30);
  --warning: oklch(0.7 0.1 100);
  --success: oklch(0.7 0.1 160);
  --info: oklch(0.7 0.1 260);
}
body.light {
  /* hsl (fallback color) */
  --bg-dark: hsl(200 100% 89%);
  --bg: hsl(200 100% 94%);
  --bg-light: hsl(200 100% 99%);
  --txt: hsl(212 100% 6%);
  --txt-m: hsl(194 100% 16%);
  --highlight: hsl(200 100% 97%);
  --border: hsl(198 56% 44%);
  --border-muted: hsl(199 57% 57%);
  --primary: hsl(194 100% 16%);
  --secondary: hsl(25 87% 24%);
  --danger: hsl(8 40% 42%);
  --warning: hsl(52 82% 24%);
  --success: hsl(154 58% 29%);
  --info: hsl(217 42% 43%);
  /* oklch */
  --bg-dark: oklch(0.92 0.05 230);
  --bg: oklch(0.96 0.05 230);
  --bg-light: oklch(1 0.05 230);
  --txt: oklch(0.15 0.1 230);
  --txt-m: oklch(0.4 0.1 230);
  --highlight: oklch(1 0.1 230);
  --border: oklch(0.6 0.1 230);
  --border-muted: oklch(0.7 0.1 230);
  --primary: oklch(0.4 0.1 230);
  --secondary: oklch(0.4 0.1 50);
  --danger: oklch(0.5 0.1 30);
  --warning: oklch(0.5 0.1 100);
  --success: oklch(0.5 0.1 160);
  --info: oklch(0.5 0.1 260);
}

html {
    padding: 0;
    margin: 0;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-dark);
    color: var(--txt-m);
    padding: 0;
    margin: 0;
}

h1, h2, h3, h4, h5, h6 {
    margin: 0 0 10px 0;
    color: var(--txt);
}

a {
    display: block;
    text-decoration: none;
    color: inherit;
}

.navbar {
    background-color: var(--bg);
    height: 48px;
    width: 100%;
    border-bottom: 1px solid var(--border-muted);
    margin-bottom: 16px;
}

.navbar > a {
    display: inline-block;
    height: 100%;
    text-align: center;
    align-content: center;
    width: 100px;
}

.navbar > a:hover {
    background-color: var(--bg-light);
    cursor: pointer;
}

.float-right {
    float: right;
}

.content {
    width: min(80%, 800px);
    margin: auto;
}

.bg-dark {
    background-color: var(--bg-dark);
}

.bg {
    background-color: var(--bg);
}

.bg-light {
    background-color: var(--bg-light);
}

.txt {
    color: var(--txt);
}

.block {
    background-color: var(--bg);
    width: calc(100% - 2 * 16px);
    height: fit-content;
    border-radius: 15px;
    border: 1px solid var(--border);
    border-top: 1px solid var(--highlight);
    padding: 16px;
    margin-bottom: 48px;
}

.btn-holder {
    margin-top: 16px;
    columns: 4;
    column-gap: 32px;
}

.btn {
    width: 100%;
}

.btn > button {
    align-items: center;
    appearance: none;
    background-color: var(--bg-light);
    border-radius: 8px;
    border-width: 1px;
    border-color: var(--border);
    border-top-color: var(--highlight);
    box-sizing: border-box;
    color: var(--txt-m);
    cursor: pointer;
    display: inline-flex;
    height: 48px;
    justify-content: center;
    line-height: 1;
    list-style: none;
    overflow: hidden;
    padding-left: 12px;
    padding-right: 12px;
    position: relative;
    text-align: center;
    text-decoration: none;
    white-space: nowrap;
    font-size: 16px;
    transition: transform 0.15s;
    width: 100%;
    font-weight: bold;
}

.btn > button:hover {
    transform: translateY(-2px);    
}

.button-holder > a {
    background-color: var(--bg-light);
    display: inline-block;
    text-align: center;
    height: 32px;
    width: 128px;
    border: 1px solid var(--border);
    border-top: 1px solid var(--highlight);
    border-radius: 8px;
}

.button-holder > a > span {
    display: inline-block;
    vertical-align: middle;
}

.title {
    font-size: 48px;
    color: var(--txt-m);
    margin-bottom: 64px;
}

.tree {
    list-style-type: none;
    padding-left: 0px;
}

.tree-project {
    border-radius: 15px;
    border: 1px solid var(--border);
    border-top: 1px solid var(--highlight);
    padding: 16px;
    width: 100%;
    text-align: left;
    margin-bottom: 16px;
}

.tree-button {
    background-color: var(--bg);
    color: var(--txt-m);
    border: none;
    font-size: 32px;
    cursor: pointer;
}

.tree-list {
    padding-left: calc(1em / 2);
    margin-left: calc(1em / 2);
    list-style-type: none;
}

.tree-list-item {
    border-left: 2px solid var(--border-muted);
}

.small {
    font-size: 12px;
    color: var(--border);
}