/* The Case Converter · SM/TCC N°019 · the typesetter's workbench
   Warm paper, ink rules & hairlines, caret-blue accent. No CDNs, no tracking. */

/* ---------- fonts (bundled, self-hosted) ---------- */
@font-face { font-family: 'Archivo'; font-style: normal; font-weight: 400; src: url('../fonts/Archivo-400.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'Archivo'; font-style: normal; font-weight: 500; src: url('../fonts/Archivo-500.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'Archivo'; font-style: normal; font-weight: 700; src: url('../fonts/Archivo-700.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'IBM Plex Mono'; font-style: normal; font-weight: 400; src: url('../fonts/IBMPlexMono-400.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'IBM Plex Mono'; font-style: normal; font-weight: 500; src: url('../fonts/IBMPlexMono-500.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'Fraunces'; font-style: normal; font-weight: 900; src: url('../fonts/Fraunces-900.woff2') format('woff2'); font-display: swap; }
@font-face { font-family: 'Fraunces'; font-style: italic; font-weight: 400; src: url('../fonts/Fraunces-400i.woff2') format('woff2'); font-display: swap; }

/* ---------- tokens ---------- */
:root {
  --paper: #FAF8F2;
  --card: #FFFDF7;
  --ink: #17150F;
  --muted: #6E675C;
  --agate: #A89F8C;
  --hair: #E7E1D2;
  --hair-strong: #D8D0BC;
  --accent: #2B4EA2;
  --accent-ink: #FFFFFF;
  --accent-soft: #EDF0F9;
  --baseline: rgba(23, 21, 15, 0.045);
  --sans: 'Archivo', system-ui, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, Menlo, monospace;
  --display: 'Fraunces', Georgia, serif;
  --ease: cubic-bezier(0.2, 0, 0, 1);
  --shell: 72rem;
}
.theme-dark {
  --paper: #17130E;
  --card: #1F1A13;
  --ink: #F2EDE0;
  --muted: #A79D8B;
  --agate: #7C7361;
  --hair: #332C20;
  --hair-strong: #453C2C;
  --accent: #93ABE8;
  --accent-ink: #10142A;
  --accent-soft: #232B44;
  --baseline: rgba(242, 237, 224, 0.05);
}

/* ---------- reset & base ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  background: var(--paper);
  color: var(--ink);
  font: 400 1rem/1.6 var(--sans);
  transition: background 200ms var(--ease), color 200ms var(--ease);
}
img, svg { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
::selection { background: var(--accent); color: var(--accent-ink); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.shell { max-width: var(--shell); margin: 0 auto; padding: 0 1.25rem; }

/* ---------- header / masthead ---------- */
.masthead { padding-top: 1.1rem; }
.masthead-inner {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding-bottom: 0.85rem;
  border-bottom: 2.5px solid var(--ink);
  position: relative;
}
.masthead-inner::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -5px;
  border-bottom: 1px solid var(--ink);
}
.wordmark { display: flex; align-items: baseline; gap: 0.55rem; text-decoration: none; color: var(--ink); }
.wordmark-glyph {
  font-family: var(--display); font-weight: 900; font-size: 1.5rem; line-height: 1;
  color: var(--accent-ink); background: var(--accent);
  padding: 0.18em 0.3em 0.24em; letter-spacing: -0.02em;
}
.wordmark-name { font-family: var(--display); font-weight: 900; font-size: 1.28rem; letter-spacing: -0.01em; white-space: nowrap; }
.wordmark-name em { font-style: italic; font-weight: 400; color: var(--accent); font-size: 1.06em; }
.masthead-side { display: flex; align-items: center; gap: 0.9rem; }
.masthead-nav { display: flex; gap: 1.1rem; }
.masthead-nav a {
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted); text-decoration: none;
  display: inline-flex; align-items: center; min-height: 44px; padding: 0 0.15rem;
}
.masthead-nav a:hover, .masthead-nav a[aria-current="page"] { color: var(--accent); }
.theme-btn {
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em;
  background: none; border: 1px solid var(--hair-strong); color: var(--muted);
  min-width: 44px; min-height: 38px; padding: 0.3rem 0.6rem; cursor: pointer;
}
.theme-btn:hover { border-color: var(--ink); color: var(--ink); }
.theme-btn .moon { display: inline; } .theme-btn .sun { display: none; }
.theme-dark .theme-btn .moon { display: none; } .theme-dark .theme-btn .sun { display: inline; }
.dateline {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--agate); display: flex; justify-content: space-between; gap: 1rem;
  padding: 0.5rem 0 0;
}
.dateline .private { color: var(--accent); }

/* ---------- hero ---------- */
.hero { padding: 2.6rem 0 1.6rem; }
.hero h1 {
  font-family: var(--display); font-weight: 900;
  font-size: clamp(2rem, 5.2vw, 3.6rem);
  line-height: 1.04; letter-spacing: -0.015em; max-width: 21ch;
}
.hero h1 em { font-style: italic; font-weight: 400; color: var(--accent); }
.hero .lede {
  margin-top: 0.9rem; max-width: 58ch; color: var(--muted); font-size: 1.06rem;
}
.hero .lede strong { color: var(--ink); }

/* ---------- tool ---------- */
.tool { margin: 1.4rem 0 0; }
.tool-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 0.8rem; flex-wrap: wrap;
  border-top: 2px solid var(--ink);
  padding: 0.55rem 0;
}
.tool-bar-label {
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted);
}
.tool-actions { display: flex; gap: 0.45rem; flex-wrap: wrap; }
.act-btn {
  font-family: var(--sans); font-weight: 500; font-size: 0.85rem;
  background: var(--card); color: var(--ink);
  border: 1px solid var(--hair-strong);
  min-height: 44px; padding: 0.45rem 0.95rem; cursor: pointer;
  transition: border-color 150ms var(--ease), background 150ms var(--ease), transform 150ms var(--ease);
}
.act-btn:hover:not(:disabled) { border-color: var(--ink); }
.act-btn:active:not(:disabled) { transform: translateY(1px); }
.act-btn:disabled { opacity: 0.4; cursor: default; }
.act-primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.act-primary:hover:not(:disabled) { border-color: var(--accent); filter: brightness(1.08); }
.tool-input {
  width: 100%; resize: vertical; min-height: 13rem;
  font: 400 1rem/1.75 var(--mono);
  color: var(--ink);
  background:
    repeating-linear-gradient(to bottom, transparent 0, transparent calc(1.75em - 1px), var(--baseline) calc(1.75em - 1px), var(--baseline) 1.75em)
    var(--card);
  background-attachment: local;
  border: 1px solid var(--hair-strong);
  border-top: none;
  padding: 1rem 1.1rem;
}
.tool-input:focus { outline: none; border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.tool-input::placeholder { color: var(--agate); }

/* stats */
.tool-stats {
  display: flex; flex-wrap: wrap;
  border: 1px solid var(--hair-strong); border-top: none;
  background: var(--card);
}
.stat {
  flex: 1 1 auto; display: flex; align-items: baseline; gap: 0.45rem;
  padding: 0.55rem 1rem;
  border-right: 1px solid var(--hair);
}
.stat:last-child { border-right: none; }
.stat-value { font-family: var(--mono); font-weight: 500; font-size: 1rem; font-variant-numeric: tabular-nums; }
.stat-label { font-family: var(--mono); font-size: 0.64rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--agate); }

/* deck */
.deck { margin-top: 2.2rem; }
.deck-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; flex-wrap: wrap; border-bottom: 1px solid var(--hair-strong); padding-bottom: 0.5rem; }
.deck-title { font-family: var(--display); font-weight: 900; font-size: 1.25rem; }
.deck-hint { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.06em; color: var(--agate); }
.deck-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(15.5rem, 1fr));
  gap: 0; border-left: 1px solid var(--hair); border-top: 1px solid var(--hair); margin-top: 1rem;
}
.case-btn {
  display: flex; flex-direction: column; gap: 0.45rem; text-align: left;
  background: none; border: none; cursor: pointer; color: var(--ink);
  border-right: 1px solid var(--hair); border-bottom: 1px solid var(--hair);
  padding: 0.9rem 1rem 1rem; min-height: 44px; position: relative;
  transition: background 150ms var(--ease);
}
.case-btn::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--accent); transform: scaleY(0); transform-origin: top;
  transition: transform 180ms var(--ease);
}
.case-btn:hover { background: var(--accent-soft); }
.case-btn:hover::before { transform: scaleY(1); }
.case-btn.is-active { background: var(--accent-soft); }
.case-btn.is-active::before { transform: scaleY(1); }
.case-btn.is-preset .case-name::after { content: " ·"; color: var(--accent); }
.case-top { display: flex; align-items: center; justify-content: space-between; gap: 0.5rem; width: 100%; }
.case-name { font-family: var(--sans); font-weight: 700; font-size: 0.9rem; }
.case-kbd {
  font-family: var(--mono); font-size: 0.62rem; color: var(--agate);
  border: 1px solid var(--hair-strong); padding: 0.05rem 0.35rem;
}
.case-preview {
  font-family: var(--mono); font-size: 0.78rem; color: var(--muted);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; width: 100%;
  border-top: 1px dotted var(--hair-strong); padding-top: 0.45rem;
}
.case-btn.is-sample .case-preview { color: var(--agate); font-style: italic; }
.case-btn.is-active .case-preview, .case-btn:hover .case-preview { color: var(--accent); }

/* ---------- style selector (Title Case card, checker) ---------- */
.style-select {
  font-family: var(--mono); font-size: 0.66rem; letter-spacing: 0.06em;
  background: var(--card); color: var(--ink);
  border: 1px solid var(--hair-strong); padding: 0.15rem 0.3rem; cursor: pointer;
}
.style-select:hover { border-color: var(--accent); }
.style-select-lg { font-size: 0.8rem; padding: 0.45rem 0.6rem; min-height: 44px; max-width: 100%; }

/* ---------- headline checker ---------- */
.checker-input { border-top: none; min-height: 6rem; }
.checker-style { display: flex; align-items: center; gap: 0.6rem; }
.checker-style-label { font-family: var(--mono); font-size: 0.64rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--agate); }
.checker-report { border: 1px solid var(--hair-strong); border-top: none; background: var(--card); padding: 1rem 1.1rem; }
.checker-verdict { font-family: var(--sans); font-weight: 700; font-size: 0.95rem; color: var(--muted); }
.checker-verdict.is-ok { color: #33582F; }
.theme-dark .checker-verdict.is-ok { color: #8FBA6E; }
.checker-verdict.is-bad { color: #7C2B2B; }
.theme-dark .checker-verdict.is-bad { color: #D89090; }
.checker-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0.8rem 0; }
.checker-break { flex-basis: 100%; height: 0; }
.chip-ok, .chip-bad {
  font-family: var(--mono); font-size: 0.85rem; padding: 0.2rem 0.5rem;
  border: 1px solid var(--hair-strong);
}
.chip-bad { border-color: #7C2B2B; text-decoration: line-through; text-decoration-thickness: 1px; }
.theme-dark .chip-bad { border-color: #D89090; }
.chip-fix { margin-left: 0.45rem; text-decoration: none; color: var(--accent); font-weight: 500; }
.chip-fix::before { content: "→ "; color: var(--agate); }
.checker-actions { display: flex; gap: 0.45rem; flex-wrap: wrap; }

/* ---------- slug generator ---------- */
.slug-input { border-top: none; min-height: 6rem; }
.slug-option {
  display: inline-flex; align-items: center; gap: 0.45rem; cursor: pointer;
  font-family: var(--sans); font-size: 0.85rem; min-height: 44px; padding: 0 0.3rem;
}
.slug-option input { accent-color: var(--accent); width: 1rem; height: 1rem; }
.slug-out-wrap {
  border: 1px solid var(--hair-strong); border-top: none; background: var(--card);
  padding: 1rem 1.1rem; display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
}
.slug-out {
  font-family: var(--mono); font-size: 1rem; color: var(--accent);
  background: var(--paper); border: 1px dashed var(--hair-strong);
  padding: 0.5rem 0.8rem; flex: 1 1 14rem; overflow-wrap: anywhere; min-height: 44px;
  display: flex; align-items: center;
}

/* ---------- AI assistant (BYOK) ---------- */
.ai-settings { border: 1px solid var(--hair-strong); background: var(--card); padding: 0 1.1rem 1rem; margin-bottom: 1.6rem; }
.ai-settings .tool-bar { border-top: 2px solid var(--ink); margin: 0 -1.1rem 0.8rem; padding: 0.55rem 1.1rem; }
.ai-key-status { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.08em; color: var(--agate); }
.ai-key-status.is-ok { color: #33582F; }
.theme-dark .ai-key-status.is-ok { color: #8FBA6E; }
.ai-key-row { display: flex; gap: 0.45rem; flex-wrap: wrap; }
.ai-key-input {
  flex: 1 1 16rem; font-family: var(--mono); font-size: 0.85rem;
  background: var(--paper); color: var(--ink);
  border: 1px solid var(--hair-strong); padding: 0.5rem 0.8rem; min-height: 44px;
}
.ai-key-input:focus { outline: none; border-color: var(--accent); }
.ai-model-row { display: flex; align-items: center; gap: 0.7rem; margin-top: 0.8rem; flex-wrap: wrap; min-width: 0; }
.ai-model-row .style-select-lg { flex: 0 1 auto; min-width: 0; }
.ai-actions { display: flex; gap: 0.45rem; flex-wrap: wrap; margin-top: 0.8rem; }
.ai-note { font-family: var(--mono); font-size: 0.7rem; color: var(--agate); margin: 0.7rem 0 1.4rem; max-width: 70ch; }
.ai-out-wrap { margin-top: 0.4rem; }
.ai-out {
  font-family: var(--mono); font-size: 0.92rem; line-height: 1.65; color: var(--ink);
  background: var(--card); border: 1px solid var(--hair-strong); border-top: none;
  padding: 1rem 1.1rem; white-space: pre-wrap; overflow-wrap: anywhere; min-height: 5rem;
}
.ai-out.is-error { color: #7C2B2B; }
.theme-dark .ai-out.is-error { color: #D89090; }

/* ---------- prose / article sections ---------- */
.section { padding: 2.8rem 0 0; }
.section-rule { border-top: 2px solid var(--ink); margin-top: 2.8rem; }
.kicker {
  font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 0.6rem;
}
.section h2, .prose h2 { font-family: var(--display); font-weight: 900; font-size: 1.6rem; letter-spacing: -0.01em; }
.prose { max-width: 66ch; }
.prose h1 { font-family: var(--display); font-weight: 900; font-size: clamp(1.8rem, 4.5vw, 2.6rem); line-height: 1.1; margin-bottom: 0.4rem; }
.prose h2 { font-size: 1.3rem; margin: 2rem 0 0.6rem; }
.prose h3 { font-family: var(--sans); font-weight: 700; font-size: 1.02rem; margin: 1.4rem 0 0.4rem; }
.prose p, .prose li { color: var(--ink); margin: 0.6rem 0; }
.prose ul, .prose ol { padding-left: 1.3rem; }
.prose .meta { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--agate); margin: 0.4rem 0 1.6rem; }
.prose code { font-family: var(--mono); font-size: 0.88em; background: var(--card); border: 1px solid var(--hair); padding: 0.06em 0.3em; }
.prose .card {
  background: var(--card); border: 1px solid var(--hair-strong); padding: 1rem 1.2rem; margin: 1rem 0;
}
.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: 0; border-left: 1px solid var(--hair); border-top: 1px solid var(--hair); margin-top: 1.2rem;
}
.feature {
  border-right: 1px solid var(--hair); border-bottom: 1px solid var(--hair); padding: 1.1rem 1.2rem;
}
.feature h3 { font-family: var(--sans); font-weight: 700; font-size: 0.95rem; margin-bottom: 0.35rem; }
.feature p { color: var(--muted); font-size: 0.9rem; }
.feature .num { font-family: var(--mono); font-size: 0.66rem; letter-spacing: 0.14em; color: var(--accent); display: block; margin-bottom: 0.5rem; }

/* popular conversions list */
.pop-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(13rem, 1fr)); gap: 0.6rem; margin-top: 1.2rem; padding: 0; list-style: none; }
.pop-list a {
  display: flex; justify-content: space-between; align-items: center; gap: 0.5rem;
  font-family: var(--sans); font-weight: 500; font-size: 0.92rem; text-decoration: none; color: var(--ink);
  border: 1px solid var(--hair-strong); padding: 0.7rem 0.9rem; min-height: 44px;
  transition: border-color 150ms var(--ease), background 150ms var(--ease);
}
.pop-list a::after { content: "→"; color: var(--agate); transition: transform 150ms var(--ease), color 150ms var(--ease); }
.pop-list a:hover { border-color: var(--accent); background: var(--accent-soft); }
.pop-list a:hover::after { color: var(--accent); transform: translateX(3px); }

/* FAQ */
.faq details { border-bottom: 1px solid var(--hair-strong); }
.faq details:first-of-type { border-top: 1px solid var(--hair-strong); }
.faq summary {
  font-family: var(--sans); font-weight: 700; font-size: 0.98rem; cursor: pointer;
  padding: 0.9rem 0.2rem; list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 1rem;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--mono); color: var(--accent); font-size: 1.1rem; }
.faq details[open] summary::after { content: "−"; }
.faq details p { color: var(--muted); max-width: 66ch; padding: 0 0.2rem 1rem; }

/* ---------- footer ---------- */
.footer { margin-top: 4rem; border-top: 2.5px solid var(--ink); position: relative; }
.footer::before { content: ""; position: absolute; left: 0; right: 0; top: 3px; border-top: 1px solid var(--ink); }
.footer-grid {
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 2rem;
  padding: 2rem 0 1.4rem;
}
.footer h3 { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--agate); margin-bottom: 0.7rem; }
.footer ul { list-style: none; padding: 0; }
.footer li { margin: 0.35rem 0; }
.footer a { color: var(--ink); text-decoration: none; font-size: 0.9rem; }
.footer a:hover { color: var(--accent); text-decoration: underline; }
.footer-brand p { color: var(--muted); font-size: 0.9rem; max-width: 34ch; margin-top: 0.7rem; }
.hallmark {
  display: inline-flex; flex-direction: column; align-items: center; justify-content: center;
  width: 52px; height: 52px; border: 2px solid var(--ink); position: relative; text-decoration: none;
}
.hallmark::before { content: ""; position: absolute; inset: 2px; border: 1px solid var(--accent); }
.hallmark .sm { font-family: var(--display); font-weight: 900; font-size: 1.05rem; color: var(--ink); line-height: 1; position: relative; }
.hallmark .no { font-family: var(--mono); font-size: 0.5rem; letter-spacing: 0.08em; color: var(--muted); position: relative; }
.footer-house {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap;
  border-top: 1px solid var(--hair-strong); padding: 1rem 0 1.6rem;
}
.footer-house-left { display: flex; align-items: center; gap: 0.9rem; }
.house-code { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.12em; color: var(--muted); }
.attribution { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.attribution a { color: var(--accent); font-size: inherit; }
.copyline { font-family: var(--mono); font-size: 0.68rem; color: var(--agate); }

/* ---------- motion & a11y ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

/* ---------- responsive ---------- */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
  .shell { padding: 0 1rem; }
  .masthead-inner { flex-wrap: wrap; }
  .masthead-nav { gap: 0.9rem; }
  .dateline { flex-wrap: wrap; gap: 0.3rem; }
  .hero { padding-top: 1.8rem; }
  .tool-actions { width: 100%; }
  .act-btn { flex: 1 1 auto; padding: 0.45rem 0.5rem; font-size: 0.82rem; }
  .deck-grid { grid-template-columns: 1fr; }
  .stat { padding: 0.5rem 0.7rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.4rem; }
}

/* print: the tool is useless on paper, the text isn't */
@media print {
  .masthead, .deck, .tool-bar, .footer, .section { display: none; }
  .tool-input { border: none; background: none; }
}