/* ==========================================================================
   CodeStep Academy — Design Tokens
   Palette: deep teal (trust) + warm amber (CTA) on a soft paper background.
   Signature: mega-menu columns styled like binder tabs/dividers.
   ========================================================================== */
:root {
  --color-bg:        #F7F5EF;
  --color-surface:   #FFFFFF;
  --color-border:    #E4DFD2;
  --color-text:      #1B2A2A;
  --color-text-soft: #4A5854;
  --color-primary:   #0F3D3E;   /* deep teal */
  --color-primary-2: #17595B;
  --color-accent:    #E8A33D;   /* warm amber - CTAs */
  --color-accent-2:  #D68C1F;
  --color-tag-a:     #3E8E7E;   /* subject tag - science */
  --color-tag-b:     #7C4FB0;   /* subject tag - maths */
  --color-tag-c:     #A94A32;   /* subject tag - social science */
  --color-tag-d:     #3E8E2E;   /* subject tag - AI */
  --color-tag-e:     #7C4FD0;   /* subject tag - english */	
  --color-tag-f:     #7C4FD0;   /* subject tag - CS */	
  --color-tag-g:     #7C9FD0;   /* subject tag - IP */		

  --font-display: 'Fraunces', Georgia, serif;
  --font-body:    'Inter', system-ui, -apple-system, sans-serif;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --header-h: 68px;

  --shadow-card: 0 2px 10px rgba(15, 61, 62, 0.06);
  --shadow-hover: 0 8px 24px rgba(15, 61, 62, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

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

h1, h2, h3, .brand-text {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--color-primary);
  line-height: 1.2;
}

a { color: var(--color-primary-2); text-decoration: none; }
a:hover { color: var(--color-accent-2); }

.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--color-primary);
  color: #fff; padding: 10px 16px; z-index: 1000; border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

/* ---------------- Header / Sticky Nav ---------------- */
.site-header {
  position: sticky; top: 0; z-index: 500;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-h);
}
.header-inner {
  max-width: 1200px; margin: 0 auto; height: 100%;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 20px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: var(--radius-sm);
  background: var(--color-primary); color: #fff; font-family: var(--font-display);
  font-weight: 600;
}
.brand-text { font-size: 1.15rem; }
.brand-text em { font-style: normal; color: var(--color-accent-2); }

.main-nav .menu {
  list-style: none; display: flex; gap: 4px; margin: 0; padding: 0;
  align-items: center;
}
.main-nav .menu > li > a {
  display: block; padding: 10px 14px; border-radius: var(--radius-sm);
  color: var(--color-text); font-weight: 500; font-size: 0.95rem;
}
.main-nav .menu > li > a:hover { background: var(--color-bg); color: var(--color-primary); }
.caret { font-size: 0.7em; opacity: 0.6; }

.has-submenu { position: relative; }
.mega-menu {
  display: none;
  position: absolute; top: 100%; left: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: 3px solid var(--color-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) var(--radius-md);
  box-shadow: var(--shadow-hover);
  padding: 16px; gap: 24px; min-width: 380px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}
.has-submenu:hover .mega-menu,
.has-submenu.open .mega-menu { display: grid; }
.mega-col h4 {
  margin: 0 0 8px; font-size: 0.75rem; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--color-text-soft); font-family: var(--font-body);
  border-bottom: 2px solid var(--color-bg); padding-bottom: 6px;
}
.mega-col a { display: block; padding: 5px 0; font-size: 0.9rem; color: var(--color-text); }
.mega-col a:hover { color: var(--color-accent-2); padding-left: 4px; transition: padding .15s; }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer;
}
.nav-toggle span { width: 24px; height: 2px; background: var(--color-primary); }

/* ---------------- Layout ---------------- */
.site-main { max-width: 1200px; margin: 0 auto; padding: 32px 20px 64px; min-height: 60vh; }

/* ---------------- Hero ---------------- */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-2) 100%);
  color: #fff; border-radius: var(--radius-lg); padding: 56px 40px; margin-bottom: 40px;
  display: grid; grid-template-columns: 1.3fr 1fr; gap: 32px; align-items: center;
}
.hero h1 { color: #fff; font-size: 2.2rem; margin: 0 0 12px; }
.hero p { color: rgba(255,255,255,0.85); font-size: 1.05rem; max-width: 46ch; }
.hero-tabs { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-tabs a {
  background: rgba(255,255,255,0.12); color: #fff; padding: 8px 14px;
  border-radius: var(--radius-sm); font-size: 0.9rem; font-weight: 500;
}
.hero-tabs a:hover { background: var(--color-accent); color: var(--color-primary); }

.btn {
  display: inline-block; padding: 11px 22px; border-radius: var(--radius-sm);
  background: var(--color-accent); color: var(--color-primary); font-weight: 600;
  margin-top: 18px;
}
.btn:hover { background: var(--color-accent-2); color: #fff; }

/* ---------------- Cards ---------------- */
.section-title { display: flex; align-items: baseline; justify-content: space-between; margin: 40px 0 16px; }
.section-title a { font-size: 0.9rem; }

.card-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 18px;
}
.resource-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 18px; box-shadow: var(--shadow-card);
  transition: transform .15s, box-shadow .15s;
}
.resource-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.tag {
  display: inline-block; font-size: 0.72rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.04em; padding: 3px 9px; border-radius: 20px; color: #fff; margin-bottom: 10px;
}
.tag.science { background: var(--color-tag-a); }
.tag.mathematics { background: var(--color-tag-b); }
.tag.social-science { background: var(--color-tag-c); }
.tag.artificial-intelligence { background: var(--color-tag-d); }
.tag.english { background: var(--color-tag-e); }
.tag.computer-science { background: var(--color-tag-f); }
.tag.informatics-practices { background: var(--color-tag-g); }
.resource-card h3 { font-size: 1.05rem; margin: 0 0 8px; }
.resource-card p { font-size: 0.88rem; color: var(--color-text-soft); margin: 0 0 12px; }
.resource-card .card-link { font-size: 0.85rem; font-weight: 600; }

/* ---------------- Chapter-grouped listing (notes/worksheets/qa by subject) ---------------- */
.chapter-jumpnav {
  display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 32px;
  padding: 16px; background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}
.chapter-jumpnav a {
  font-size: 0.82rem; padding: 5px 12px; border-radius: 14px; background: var(--color-bg);
  color: var(--color-text); border: 1px solid var(--color-border);
}
.chapter-jumpnav a:hover { background: var(--color-accent); color: var(--color-primary); border-color: var(--color-accent); }

.chapter-section { margin-bottom: 32px; scroll-margin-top: 84px; }
.chapter-heading {
  font-size: 1.05rem; margin: 0 0 12px; padding-bottom: 8px; border-bottom: 2px solid var(--color-border);
}

.related-notes { margin-top: 48px; padding-top: 28px; border-top: 1px solid var(--color-border); max-width: 640px; }
.related-notes h2 { font-size: 1.1rem; margin: 0 0 14px; }

.lesson-list { display: flex; flex-direction: column; gap: 8px; }
.lesson-row {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  padding: 14px 18px; color: var(--color-text); transition: border-color .15s, transform .15s;
}
.lesson-row:hover { border-color: var(--color-accent); transform: translateX(2px); color: var(--color-text); }
.lesson-row-text { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.lesson-title { font-weight: 600; font-size: 0.95rem; }
.lesson-summary {
  font-size: 0.82rem; color: var(--color-text-soft);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 60ch;
}
.lesson-arrow { flex-shrink: 0; color: var(--color-accent-2); font-weight: 600; }

@media (max-width: 600px) {
  .lesson-summary { display: none; } /* keep rows to one line on small screens */
}

/* ---------------- Back to top button ---------------- */
.back-to-top {
  position: fixed; bottom: 24px; right: 24px; z-index: 400;
  width: 44px; height: 44px; border-radius: 50%; border: none;
  background: var(--color-primary); color: #fff; font-size: 1.2rem; cursor: pointer;
  box-shadow: var(--shadow-hover);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity .2s, transform .2s, visibility .2s, background .15s;
}
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--color-accent-2); }

@media (max-width: 600px) {
  .back-to-top { bottom: 16px; right: 16px; width: 40px; height: 40px; }
}

/* ---------------- Contact form ---------------- */
.contact-page { max-width: 640px; }
.contact-page h1 { margin-bottom: 8px; }

.form-success { background: #E6F4EA; color: #1E5C34; padding: 10px 14px; border-radius: var(--radius-sm); font-size: 0.9rem; margin: 16px 0; }
.form-error   { background: #FDECEA; color: #B3261E; padding: 10px 14px; border-radius: var(--radius-sm); font-size: 0.9rem; margin: 16px 0; }

.contact-form { margin-top: 20px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-row-3 { grid-template-columns: 1fr 1fr 1fr; }
.form-field { margin-bottom: 16px; }

.contact-form label {
  display: block; font-size: 0.82rem; font-weight: 600; margin: 0 0 6px; color: var(--color-text);
}
.contact-form input, .contact-form textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  font-family: var(--font-body); font-size: 0.92rem; background: var(--color-surface);
  transition: border-color .15s;
}
.contact-form input:focus, .contact-form textarea:focus {
  outline: none; border-color: var(--color-primary-2);
}
.contact-form input:invalid:not(:placeholder-shown) { border-color: #D68C1F; }
.contact-form textarea { min-height: 130px; resize: vertical; }
.contact-form button {
  padding: 11px 26px; border: none; border-radius: var(--radius-sm);
  background: var(--color-accent); color: var(--color-primary); font-weight: 600; cursor: pointer;
}
.contact-form button:hover { background: var(--color-accent-2); color: #fff; }
.contact-form .form-note { font-size: 0.78rem; color: var(--color-text-soft); margin-top: 10px; }

@media (max-width: 600px) {
  .form-row, .form-row-3 { grid-template-columns: 1fr; }
}

/* ---------------- Blog engagement: like / share / comments ---------------- */
.engage-bar {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px;
  margin-top: 32px; padding: 16px 20px; background: var(--color-surface);
  border: 1px solid var(--color-border); border-radius: var(--radius-md);
}
.like-btn {
  display: inline-flex; align-items: center; gap: 8px; background: var(--color-bg);
  border: 1px solid var(--color-border); border-radius: 20px; padding: 8px 16px;
  font-weight: 600; font-size: 0.9rem; cursor: pointer; color: var(--color-text);
  margin: 14px 0;
}
.like-btn:hover { border-color: var(--color-accent); }
.like-heart { font-size: 1.1rem; }
.share-links { display: flex; align-items: center; gap: 12px; font-size: 0.88rem; flex-wrap: wrap; }
.share-links span { color: var(--color-text-soft); }
.share-links a {
  padding: 5px 12px; border-radius: 16px; background: var(--color-bg); color: var(--color-text);
  border: 1px solid var(--color-border);
}
.share-links a:hover { background: var(--color-accent); color: var(--color-primary); border-color: var(--color-accent); }

.comments-section { margin-top: 40px; max-width: 640px; }
.comments-section h2 { font-size: 1.3rem; }

.comment-item {
  display: flex; gap: 14px; padding: 18px 0; border-bottom: 1px solid var(--color-border);
}
.comment-avatar {
  flex-shrink: 0; width: 40px; height: 40px; border-radius: 50%;
  background: var(--color-primary-2); color: #fff; display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display); font-weight: 600; font-size: 1rem;
}
.comment-body { flex: 1; }
.comment-item strong { color: var(--color-primary); font-size: 0.95rem; }
.comment-date { font-size: 0.78rem; color: var(--color-text-soft); margin-left: 8px; }
.comment-item p { margin: 6px 0 0; font-size: 0.92rem; line-height: 1.55; }

.comment-form-wrap {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 22px 24px; margin-top: 24px;
}
.comment-form-wrap h3 { font-size: 1rem; margin: 0 0 4px; }
.comment-form-wrap .hint { font-size: 0.82rem; color: var(--color-text-soft); margin: 0 0 16px; }

.comment-form label {
  display: block; font-size: 0.82rem; font-weight: 600; margin: 14px 0 6px; color: var(--color-text);
}
.comment-form input[type="text"], .comment-form textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  font-family: var(--font-body); font-size: 0.92rem; background: var(--color-bg);
  transition: border-color .15s;
}
.comment-form input[type="text"]:focus, .comment-form textarea:focus {
  outline: none; border-color: var(--color-primary-2); background: #fff;
}
.comment-form textarea { min-height: 100px; resize: vertical; }
.comment-form button {
  margin-top: 16px; padding: 10px 24px; border: none; border-radius: var(--radius-sm);
  background: var(--color-accent); color: var(--color-primary); font-weight: 600; cursor: pointer;
}
.comment-form button:hover { background: var(--color-accent-2); color: #fff; }
.comment-form .form-note { font-size: 0.78rem; color: var(--color-text-soft); margin-top: 10px; }
.comment-honeypot { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

/* ---------------- Footer ---------------- */
.site-footer { background: var(--color-primary); color: rgba(255,255,255,0.85); margin-top: 60px; }
.footer-inner {
  max-width: 1200px; margin: 0 auto; padding: 40px 20px;
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 24px;
}
.footer-col .footer-heading { color: #fff; margin: 0 0 10px; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; font-weight: 700; }
.footer-col a { display: block; color: rgba(255,255,255,0.75); padding: 3px 0; font-size: 0.9rem; }
.footer-col a:hover { color: var(--color-accent); }
.footer-bottom { text-align: center; padding: 16px; border-top: 1px solid rgba(255,255,255,0.12); font-size: 0.8rem; }

/* ---------------- Responsive ---------------- */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; padding: 36px 24px; }
}

@media (max-width: 760px) {
  .nav-toggle { display: flex; }
  .main-nav {
    position: fixed; top: var(--header-h); left: 0; right: 0; bottom: 0;
    background: var(--color-surface); transform: translateX(100%);
    transition: transform .25s ease; overflow-y: auto; padding: 12px;
  }
  .main-nav.open { transform: translateX(0); }
  .main-nav .menu { flex-direction: column; align-items: stretch; gap: 0; }
  .main-nav .menu > li { border-bottom: 1px solid var(--color-border); }
  .mega-menu {
    display: none; position: static; border: none; box-shadow: none;
    grid-template-columns: 1fr; padding: 4px 0 12px 12px;
  }
  .has-submenu.open .mega-menu { display: grid; }
  .footer-inner { grid-template-columns: 1fr; }
}

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







/* ---------------- AdSense Ad Slots ---------------- */
.ad-slot {
  margin: 32px 0;
  padding: 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-align: center;
  overflow: hidden;
  min-height: 100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.ad-slot::before {
  content: "Advertisement";
  display: block;
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-soft);
  margin-bottom: 10px;
}

.ad-slot.ad-top    { margin-top: 20px; }
.ad-slot.ad-mid     { margin: 40px 0; border-color: var(--color-accent); border-style: dashed; }
.ad-slot.ad-bottom { margin-bottom: 36px; }
.ad-slot.ad-listing { max-width: 1200px; margin: 0 auto 32px; }

@media (max-width: 600px) {
  .ad-slot { padding: 12px; margin: 24px 0; }
}