/* ==========================================================================
   Pro Calculator AI — frontend
   "Precision instrument" aesthetic: Space Grotesk display, Inter body,
   JetBrains Mono for figures. Electric ink blue + teal. Light/dark.
   ========================================================================== */

:root {
  --ink:        #0b1220;
  --ink-soft:   #1b2536;
  --paper:      #ffffff;
  --surface:    #f5f7fb;
  --surface-2:  #eef1f7;
  --line:       #dfe4ee;
  --muted:      #5b6678;
  --text:       #18202e;

  --brand:      #1d4ed8;   /* electric ink blue */
  --brand-ink:  #1640b0;
  --accent:     #0d9488;   /* teal */
  --accent-soft:#d6f3ee;

  --danger:     #c0392b;
  --ok:         #15803d;

  --radius:     14px;
  --radius-sm:  9px;
  --shadow:     0 1px 2px rgba(16,24,40,.06), 0 8px 24px -12px rgba(16,24,40,.18);
  --shadow-sm:  0 1px 2px rgba(16,24,40,.08);

  --wrap:       1120px;
  --gap:        clamp(1rem, 3vw, 2rem);

  --font-display: "Space Grotesk", system-ui, sans-serif;
  --font-body:    "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  --font-mono:    "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

[data-theme="dark"] {
  --ink:        #e8edf6;
  --ink-soft:   #c3ccda;
  --paper:      #0d1320;
  --surface:    #121a29;
  --surface-2:  #18202f;
  --line:       #26303f;
  --muted:      #8a96a8;
  --text:       #e8edf6;

  --brand:      #5b8bff;
  --brand-ink:  #7aa2ff;
  --accent:     #2dd4bf;
  --accent-soft:#0f2e2b;

  --shadow:     0 1px 2px rgba(0,0,0,.4), 0 12px 32px -14px rgba(0,0,0,.6);
  --shadow-sm:  0 1px 2px rgba(0,0,0,.4);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.15; color: var(--ink); }

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

.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gap); }

.muted { color: var(--muted); }
.small { font-size: .85rem; }
.accent { color: var(--accent); }

:focus-visible { outline: 3px solid var(--brand); outline-offset: 2px; border-radius: 4px; }

.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--brand); color: #fff;
  padding: .6rem 1rem; border-radius: 0 0 var(--radius-sm) 0; z-index: 100;
}
.skip-link:focus { left: 0; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 40;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 1.5rem; min-height: 64px; }
.brand { display: inline-flex; align-items: center; }
.brand-mark { display: block; height: 32px; width: auto; }
.logo-dark { display: none; }
[data-theme="dark"] .logo-light { display: none; }
[data-theme="dark"] .logo-dark { display: block; }

.site-nav { display: flex; align-items: center; gap: 1.25rem; margin-left: auto; }
.site-nav > a { color: var(--ink-soft); font-weight: 500; }
.nav-search { display: flex; align-items: center; background: var(--surface); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.nav-search input { border: 0; background: transparent; padding: .5rem .9rem; font: inherit; color: var(--text); width: 200px; }
.nav-search input:focus { outline: none; }
.nav-search button { border: 0; background: transparent; padding: 0 .8rem; color: var(--muted); cursor: pointer; font-size: 1.1rem; }

.theme-toggle {
  border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  width: 38px; height: 38px; border-radius: 50%; cursor: pointer; font-size: 1.05rem;
}
.theme-toggle:hover { border-color: var(--brand); }

/* ---------- hero ---------- */
.hero { padding: clamp(2.5rem, 7vw, 5rem) 0 clamp(1.5rem, 4vw, 3rem); text-align: center; }
.eyebrow { font-family: var(--font-mono); font-size: .8rem; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin: 0 0 .5rem; }
.hero-title { font-size: clamp(2.2rem, 6vw, 3.6rem); font-weight: 700; margin: 0 0 1rem; letter-spacing: -.02em; }
.hero-sub { max-width: 60ch; margin: 0 auto 2rem; color: var(--muted); font-size: 1.1rem; }
.hero-search { display: flex; gap: .5rem; max-width: 540px; margin: 0 auto; }
.hero-search input { flex: 1; padding: .9rem 1.1rem; border: 1px solid var(--line); border-radius: var(--radius-sm); font: inherit; background: var(--paper); color: var(--text); }
.hero-search button { padding: .9rem 1.5rem; border: 0; border-radius: var(--radius-sm); background: var(--brand); color: #fff; font-weight: 600; cursor: pointer; }
.hero-search button:hover { background: var(--brand-ink); }

/* ---------- blocks & grids ---------- */
.block { margin: clamp(2rem, 5vw, 3.5rem) 0; }
.block-title { font-size: 1.35rem; margin: 0 0 1.1rem; }
.page-head { margin: 2rem 0 1.5rem; }
.page-head h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); margin: .2rem 0; }

.card-grid { list-style: none; margin: 0; padding: 0; display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
.post-grid { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.25rem; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

.calc-card, .hub-card {
  display: flex; flex-direction: column; gap: .35rem; height: 100%;
  padding: 1.1rem 1.2rem; background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); color: var(--ink); text-decoration: none; transition: transform .12s, border-color .12s, box-shadow .12s;
}
.calc-card:hover, .hub-card:hover { transform: translateY(-2px); border-color: var(--brand); box-shadow: var(--shadow); text-decoration: none; }
.calc-card-name, .hub-card-name { font-family: var(--font-display); font-weight: 600; font-size: 1.05rem; }
.calc-card-meta, .hub-card-meta { font-family: var(--font-mono); font-size: .8rem; color: var(--muted); }
.hub-card { background: linear-gradient(180deg, var(--surface), var(--surface-2)); }

.post-card {
  display: block; height: 100%; padding: 1.3rem 1.4rem; background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius); color: var(--ink); transition: border-color .12s, box-shadow .12s;
}
.post-card:hover { border-color: var(--brand); box-shadow: var(--shadow); text-decoration: none; }
.post-card h3 { margin: 0 0 .5rem; font-size: 1.15rem; }

/* ---------- breadcrumbs ---------- */
.breadcrumbs { margin: 1.25rem 0 .5rem; font-size: .85rem; }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: .35rem; margin: 0; padding: 0; }
.breadcrumbs .sep { color: var(--muted); margin-left: .35rem; }
.breadcrumbs [aria-current="page"] { color: var(--muted); }

/* ---------- calculator page ---------- */
.calc-page { max-width: 820px; margin: 0 auto; padding-bottom: 3rem; }
.calc-head { margin: .5rem 0 1.5rem; }
.calc-head h1 { font-size: clamp(1.9rem, 4.5vw, 2.8rem); margin: .25rem 0 0; letter-spacing: -.02em; }

.calc-tool {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: clamp(1.25rem, 3vw, 2rem); margin-bottom: 2.5rem; box-shadow: var(--shadow-sm);
}
.pca-calculator { font-family: var(--font-body); }
/* sensible defaults for admin-authored tools that ship no CSS */
.pca-calculator input:not([type=checkbox]):not([type=radio]):not([type=submit]),
.pca-calculator select, .pca-calculator textarea {
  font: inherit; padding: .6rem .75rem; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--paper); color: var(--text); max-width: 100%;
}
.pca-calculator button {
  font: inherit; font-weight: 600; cursor: pointer; padding: .6rem 1.1rem; border: 0;
  border-radius: var(--radius-sm); background: var(--brand); color: #fff;
}
.pca-calculator button:hover { background: var(--brand-ink); }
.pca-calculator label { font-weight: 500; }

/* article body — content rendered exactly as entered */
.article-body { font-size: 1.06rem; }
.article-body h2 { font-size: 1.6rem; margin: 2rem 0 .8rem; }
.article-body h3 { font-size: 1.25rem; margin: 1.6rem 0 .6rem; }
.article-body p { margin: 0 0 1.1rem; }
.article-body ul, .article-body ol { margin: 0 0 1.1rem 1.3rem; }
.article-body li { margin: .3rem 0; }
.article-body img { max-width: 100%; height: auto; border-radius: var(--radius-sm); }
.article-body table { width: 100%; border-collapse: collapse; margin: 1.2rem 0; font-size: .95rem; }
.article-body th, .article-body td { border: 1px solid var(--line); padding: .6rem .75rem; text-align: left; }
.article-body th { background: var(--surface); }
.article-body code { font-family: var(--font-mono); background: var(--surface-2); padding: .1em .4em; border-radius: 5px; font-size: .9em; }
.article-body pre { background: var(--ink); color: #e8edf6; padding: 1rem; border-radius: var(--radius-sm); overflow: auto; }
.article-body blockquote { margin: 1.2rem 0; padding: .5rem 1.1rem; border-left: 3px solid var(--accent); color: var(--muted); }

/* ---------- FAQ accordion ---------- */
.faqs { margin: 2.5rem 0; }
.faqs h2 { font-size: 1.5rem; margin: 0 0 1rem; }
.accordion { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.accordion-item { border-bottom: 1px solid var(--line); }
.accordion-item:last-child { border-bottom: 0; }
.accordion-item summary {
  cursor: pointer; padding: 1rem 1.2rem; font-weight: 600; font-family: var(--font-display);
  list-style: none; display: flex; justify-content: space-between; align-items: center; background: var(--surface);
}
.accordion-item summary::-webkit-details-marker { display: none; }
.accordion-item summary::after { content: "+"; color: var(--brand); font-size: 1.3rem; line-height: 1; }
.accordion-item[open] summary::after { content: "–"; }
.accordion-body { padding: .5rem 1.2rem 1.2rem; }
.accordion-body > :first-child { margin-top: 0; }

/* ---------- related ---------- */
.related { margin: 2.5rem 0; }
.related h2 { font-size: 1.4rem; margin: 0 0 1rem; }
.mini-card {
  display: block; padding: .85rem 1rem; background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); color: var(--ink); font-weight: 500;
}
.mini-card:hover { border-color: var(--brand); text-decoration: none; }

/* ---------- article (blog) ---------- */
.post { max-width: 760px; margin: 0 auto; padding-bottom: 3rem; }
.post-head h1 { font-size: clamp(2rem, 5vw, 3rem); margin: .3rem 0 .6rem; letter-spacing: -.02em; }
.post-meta { font-family: var(--font-mono); font-size: .82rem; color: var(--muted); }
.post-cover { width: 100%; height: auto; border-radius: var(--radius); margin: 1.5rem 0; }

/* ---------- search / tags ---------- */
.tag { display: inline-block; font-family: var(--font-mono); font-size: .78rem; background: var(--accent-soft); color: var(--accent); padding: .15rem .55rem; border-radius: 999px; }

/* ---------- sitemap ---------- */
.link-list { columns: 2 240px; gap: 2rem; list-style: none; padding: 0; }
.link-list li { margin: .3rem 0; break-inside: avoid; }

/* ---------- pagination ---------- */
.pagination { display: flex; gap: .4rem; justify-content: center; margin: 2.5rem 0; list-style: none; padding: 0; }
.pagination a, .pagination span { display: inline-flex; min-width: 40px; height: 40px; align-items: center; justify-content: center; border: 1px solid var(--line); border-radius: var(--radius-sm); color: var(--ink); font-family: var(--font-mono); font-size: .9rem; }
.pagination .is-active { background: var(--brand); color: #fff; border-color: var(--brand); }

/* ---------- flash ---------- */
.flash { padding: .8rem 1.1rem; border-radius: var(--radius-sm); margin: 1rem 0; border: 1px solid var(--line); }
.flash--success { background: color-mix(in srgb, var(--ok) 12%, var(--paper)); border-color: var(--ok); }
.flash--error { background: color-mix(in srgb, var(--danger) 12%, var(--paper)); border-color: var(--danger); }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); margin-top: 4rem; padding: 2.5rem 0; background: var(--surface); }
.footer-inner { display: grid; gap: 1.25rem; grid-template-columns: 1fr auto; align-items: start; }
.footer-inner nav { display: flex; gap: 1.25rem; }
.footer-inner nav a { color: var(--ink-soft); }
.footer-inner p { margin: .3rem 0 0; }
.footer-inner .small { grid-column: 1 / -1; }

/* ---------- responsive ---------- */
@media (max-width: 720px) {
  .nav-search { display: none; }
  .footer-inner { grid-template-columns: 1fr; }
  .link-list { columns: 1; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}