:root {
  --bg: #0b0e14;
  --panel: #141923;
  --panel2: #1b2231;
  --border: #27303f;
  --text: #e8ebf1;
  --muted: #8b95a7;
  --accent: #f0b429;
  --accent2: #38bdf8;
  --ok: #34d399;
  --warn: #fbbf24;
  --err: #f87171;
  --radius: 10px;
}
* { box-sizing: border-box; }
html { scrollbar-color: var(--border) var(--bg); }
body { margin: 0; background: var(--bg); color: var(--text); font: 15px/1.55 system-ui, "Segoe UI", Roboto, sans-serif; }
a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { max-width: 1150px; margin: 0 auto; padding: 0 16px; }
main.container { padding-top: 24px; padding-bottom: 48px; }
h1 { font-size: 1.6rem; margin: 0.2em 0 0.3em; }
h2 { font-size: 1.15rem; margin: 1.2em 0 0.5em; }
h3 { font-size: 1rem; }
.lead { color: var(--muted); margin: 0 0 1.3em; max-width: 75ch; }
.muted { color: var(--muted); }
.small { font-size: 0.85em; }
.mono { font-family: ui-monospace, Consolas, "Cascadia Mono", monospace; }
.nowrap { white-space: nowrap; }

/* Nav */
nav.top { background: var(--panel); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 10; }
nav.top .inner { display: flex; align-items: center; gap: 3px; padding: 9px 16px; max-width: 1150px; margin: 0 auto; }
nav.top .brand { font-weight: 700; color: var(--accent); white-space: nowrap; margin-right: 12px; font-size: 1.05rem; }
nav.top .brand:hover { text-decoration: none; }
nav.top .brand .dev { color: var(--muted); font-weight: 400; }
nav.top .menu { display: flex; align-items: center; gap: 3px; flex-wrap: wrap; }
nav.top a.item { color: var(--muted); padding: 4px 9px; border-radius: 6px; white-space: nowrap; font-size: 0.9rem; }
nav.top a.item:hover { color: var(--text); text-decoration: none; background: var(--panel2); }
nav.top a.item.active { color: #0b0e14; background: var(--accent); font-weight: 600; }
/* Hamburger toggle — hidden until the menu needs to collapse */
nav.top .nav-toggle, nav.top .nav-burger { display: none; }

@media (max-width: 820px) {
  nav.top .inner { flex-wrap: wrap; }
  nav.top .brand { margin-right: auto; }
  /* Visually-hidden but still keyboard-focusable checkbox drives the toggle */
  nav.top .nav-toggle { display: block; position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; border: 0; overflow: hidden; clip: rect(0 0 0 0); }
  nav.top .nav-burger { display: flex; flex-direction: column; justify-content: center; gap: 4px; width: 42px; height: 36px; padding: 8px; cursor: pointer; border: 1px solid var(--border); border-radius: 8px; background: var(--panel2); }
  nav.top .nav-burger span { display: block; height: 2px; border-radius: 2px; background: var(--text); }
  nav.top .nav-toggle:focus-visible + .nav-burger { outline: 2px solid var(--accent2); outline-offset: 2px; }
  nav.top .menu { display: none; flex-basis: 100%; flex-direction: column; align-items: stretch; gap: 2px; margin-top: 8px; }
  nav.top .nav-toggle:checked + .nav-burger { background: var(--accent); border-color: var(--accent); }
  nav.top .nav-toggle:checked + .nav-burger span { background: #0b0e14; }
  nav.top .nav-toggle:checked ~ .menu { display: flex; }
  nav.top a.item { padding: 10px 12px; font-size: 1rem; border-radius: 8px; }
}

/* Layout */
.card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; margin-bottom: 18px; }
.card > :first-child { margin-top: 0; }
.grid { display: grid; gap: 18px; align-items: start; }
/* Let grid items shrink to the column instead of overflowing the viewport on mobile. */
.grid > * { min-width: 0; }
@media (min-width: 900px) {
  .g2 { grid-template-columns: 1fr 1fr; }
  .g13 { grid-template-columns: 1fr 2fr; }
}
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }

/* Forms */
label { display: block; font-size: 0.85rem; color: var(--muted); margin: 10px 0 4px; }
input, select, textarea { width: 100%; background: #0e1320; color: var(--text); border: 1px solid var(--border); border-radius: 8px; padding: 8px 10px; font: inherit; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--accent2); }
textarea { font-family: ui-monospace, Consolas, monospace; min-height: 120px; resize: vertical; }
input.big { font-size: 1.2rem; font-family: ui-monospace, Consolas, monospace; }
input[type="checkbox"] { width: auto; }

.btn { display: inline-block; background: var(--panel2); color: var(--text); border: 1px solid var(--border); border-radius: 8px; padding: 8px 14px; font: inherit; cursor: pointer; white-space: nowrap; }
.btn:hover { border-color: var(--accent2); text-decoration: none; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #0b0e14; font-weight: 600; }
.btn-primary:hover { filter: brightness(1.1); }
.btn-sm { padding: 3px 9px; font-size: 0.82rem; border-radius: 6px; }
.btn-ghost { background: transparent; }

/* Tables */
table { border-collapse: collapse; width: 100%; font-size: 0.92rem; }
th, td { text-align: left; padding: 7px 10px; border-bottom: 1px solid var(--border); vertical-align: top; overflow-wrap: anywhere; }
th { color: var(--muted); font-weight: 600; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
tr:last-child td { border-bottom: none; }
.kv td:first-child { color: var(--muted); width: 34%; }
.table-wrap { overflow-x: auto; }

/* Badges & notes */
.badge { display: inline-block; padding: 2px 10px; border-radius: 99px; font-size: 0.78rem; font-weight: 600; border: 1px solid; }
.badge.ok { color: var(--ok); border-color: var(--ok); }
.badge.warn { color: var(--warn); border-color: var(--warn); }
.badge.err { color: var(--err); border-color: var(--err); }
.badge.info { color: var(--accent2); border-color: var(--accent2); }
.note { border-left: 3px solid var(--accent2); padding: 8px 12px; background: var(--panel2); border-radius: 0 8px 8px 0; font-size: 0.88rem; margin: 12px 0; }
.ok-text { color: var(--ok); }
.warn-text { color: var(--warn); }
.err-text { color: var(--err); }

/* Code */
pre { background: #0e1320; border: 1px solid var(--border); border-radius: 8px; padding: 12px; overflow: auto; font-size: 0.85rem; line-height: 1.5; }
code { background: #0e1320; padding: 1px 5px; border-radius: 5px; font-size: 0.9em; font-family: ui-monospace, Consolas, monospace; }
pre code { background: none; padding: 0; }
.hl { background: rgba(240, 180, 41, 0.18); border-radius: 3px; }

/* Results */
.result-big { font-size: 1.45rem; font-weight: 600; font-family: ui-monospace, Consolas, monospace; word-break: break-all; }
.delta { color: var(--ok); }

/* Footer */
.footer { border-top: 1px solid var(--border); margin-top: 30px; padding: 18px 16px; display: flex; justify-content: space-between; gap: 10px; flex-wrap: wrap; color: var(--muted); font-size: 0.85rem; }

/* Homepage tool grid */
.tool-grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); margin: 20px 0; }
.tool-card { display: block; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; color: var(--text); transition: border-color 0.15s; }
.tool-card:hover { border-color: var(--accent); text-decoration: none; }
.tool-card h3 { margin: 0 0 6px; color: var(--accent); }
.tool-card p { margin: 0; font-size: 0.85rem; color: var(--muted); }

/* 2038 page */
.countdown { font-size: clamp(1.8rem, 7vw, 4.2rem); font-weight: 700; font-family: ui-monospace, Consolas, monospace; letter-spacing: 0.02em; text-align: center; margin: 18px 0; color: var(--accent); }
.bits { font-family: ui-monospace, Consolas, monospace; font-size: clamp(0.78rem, 2.1vw, 1.05rem); letter-spacing: 1.5px; word-break: break-all; text-align: center; }
.bits .sign { color: var(--err); font-weight: bold; }

/* Backoff bars */
.bar { height: 10px; background: var(--accent2); border-radius: 4px; min-width: 2px; }