/* base.css — reusable design foundation for the tools brand.
   Framework-free, fast, accessible, dark-mode aware. Re-theme via the
   --brand-* tokens only. ~4KB, no external requests. */

:root {
  /* Brand tokens — override per brand */
  --brand-h: 222;                 /* primary hue */
  --brand: hsl(var(--brand-h) 80% 52%);
  --brand-ink: hsl(var(--brand-h) 80% 42%);
  --brand-soft: hsl(var(--brand-h) 80% 96%);

  /* Neutrals */
  --bg: #ffffff;
  --surface: #f7f8fa;
  --card: #ffffff;
  --border: #e6e8ec;
  --text: #1a1d23;
  --muted: #5b626e;
  --shadow: 0 1px 2px rgba(16,24,40,.04), 0 4px 16px rgba(16,24,40,.06);

  --radius: 12px;
  --radius-sm: 8px;
  --maxw: 760px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --surface: #15181e;
    --card: #181b22;
    --border: #262b34;
    --text: #e8eaed;
    --muted: #9aa3b2;
    --brand: hsl(var(--brand-h) 85% 62%);
    --brand-ink: hsl(var(--brand-h) 85% 70%);
    --brand-soft: hsl(var(--brand-h) 40% 16%);
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 4px 16px rgba(0,0,0,.35);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; font-family: var(--font); color: var(--text); background: var(--bg);
  line-height: 1.6; font-size: 17px; -webkit-font-smoothing: antialiased;
}
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* Header / footer */
header.site { padding: 18px 0; border-bottom: 1px solid var(--border); }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; }
.logo { font-weight: 800; letter-spacing: -.02em; color: var(--text); text-decoration: none; font-size: 18px; }
.logo b { color: var(--brand); }
nav.site a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 15px; }
nav.site a:hover { color: var(--text); }
footer.site { margin-top: 64px; padding: 32px 0; border-top: 1px solid var(--border); color: var(--muted); font-size: 14px; }
footer.site a { color: var(--muted); }

/* Typography */
h1 { font-size: clamp(28px, 5vw, 40px); line-height: 1.15; letter-spacing: -.02em; margin: .4em 0 .3em; }
h2 { font-size: 24px; letter-spacing: -.01em; margin: 1.6em 0 .5em; }
h3 { font-size: 19px; margin: 1.4em 0 .4em; }
p.lead { font-size: 19px; color: var(--muted); margin-top: 0; }
a { color: var(--brand-ink); }

/* Card / tool surface */
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
        box-shadow: var(--shadow); padding: 24px; }
.tool { margin: 28px 0; }

/* Form controls */
label { display: block; font-weight: 600; font-size: 14px; margin: 14px 0 6px; }
.hint { color: var(--muted); font-weight: 400; font-size: 13px; }
input, select, textarea {
  width: 100%; padding: 11px 13px; font-size: 16px; font-family: inherit;
  color: var(--text); background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-sm); transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus, textarea:focus {
  outline: none; border-color: var(--brand);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 22%, transparent);
}
.row { display: flex; gap: 14px; flex-wrap: wrap; }
.row > * { flex: 1 1 160px; }

button, .btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  padding: 12px 20px; font-size: 16px; font-weight: 600; font-family: inherit;
  color: #fff; background: var(--brand); border: none; border-radius: var(--radius-sm);
  cursor: pointer; transition: filter .15s, transform .05s;
}
button:hover, .btn:hover { filter: brightness(1.06); }
button:active { transform: translateY(1px); }
.btn-ghost { background: transparent; color: var(--brand-ink); border: 1px solid var(--border); }

/* Result display */
.result { margin-top: 20px; padding: 20px; background: var(--brand-soft); border-radius: var(--radius-sm); }
.result .big { font-size: 34px; font-weight: 800; letter-spacing: -.02em; color: var(--brand-ink); }
.kv { display: flex; justify-content: space-between; padding: 7px 0; border-bottom: 1px dashed var(--border); }
.kv:last-child { border-bottom: none; }
.kv .k { color: var(--muted); }
.kv .v { font-weight: 600; font-variant-numeric: tabular-nums; }

/* Content / article */
article { margin: 32px 0; }
article p, article li { color: var(--text); }
article ul { padding-left: 22px; }
.faq h3 { margin-top: 1.6em; }

.muted { color: var(--muted); }
.small { font-size: 14px; }
hr { border: none; border-top: 1px solid var(--border); margin: 32px 0; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 600; }