/* ==========================================================================
   KidsMathLogic.org — School (chalkboard & notebook) theme
   ========================================================================== */

:root {
  --chalkboard: #2f5d46;
  --chalkboard-dark: #234a37;
  --chalk: #f7f4e9;
  --paper: #fbf7ee;
  --paper-line: #efe7d3;
  --ink: #2b2b2b;
  --muted: #6f675a;
  --yellow: #ffd166;
  --yellow-deep: #f4b942;
  --red: #ef476f;
  --blue: #118ab2;
  --green: #06a77d;
  --orange: #f78c6b;
  --purple: #8e7cc3;
  --shadow-sm: 0 3px 10px rgba(43, 43, 43, 0.08);
  --shadow: 0 8px 22px rgba(43, 43, 43, 0.1);
  --radius: 18px;
  --radius-sm: 12px;
  --font-head: "Baloo 2", "Comic Sans MS", system-ui, sans-serif;
  --font-body: "Nunito", "Segoe UI", system-ui, sans-serif;
  --font-hand: "Patrick Hand", "Comic Sans MS", cursive;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.55), rgba(255, 255, 255, 0.55)),
    repeating-linear-gradient(0deg, transparent, transparent 27px, var(--paper-line) 27px, var(--paper-line) 28px);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.2; margin: 0 0 0.5em; color: var(--chalkboard-dark); }
p { margin: 0 0 1em; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }

.container { width: min(1180px, 100% - 2.5rem); margin-inline: auto; }
.container-narrow { width: min(820px, 100% - 2.5rem); margin-inline: auto; }

/* Skip link */
.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--yellow); color: var(--ink);
  padding: 0.6rem 1rem; border-radius: 0 0 var(--radius-sm) 0;
  z-index: 100; font-weight: 700;
}
.skip-link:focus { left: 0; }

/* Header (chalkboard) */
.site-header {
  background: var(--chalkboard);
  background-image:
    radial-gradient(circle at 20% 10%, rgba(255,255,255,0.06), transparent 40%),
    linear-gradient(180deg, var(--chalkboard), var(--chalkboard-dark));
  color: var(--chalk);
  border-bottom: 5px solid var(--yellow);
  box-shadow: var(--shadow);
  position: sticky; top: 0; z-index: 50;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; padding: 0.85rem 0; }
.brand { display: flex; align-items: center; gap: 0.7rem; color: var(--chalk); text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand-icon { font-size: 2rem; filter: drop-shadow(0 2px 2px rgba(0,0,0,0.25)); }
.brand-title { font-family: var(--font-head); font-weight: 800; font-size: 1.35rem; line-height: 1.1; display: block; }
.brand-tag { font-family: var(--font-hand); font-size: 0.95rem; opacity: 0.9; display: block; }
.site-nav { display: flex; align-items: center; gap: 0.35rem; flex-wrap: wrap; }
.nav-link {
  color: var(--chalk); padding: 0.45rem 0.85rem; border-radius: 999px;
  font-weight: 700; font-size: 0.95rem; border: 2px dashed rgba(255,255,255,0.35);
}
.nav-link:hover { background: rgba(255,255,255,0.12); text-decoration: none; border-color: var(--yellow); color: var(--yellow); }

/* Hero */
.hero {
  background: linear-gradient(135deg, #fff6df, #ffefc9);
  border-bottom: 4px dashed var(--yellow-deep);
  padding: 3.5rem 0 3rem; text-align: center;
}
.hero-title { font-size: clamp(1.9rem, 4.5vw, 3.2rem); font-weight: 800; color: var(--chalkboard-dark); }
.hero-title .highlight {
  color: var(--red); font-family: var(--font-hand);
  background: var(--yellow); padding: 0 0.35rem; border-radius: 8px; transform: rotate(-2deg); display: inline-block;
}
.hero-sub { max-width: 640px; margin: 0 auto 1.5rem; color: var(--muted); font-size: 1.1rem; }
.hero-badges { display: flex; gap: 0.6rem; justify-content: center; flex-wrap: wrap; }
.hero-badges span {
  background: #fff; border: 2px solid var(--yellow-deep); border-radius: 999px;
  padding: 0.4rem 0.95rem; font-weight: 800; font-size: 0.9rem; box-shadow: var(--shadow-sm);
}

/* Section */
.section { padding: 2.75rem 0; }
.section-title { font-size: 1.7rem; margin-bottom: 1.4rem; }
.section-title span {
  background: var(--yellow); padding: 0.1rem 0.8rem; border-radius: 10px;
  box-shadow: 3px 3px 0 var(--chalkboard);
  display: inline-block; transform: rotate(-1deg);
}

/* Category grid */
.category-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 1rem; }
.category-card {
  background: #fff; border: 2px solid var(--paper-line); border-radius: var(--radius);
  padding: 1.2rem 1.3rem; box-shadow: var(--shadow-sm); color: var(--ink);
  display: flex; flex-direction: column; gap: 0.2rem; transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.category-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--yellow-deep); text-decoration: none; }
.category-emoji { font-size: 2rem; }
.category-name { font-family: var(--font-head); font-weight: 700; font-size: 1.08rem; line-height: 1.25; }
.category-count { color: var(--muted); font-size: 0.9rem; font-weight: 600; }

/* Post grid & cards */
.post-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 1.4rem; }
.post-card { background: #fff; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); border: 2px solid var(--paper-line); transition: transform 0.15s ease, box-shadow 0.15s ease; }
.post-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.post-card-link { color: inherit; display: block; }
.post-card-link:hover { text-decoration: none; }
.post-card-media { aspect-ratio: 16 / 9; background: #f4ead0; display: grid; place-items: center; overflow: hidden; }
.post-card-media img { width: 100%; height: 100%; object-fit: cover; }
.post-card-emoji { font-size: 3.4rem; }
.post-card-body { padding: 1.1rem 1.2rem 1.25rem; }
.post-card-badges { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 0.5rem; }
.badge {
  background: var(--yellow); color: var(--ink); border-radius: 999px;
  padding: 0.15rem 0.7rem; font-size: 0.78rem; font-weight: 800; display: inline-block;
}

.post-card-title { font-size: 1.15rem; font-weight: 700; line-height: 1.3; margin-bottom: 0.35rem; }
.post-card-desc { color: var(--muted); font-size: 0.92rem; margin-bottom: 0.75rem; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.post-card-meta { color: var(--muted); font-size: 0.82rem; font-weight: 600; }

.view-all { text-align: center; margin-top: 1.75rem; }

.btn {
  display: inline-block; background: var(--chalkboard); color: var(--chalk);
  padding: 0.7rem 1.4rem; border-radius: 999px; font-weight: 800; font-family: var(--font-head);
  box-shadow: 3px 3px 0 var(--yellow-deep); transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.btn:hover { transform: translate(-1px, -1px); box-shadow: 4px 4px 0 var(--yellow-deep); text-decoration: none; }
.btn-outline { background: #fff; color: var(--chalkboard); border: 2px solid var(--chalkboard); box-shadow: 3px 3px 0 var(--chalkboard); }

/* Page header (list / taxonomy / term) */
.page-header { background: #fff; border-bottom: 2px dashed var(--paper-line); padding: 2.4rem 0 2rem; text-align: center; }
.page-title { font-size: clamp(1.7rem, 4vw, 2.5rem); font-weight: 800; }
.page-desc { color: var(--muted); max-width: 620px; margin: 0 auto; font-size: 1.05rem; }
.page-content { max-width: 720px; margin: 1.2rem auto 0; text-align: left; }
.term-emoji { font-size: 3rem; display: block; margin-bottom: 0.2rem; }

/* Single post */
.post-header { background: #fff; border-bottom: 2px dashed var(--paper-line); padding: 2.4rem 0 2rem; text-align: center; }
.post-badges { display: flex; justify-content: center; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 0.8rem; }
.post-title { font-size: clamp(1.7rem, 4.5vw, 2.6rem); font-weight: 800; }
.post-desc { color: var(--muted); max-width: 680px; margin: 0 auto 0.9rem; }
.post-meta { color: var(--muted); font-weight: 600; font-size: 0.95rem; display: flex; gap: 0.6rem; justify-content: center; flex-wrap: wrap; }
.meta-dot { opacity: 0.5; }

.featured { margin: 1.75rem 0 0; }
.featured img { width: 100%; border-radius: var(--radius); box-shadow: var(--shadow); }

.post-layout { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: 2.5rem; align-items: start; padding: 2.5rem 0; }
.post-body { background: #fff; border: 2px solid var(--paper-line); border-radius: var(--radius); padding: 2rem clamp(1.2rem, 4vw, 2.5rem); box-shadow: var(--shadow-sm); }
.post-body h2 { margin-top: 1.6em; font-size: 1.6rem; }
.post-body h3 { font-size: 1.25rem; margin-top: 1.4em; }
.post-body ul, .post-body ol { padding-left: 1.4rem; }
.post-body blockquote {
  margin: 1.2rem 0; padding: 0.5rem 1.2rem; background: #fff6df;
  border-left: 5px solid var(--yellow-deep); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* Table of contents */
.toc { position: sticky; top: 90px; background: #fff; border: 2px solid var(--paper-line); border-radius: var(--radius-sm); padding: 1.1rem 1.2rem; box-shadow: var(--shadow-sm); font-size: 0.92rem; }
.toc-title { font-family: var(--font-head); font-weight: 800; margin-bottom: 0.5rem; color: var(--chalkboard-dark); }
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc ul ul { padding-left: 1rem; margin-top: 0.25rem; }
.toc li { margin: 0.25rem 0; }
.toc a { color: var(--ink); }

/* FAQ */
.faq { margin-top: 2.5rem; border-top: 3px dashed var(--yellow-deep); padding-top: 1.5rem; }
.faq-title { font-size: 1.5rem; }
.faq-item { border: 2px solid var(--paper-line); border-radius: var(--radius-sm); margin-bottom: 0.7rem; background: #fffdf6; overflow: hidden; }
.faq-item summary {
  cursor: pointer; padding: 0.9rem 1.1rem; font-weight: 800; font-family: var(--font-head);
  color: var(--chalkboard-dark); list-style: none; position: relative; padding-right: 2.4rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; position: absolute; right: 1rem; top: 0.65rem; font-size: 1.4rem; color: var(--red); }
.faq-item[open] summary::after { content: "–"; }
.faq-answer { padding: 0 1.1rem 1rem; color: var(--muted); }

/* Post nav */
.post-nav { display: flex; gap: 1rem; justify-content: space-between; padding: 0 0 3rem; flex-wrap: wrap; }
.post-nav-link { background: #fff; border: 2px solid var(--paper-line); border-radius: var(--radius-sm); padding: 0.7rem 1rem; font-weight: 700; color: var(--ink); max-width: 46%; }
.post-nav-next { text-align: right; margin-left: auto; }

/* Footer */
.site-footer { background: var(--chalkboard-dark); color: var(--chalk); margin-top: 2rem; border-top: 5px solid var(--yellow); }
.footer-inner { display: flex; justify-content: space-between; gap: 1.5rem; flex-wrap: wrap; padding: 2.25rem 0 1.5rem; }
.footer-brand { display: flex; gap: 0.7rem; align-items: flex-start; max-width: 460px; }
.footer-icon { font-size: 2rem; }
.footer-title { font-family: var(--font-head); font-weight: 800; font-size: 1.2rem; }
.footer-tag { opacity: 0.85; font-size: 0.92rem; margin: 0.2rem 0 0; }
.footer-nav { display: flex; gap: 1.1rem; align-items: center; flex-wrap: wrap; }
.footer-nav a { color: var(--chalk); font-weight: 700; }
.footer-nav a:hover { color: var(--yellow); }
.footer-bottom { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; border-top: 1px solid rgba(255,255,255,0.18); padding: 1rem 0 1.2rem; font-size: 0.88rem; opacity: 0.85; }
.footer-bottom p { margin: 0; }
.footer-bottom a { color: var(--yellow); }

/* 404 */
.notfound { padding: 4.5rem 0 5rem; text-align: center; }
.notfound-inner { max-width: 640px; }
.notfound-chalk {
  font-family: var(--font-hand); font-size: 7rem; line-height: 1; color: var(--chalk);
  background: var(--chalkboard); border-radius: var(--radius); display: inline-block;
  padding: 0.4rem 1.6rem; box-shadow: 6px 6px 0 var(--yellow-deep); transform: rotate(-2deg);
}
.notfound-zero { color: var(--yellow); }
.notfound-title { font-size: 1.9rem; margin: 1.4rem 0 0.5rem; }
.notfound-desc { color: var(--muted); font-size: 1.05rem; }
.notfound-actions { display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; margin-top: 1.5rem; }

/* Responsive */
@media (max-width: 860px) {
  .post-layout { grid-template-columns: 1fr; }
  .toc { position: static; order: -1; }
}

@media (max-width: 560px) {
  .header-inner { justify-content: center; text-align: center; }
  .post-nav-link { max-width: 100%; }
  .post-nav-next { margin-left: 0; }
}

@media print {
  .site-header, .site-footer, .toc, .post-nav, .hero-badges { display: none; }
  body { background: #fff; }
}