/* ─────────────────────────────────────────────────────────────
   TronKits — Playful Blueprint design system
   Cream paper · ink navy · solder orange · LED green
   ───────────────────────────────────────────────────────────── */

:root {
  --paper:      #F5EFDD;
  --paper-deep: #EDE5CD;
  --paper-edge: #E0D6B5;
  --ink:        #15263A;
  --ink-soft:   #4A5B72;
  --ink-faint:  #8A95A6;
  --accent:     #E25C2C;
  --orange:     #E25C2C;
  --yellow:     #E5B043;
  --green:      #2D8F60;
  --red:        #C9442C;
  --blue:       #2E6DA4;
  --violet:     #6B47B8;
  --copper:     #B87333;
  --white:      #FFFCF2;
  --ink-soft-rgb: 74, 91, 114;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 16px;
  line-height: 1.55;
}

a { color: var(--ink); }

/* ─── Graph paper background ───────────────────────────────── */
.tk-graph-paper {
  background-color: var(--paper);
  background-image:
    linear-gradient(to right, rgba(46,109,164,0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(46,109,164,0.07) 1px, transparent 1px),
    linear-gradient(to right, rgba(46,109,164,0.18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(46,109,164,0.18) 1px, transparent 1px);
  background-size: 24px 24px, 24px 24px, 120px 120px, 120px 120px;
  background-position: 0 0;
}
.tk-graph-paper-mini {
  background-color: var(--paper-deep);
  background-image:
    linear-gradient(to right, rgba(46,109,164,0.10) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(46,109,164,0.10) 1px, transparent 1px);
  background-size: 16px 16px;
}

/* ─── Layout shell ─────────────────────────────────────────── */
main.tk-main {
  min-height: calc(100vh - 84px);
}
.tk-section {
  padding: 40px 56px 80px;
}
.tk-section-tight { padding: 0 56px 56px; }

/* ─── Nav ──────────────────────────────────────────────────── */
.tk-nav {
  height: 84px;
  padding: 0 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1.5px solid var(--ink);
  background: var(--paper);
  position: relative;
}
.tk-nav .reg-mark {
  position: absolute;
  width: 14px;
  height: 14px;
  pointer-events: none;
}
.tk-nav .reg-mark.tl { left: 8px; top: 8px; }
.tk-nav .reg-mark.tr { right: 8px; top: 8px; }

.tk-wordmark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
}
.tk-wordmark__text {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.tk-wordmark__text .slash { color: var(--accent); }

.tk-nav__links {
  display: flex;
  align-items: center;
  gap: 0;
}
.tk-nav__link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink);
  padding: 10px 18px;
  text-decoration: none;
  position: relative;
  white-space: nowrap;
}
.tk-nav__link .num {
  color: var(--ink-faint);
  margin-right: 8px;
  font-weight: 400;
}
.tk-nav__link.active .label {
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 2px;
  text-decoration-color: var(--accent);
}
.tk-nav__link.active::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 50%;
  width: 5px;
  height: 5px;
  background: var(--accent);
  transform: translateY(-50%);
}
.tk-nav__toggle {
  display: none;
  background: transparent;
  border: 1.5px solid var(--ink);
  padding: 8px 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 16px;
  cursor: pointer;
  color: var(--ink);
}

/* ─── Footer ───────────────────────────────────────────────── */
.tk-footer {
  background: var(--ink);
  color: var(--paper);
  padding: 40px 56px 28px;
  position: relative;
  border-top: 1.5px solid var(--ink);
}
.tk-footer__circuit {
  position: absolute;
  top: -10px;
  left: 0;
  width: 100%;
  height: 20px;
}
.tk-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}
.tk-footer__tagline {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  line-height: 1.7;
  margin-top: 18px;
  color: #B8C2D0;
  max-width: 320px;
}
.tk-footer__col-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--yellow);
  margin-bottom: 14px;
}
.tk-footer__col a {
  display: block;
  padding: 4px 0;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 13px;
  color: var(--paper);
  text-decoration: none;
}
.tk-footer__col a:hover { text-decoration: underline; }
.tk-footer__bottom {
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px dashed rgba(245, 239, 221, 0.2);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: #B8C2D0;
  letter-spacing: 0.05em;
}

/* ─── Typography ───────────────────────────────────────────── */
.tk-h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 76px;
  line-height: 0.96;
  margin: 0;
  letter-spacing: -0.035em;
  color: var(--ink);
  text-wrap: pretty;
}
.tk-h1--xl { font-size: 84px; line-height: 0.95; letter-spacing: -0.04em; }
.tk-h1 .accent { color: var(--accent); }
.tk-h1__sub {
  display: block;
  color: var(--ink-soft);
  font-size: 36px;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-top: 4px;
}
.tk-h1__sub--accent {
  color: var(--accent);
  font-style: italic;
  font-weight: 600;
  font-size: 56px;
}
.tk-h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 40px;
  margin: 0;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.tk-h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 22px;
  margin: 0;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.tk-body {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 0;
  text-wrap: pretty;
}
.tk-lede {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 19px;
  line-height: 1.55;
  color: var(--ink-soft);
  text-wrap: pretty;
}
.tk-mono {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.tk-breadcrumb {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 18px;
}
.tk-kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--ink-soft);
}

/* ─── Section head ─────────────────────────────────────────── */
.tk-section-head {
  display: flex;
  align-items: flex-end;
  gap: 24px;
  margin-bottom: 32px;
}
.tk-section-head__n {
  font-family: 'JetBrains Mono', monospace;
  font-size: 56px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  letter-spacing: -0.02em;
}
.tk-section-head__body { flex: 1; padding-bottom: 6px; }
.tk-section-head__kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--ink-soft);
  margin-bottom: 4px;
}
.tk-section-head__rule {
  flex-shrink: 0;
  padding-bottom: 12px;
  border-bottom: 1.5px solid var(--ink);
  min-width: 80px;
}

/* ─── Button ───────────────────────────────────────────────── */
.tk-btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 12px 22px;
  border: 1.5px solid var(--ink);
  border-radius: 0;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-transform: uppercase;
  transition: transform 0.1s, box-shadow 0.1s;
  position: relative;
  text-decoration: none;
  background: var(--ink);
  color: var(--paper);
  box-shadow: 4px 4px 0 0 var(--orange);
}
.tk-btn:hover { transform: translate(-1px, -1px); box-shadow: 5px 5px 0 0 var(--orange); text-decoration: none; }
.tk-btn--accent {
  background: var(--accent);
  color: var(--paper);
  box-shadow: 4px 4px 0 0 var(--ink);
}
.tk-btn--accent:hover { box-shadow: 5px 5px 0 0 var(--ink); }
.tk-btn--ghost {
  background: transparent;
  color: var(--ink);
  box-shadow: 4px 4px 0 0 rgba(21, 38, 58, 0.13);
}
.tk-btn--ghost:hover { box-shadow: 5px 5px 0 0 rgba(21, 38, 58, 0.13); }
.tk-btn--sm { padding: 8px 14px; font-size: 12px; }
.tk-btn--block { display: flex; width: 100%; justify-content: center; }

/* ─── Card ─────────────────────────────────────────────────── */
.tk-card {
  background: var(--white);
  border: 1.5px dashed var(--ink);
  padding: 24px;
  position: relative;
  box-shadow: 5px 5px 0 0 rgba(21, 38, 58, 0.1);
}
.tk-card--solid { border-style: solid; }
.tk-card--flat { box-shadow: none; }
.tk-card--ink { background: var(--ink); color: var(--paper); }

/* ─── Tag ──────────────────────────────────────────────────── */
.tk-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink);
  padding: 4px 10px;
  border: 1px solid var(--ink);
  background: rgba(255,255,255,0.4);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}
.tk-tag--accent { color: var(--accent); border-color: var(--accent); }
.tk-tag--green  { color: var(--green);  border-color: var(--green); }
.tk-tag--blue   { color: var(--blue);   border-color: var(--blue); }
.tk-tag--violet { color: var(--violet); border-color: var(--violet); }
.tk-tag--red    { color: var(--red);    border-color: var(--red); }
.tk-tag--copper { color: var(--copper); border-color: var(--copper); }
.tk-tag--yellow { color: var(--yellow); border-color: var(--yellow); }

/* ─── Stamp ────────────────────────────────────────────────── */
.tk-stamp {
  display: grid;
  place-items: center;
  border-radius: 50%;
  border: 2px solid var(--accent);
  color: var(--accent);
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-align: center;
  padding: 8px;
  opacity: 0.85;
  width: 92px;
  height: 92px;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,0.1);
  flex-shrink: 0;
}
.tk-stamp--green  { border-color: var(--green);  color: var(--green); }
.tk-stamp--accent { border-color: var(--accent); color: var(--accent); }
.tk-stamp--red    { border-color: var(--red);    color: var(--red); }

/* ─── Code block ───────────────────────────────────────────── */
.tk-code {
  background: var(--ink);
  color: var(--paper);
  border: 1.5px solid var(--ink);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  line-height: 1.6;
  position: relative;
  overflow: auto;
}
.tk-code__header {
  background: #0c1828;
  color: var(--paper);
  padding: 8px 14px;
  font-size: 11px;
  letter-spacing: 0.1em;
  border-bottom: 1px solid rgba(226, 92, 44, 0.4);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.tk-code__lang { color: var(--accent); }
.tk-code__body {
  padding: 14px 18px;
  white-space: pre;
  overflow-x: auto;
}

/* In-line content code */
.tk-prose code, code.tk-inline {
  font-family: 'JetBrains Mono', monospace;
  background: var(--paper-deep);
  color: var(--ink);
  padding: 1px 6px;
  border: 1px solid var(--paper-edge);
  font-size: 0.9em;
}
.tk-prose pre {
  background: var(--ink);
  color: var(--paper);
  border: 1.5px solid var(--ink);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  line-height: 1.6;
  padding: 14px 18px;
  overflow-x: auto;
}
.tk-prose pre code {
  background: transparent;
  border: none;
  color: var(--paper);
  padding: 0;
}

/* ─── Hero status strip ────────────────────────────────────── */
.tk-status-strip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 36px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.tk-status-strip .pulse {
  width: 8px;
  height: 8px;
  background: var(--green);
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(45, 143, 96, 0.2);
  display: inline-block;
  margin-right: 8px;
}

/* ─── Hero stats ───────────────────────────────────────────── */
.tk-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1.5px solid var(--ink);
  padding-top: 18px;
  margin-top: 56px;
}
.tk-stats__n {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ink);
}
.tk-stats__label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-top: 6px;
}

/* ─── Tutorial / utility cards ─────────────────────────────── */
.tk-tut-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.tk-tut-card {
  background: var(--white);
  border: 1.5px solid var(--ink);
  position: relative;
  box-shadow: 6px 6px 0 0 rgba(21, 38, 58, 0.1);
  text-decoration: none;
  color: var(--ink);
  display: block;
}
.tk-tut-card__visual {
  height: 180px;
  border-bottom: 1.5px solid var(--ink);
  position: relative;
  overflow: hidden;
  display: grid;
  place-items: center;
}
.tk-tut-card__body { padding: 22px 24px 24px; }
.tk-tut-card__meta-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.tk-tut-card__meta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.08em;
}
.tk-tut-card h3 { margin: 0 0 10px; }
.tk-tut-card p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 0 0 20px;
  text-wrap: pretty;
}
.tk-tut-card__cta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0.06em;
}

/* Tutorial list (2-col, side visual) */
.tk-tut-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.tk-tut-row {
  display: grid;
  grid-template-columns: 160px 1fr;
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 0 rgba(21,38,58,0.1);
  text-decoration: none;
  color: var(--ink);
}
.tk-tut-row__visual {
  border-right: 1.5px solid var(--ink);
  position: relative;
  display: grid;
  place-items: center;
}
.tk-tut-row__badge {
  position: absolute;
  top: 6px;
  left: 6px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0.08em;
  background: var(--paper);
  padding: 2px 6px;
  border: 1px solid var(--ink);
  z-index: 1;
}
.tk-tut-row__body { padding: 20px 22px; }
.tk-tut-row__meta-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}
.tk-tut-row h3 {
  font-size: 21px;
  margin: 0 0 6px;
}
.tk-tut-row p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
  margin: 0 0 14px;
  text-wrap: pretty;
}
.tk-tut-row__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 10px;
  border-top: 1px dashed rgba(21, 38, 58, 0.25);
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
}

/* ─── Utility tile grid (home preview) ─────────────────────── */
.tk-util-tile-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}
.tk-util-tile {
  padding: 32px 28px;
  border: 1.5px solid var(--ink);
  margin: -0.75px 0 0 -0.75px; /* collapse double borders */
  background: var(--white);
  position: relative;
  text-decoration: none;
  color: var(--ink);
  cursor: pointer;
  display: block;
}
.tk-util-tile__top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 18px;
}
.tk-util-tile__idx {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
}
.tk-util-tile__sub {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.04em;
}
.tk-util-tile__cta {
  margin-top: 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
}

/* ─── Utility full cards (utility index) ───────────────────── */
.tk-util-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.tk-util-card {
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 0 rgba(21, 38, 58, 0.1);
  display: grid;
  grid-template-columns: 120px 1fr;
  overflow: hidden;
  position: relative;
  text-decoration: none;
  color: var(--ink);
}
.tk-util-card__icon {
  border-right: 1.5px solid var(--ink);
  display: grid;
  place-items: center;
  position: relative;
  min-height: 130px;
}
.tk-util-card__body { padding: 22px 24px 18px; }
.tk-util-card__top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 8px;
  gap: 12px;
}
.tk-util-card__sub {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.04em;
}
.tk-util-card__popular {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 4px 8px;
  border: 1px solid var(--accent);
  background: var(--paper);
  color: var(--accent);
  white-space: nowrap;
}
.tk-util-card__desc {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 12px 0 16px;
  text-wrap: pretty;
}
.tk-util-card__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 12px;
  border-top: 1px dashed rgba(21, 38, 58, 0.25);
}
.tk-util-card__meta-list {
  display: flex;
  gap: 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
  flex-wrap: wrap;
}
.tk-util-card__cta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

/* ─── Blog list & post rows ────────────────────────────────── */
.tk-post-list {
  display: grid;
  grid-template-columns: 1fr;
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 0 rgba(21,38,58,0.1);
}
.tk-post-row {
  display: grid;
  grid-template-columns: 70px 120px 140px 1fr 100px;
  gap: 24px;
  padding: 22px 28px;
  align-items: center;
  border-bottom: 1px dashed rgba(21, 38, 58, 0.25);
  text-decoration: none;
  color: var(--ink);
}
.tk-post-row:last-child { border-bottom: none; }
.tk-post-row__num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--accent);
  font-weight: 700;
}
.tk-post-row__date {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.04em;
}
.tk-post-row h3 { font-size: 19px; margin: 0 0 4px; font-weight: 700; }
.tk-post-row p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
  margin: 0;
  text-wrap: pretty;
}
.tk-post-row__read {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.08em;
  text-align: right;
}

/* Home "latest field notes" — simpler 4-col row */
.tk-home-row {
  display: grid;
  grid-template-columns: 180px 100px 1fr 100px;
  gap: 24px;
  padding: 22px 28px;
  align-items: center;
  border-bottom: 1px dashed rgba(21, 38, 58, 0.3);
  text-decoration: none;
  color: var(--ink);
}
.tk-home-row:last-child { border-bottom: none; }

/* ─── Form fields ──────────────────────────────────────────── */
.tk-form-group { margin-bottom: 18px; }
.tk-label {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 6px;
}
.tk-input, .tk-textarea, .tk-select {
  display: block;
  width: 100%;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 15px;
  padding: 10px 12px;
  background: var(--white);
  border: 1.5px solid var(--ink);
  border-radius: 0;
  color: var(--ink);
}
.tk-input:focus, .tk-textarea:focus, .tk-select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.tk-textarea { min-height: 140px; resize: vertical; }
.tk-alert {
  padding: 12px 16px;
  border: 1.5px solid var(--ink);
  background: var(--white);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.06em;
  margin-bottom: 18px;
  color: var(--ink);
}
.tk-alert--success { border-color: var(--green); color: var(--green); }
.tk-alert--error   { border-color: var(--red);   color: var(--red); }

/* ─── Filter bar (tutorials) ───────────────────────────────── */
.tk-filter-bar {
  display: flex;
  align-items: stretch;
  border: 1.5px solid var(--ink);
  background: var(--white);
  margin-top: 12px;
}
.tk-filter-bar__label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 14px 20px;
  border-right: 1.5px solid var(--ink);
  display: flex;
  align-items: center;
}
.tk-filter-bar__btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 14px 20px;
  border: none;
  border-right: 1px dashed rgba(21, 38, 58, 0.35);
  cursor: pointer;
  background: transparent;
  color: var(--ink);
}
.tk-filter-bar__btn.is-active { background: var(--ink); color: var(--paper); }
.tk-filter-bar__search {
  margin-left: auto;
  padding: 14px 20px;
  border-left: 1.5px solid var(--ink);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ─── Education / generic 3-col card grid ──────────────────── */
.tk-3col { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.tk-edu-card {
  background: var(--white);
  border: 1.5px dashed var(--ink);
  padding: 22px 24px;
}
.tk-edu-card__num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 38px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 10px;
  letter-spacing: -0.03em;
}
.tk-edu-card h4 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 19px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.tk-edu-card p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 0;
  text-wrap: pretty;
}

/* ─── Resistor calculator ──────────────────────────────────── */
.tk-resistor-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 36px;
  align-items: start;
}
.tk-card-headed {
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 0 rgba(21,38,58,0.1);
}
.tk-card-headed--ink {
  background: var(--ink);
  color: var(--paper);
  box-shadow: 5px 5px 0 0 var(--accent);
}
.tk-card-headed__head {
  padding: 12px 18px;
  background: var(--ink);
  color: var(--paper);
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  display: flex;
  justify-content: space-between;
}
.tk-card-headed__head .yellow { color: var(--yellow); }
.tk-card-headed__body { padding: 20px 22px; }
.tk-card-headed--ink .tk-card-headed__head {
  background: transparent;
  border-bottom: 1px solid rgba(245, 239, 221, 0.13);
  color: var(--yellow);
}

.tk-band-picker { margin-bottom: 16px; }
.tk-band-picker__swatches { display: flex; gap: 6px; flex-wrap: wrap; }
.tk-band-swatch {
  width: 36px;
  height: 36px;
  padding: 0;
  cursor: pointer;
  border: 2px solid transparent;
  box-shadow: inset 0 0 0 1px rgba(21, 38, 58, 0.2);
  position: relative;
  border-radius: 0;
}
.tk-band-swatch.is-selected {
  border-color: var(--ink);
  box-shadow: 2px 2px 0 0 var(--ink);
}
.tk-band-swatch__label {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #fff;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 700;
  text-shadow: 0 0 4px rgba(0,0,0,0.6);
}
.tk-band-picker__live {
  margin-top: 6px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
}

.tk-result-value {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 56px;
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  letter-spacing: -0.03em;
}
.tk-result-tol {
  margin-top: 4px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  color: var(--accent);
  font-weight: 600;
}
.tk-result-minmax {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px dashed rgba(245, 239, 221, 0.2);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.tk-result-mini-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  color: #B8C2D0;
  letter-spacing: 0.1em;
}
.tk-result-mini-value {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 22px;
  font-weight: 600;
}
.tk-result-terminal {
  margin-top: 22px;
  padding: 12px 14px;
  background: #0c1828;
  border: 1px solid rgba(226, 92, 44, 0.35);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--paper);
  line-height: 1.6;
  word-wrap: break-word;
}
.tk-result-terminal .accent { color: var(--accent); }
.tk-result-terminal .muted  { color: #B8C2D0; }

.tk-mode-btns { display: flex; gap: 8px; }
.tk-mode-btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  font-weight: 700;
  padding: 12px 18px;
  cursor: pointer;
  border: 1.5px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  box-shadow: 3px 3px 0 0 var(--accent);
  letter-spacing: 0.08em;
}
.tk-mode-btn.is-active { background: var(--ink); color: var(--paper); }

/* Resistor preview block */
.tk-resistor-preview {
  margin-top: 32px;
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 0 rgba(21, 38, 58, 0.1);
  padding: 32px 40px;
  position: relative;
}
.tk-resistor-preview__caption {
  position: absolute;
  top: 12px;
  left: 12px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--ink-soft);
}

/* Reference table */
.tk-table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
}
.tk-table thead tr {
  background: var(--paper-deep);
  border-bottom: 1.5px solid var(--ink);
}
.tk-table th {
  text-align: left;
  padding: 10px 18px;
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--ink-soft);
  font-weight: 600;
  text-transform: uppercase;
}
.tk-table td {
  padding: 10px 18px;
  color: var(--ink);
}
.tk-table tbody tr { border-bottom: 1px dashed rgba(21, 38, 58, 0.2); }
.tk-table tbody tr:last-child { border-bottom: none; }
.tk-table .swatch {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 1px solid var(--ink);
  vertical-align: middle;
  margin-right: 10px;
}
.tk-table .tol-active { color: var(--accent); font-weight: 700; }
.tk-table .muted { color: var(--ink-faint); }

/* ─── CTA strip ────────────────────────────────────────────── */
.tk-cta-strip {
  background: var(--ink);
  color: var(--paper);
  padding: 32px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 40px;
  position: relative;
  overflow: hidden;
}
.tk-cta-strip__kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--yellow);
  letter-spacing: 0.15em;
  margin-bottom: 8px;
}
.tk-cta-strip h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 6px;
  letter-spacing: -0.02em;
  color: var(--paper);
}
.tk-cta-strip p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 15px;
  color: #B8C2D0;
  margin: 0;
  max-width: 580px;
}

/* ─── Hero & generic utilities ─────────────────────────────── */
.tk-hero { padding: 56px 56px 80px; position: relative; }
.tk-hero--tight { padding: 56px 56px 32px; }
.tk-hero__grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 56px;
  align-items: center;
}
.tk-hero__tags {
  margin-bottom: 20px;
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}
.tk-hero__btns { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; margin-top: 36px; }

.tk-flex-between { display: flex; justify-content: space-between; align-items: flex-end; gap: 40px; }
.tk-mt-12 { margin-top: 12px; }
.tk-mt-18 { margin-top: 18px; }
.tk-mt-36 { margin-top: 36px; }
.tk-mb-18 { margin-bottom: 18px; }
.tk-mb-32 { margin-bottom: 32px; }
.tk-mb-56 { margin-bottom: 56px; }

/* Featured post (blog) */
.tk-featured-post {
  background: var(--white);
  border: 1.5px solid var(--ink);
  box-shadow: 6px 6px 0 0 rgba(21,38,58,0.1);
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  overflow: hidden;
}
.tk-featured-post__body { padding: 36px 40px; }
.tk-featured-post__visual {
  background: var(--ink);
  display: grid;
  place-items: center;
  min-height: 320px;
  padding: 32px;
}
.tk-featured-post__date {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
  margin: 12px 0;
}
.tk-featured-post h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 38px;
  font-weight: 700;
  margin: 0 0 16px;
  letter-spacing: -0.02em;
  line-height: 1.05;
  text-wrap: pretty;
}
.tk-featured-post p {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 0 0 24px;
  text-wrap: pretty;
}

/* Blog scratch-pad counter (hero right side) */
.tk-counter-block { text-align: right; }
.tk-counter-block__n {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 42px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1;
}
.tk-counter-block__label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  letter-spacing: 0.12em;
  margin-bottom: 6px;
}
.tk-counter-block__note {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--ink-soft);
  margin-top: 6px;
}

/* Banner section (the deep-cream wells) */
.tk-band-deep {
  background: var(--paper-deep);
  border-top: 1.5px solid var(--ink);
  border-bottom: 1.5px solid var(--ink);
  padding: 40px 56px 80px;
}

/* Prose container for content pages (markdown blog posts, tutorials) */
.tk-prose {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  max-width: 760px;
  margin: 0 auto;
}
.tk-prose h1, .tk-prose h2, .tk-prose h3, .tk-prose h4 {
  font-family: 'Space Grotesk', sans-serif;
  color: var(--ink);
  letter-spacing: -0.02em;
  text-wrap: pretty;
  margin: 1.6em 0 0.5em;
}
.tk-prose h1 { font-size: 48px; }
.tk-prose h2 { font-size: 32px; }
.tk-prose h3 { font-size: 22px; }
.tk-prose h4 { font-size: 18px; }
.tk-prose p { margin: 0 0 1.1em; text-wrap: pretty; color: var(--ink); }
.tk-prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
.tk-prose ul, .tk-prose ol { padding-left: 1.4em; margin: 0 0 1em; }
.tk-prose li { margin: 0.3em 0; }
.tk-prose blockquote {
  border-left: 4px solid var(--accent);
  background: var(--paper-deep);
  padding: 14px 18px;
  margin: 1em 0;
}
.tk-prose img { max-width: 100%; border: 1.5px solid var(--ink); }
.tk-prose hr { border: none; border-top: 1.5px solid var(--ink); margin: 2em 0; }

/* ─── Calculator helpers (shared across utility pages) ─────── */
.tk-calc-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
.tk-calc-grid--3 { grid-template-columns: repeat(3, 1fr); }
.tk-calc-grid--2 { grid-template-columns: repeat(2, 1fr); }
.tk-calc-grid > .tk-form-group { margin-bottom: 0; }

/* Compound input: number + unit selector */
.tk-input-group {
  display: flex;
  width: 100%;
  border: 1.5px solid var(--ink);
  background: var(--white);
}
.tk-input-group > .tk-input,
.tk-input-group > .tk-select {
  border: none;
  background: transparent;
  flex: 1;
  min-width: 0;
}
.tk-input-group > .tk-input { padding-right: 6px; }
.tk-input-group > .tk-input:focus,
.tk-input-group > .tk-select:focus { outline: none; }
.tk-input-group:focus-within { outline: 2px solid var(--accent); outline-offset: 1px; }
.tk-input-group > .tk-input-suffix,
.tk-input-group > .tk-select {
  flex: 0 0 auto;
  width: auto;
  padding: 10px 12px;
  background: var(--paper-deep);
  border-left: 1px dashed rgba(21, 38, 58, 0.4);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--ink);
  cursor: pointer;
}
.tk-input-group > .tk-input-suffix {
  display: grid;
  place-items: center;
  cursor: default;
  font-weight: 600;
  min-width: 40px;
}

/* Calculator result list (key: value pairs) */
.tk-results-list { list-style: none; padding: 0; margin: 0; }
.tk-results-list li {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(21, 38, 58, 0.25);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 15px;
  color: var(--ink-soft);
  align-items: baseline;
}
.tk-results-list li:last-child { border-bottom: none; }
.tk-results-list li strong {
  font-family: 'JetBrains Mono', monospace;
  font-size: 16px;
  color: var(--ink);
  font-weight: 700;
  text-align: right;
}
.tk-results-list li sub { font-size: 0.7em; }

/* When the results list sits on the dark ink card, flip colors */
.tk-card-headed--ink .tk-results-list li {
  color: #B8C2D0;
  border-bottom-color: rgba(245, 239, 221, 0.18);
}
.tk-card-headed--ink .tk-results-list li strong { color: var(--paper); }

/* Inline formula card */
.tk-formula {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  background: var(--paper-deep);
  border: 1px solid var(--paper-edge);
  padding: 8px 12px;
  margin-bottom: 6px;
  color: var(--ink);
  display: block;
}
.tk-formula code { background: transparent; border: none; padding: 0; }

.tk-formula-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}
.tk-formula-grid .tk-formula { margin: 0; text-align: center; }

/* Inline status message */
.tk-status-msg {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  margin-top: 12px;
  padding: 8px 12px;
  border-left: 3px solid var(--ink-faint);
  background: var(--paper-deep);
}
.tk-status-msg.is-success { color: var(--green); border-color: var(--green); }
.tk-status-msg.is-error   { color: var(--red);   border-color: var(--red); }
.tk-status-msg.is-warning { color: var(--copper); border-color: var(--copper); }
.tk-status-msg:empty { display: none; }

/* Form switches & checkboxes */
.tk-check {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink);
  cursor: pointer;
}
.tk-check input[type="checkbox"] {
  appearance: none;
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--ink);
  background: var(--white);
  cursor: pointer;
  display: grid;
  place-items: center;
  margin: 0;
}
.tk-check input[type="checkbox"]:checked { background: var(--accent); border-color: var(--ink); }
.tk-check input[type="checkbox"]:checked::after {
  content: '✓';
  color: var(--paper);
  font-size: 13px;
  font-weight: 700;
}

/* Mode/preset chip row */
.tk-chip-row { display: flex; gap: 6px; flex-wrap: wrap; }
.tk-chip {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 8px 12px;
  border: 1.5px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
}
.tk-chip.is-active { background: var(--ink); color: var(--paper); }

/* Field marked as auto-calculated */
.tk-input.is-calculated {
  background: var(--paper-deep);
  font-weight: 700;
  color: var(--accent);
}

/* Generic 2-col content grid */
.tk-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; align-items: start; }

/* Code output textarea */
.tk-code-output {
  width: 100%;
  background: var(--ink);
  color: var(--paper);
  border: 1.5px solid var(--ink);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  line-height: 1.55;
  padding: 14px 18px;
  min-height: 360px;
  resize: vertical;
  border-radius: 0;
}

/* List rows (passphrase list, etc.) */
.tk-row-list { list-style: none; padding: 0; margin: 0; border: 1.5px solid var(--ink); background: var(--white); }
.tk-row-list li {
  padding: 14px 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 15px;
  color: var(--ink);
  border-bottom: 1px dashed rgba(21, 38, 58, 0.25);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.tk-row-list li:last-child { border-bottom: none; }
.tk-row-list li:hover { background: var(--paper-deep); }
.tk-row-list .copy-btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: transparent;
  border: 1px solid var(--ink);
  padding: 4px 8px;
  cursor: pointer;
  color: var(--ink);
}
.tk-row-list .copy-btn:hover { background: var(--ink); color: var(--paper); }

/* CSV preview table (dynamically built) */
.tk-csv-preview {
  max-height: 70vh;
  overflow: auto;
  border: 1.5px solid var(--ink);
  background: var(--white);
}
.tk-csv-preview table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}
.tk-csv-preview thead th {
  position: sticky;
  top: 0;
  background: var(--ink);
  color: var(--paper);
  padding: 10px 14px;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  cursor: pointer;
  user-select: none;
  border-bottom: 1.5px solid var(--ink);
  font-weight: 600;
}
.tk-csv-preview thead th:hover { background: #1f3148; }
.tk-csv-preview tbody td {
  padding: 7px 14px;
  color: var(--ink);
  border-bottom: 1px dashed rgba(21, 38, 58, 0.18);
  white-space: nowrap;
}
.tk-csv-preview tbody tr:nth-child(even) { background: rgba(237, 229, 205, 0.4); }

select[multiple].tk-select {
  background: var(--white);
  padding: 6px;
}
select[multiple].tk-select option {
  padding: 4px 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}

/* File input */
input[type="file"].tk-input { padding: 8px 10px; cursor: pointer; }

/* ─── Responsive ───────────────────────────────────────────── */
@media (max-width: 1000px) {
  .tk-nav { padding: 0 20px; }
  .tk-nav__toggle { display: inline-flex; }
  .tk-nav__links {
    display: none;
    position: absolute;
    top: 84px;
    left: 0;
    right: 0;
    background: var(--paper);
    border-bottom: 1.5px solid var(--ink);
    flex-direction: column;
    align-items: stretch;
    padding: 12px 20px;
    z-index: 20;
  }
  .tk-nav__links.is-open { display: flex; }
  .tk-nav__links .tk-btn { margin-left: 0; margin-top: 10px; align-self: flex-start; }

  .tk-section, .tk-hero, .tk-hero--tight, .tk-band-deep, .tk-footer { padding-left: 20px; padding-right: 20px; }
  .tk-section-tight { padding-left: 20px; padding-right: 20px; }
  .tk-hero__grid { grid-template-columns: 1fr; gap: 40px; }
  .tk-h1 { font-size: 48px; }
  .tk-h1--xl { font-size: 56px; }
  .tk-h1__sub { font-size: 24px; }
  .tk-h1__sub--accent { font-size: 36px; }
  .tk-section-head__n { font-size: 38px; }
  .tk-h2 { font-size: 28px; }
  .tk-tut-grid { grid-template-columns: 1fr; }
  .tk-tut-list { grid-template-columns: 1fr; }
  .tk-util-grid { grid-template-columns: 1fr; }
  .tk-util-tile-grid { grid-template-columns: 1fr 1fr; }
  .tk-resistor-grid { grid-template-columns: 1fr; }
  .tk-featured-post { grid-template-columns: 1fr; }
  .tk-3col { grid-template-columns: 1fr; }
  .tk-footer__grid { grid-template-columns: 1fr 1fr; }
  .tk-post-row { grid-template-columns: 50px 1fr 80px; }
  .tk-post-row__date, .tk-post-row .tk-tag { display: none; }
  .tk-home-row { grid-template-columns: 1fr; gap: 6px; }
  .tk-flex-between { flex-direction: column; align-items: flex-start; }
  .tk-cta-strip { flex-direction: column; align-items: flex-start; }
  .tk-status-strip { flex-direction: column; gap: 10px; align-items: flex-start; }
  .tk-filter-bar { flex-wrap: wrap; }
  .tk-filter-bar__search { margin-left: 0; border-left: none; border-top: 1px dashed rgba(21,38,58,0.3); width: 100%; }
  .tk-calc-grid, .tk-calc-grid--3, .tk-calc-grid--2 { grid-template-columns: 1fr 1fr; }
  .tk-formula-grid { grid-template-columns: 1fr 1fr; }
  .tk-2col { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .tk-util-tile-grid { grid-template-columns: 1fr; }
  .tk-footer__grid { grid-template-columns: 1fr; }
  .tk-footer__bottom { flex-direction: column; gap: 8px; align-items: flex-start; }
  .tk-calc-grid, .tk-calc-grid--3, .tk-calc-grid--2 { grid-template-columns: 1fr; }
  .tk-formula-grid { grid-template-columns: 1fr; }
}