/* SPDX-License-Identifier: AGPL-3.0-only */
/* The fonts: see fonts/README.md. */
@font-face { font-family: "Forum"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/forum-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Forum"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/forum-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Forum"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/forum-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-mono-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-mono-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-mono-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/ibm-plex-mono-500-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/ibm-plex-mono-500-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/ibm-plex-mono-500-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-sans-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-sans-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/ibm-plex-sans-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/ibm-plex-sans-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/ibm-plex-sans-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/ibm-plex-sans-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/jost-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/jost-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/jost-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/jost-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/jost-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 500; font-display: swap; src: url(fonts/jost-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/jost-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/jost-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Jost"; font-style: normal; font-weight: 600; font-display: swap; src: url(fonts/jost-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Old Standard TT"; font-style: italic; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400i-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Old Standard TT"; font-style: italic; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400i-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Old Standard TT"; font-style: italic; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400i-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 400; font-display: swap; src: url(fonts/old-standard-tt-400-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 700; font-display: swap; src: url(fonts/old-standard-tt-700-cyrillic.woff2) format("woff2"); unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 700; font-display: swap; src: url(fonts/old-standard-tt-700-latin-ext.woff2) format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Old Standard TT"; font-style: normal; font-weight: 700; font-display: swap; src: url(fonts/old-standard-tt-700-latin.woff2) format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }

/* Two designs while the owner picks one, switched by data-skin on <html>
   (static/skin.js):
   - slate, the default: the app's icon at the size of the page, a brass
     clipboard holding a sheet of slate (dark) or paper (light), drawn on
     in one line like the icon;
   - deco: art deco, gold lines on deep teal with neon tubes, dark only.
   Every colour is a token, and the components take them from the tokens. */

:root {
  --f-display: "Old Standard TT", Georgia, "Times New Roman", serif;
  --f-body: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Arabic", "Noto Sans Hebrew", "Noto Sans Devanagari", "PingFang SC", "Microsoft YaHei", sans-serif;
  --f-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --bg: #F3EFE4;
  --sheet: #F2F1EC;
  --raised: #FBFAF6;
  --text: #141A3A;
  --dim: #4E5370;
  --accent: #7E560C;
  --on-accent: #241604;
  --line: rgba(20, 26, 58, .16);
  --grid: rgba(20, 26, 58, .055);
  --code: #E6E1D2;
  --shadow: 0 1px 2px rgba(60, 40, 10, .08), 0 14px 30px -18px rgba(60, 40, 10, .35);
  /* The brass of the board and the clip, from its light to its shade. */
  --b1: #F2D78A;
  --b2: #D9B04E;
  --b3: #C49A3A;
  --b4: #A9822C;
  --b5: #8C6A1E;
  --b-hi: rgba(255, 246, 214, .7);
  --b-lo: rgba(90, 60, 10, .45);
  --curl-1: #FFFFFF;
  --curl-2: #D8D6CE;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-skin="deco"]) {
    --bg: #0A0F0C;
    --sheet: #2A2A28;
    --raised: #222220;
    --text: #ECE9E0;
    --dim: #ABA79B;
    --accent: #E0B566;
    --on-accent: #1E1405;
    --line: rgba(236, 233, 224, .16);
    --grid: rgba(236, 233, 224, .045);
    --code: #353431;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 18px 36px -18px rgba(0, 0, 0, .8);
    --b1: #B48A50;
    --b2: #8A6634;
    --b3: #6E5027;
    --b4: #523A1C;
    --b5: #33240F;
    --b-hi: rgba(255, 222, 160, .32);
    --b-lo: rgba(0, 0, 0, .55);
    --curl-1: #4A4A46;
    --curl-2: #222220;
    color-scheme: dark;
  }
}
:root[data-skin="deco"] {
  --f-display: "Forum", "Didot", Georgia, serif;
  --f-body: "Jost", "Futura", system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Arabic", "Noto Sans Hebrew", "Noto Sans Devanagari", "PingFang SC", "Microsoft YaHei", sans-serif;
  --bg: #08151B;
  --sheet: transparent;
  --raised: rgba(241, 234, 216, .045);
  --text: #F1EAD8;
  --dim: #A8B9B9;
  --accent: #D8B46A;
  --on-accent: #1A1206;
  --line: rgba(216, 180, 106, .32);
  --grid: rgba(216, 180, 106, .07);
  --code: #0F252D;
  --shadow: 0 18px 40px -20px rgba(0, 0, 0, .8);
  --neon-warm: #FF7A59;
  --neon-cold: #5EE6FF;
  --gold: linear-gradient(180deg, #F6DC9C, #D2A552 55%, #B4863A);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 80px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 var(--f-body);
  overflow-x: clip;
}
[data-skin="deco"] body {
  background: radial-gradient(ellipse 70% 50% at 50% 0%, #0F2730, transparent 70%) no-repeat, var(--bg);
}
a { color: var(--accent); text-underline-offset: 3px; }
code, pre { font-family: var(--f-mono); font-size: .88em; }
code { background: var(--code); padding: .1em .4em; border-radius: 5px; direction: ltr; unicode-bidi: isolate; white-space: nowrap; display: inline-block; max-width: 100%; overflow-x: auto; vertical-align: bottom; }
pre { background: var(--code); padding: 12px 14px; border-radius: 8px; overflow-x: auto; direction: ltr; text-align: left; white-space: pre; }
pre code { background: none; padding: 0; white-space: pre; display: block; max-width: none; overflow: visible; } /* keeps the lines of a command */
h1, h2, h3 { font-family: var(--f-display); line-height: 1.1; text-wrap: balance; }
h1 { font-size: clamp(34px, 4.1vw, 52px); margin: 0 0 20px; font-weight: 700; letter-spacing: -.005em; }
h2 { font-size: clamp(28px, 3.2vw, 38px); margin: 88px 0 18px; font-weight: 700; }
h3 { font-size: 21px; margin: 0 0 8px; font-weight: 700; }
[data-skin="deco"] h1, [data-skin="deco"] h2, [data-skin="deco"] h3 { font-weight: 400; text-transform: uppercase; letter-spacing: .05em; }
[data-skin="deco"] h1 { font-size: clamp(34px, 4.4vw, 60px); letter-spacing: .04em; }
[data-skin="deco"] h2 { text-align: center; color: var(--accent); }
[data-skin="deco"] h2::after { content: ""; display: block; width: 120px; height: 7px; margin: 16px auto 0; border-block: 1px solid var(--accent); }
[data-skin="deco"] h3 { font-size: 20px; }

.wrap { max-width: 1160px; margin: 0 auto; padding-inline: max(20px, env(safe-area-inset-left, 0px)) max(20px, env(safe-area-inset-right, 0px)); }
.dim { color: var(--dim); }
.lead { font-size: clamp(18px, 1.7vw, 20px); color: var(--dim); max-width: 36em; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }

/* The header. */
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 82%, transparent); border-bottom: 1px solid var(--line); -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px); }
.bar { display: flex; align-items: center; gap: 14px; min-height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font: 700 21px/1 var(--f-display); }
[data-skin="deco"] .brand { font-weight: 400; text-transform: uppercase; letter-spacing: .12em; font-size: 20px; }
.brand img { display: block; }
nav { display: flex; gap: 4px; margin-inline-start: auto; }
nav a { color: var(--dim); text-decoration: none; font-weight: 500; padding: 8px 12px; border-radius: 8px; white-space: nowrap; }
nav a:hover { color: var(--text); }
nav a[aria-current] { color: var(--accent); }
[data-skin="deco"] nav a { text-transform: uppercase; letter-spacing: .14em; font-size: 13.5px; }

.skin, .langs summary {
  display: flex; align-items: center; gap: 8px; min-height: 44px; padding: 4px 12px; cursor: pointer;
  font: 500 14px/1 var(--f-mono); color: var(--text); background: transparent; border: 1px solid var(--line); border-radius: 8px;
}
.skin[hidden] { display: none; }
.skin span { padding: 6px 8px; border-radius: 5px; color: var(--dim); }
:root:not([data-skin="deco"]) .skin span:first-child, [data-skin="deco"] .skin span:last-child { background: var(--accent); color: var(--on-accent); }
.langs { position: relative; }
.langs summary { list-style: none; }
.langs summary::-webkit-details-marker { display: none; }
.globe { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.6; color: var(--dim); }
.langs ul {
  position: absolute; inset-inline-end: 0; top: calc(100% + 8px); margin: 0; padding: 6px; list-style: none; min-width: 190px; z-index: 20;
  background: var(--raised); border: 1px solid var(--line); border-radius: 10px; box-shadow: var(--shadow);
}
[data-skin="deco"] .langs ul { background: #0C1E25; }
.langs li a { display: block; padding: 10px 12px; border-radius: 6px; color: var(--text); text-decoration: none; }
.langs li a:hover { background: var(--grid); }
.langs li a[aria-current] { color: var(--accent); font-weight: 600; }

/* The hero: the board, its clip and the sheet with the drawing. */
.hero { padding: 150px 0 24px; }
.board {
  --pad-x: clamp(16px, 3vw, 38px); --pad-b: clamp(26px, 4.4vw, 56px); --curl: clamp(46px, 7vw, 92px);
  position: relative; border-radius: clamp(28px, 4.4vw, 56px); padding: clamp(18px, 3.2vw, 40px) var(--pad-x) var(--pad-b);
  background:
    radial-gradient(ellipse 60% 40% at 18% 0%, var(--b-hi), transparent 70%),
    linear-gradient(155deg, var(--b2), var(--b3) 45%, var(--b4) 85%, var(--b3));
  box-shadow:
    inset 0 3px 2px var(--b-hi), inset 0 -8px 12px var(--b-lo), inset 8px 0 12px -6px var(--b-hi), inset -10px 0 14px -6px var(--b-lo),
    0 2px 0 var(--b5), 0 40px 70px -30px rgba(20, 12, 2, .55);
}
.clamp {
  position: absolute; z-index: 3; left: 50%; top: 0; width: clamp(240px, 52%, 600px); height: auto; transform: translate(-50%, -44%);
  filter: drop-shadow(0 12px 10px rgba(20, 12, 2, .45));
}
.m1 { stop-color: var(--b1); }
.m2 { stop-color: var(--b3); }
.m3 { stop-color: var(--b2); }
.m4 { stop-color: var(--b4); }
.m5 { stop-color: var(--b5); }
.h1 { stop-color: var(--b-hi); }
.h2 { stop-color: var(--b-hi); stop-opacity: 0; }
.metal { fill: url(#metal); }
.sheen { fill: url(#sheen); }
.lip { fill: none; stroke: var(--b-lo); stroke-width: 6; opacity: .6; }
.hole { fill: none; stroke: var(--b-lo); stroke-width: 4; }
.sheet {
  position: relative; border-radius: clamp(8px, 1.2vw, 14px); padding: clamp(64px, 9vw, 112px) clamp(20px, 4.4vw, 60px) clamp(36px, 5vw, 60px);
  background: linear-gradient(var(--grid) 1px, transparent 1px) 0 0 / 30px 30px, linear-gradient(90deg, var(--grid) 1px, transparent 1px) 0 0 / 30px 30px,
    linear-gradient(170deg, color-mix(in srgb, var(--sheet) 92%, #fff), var(--sheet) 40%, color-mix(in srgb, var(--sheet) 92%, #000));
  box-shadow: 0 1px 0 rgba(255, 255, 255, .06) inset, 0 3px 6px rgba(0, 0, 0, .25), 0 0 0 1px rgba(0, 0, 0, .12);
  /* The lifted corner: the sheet ends at a quarter circle, and .curl draws
     the rolled paper over it. */
  -webkit-mask: radial-gradient(circle at 100% 100%, transparent var(--curl), #000 calc(var(--curl) + .5px));
  mask: radial-gradient(circle at 100% 100%, transparent var(--curl), #000 calc(var(--curl) + .5px));
}
/* The sheet masks its own corner, so the curl sits on the board, over the
   sheet's corner. */
.curl { position: absolute; z-index: 2; right: var(--pad-x); bottom: var(--pad-b); width: calc(var(--curl) * 100 / 76); height: auto; overflow: visible; filter: drop-shadow(-4px -3px 4px rgba(0, 0, 0, .28)) drop-shadow(3px 4px 5px rgba(0, 0, 0, .35)); }
.c1 { stop-color: var(--curl-1); }
.c2 { stop-color: var(--curl-2); }
.curl .flap { fill: url(#fold); }
.curl .edge { fill: none; stroke: rgba(0, 0, 0, .2); stroke-width: 1; }
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 56px); align-items: center; position: relative; }
.hero-text { min-width: 0; }
.platforms { color: var(--dim); font: 500 14px/1.4 var(--f-mono); letter-spacing: .06em; margin: 10px 0 0; }
[dir="rtl"] .platforms { text-align: right; }

.fig { width: 100%; height: auto; overflow: visible; }
.fig text { font: 500 14px var(--f-mono); fill: var(--dim); letter-spacing: .06em; }
.chalk { fill: none; stroke: var(--text); stroke-width: 3.4; stroke-linecap: round; stroke-linejoin: round; }
.chalk.dots { stroke-width: 5; }
.signal { fill: none; stroke: var(--accent); stroke-width: 3.4; stroke-linecap: round; stroke-dasharray: 2 22; }
.neon, .deco-badge, .sun, .fig .for-deco { display: none; }
[data-skin="deco"] .fig .for-slate { display: none; }
[data-skin="deco"] .fig .for-deco { display: inline; }

/* Deco: no board, only what is on the sheet, under a gold sunburst. */
[data-skin="deco"] .hero { padding-top: 40px; }
[data-skin="deco"] .board { background: none; box-shadow: none; padding: 0; border-radius: 0; }
[data-skin="deco"] .clamp, [data-skin="deco"] .curl, [data-skin="deco"] .chalk, [data-skin="deco"] .signal { display: none; }
[data-skin="deco"] .sheet { background: none; box-shadow: none; -webkit-mask: none; mask: none; padding: 40px 0 0; overflow: hidden; }
[data-skin="deco"] .sun { display: block; position: absolute; inset: 0 -20%; width: 140%; height: 100%; fill: none; stroke: var(--accent); stroke-width: 1; opacity: .2;
  -webkit-mask: linear-gradient(180deg, transparent 5%, #000 70%); mask: linear-gradient(180deg, transparent 5%, #000 70%); }
[data-skin="deco"] .hero-grid { grid-template-columns: 1fr; text-align: center; justify-items: center; gap: 8px; }
[data-skin="deco"] .hero-text .lead { margin-inline: auto; }
[data-skin="deco"] .hero .actions { justify-content: center; }
[data-skin="deco"] .platforms { text-align: center; letter-spacing: .22em; text-transform: uppercase; font-size: 13px; order: 3; }
[data-skin="deco"] .fig { max-width: 600px; order: -1; margin-bottom: 8px; }
[data-skin="deco"] .neon { display: inline; fill: none; stroke-width: 4; stroke-linecap: round; stroke-linejoin: round; }
[data-skin="deco"] .neon.warm { stroke: var(--neon-warm); filter: drop-shadow(0 0 3px var(--neon-warm)) drop-shadow(0 0 10px var(--neon-warm)); }
[data-skin="deco"] .neon.cold { stroke: var(--neon-cold); filter: drop-shadow(0 0 3px var(--neon-cold)) drop-shadow(0 0 10px var(--neon-cold)); }
[data-skin="deco"] .wire { stroke-dasharray: 14 20; }
[data-skin="deco"] .deco-badge { display: inline; fill: var(--bg); stroke: var(--accent); stroke-width: 1.6; }
[data-skin="deco"] .deco-badge rect, [data-skin="deco"] .deco-badge path + rect + path { stroke: var(--text); }
[data-skin="deco"] .fig text { fill: var(--accent); letter-spacing: .24em; text-transform: uppercase; font-size: 13px; }

/* Buttons. */
.actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 30px; }
.button {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 50px; padding: 10px 24px;
  border-radius: 999px; text-decoration: none; font-weight: 600; color: var(--text);
  border: 1.5px dashed color-mix(in srgb, var(--text) 45%, transparent); background: transparent;
}
.button.accent {
  color: var(--on-accent); border: 0;
  background: linear-gradient(180deg, #F6DB94, #DDAF52 55%, #BF8E35);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .65), inset 0 -2px 0 rgba(80, 50, 5, .3), 0 8px 20px -10px rgba(60, 35, 0, .7);
}
.button.go::after { content: "→"; display: inline-block; }
[dir="rtl"] .button.go::after { content: "←"; }
[data-skin="deco"] .button { border-radius: 0; border: 1px solid var(--accent); color: var(--accent); text-transform: uppercase; letter-spacing: .14em; font-weight: 500; font-size: 15px; }
[data-skin="deco"] .button.accent { border: 0; color: var(--on-accent); background: var(--gold); box-shadow: none; padding-inline: 32px;
  clip-path: polygon(12px 0, calc(100% - 12px) 0, 100% 50%, calc(100% - 12px) 100%, 12px 100%, 0 50%); }
.button:focus-visible, a:focus-visible, summary:focus-visible, .skin:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }

.skip { position: absolute; inset-inline-start: 16px; top: -100px; z-index: 30; }
.skip:focus { top: 8px; background: var(--raised); padding: 10px 14px; border-radius: 8px; }

/* Raised surfaces: in slate, small sheets on the desk; in deco, glass
   panes with cut corners and a gold bar. */
.card, .facts div, .faq details, table, .note, .steps li {
  background: var(--raised); border: 1px solid var(--line); box-shadow: var(--shadow);
}
[data-skin="deco"] .card, [data-skin="deco"] .facts div, [data-skin="deco"] .steps li, [data-skin="deco"] .note {
  -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px); box-shadow: none; position: relative;
  clip-path: polygon(14px 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%, 0 14px);
}
[data-skin="deco"] .card::before, [data-skin="deco"] .facts div::before {
  content: ""; position: absolute; left: 50%; top: 0; width: 44px; height: 2px; margin-left: -22px; background: var(--accent);
}

.facts { display: grid; gap: 14px; grid-template-columns: repeat(4, 1fr); margin-top: 22px; }
.facts div { border-radius: 10px; padding: 18px 20px; display: grid; grid-template-columns: auto 1fr; column-gap: 14px; align-items: center; }
.facts .ico { grid-row: span 2; width: 34px; height: 34px; fill: none; stroke: var(--accent); stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; overflow: visible; }
.facts strong { display: block; font: 700 18px/1.25 var(--f-display); }
.facts span { color: var(--dim); font-size: 14.5px; line-height: 1.35; }
[data-skin="deco"] .facts div { grid-template-columns: 1fr; justify-items: center; text-align: center; padding-top: 24px; }
[data-skin="deco"] .facts .ico { grid-row: auto; margin-bottom: 8px; }
[data-skin="deco"] .facts strong { font-weight: 400; text-transform: uppercase; letter-spacing: .06em; color: var(--accent); }

.table { overflow-x: auto; }
table { border-collapse: separate; border-spacing: 0; width: 100%; border-radius: 10px; overflow: hidden; }
th, td { padding: 14px 18px; text-align: start; vertical-align: top; border-bottom: 1px dashed var(--line); }
tr:last-child th, tr:last-child td { border-bottom: none; }
th { white-space: nowrap; }
thead th { font: 500 13px/1.3 var(--f-mono); letter-spacing: .06em; text-transform: uppercase; color: var(--dim); }
.compare td { text-align: center; color: var(--accent); font-weight: 700; font-size: 20px; }
.compare td.no { color: var(--dim); font-weight: 400; }
.compare tr.us th, .compare tr.us td { background: color-mix(in srgb, var(--accent) 12%, transparent); }
.compare tr.us th { color: var(--accent); font-family: var(--f-display); font-size: 18px; }
.compare th { white-space: normal; }
[data-skin="deco"] table { border-radius: 0; background: var(--raised); border-color: var(--line); }
[data-skin="deco"] th, [data-skin="deco"] td { border-bottom-style: solid; }

.faq details { border-radius: 8px; margin-bottom: 10px; }
.faq summary { cursor: pointer; padding: 16px 20px; font-weight: 600; min-height: 44px; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--accent); font: 400 24px/1 var(--f-mono); transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin: 0; padding: 0 20px 18px; color: var(--dim); }
[data-skin="deco"] .faq details { border-radius: 0; background: none; box-shadow: none; border-width: 0 0 1px; margin: 0; }

/* The closing call: in slate, a small clipboard of its own. */
.final {
  margin-top: 88px; text-align: center; position: relative;
  padding: 12px 36px 40px; border-radius: 26px;
  border: clamp(12px, 1.6vw, 18px) solid transparent;
  background: linear-gradient(var(--sheet), var(--sheet)) padding-box, linear-gradient(155deg, var(--b2), var(--b3) 45%, var(--b4) 85%, var(--b3)) border-box;
  box-shadow: 0 30px 60px -30px rgba(20, 12, 2, .55);
}
.final h2 { margin-top: 28px; }
.final .actions { justify-content: center; }
.page .final { text-align: start; }
.page .final .actions { justify-content: flex-start; }
[data-skin="deco"] .final { border: 1px solid var(--accent); border-radius: 0; background: var(--raised); outline: 1px solid var(--line); outline-offset: 6px; box-shadow: none; }
[data-skin="deco"] .final h2::after { display: none; }

.oops { text-align: center; padding-bottom: 40px; }
.oops .lead { margin-inline: auto; }
.oops .actions { justify-content: center; }
.oops .code { font: 700 96px/1 var(--f-display); color: var(--accent); margin: 32px 0 8px; }

.dock { display: none; }

.cards { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
/* Four cards are four in a row or two by two, and the cards of the
   download page, which hold commands, two by two: never three and one. */
.cards.four { grid-template-columns: repeat(4, 1fr); }
.cards.pairs { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 960px) { .cards.four, .facts { grid-template-columns: repeat(2, 1fr); } }
.cards.two { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.card { border-radius: 10px; padding: 24px; min-width: 0; position: relative; }
:root:not([data-skin="deco"]) .card {
  background: linear-gradient(var(--grid) 1px, transparent 1px) 0 0 / 24px 24px, linear-gradient(90deg, var(--grid) 1px, transparent 1px) 0 0 / 24px 24px, var(--raised);
}
.lead, .page p, .page li, section > p { max-width: 75ch; }
.card p { margin: 0 0 10px; color: var(--dim); }
.card h3 + p { margin-top: 4px; }
.card ul { padding-inline-start: 20px; margin: 12px 0 0; }
.card li { margin-bottom: 8px; }
.card li::marker { color: var(--accent); }
.card .badge, .badge {
  display: inline-block; font: 500 12px/1 var(--f-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--on-accent);
  background: linear-gradient(180deg, #F6DB94, #D2A54A); padding: 6px 10px; border-radius: 4px; margin: 0 0 12px;
}
[data-skin="deco"] .card { text-align: start; }
.note { border-inline-start: 3px solid var(--accent); padding: 16px 20px; border-radius: 8px; margin-top: 20px; }

/* A group: the hub in the middle, four devices around it, and the links
   between them, along which copies flow. */
.orbit { position: relative; display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: 1fr 1.15fr 1fr; max-width: 400px; aspect-ratio: 5 / 4; margin: 12px auto 16px; }
.orbit .links { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.orbit path { stroke: var(--text); stroke-width: 1.5; fill: none; vector-effect: non-scaling-stroke; opacity: .35; stroke-dasharray: 4 5; }
.orbit path.flow { stroke: var(--accent); stroke-width: 2.6; stroke-dasharray: 2 14; stroke-linecap: round; opacity: 1; }
.dev { margin: 0; display: grid; justify-items: center; align-content: center; gap: 4px; position: relative; min-width: 0; }
.dev svg { width: 100%; max-width: 84px; height: 72px; overflow: visible; }
.dev figcaption { font: 500 12.5px/1.4 var(--f-mono); padding: 2px 8px; border-radius: 4px; white-space: nowrap; color: var(--dim); background: var(--raised); border: 1px solid var(--line); }
.dev.d0 { grid-area: 2 / 2; }
.dev.d0 svg { max-width: 124px; height: 104px; }
.dev.d0 figcaption { background: var(--accent); color: var(--on-accent); border-color: transparent; font-weight: 600; }
.dev.d1 { grid-area: 1 / 1; }
.dev.d2 { grid-area: 1 / 3; }
.dev.d3 { grid-area: 3 / 1; }
.dev.d4 { grid-area: 3 / 3; }
[data-skin="deco"] .orbit path { stroke: var(--accent); opacity: .4; stroke-dasharray: none; }
[data-skin="deco"] .orbit path.flow { stroke: var(--neon-warm); opacity: 1; stroke-dasharray: 10 14; filter: drop-shadow(0 0 4px var(--neon-warm)); }
[data-skin="deco"] .dev svg { filter: drop-shadow(0 0 3px var(--neon-cold)) drop-shadow(0 0 8px var(--neon-cold)); }
[data-skin="deco"] .dev.d0 svg { filter: drop-shadow(0 0 3px var(--neon-warm)) drop-shadow(0 0 8px var(--neon-warm)); }
[data-skin="deco"] .dev figcaption { border-radius: 0; text-transform: uppercase; letter-spacing: .14em; font-size: 11px; background: var(--bg); }
[data-skin="deco"] .dev.d0 figcaption { background: var(--gold); }

/* The devices: drawn in one line in slate, as neon tubes in deco; see the
   drawings in index.html. */
.sprites { position: absolute; width: 0; height: 0; overflow: hidden; }
.body, .keys, .pad, .chin, .screen { fill: var(--sheet); stroke: var(--text); stroke-width: 1.3; stroke-linejoin: round; }
:root:not([data-skin="deco"]) .body, :root:not([data-skin="deco"]) .screen { fill: var(--raised); }
.ft { fill: color-mix(in srgb, var(--text) 10%, var(--raised)); }
.fr { fill: color-mix(in srgb, var(--text) 18%, var(--raised)); }
.cam { fill: var(--text); }
.ui { fill: var(--text); opacity: .45; }
.ui.dim { opacity: .25; }
.ui.card { fill: var(--accent); opacity: .5; }
[data-skin="deco"] .body, [data-skin="deco"] .keys, [data-skin="deco"] .pad, [data-skin="deco"] .chin, [data-skin="deco"] .screen { fill: none; stroke: var(--neon-cold); stroke-width: 1.6; }
[data-skin="deco"] .ui, [data-skin="deco"] .cam { fill: var(--neon-cold); opacity: .55; }
[data-skin="deco"] .ui.card { fill: var(--neon-warm); }

.steps { padding: 0; list-style: none; counter-reset: step; display: grid; gap: 14px; }
.steps li { counter-increment: step; position: relative; padding: 18px 20px 18px 70px; border-radius: 10px; }
[dir="rtl"] .steps li { padding: 18px 70px 18px 20px; }
.steps li::before {
  content: counter(step); position: absolute; inset-inline-start: 18px; top: 15px; width: 36px; height: 36px;
  display: grid; place-items: center; border-radius: 50%; font: 700 17px/1 var(--f-display); color: var(--on-accent);
  background: radial-gradient(circle at 35% 30%, #F6DB94, #C4973C 70%); box-shadow: 0 2px 3px rgba(40, 25, 0, .4), inset 0 -2px 2px rgba(80, 50, 5, .35);
}
[data-skin="deco"] .steps li::before { border-radius: 0; background: var(--gold); box-shadow: none; font: 400 18px/1 var(--f-display); clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%); width: 40px; height: 40px; top: 13px; }
.page { padding-top: 48px; }
.page ul { padding-inline-start: 22px; }

.foot { margin-top: 96px; padding: 32px 0 44px; border-top: 1px solid var(--line); color: var(--dim); font-size: 15px; }
.foot a { color: var(--dim); }

@media (max-width: 860px) {
  .hero { padding-top: 110px; }
  .hero-grid { grid-template-columns: 1fr; gap: 12px; }
  .fig { order: -1; max-width: 520px; margin-inline: auto; }
}

/* Phones: one column, the menu in a row of its own that scrolls sideways,
   the languages in a sheet from the bottom, and the download button
   docked at the bottom. */
@media (max-width: 640px) {
  body { font-size: 16px; padding-bottom: 84px; }
  .wrap { padding-inline: max(16px, env(safe-area-inset-left, 0px)) max(16px, env(safe-area-inset-right, 0px)); }
  .bar { flex-wrap: wrap; gap: 8px 10px; min-height: 56px; padding-top: 6px; }
  .brand { font-size: 17px; gap: 8px; }
  [data-skin="deco"] .brand { font-size: 15px; letter-spacing: .06em; }
  .brand img { width: 28px; height: 28px; }
  .lname { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
  nav { order: 3; margin: 0 -16px; padding: 0 12px 8px; gap: 2px; overflow-x: auto; scrollbar-width: none; width: calc(100% + 32px); }
  nav::-webkit-scrollbar { display: none; }
  nav a { padding: 6px 10px; font-size: 15px; }
  /* A blurred header would hold the fixed sheet inside itself, so here it
     is opaque instead. */
  .top { -webkit-backdrop-filter: none; backdrop-filter: none; background: var(--bg); }
  .skin { margin-inline-start: auto; padding: 3px; min-height: 40px; font-size: 11.5px; gap: 2px; }
  .skin span { padding: 5px 6px; }
  .langs summary { min-height: 40px; padding: 4px 10px; }
  .langs ul { position: fixed; inset: auto 12px calc(12px + env(safe-area-inset-bottom)); top: auto; border-radius: 14px; padding: 8px; display: grid; grid-template-columns: 1fr 1fr; gap: 2px; }
  .langs li a { padding: 14px; text-align: center; }
  /* A tap outside the sheet closes it: the dimmed page is the summary. */
  .langs[open] summary::after { content: ""; position: fixed; inset: 0; z-index: 15; background: rgba(0, 0, 0, .4); cursor: default; }
  .dock {
    display: block; position: fixed; inset-inline: 10px; bottom: calc(10px + env(safe-area-inset-bottom)); z-index: 9; margin: 0; padding: 8px; border-radius: 30px;
    background: color-mix(in srgb, var(--bg) 70%, transparent); border: 1px solid var(--line); -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
  }
  [data-skin="deco"] .dock { border-radius: 0; }
  .dock .button { width: 100%; }
  .hero { padding-top: 84px; }
  .hero .actions .accent { display: none; }
  .hero .actions .button { flex: 1; }
  .board { --pad-x: 10px; --pad-b: 22px; --curl: 44px; border-radius: 26px; padding: 12px 10px 22px; }
  .clamp { width: 66%; }
  .sheet { padding: 54px 18px 40px; }
  .facts, .cards.four, .cards.pairs, .cards.two { grid-template-columns: 1fr; }
  .facts { grid-template-columns: 1fr 1fr; }
  .facts div { grid-template-columns: 1fr; padding: 16px; }
  .facts .ico { grid-row: auto; margin-bottom: 8px; }
  .card { padding: 20px; }
  h2 { margin-top: 60px; }
  th { white-space: normal; }
  .compare { font-size: 14px; hyphens: auto; }
  .compare th, .compare td { padding: 10px 8px; }
  .orbit { max-width: 340px; }
  .dev svg { max-width: 60px; height: 52px; }
  .dev.d0 svg { max-width: 90px; height: 76px; }
  .final { padding: 6px 18px 28px; }
  .steps li { padding: 16px 16px 16px 62px; }
  [dir="rtl"] .steps li { padding: 16px 62px 16px 16px; }
  .steps li::before { inset-inline-start: 14px; }
}

/* Motion: short, and none for those who ask for less. */
@media (prefers-reduced-motion: no-preference) {
  .hero-text > * { animation: rise .7s cubic-bezier(.2, .7, .2, 1) both; }
  .hero-text .lead { animation-delay: .08s; }
  .hero-text .platforms { animation-delay: .16s; }
  .hero-text .actions { animation-delay: .24s; }
  .chalk { stroke-dasharray: 1400; animation: draw 2.4s .2s ease-out both; }
  .signal { animation: flow 1.4s linear infinite; }
  .neon.warm:not(.wire) { animation: flicker 6s infinite; }
  .wire { animation: flow 1.4s linear infinite; }
  .orbit path.flow { animation: flow 1.6s linear infinite; }
  .card, .facts div, .steps li { transition: transform .3s cubic-bezier(.2, .7, .2, 1); }
  .card:hover, .facts div:hover, .steps li:hover { transform: translateY(-3px); }
  .button { transition: filter .2s, transform .2s; }
  .button:hover { filter: brightness(1.07); transform: translateY(-1px); }
  .button.go::after { transition: transform .2s ease-out; }
  .button.go:hover::after { transform: translateX(4px); }
  [dir="rtl"] .button.go:hover::after { transform: translateX(-4px); }
  @supports (animation-timeline: view()) {
    .reveal { animation: rise linear both; animation-timeline: view(); animation-range: entry 0% entry 35%; }
  }
}
@keyframes rise { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }
@keyframes draw { from { stroke-dashoffset: 1400; } to { stroke-dashoffset: 0; } }
@keyframes flow { to { stroke-dashoffset: -48; } }
@keyframes flicker { 0%, 17%, 21%, 60%, 63%, 100% { opacity: 1; } 19%, 61.5% { opacity: .45; } }

.soon { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding-block: 40px; }
.soon img { display: block; }
.soon h1 { margin-top: 20px; }
.soon p { margin: 6px 0; }