/*  Loment — site design system

    Canvas is indigo-black, not neutral black: the language's own mark is a
    blue rounded square, and the whole page keeps that bias rather than
    dropping a bright accent onto grey. One accent, --blue, and it is spent
    only where the page is talking about a *range* or a *hop out* — a
    capability declaration, a link, the compiler settling an index. It is
    never chrome.

    Type does the personality: IBM Plex Mono carries the display and every
    piece of code, because on a language's site the material is the source.
    IBM Plex Sans carries prose. Two families of one design, so the page
    reads as one voice across code and argument.
*/

/* ------------------------------------------------------------- tokens */

:root {
  --ink:      #0e1222;
  --ink-2:    #141a2c;
  --ink-3:    #1b2237;
  --line:     #252d47;
  --line-2:   #333c5c;

  --paper:    #e8ecf7;
  --dim:      #98a0b8;
  --faint:    #626c88;

  --blue:     #5468ff;
  --blue-2:   #8494ff;

  --sans: "IBM Plex Sans", ui-sans-serif, system-ui, -apple-system,
          "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "Cascadia Mono", "SF Mono",
          Menlo, Consolas, monospace;

  --t-hero: clamp(2.6rem, 7vw, 4.75rem);
  --t-h2:   clamp(1.5rem, 3.2vw, 2.1rem);
  --t-h3:   1.0625rem;
  --t-body: 1.0625rem;
  --t-sm:   0.9375rem;
  --t-code: 0.875rem;

  --page:    1120px;
  --measure: 62ch;

  --s1: 8px;
  --s2: 16px;
  --s3: 24px;
  --s4: 32px;
  --s5: 48px;
  --s6: 64px;
  --s7: 96px;
  --s8: 128px;

  --r-sm: 4px;
  --r-md: 8px;
}

/* --------------------------------------------------------------- base */

*, *::before, *::after { box-sizing: border-box; }

html {
  background: var(--ink);
  color-scheme: dark;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font: 400 var(--t-body) / 1.65 var(--sans);
  font-feature-settings: "kern" 1;
  text-rendering: optimizeLegibility;
}

a { color: var(--blue-2); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--paper); }

h1, h2, h3 { margin: 0; font-weight: 600; line-height: 1.15; letter-spacing: -0.01em; }

p { margin: 0; }
p + p { margin-top: var(--s2); }

:focus-visible {
  outline: 2px solid var(--blue-2);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip {
  position: absolute; left: -9999px;
  padding: var(--s2) var(--s3);
  background: var(--blue); color: #fff; font-weight: 600;
}
.skip:focus { left: var(--s3); top: var(--s3); z-index: 10; }

.wrap {
  width: 100%;
  max-width: var(--page);
  margin-inline: auto;
  padding-inline: clamp(20px, 5vw, 48px);
}

/* ---------------------------------------------------------------- bar */

.bar {
  position: sticky; top: 0; z-index: 5;
  background: color-mix(in srgb, var(--ink) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.bar .wrap {
  display: flex; align-items: center; gap: var(--s3);
  min-height: 60px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  margin-right: auto;
  color: var(--paper); text-decoration: none;
  font: 600 1.0625rem/1 var(--mono); letter-spacing: -0.01em;
}
.brand svg { display: block; }
.brand:hover { color: var(--paper); }

.bar nav { display: flex; align-items: center; gap: var(--s3); }
.bar nav a {
  color: var(--dim); text-decoration: none;
  font-size: var(--t-sm); font-weight: 500;
}
.bar nav a:hover { color: var(--paper); }
.bar nav a[aria-current="page"] { color: var(--paper); }

/* --------------------------------------------------------------- hero */

.hero { padding-block: clamp(var(--s6), 9vw, var(--s8)) var(--s6); }

.hero h1 {
  font: 600 var(--t-hero) / 1 var(--mono);
  letter-spacing: -0.035em;
}

/* Inner pages: the same head, at the size a page title needs rather than
   the size a front page needs. */
.head { padding-block: clamp(var(--s5), 6vw, var(--s7)) var(--s5); }
.head h1 {
  font: 600 var(--t-h2) / 1.15 var(--mono);
  letter-spacing: -0.025em;
}

.hero .lede, .head .lede {
  max-width: var(--measure);
  margin-top: var(--s3);
  font-size: clamp(1.125rem, 1.8vw, 1.3125rem);
  line-height: 1.6;
  color: var(--paper);
}
.head .lede { font-size: var(--t-body); color: var(--dim); }

.actions {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: var(--s2) var(--s3);
  margin-top: var(--s4);
}
.btn {
  display: inline-flex; align-items: center;
  padding: 11px 20px;
  border-radius: var(--r-sm);
  font: 600 var(--t-sm)/1 var(--sans);
  text-decoration: none;
}
.btn-solid { background: var(--blue); color: #fff; }
.btn-solid:hover { background: var(--blue-2); color: #fff; }
.btn-quiet { color: var(--paper); border: 1px solid var(--line-2); }
.btn-quiet:hover { border-color: var(--blue); color: var(--paper); }

/* ---------------------------------------------------------------- code */

.codewrap {
  margin-top: var(--s5);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-2);
  overflow: hidden;
}

pre.code {
  margin: 0;
  padding: var(--s3) 0 var(--s3);
  overflow-x: auto;
  font: 400 var(--t-code) / 1.75 var(--mono);
  tab-size: 4;
}
pre.code code { display: block; }

.ln {                     /* one line: real gutter numbers, no faked ones */
  display: block;
  padding-inline: var(--s3);
  white-space: pre;
}
.ln::before {
  content: attr(data-n);
  display: inline-block;
  width: 2ch; margin-right: var(--s3);
  color: var(--faint);
  text-align: right;
  user-select: none;
}

/* The one boldness: a guard line is marked by a blue rule down its left
   edge — the page's single structural device, and it encodes the only thing
   the language is really about. */
.ln-mark {
  border-left: 2px solid var(--blue);
  padding-left: calc(var(--s3) - 2px);
  background: color-mix(in srgb, var(--blue) 7%, transparent);
}
.ln-mark::before { margin-left: 0; }

.k { color: var(--blue-2); }        /* keyword   */
.s { color: #9fd6a8; }              /* string    */
.n { color: #e6c07b; }              /* number    */
.c { color: var(--faint); font-style: italic; }
.t { color: #7fd4e0; }              /* type      */
.rng { color: var(--blue-2); font-weight: 600; }   /* a declared range */

.out {
  border-top: 1px solid var(--line);
  padding: var(--s2) var(--s3);
  background: var(--ink);
  font: 400 var(--t-code) / 1.7 var(--mono);
  color: var(--dim);
}
.out b { color: var(--paper); font-weight: 400; }
.out .prompt { color: var(--faint); }

/* ------------------------------------------------------------ sections */

.sec { padding-block: var(--s7); border-top: 1px solid var(--line); }
.sec h2 {
  font: 600 var(--t-h2) / 1.2 var(--mono);
  letter-spacing: -0.025em;
  max-width: 34ch;
}
.sec .body { max-width: var(--measure); margin-top: var(--s3); color: var(--dim); }
.sec .body strong { color: var(--paper); font-weight: 600; }

/* Rows, not cards: a hairline between items and nothing else. A rounded
   box with a soft shadow per item is the default this brief does not need. */
.rows { margin-top: var(--s5); border-top: 1px solid var(--line); }
.row {
  display: grid;
  grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
  gap: var(--s2) var(--s4);
  padding: var(--s4) 0;
  border-bottom: 1px solid var(--line);
}
.row h3 {
  font: 600 var(--t-h3) / 1.4 var(--mono);
  color: var(--paper);
}
.row p { color: var(--dim); max-width: var(--measure); }
.row p + p { margin-top: var(--s2); }

@media (max-width: 720px) {
  .row { grid-template-columns: 1fr; gap: var(--s2); }
}

/* --------------------------------------------------------------- misc */

.doclink {
  display: grid;
  grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
  gap: var(--s2) var(--s4);
  padding: var(--s3) 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  color: inherit;
}
.doclink:hover { background: var(--ink-2); }
.doclink .who { font: 500 var(--t-sm)/1.5 var(--mono); color: var(--blue-2); }
.doclink .what { color: var(--dim); font-size: var(--t-sm); }
@media (max-width: 720px) { .doclink { grid-template-columns: 1fr; gap: 4px; } }

footer {
  border-top: 1px solid var(--line);
  padding-block: var(--s5);
  color: var(--faint);
  font-size: var(--t-sm);
}
footer .wrap {
  display: flex; flex-wrap: wrap; gap: var(--s2) var(--s4);
  align-items: baseline; justify-content: space-between;
}
footer a { color: var(--dim); text-decoration: none; }
footer a:hover { color: var(--paper); text-decoration: underline; }
footer nav { display: flex; flex-wrap: wrap; gap: var(--s3); }

.note {
  margin-top: var(--s4);
  padding-left: var(--s3);
  border-left: 2px solid var(--line-2);
  color: var(--faint);
  font-size: var(--t-sm);
  max-width: var(--measure);
}

/* A line of prose that belongs to the block above it. No rule of its own —
   the block already has one, and a second would read as a second block. */
.caption {
  margin-top: var(--s2);
  color: var(--faint);
  font-size: var(--t-sm);
  max-width: var(--measure);
}
.caption code { font-size: inherit; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Narrow phones: the nav is the first thing to break, and a wrapped
   two-line "Get / started" in a 60px bar is worse than a smaller one. */
@media (max-width: 560px) {
  .bar .wrap { padding-inline: 16px; gap: var(--s2); }
  .bar nav { gap: var(--s2); }
  .bar nav a { font-size: 0.8125rem; white-space: nowrap; }
  .brand { font-size: 1rem; }

  /* Gutter and code inset are pure overhead on a 375px screen: the code is
     scrolling sideways regardless, so give it the room. */
  .ln { padding-inline: var(--s2); }
  .ln::before { margin-right: var(--s2); }
  .ln-mark { padding-left: calc(var(--s2) - 2px); }
  .out { padding-inline: var(--s2); }
}