:root {
  color-scheme: light;
  /* KATR Software palette (matches www.katr.com / site.css) */
  --bg: #f3f6f8;
  --surface: #ffffff;
  --surface-2: #eaf3f5;
  --border: #dbe3e9;
  --text: #16212b;
  --muted: #54626f;
  --accent: #0f6f7c;
  --accent-hover: #0a5560;
  --accent2: #5cc4d0;
  --dark: #17242f;
  --on-accent: #ffffff;
  --code-bg: #f6f9fb;
  --shadow: rgba(23, 36, 47, 0.18);
  --ok: #15803d;
  --warn: #b45309;
  --err: #b91c1c;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header__inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.site-header__brand {
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
  letter-spacing: 0.5px;
}
.site-header__brand:hover { text-decoration: none; color: var(--accent); }
.site-nav { display: flex; gap: 18px; }
.site-nav a {
  color: var(--muted);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.site-nav a.is-active { color: var(--text); border-bottom-color: var(--accent); }
.site-nav a:hover { color: var(--text); text-decoration: none; }

.site-main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 24px 48px;
}

.site-footer {
  text-align: center;
  color: var(--muted);
  padding: 24px;
  border-top: 1px solid var(--border);
  background: var(--surface);
}

h1 { margin-top: 0; font-size: 28px; }
h2 { margin-top: 0; font-size: 18px; }
h3 { margin: 24px 0 8px; font-size: 14px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }

.page--narrow { max-width: 800px; margin: 0 auto; }
.lede { color: var(--muted); font-size: 17px; }

.tool-grid {
  list-style: none;
  padding: 0;
  margin: 32px 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}
.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: border-color 0.15s, transform 0.15s;
}
.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.tool-card a {
  display: block;
  padding: 20px;
  color: var(--text);
}
.tool-card a:hover { text-decoration: none; }
.tool-card h2 { color: var(--accent); margin-bottom: 8px; }
.tool-card p { color: var(--muted); margin: 0; }

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0 16px;
  align-items: center;
}

button, .btn {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  font-family: inherit;
}
button:hover, .btn:hover { border-color: var(--accent); color: var(--accent); }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); font-weight: 600; }
button.primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: var(--on-accent); }

textarea, input[type=text], select {
  width: 100%;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
}
textarea { resize: vertical; min-height: 160px; }
textarea:focus, input:focus, select:focus { outline: none; border-color: var(--accent); }

label { display: block; color: var(--muted); font-size: 13px; margin-bottom: 6px; }
label.inline { display: inline-flex; align-items: center; gap: 6px; margin: 0; font-size: 13px; color: var(--text); cursor: pointer; }
label.inline input { width: auto; }

.field { margin-bottom: 16px; }
.field-row { display: flex; gap: 16px; flex-wrap: wrap; }
.field-row > .field { flex: 1 1 240px; }

.result {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  margin-top: 12px;
}
.result.ok { border-left: 3px solid var(--ok); }
.result.err { border-left: 3px solid var(--err); }
.result.warn { border-left: 3px solid var(--warn); }
.result h3 { margin-top: 0; color: var(--text); text-transform: none; letter-spacing: 0; font-size: 15px; }

pre {
  font-family: var(--mono);
  font-size: 13px;
  background: var(--code-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px;
  overflow: auto;
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}
pre.compact { margin-top: 8px; }

.status {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  margin-left: 8px;
}
.status.ok { background: rgba(21, 128, 61, 0.12); color: var(--ok); }
.status.err { background: rgba(185, 28, 28, 0.10); color: var(--err); }

.kv {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 4px 16px;
  font-family: var(--mono);
  font-size: 13px;
}
.kv dt { color: var(--muted); }
.kv dd { margin: 0; word-break: break-word; }

.match {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  margin-top: 8px;
}
.match-header { display: flex; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.match-header strong { font-family: var(--mono); }
.match-text { font-family: var(--mono); background: rgba(15, 111, 124, 0.14); padding: 1px 4px; border-radius: 3px; }
.match-groups { margin-top: 6px; font-family: var(--mono); font-size: 12px; }
.match-groups div { color: var(--muted); }
.match-groups div span.gv { color: var(--text); }

.error-snippet {
  font-family: var(--mono);
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px;
  white-space: pre;
  overflow: auto;
}
.error-snippet .err-caret { color: var(--err); font-weight: bold; }

.muted { color: var(--muted); }
.mono { font-family: var(--mono); }

details { margin-top: 8px; }
details summary { cursor: pointer; color: var(--muted); }
details[open] summary { color: var(--text); }

/* Tabs */
.tabs {
  display: flex;
  gap: 2px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 20px;
}
.tab-btn {
  background: none;
  border: 1px solid transparent;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  padding: 8px 18px;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
  margin-bottom: -1px;
}
.tab-btn:hover { color: var(--text); border-bottom-color: var(--border); }
.tab-btn.is-active { color: var(--text); border-bottom-color: var(--accent); }

/* Password Generator */
.pw-output-row {
  display: flex;
  gap: 8px;
}
.pw-output-row input {
  font-size: 16px;
  letter-spacing: 0.03em;
}
.pw-meter {
  display: flex;
  align-items: center;
  gap: 12px;
}
.pw-meter-bar {
  flex: 1;
  height: 8px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  overflow: hidden;
}
.pw-meter-fill {
  height: 100%;
  width: 0;
  transition: width 0.15s, background-color 0.15s;
  background: var(--err);
}
.pw-meter-fill--warn { background: var(--warn); }
.pw-meter-fill--ok { background: var(--ok); }
.pw-meter-label {
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

/* Annual Calendar */
.cal-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}
.cal-year {
  font-size: 26px;
  font-weight: 700;
  min-width: 4ch;
  text-align: center;
}
.cal-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 16px;
}
.cal-month {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
}
.cal-month-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent);
  margin-bottom: 10px;
}
.cal-days {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 1px;
}
.cal-day-header {
  font-size: 10px;
  color: var(--muted);
  text-align: center;
  padding: 2px 0 5px;
  font-weight: 600;
}
.cal-day {
  font-size: 12px;
  text-align: center;
  padding: 3px 1px;
  border-radius: 4px;
  line-height: 1.5;
}
.cal-day.today {
  background: var(--accent);
  color: var(--on-accent);
  font-weight: 700;
  border-radius: 50%;
}

/* Markdown viewer */
.md-dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 24px;
  margin-bottom: 16px;
  text-align: center;
  background: var(--surface);
  border: 2px dashed var(--border);
  border-radius: 8px;
  transition: border-color 0.15s, background 0.15s;
}
.md-dropzone.is-over { border-color: var(--accent); background: var(--surface-2); }
.md-dropzone .toolbar { margin: 8px 0 0; justify-content: center; }
.md-layout[hidden] { display: none; }
.md-layout { display: flex; gap: 24px; align-items: flex-start; }
.md-files { flex: 0 0 220px; position: sticky; top: 70px; max-height: calc(100vh - 90px); overflow-y: auto; }
.md-files h3 { margin-top: 0; }
.md-files ul { list-style: none; margin: 0; padding: 0; }
.md-files li {
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  color: var(--muted);
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.md-files li:hover { color: var(--text); background: var(--surface-2); }
.md-files li.is-active { color: var(--text); background: var(--surface-2); border-left: 3px solid var(--accent); }
.md-main { flex: 1 1 0; min-width: 0; }
.md-nav { align-items: center; }
.markdown-body {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px 32px;
  overflow-wrap: break-word;
}
.markdown-body h1, .markdown-body h2 { padding-bottom: 6px; border-bottom: 1px solid var(--border); }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 { margin: 24px 0 12px; }
.markdown-body h1 { font-size: 28px; }
.markdown-body h2 { font-size: 22px; }
.markdown-body h3 { font-size: 18px; text-transform: none; letter-spacing: normal; color: var(--text); }
.markdown-body > :first-child { margin-top: 0; }
.markdown-body img { max-width: 100%; }
.markdown-body blockquote { margin: 0 0 16px; padding: 0 16px; color: var(--muted); border-left: 4px solid var(--border); }
.markdown-body code { font-family: var(--mono); font-size: 90%; background: var(--surface-2); padding: 2px 5px; border-radius: 4px; }
.markdown-body pre code { background: none; padding: 0; }
.markdown-body table { border-collapse: collapse; margin-bottom: 16px; display: block; overflow-x: auto; }
.markdown-body th, .markdown-body td { border: 1px solid var(--border); padding: 6px 12px; }
.markdown-body th { background: var(--surface-2); }
.markdown-body hr { border: 0; border-top: 1px solid var(--border); margin: 24px 0; }
.markdown-body .mermaid { text-align: center; margin-bottom: 16px; }
.markdown-body a.md-link-missing { color: var(--warn); text-decoration: underline dotted; }
@media (max-width: 800px) {
  .md-layout { flex-direction: column; }
  .md-files { flex: none; position: static; max-height: none; width: 100%; }
}
#md-status:not(:empty) { position: sticky; top: 56px; z-index: 5; }
#md-status .result { background: var(--surface-2); }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4, .markdown-body h5, .markdown-body h6 { scroll-margin-top: 70px; }

.md-banner {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: 10px 14px;
  margin-bottom: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--warn);
  border-radius: 6px;
}
.md-banner[hidden] { display: none; }
.md-banner > span:first-child { flex: 1 1 320px; }
.md-banner__actions { display: flex; gap: 8px; }

/* QR code generator */
.qr-layout { display: flex; gap: 24px; align-items: flex-start; margin-top: 16px; }
.qr-controls { flex: 1 1 460px; min-width: 0; }
.qr-preview { flex: 0 0 440px; position: sticky; top: 76px; }
.qr-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0 16px;
  margin-bottom: 12px;
}
.qr-group > summary {
  cursor: pointer;
  padding: 12px 0;
  font-weight: 600;
  color: var(--text);
}
.qr-group[open] > summary { border-bottom: 1px solid var(--border); margin-bottom: 14px; }
.qr-group[open] { padding-bottom: 2px; }
.qr-stage {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background-color: #e8eaee;
  background-image:
    linear-gradient(45deg, #d5d8de 25%, transparent 25%, transparent 75%, #d5d8de 75%),
    linear-gradient(45deg, #d5d8de 25%, transparent 25%, transparent 75%, #d5d8de 75%);
  background-size: 16px 16px;
  background-position: 0 0, 8px 8px;
}
.qr-stage svg { width: 100%; max-width: 400px; height: auto; display: block; }
.qr-actions { justify-content: center; }
button:disabled { opacity: 0.45; cursor: not-allowed; }
button:disabled:hover { border-color: var(--border); color: var(--text); }
.qr-note { margin: 8px 0 0; }
input[type=range] { width: 100%; accent-color: var(--accent); }
input[type=number] {
  width: 100%;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 9px 12px;
  font-size: 13px;
}
input[type=color] {
  width: 64px;
  height: 36px;
  padding: 2px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
}
input[type=file] { color: var(--muted); font-size: 13px; max-width: 100%; }
.qr-color { flex: 0 1 140px; }
output { color: var(--text); font-family: var(--mono); margin-left: 4px; }
@media (max-width: 960px) {
  .qr-layout { flex-direction: column-reverse; }
  .qr-preview { position: static; flex: none; width: 100%; }
}