/* Layout: one left-aligned column; the calculator is a two-pane console (inputs | results) that stacks on phones. Docs live on their own pages as plain reading columns. */
:root {
  --bg: #f5f6f8;
  --surface: #ffffff;
  --fg: #141820;
  --muted: #5a6372;
  --line: #dce0e6;
  --accent: #a8520a;
  --accent-strong: #d97706;
  --accent-soft: #fcefd9;
  --code-bg: #eef0f3;
  --bad: #b42318;
  --bad-soft: #fde8e6;
  --font-display: "Bricolage Grotesque", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --radius: 10px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1116; --surface: #161a21; --fg: #e7eaef; --muted: #9aa3b0; --line: #29303b;
    --accent: #f5a524; --accent-strong: #f5a524; --accent-soft: #2b2112; --code-bg: #1c212a;
    --bad: #f28b7d; --bad-soft: #2e1714; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e1116; --surface: #161a21; --fg: #e7eaef; --muted: #9aa3b0; --line: #29303b;
  --accent: #f5a524; --accent-strong: #f5a524; --accent-soft: #2b2112; --code-bg: #1c212a;
  --bad: #f28b7d; --bad-soft: #2e1714; color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  padding: env(safe-area-inset-top, 0px) 20px env(safe-area-inset-bottom, 0px);
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 var(--font-body);
}
img { max-width: 100%; height: auto; }
[hidden] { display: none !important; }
a { color: var(--accent); text-underline-offset: 2px; }
:focus-visible { outline: 2px solid var(--accent-strong); outline-offset: 2px; }
.wrap { max-width: 1080px; margin-inline: auto; }

/* Top bar */
.top { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px 24px; padding-block: 20px; }
.brand { display: flex; align-items: baseline; gap: 10px; text-decoration: none; color: var(--fg); }
.brand b { font: 800 24px/1 var(--font-display); letter-spacing: -0.02em; }
.brand span { font: 400 13px var(--font-mono); color: var(--muted); }
.top nav { display: flex; flex-wrap: wrap; gap: 4px 18px; font-size: 14px; }
.top nav a { color: var(--muted); text-decoration: none; }
.top nav a:hover { color: var(--fg); }

/* Intro */
.intro { padding-block: 28px 24px; max-width: 46rem; }
h1 { font: 800 clamp(34px, 6vw, 56px)/1.02 var(--font-display); letter-spacing: -0.03em; margin: 0 0 14px; text-wrap: balance; }
h1 em { font-style: normal; color: var(--accent); }
.intro p { margin: 0; color: var(--muted); font-size: 17px; max-width: 38rem; }

/* Calculator console */
.console { display: grid; grid-template-columns: minmax(0, 330px) minmax(0, 1fr); background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
@media (max-width: 820px) { .console { grid-template-columns: minmax(0, 1fr); } }
.inputs { padding: 22px; border-right: 1px solid var(--line); display: flex; flex-direction: column; gap: 18px; }
@media (max-width: 820px) { .inputs { border-right: 0; border-bottom: 1px solid var(--line); } }
.results { padding: 22px; min-width: 0; display: flex; flex-direction: column; gap: 16px; }

.modes { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; padding: 4px; background: var(--code-bg); border-radius: 8px; }
.modes button { font: 500 14px var(--font-body); border: 0; border-radius: 6px; padding: 8px 10px; background: transparent; color: var(--muted); cursor: pointer; }
.modes button[aria-selected="true"] { background: var(--surface); color: var(--fg); box-shadow: 0 1px 2px rgb(0 0 0 / 0.08); }

.field { display: flex; flex-direction: column; gap: 6px; }
.field label, .label { font-size: 12px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.field .hint { font-size: 13px; color: var(--muted); }
input[type="text"], input[type="number"] {
  width: 100%; font: 500 18px var(--font-mono); color: var(--fg); background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; padding: 9px 12px;
}
input:focus-visible { outline: 2px solid var(--accent-strong); outline-offset: 0; border-color: transparent; }
input[aria-invalid="true"] { border-color: var(--bad); }
.duration { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.duration > div { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

#presets { display: flex; flex-direction: column; gap: 8px; margin-top: 2px; container-type: inline-size; }
.nines { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; align-items: stretch; }
/* Four cards in a row need about 460px to fit "99.999%" and the AWS examples; below that, go 2 × 2. */
@container (max-width: 459px) { .nines { grid-template-columns: repeat(2, 1fr); } }
.nines button { display: grid; grid-template-rows: auto auto 1fr; justify-items: start; gap: 2px; padding: 8px; min-width: 0; border-radius: var(--radius); border: 1px solid var(--line); background: var(--surface); color: var(--fg); cursor: pointer; text-align: left; transition: border-color .12s, background-color .12s; }
.nines button b { font: 500 14px var(--font-mono); white-space: nowrap; }
.nines button span { font: 500 12px var(--font-body); color: var(--muted); }
.nines button small { font: 400 11px/1.3 var(--font-body); color: var(--muted); margin-top: 4px; padding-top: 5px; border-top: 1px solid var(--line); justify-self: stretch; align-self: start; overflow-wrap: anywhere; }
.nines button:hover { border-color: var(--accent-strong); }
.nines button[aria-pressed="true"] { background: var(--accent-soft); border-color: var(--accent-strong); }
.nines button[aria-pressed="true"] b, .nines button[aria-pressed="true"] span { color: var(--accent); }
.nines button[aria-pressed="true"] small { border-top-color: var(--accent-strong); }
.nines button:focus-visible, .chips button:focus-visible { outline: 2px solid var(--accent-strong); outline-offset: 2px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chips button { font: 500 13px var(--font-mono); padding: 4px 9px; border-radius: 999px; border: 1px solid var(--line); background: transparent; color: var(--fg); cursor: pointer; }
.chips button small { font: 400 12px var(--font-body); color: var(--muted); margin-left: 4px; }
.chips button[aria-pressed="true"] small { color: var(--accent); }
.chips button:hover { border-color: var(--accent-strong); }
.chips button[aria-pressed="true"] { background: var(--accent-soft); border-color: var(--accent-strong); color: var(--accent); }

.toggle { display: flex; align-items: center; gap: 10px; font-weight: 500; cursor: pointer; }
.toggle input { width: 18px; height: 18px; accent-color: var(--accent-strong); margin: 0; }
.probe-fields { display: flex; flex-direction: column; gap: 14px; padding-left: 12px; border-left: 2px solid var(--accent-soft); }

/* Results */
.summary { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 12px; }
.summary .big { font: 800 clamp(28px, 4vw, 40px)/1.1 var(--font-display); letter-spacing: -0.02em; }
.summary .sub { color: var(--muted); }
.error { color: var(--bad); background: var(--bad-soft); border-radius: 8px; padding: 10px 12px; margin: 0; }
.table-scroll { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th { text-align: left; font-size: 12px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); padding: 0 12px 8px 0; border-bottom: 1px solid var(--line); white-space: nowrap; }
td { padding: 11px 12px 11px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
tr:last-child td { border-bottom: 0; }
td .period { font-weight: 600; }
td .len { display: block; font-size: 13px; color: var(--muted); }
td.num { font: 500 16px var(--font-mono); white-space: nowrap; }
td.num.na { font: 400 14px var(--font-body); color: var(--bad); white-space: normal; }
.bar { display: flex; height: 6px; margin-top: 7px; border-radius: 3px; overflow: hidden; background: var(--line); min-width: 90px; }
.bar i { display: block; height: 100%; }
.bar .repair { background: var(--bad); opacity: 0.7; }
.bar .buffer { background: var(--accent-strong); }
.legend { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 13px; color: var(--muted); }
.legend span::before { content: ""; display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 6px; vertical-align: -1px; }
.legend .l-repair::before { background: var(--bad); opacity: 0.7; }
.legend .l-buffer::before { background: var(--accent-strong); }


/* Phones: tighter gutters, one-line nav, and tap targets of about 40px or more. */
@media (max-width: 520px) {
  body { padding-inline: 16px; }
  .top { padding-block: 12px 4px; gap: 4px 16px; }
  .top nav { flex-wrap: nowrap; gap: 0 14px; overflow-x: auto; scrollbar-width: none; margin-inline: -16px; padding-inline: 16px; width: calc(100% + 32px); }
  .top nav::-webkit-scrollbar { display: none; }
  .top nav a { padding-block: 10px; white-space: nowrap; font-size: 15px; }
  .top nav .nav-ext { display: none; }
  .intro { padding-block: 16px 20px; }
  .intro p { font-size: 16px; }
  .inputs, .results { padding: 16px; }
  .modes button { padding-block: 11px; font-size: 15px; }
  .nines button { padding: 10px; }
  .chips { gap: 8px; }
  .chips button { font-size: 14px; padding: 9px 14px; }
  .toggle { padding-block: 8px; }
  th { white-space: normal; }
  td { padding-right: 10px; }
  td.num { font-size: 15px; }
  .bar { min-width: 64px; }
  footer { margin-top: 40px; }
  footer a { display: inline-block; padding-block: 8px; }
  .brand { padding-block: 8px; }
}
@media (max-width: 360px) {
  td.num { font-size: 14px; }
  td { padding-right: 8px; }
  .bar { min-width: 52px; }
}

/* Docs */
.doc { max-width: 46rem; padding-block: 28px 8px; }
h2, .doc h1 { font: 800 30px/1.15 var(--font-display); letter-spacing: -0.02em; margin: 0 0 14px; text-wrap: balance; }
h3 { font: 600 18px/1.3 var(--font-body); margin: 28px 0 8px; }
.doc p, .doc li { color: var(--fg); }
.doc p { margin: 0 0 14px; }
.doc ul { padding-left: 20px; margin: 0 0 14px; }
.doc li + li { margin-top: 6px; }
code { font-family: var(--font-mono); font-size: 0.9em; background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }
.formula { font: 500 17px/1.5 var(--font-mono); background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; margin: 0 0 16px; overflow-x: auto; }
.formula div + div { margin-top: 6px; }
.formula var { font-style: normal; color: var(--accent); }
.note { border-left: 3px solid var(--accent-strong); padding: 4px 0 4px 14px; color: var(--muted); margin: 0 0 14px; }

.faq dt { font-weight: 600; margin-top: 22px; }
.faq dd { margin: 6px 0 0; }

footer { margin-top: 64px; padding-block: 24px 40px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px; }
footer a { color: var(--muted); }
nav a[aria-current="page"] { color: var(--fg); }