/* ──────────────────────────────────────────────────────────────────────────
   Calm Maths blog — the only stylesheet the /blog pages load.

   Blog pages are plain static HTML with no app bundle (see data/blog/posts.mjs
   for why), so they cannot use the CSS-module pipeline or global.css. The
   tokens below are copied from src/styles/global.css deliberately — if the
   brand palette changes there, mirror it here. Prefix: .bl-
   ────────────────────────────────────────────────────────────────────────── */

:root {
  --sm-bg: #f6f3ff;
  --sm-bg-2: #efeff6;
  --sm-card: #ffffff;
  --sm-line: #e1ddf0;
  --sm-ink: #26243e;
  --sm-ink-2: #6e7191;
  --sm-ink-3: #8a8aa3;
  --sm-primary: #0e9f4e;
  --sm-primary-deep: #0b7a3c;
  --sm-accent: #7a5af8;
  --sm-accent-2: #5b3fd4;
  --sm-accent-soft: #ece6fe;
  --sm-shadow-card: 0 14px 40px rgba(46, 42, 77, 0.1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: "Nunito", system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--sm-ink);
  background: var(--sm-bg);
  line-height: 1.65;
  font-size: 18px;
}

.bl-wrap {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ── header ──────────────────────────────────────────────────────────────── */

.bl-header {
  border-bottom: 1px solid var(--sm-line);
  background: var(--sm-card);
}
.bl-header-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.bl-logo {
  font-weight: 900;
  font-size: 21px;
  letter-spacing: -0.02em;
  text-decoration: none;
}
.bl-logo-smart {
  color: var(--sm-accent-2);
}
.bl-logo-maths {
  color: var(--sm-primary);
}
.bl-header-cta {
  display: inline-block;
  background: var(--sm-primary);
  color: #fff;
  font-weight: 800;
  font-size: 15px;
  text-decoration: none;
  padding: 9px 18px;
  border-radius: 14px;
  box-shadow: 0 3px 0 var(--sm-primary-deep);
}
.bl-header-cta:hover {
  background: var(--sm-primary-deep);
}

/* ── article ─────────────────────────────────────────────────────────────── */

.bl-article {
  padding: 40px 0 8px;
}
.bl-eyebrow {
  font-size: 13.5px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--sm-accent-2);
  margin: 0 0 10px;
}
.bl-article h1 {
  font-size: clamp(28px, 5.4vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
}
.bl-meta {
  color: var(--sm-ink-3);
  font-size: 14.5px;
  margin: 0 0 28px;
}
.bl-article h2 {
  font-size: clamp(21px, 3.4vw, 26px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 38px 0 12px;
}
.bl-article h3 {
  font-size: 18.5px;
  margin: 26px 0 6px;
}
.bl-article p {
  margin: 0 0 18px;
}
.bl-article ul {
  margin: 0 0 18px;
  padding-left: 22px;
}
.bl-article li {
  margin-bottom: 9px;
}
.bl-article a {
  color: var(--sm-accent-2);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.bl-article a:hover {
  color: var(--sm-accent);
}

/* ── figures ─────────────────────────────────────────────────────────────── */

.bl-fig {
  margin: 26px 0 28px;
}
.bl-fig img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--sm-line);
  background: var(--sm-card);
}
.bl-fig figcaption {
  margin-top: 9px;
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--sm-ink-2);
}

/* ── FAQ ─────────────────────────────────────────────────────────────────── */

.bl-faq h3 {
  margin-bottom: 4px;
}

/* ── related + footer ────────────────────────────────────────────────────── */

.bl-related {
  margin: 44px 0 0;
  padding: 22px 24px;
  background: var(--sm-card);
  border: 1px solid var(--sm-line);
  border-radius: 18px;
  box-shadow: var(--sm-shadow-card);
}
.bl-related h2 {
  font-size: 18px;
  margin: 0 0 12px;
}
.bl-related ul {
  margin: 0;
  padding-left: 20px;
}

.bl-footer {
  margin-top: 48px;
  padding: 28px 0 40px;
  border-top: 1px solid var(--sm-line);
  font-size: 15px;
  color: var(--sm-ink-2);
}
.bl-footer a {
  color: var(--sm-accent-2);
}
.bl-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin: 0 0 14px;
  padding: 0;
  list-style: none;
}

/* ── index page ──────────────────────────────────────────────────────────── */

.bl-index-head {
  padding: 44px 0 8px;
}
.bl-index-head h1 {
  font-size: clamp(30px, 6vw, 42px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}
.bl-index-head p {
  font-size: 18.5px;
  color: var(--sm-ink-2);
  margin: 0;
}
.bl-cards {
  display: grid;
  gap: 16px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}
.bl-card {
  background: var(--sm-card);
  border: 1px solid var(--sm-line);
  border-radius: 18px;
  padding: 22px 24px;
  box-shadow: var(--sm-shadow-card);
}
.bl-card h2 {
  font-size: 20px;
  line-height: 1.3;
  margin: 0 0 8px;
}
.bl-card h2 a {
  color: var(--sm-ink);
  text-decoration: none;
}
.bl-card h2 a:hover {
  color: var(--sm-accent-2);
  text-decoration: underline;
}
.bl-card p {
  margin: 0 0 10px;
  color: var(--sm-ink-2);
  font-size: 16px;
}
.bl-tag {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--sm-accent-2);
  background: var(--sm-accent-soft);
  border-radius: 999px;
  padding: 4px 11px;
}

@media (max-width: 520px) {
  body {
    font-size: 17px;
  }
  .bl-related,
  .bl-card {
    padding: 18px 18px;
  }
}