/* ==========================================================================
   Smart21Code — W3Schools-style "learn to code" section
   Reuses site design tokens (--s21-*, --radius-*, --ease) so it matches
   light/dark theme automatically.
   ========================================================================== */

.s21code-section {
  position: relative;
  isolation: isolate;
  background-color: #10201a;
  /* Unsplash photo (code on a screen) + dark green overlay for readability */
  background-image:
    linear-gradient(90deg, rgba(10,24,18,.92) 0%, rgba(10,24,18,.78) 55%, rgba(10,24,18,.6) 100%),
    url('https://images.unsplash.com/photo-1461749280684-dccba630e2f6?w=1800&q=75&auto=format&fit=crop');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  border-top: 1px solid var(--s21-border);
  border-bottom: 1px solid var(--s21-border);
}

/* Light text on the photo, in both light and dark theme */
.s21code-section .s21code-head h2 { color: #fff; }
.s21code-section .s21code-head p,
.s21code-section .s21code-head .text-soft { color: rgba(255,255,255,.82) !important; }
.s21code-section .s21code-head .btn-s21-outline {
  color: #fff;
  border-color: rgba(255,255,255,.45);
  background: rgba(255,255,255,.08);
  backdrop-filter: blur(4px);
}
.s21code-section .s21code-head .btn-s21-outline:hover {
  background: rgba(255,255,255,.18);
}

.s21code-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.s21code-head h2 {
  font-family: var(--font-display);
  font-weight: 800;
  margin-bottom: .35rem;
}

/* ---- language tabs ---- */
.s21code-lang-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1.25rem;
}

.s21code-lang-tab {
  --lang-color: var(--s21-primary);
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .55rem 1rem;
  border-radius: var(--radius-pill);
  border: 1.5px solid var(--s21-border);
  background: var(--s21-white);
  color: var(--s21-text);
  font-weight: 700;
  font-size: .88rem;
  cursor: pointer;
  transition: all .2s var(--ease);
}
.s21code-lang-tab i { color: var(--lang-color); }
.s21code-lang-tab:hover {
  border-color: var(--lang-color);
  transform: translateY(-2px);
}
.s21code-lang-tab.active {
  background: color-mix(in srgb, var(--lang-color) 14%, transparent);
  border-color: var(--lang-color);
  color: var(--lang-color);
}

/* ---- layout: sidebar + lesson ---- */
.s21code-body {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 1.5rem;
  align-items: start;
}
@media (max-width: 991px) {
  .s21code-body { grid-template-columns: 1fr; }
}

.s21code-sidebar {
  background: var(--s21-bg);
  border: 1px solid var(--s21-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  position: sticky;
  top: 90px;
  max-height: 70vh;
  overflow-y: auto;
}
@media (max-width: 991px) {
  .s21code-sidebar { position: static; max-height: none; }
}

.s21code-search-wrap {
  position: relative;
  margin-bottom: .85rem;
}
.s21code-search-wrap i {
  position: absolute; left: .75rem; top: 50%; transform: translateY(-50%);
  color: var(--s21-text-soft); font-size: .85rem;
}
.s21code-search-wrap input {
  width: 100%;
  padding: .55rem .75rem .55rem 2.1rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--s21-border);
  background: var(--s21-white);
  color: var(--s21-text);
  font-size: .85rem;
}
.s21code-search-wrap input:focus { outline: 2px solid var(--s21-primary); outline-offset: 1px; }

.s21code-topic-link {
  width: 100%;
  display: flex;
  align-items: center;
  gap: .6rem;
  text-align: left;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  padding: .55rem .6rem;
  margin-bottom: .15rem;
  color: var(--s21-text);
  font-size: .87rem;
  cursor: pointer;
  transition: background .18s var(--ease);
}
.s21code-topic-link:hover { background: var(--s21-primary-light); }
.s21code-topic-link.active {
  background: var(--s21-primary);
  color: #fff;
  font-weight: 700;
}
.s21code-topic-num {
  flex: 0 0 auto;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: rgba(127,127,127,.18);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: .68rem; font-weight: 800;
}
.s21code-topic-link.active .s21code-topic-num { background: rgba(255,255,255,.28); }
.s21code-topic-title { flex: 1 1 auto; }
.s21code-topic-level {
  flex: 0 0 auto;
  font-size: .62rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .02em;
  padding: .15rem .45rem;
  border-radius: var(--radius-pill);
  background: var(--s21-secondary-tint);
  color: #A66A00;
}
.s21code-topic-link.active .s21code-topic-level {
  background: rgba(255,255,255,.22);
  color: #fff;
}
.lvl-intermediate { background: var(--s21-accent-tint); color: var(--s21-accent); }
.lvl-advanced { background: var(--s21-primary-light); color: var(--s21-primary); }

/* ---- lesson panel ---- */
.s21code-lesson {
  background: var(--s21-white);
  border: 1px solid var(--s21-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  min-height: 320px;
}

.s21code-syntax-box {
  background: #17221C;
  color: #EDEFEC;
  border-radius: var(--radius-sm);
  padding: .85rem 1rem;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: .85rem;
  position: relative;
  overflow-x: auto;
}
.s21code-syntax-label {
  position: absolute; top: -.6rem; left: .85rem;
  background: var(--s21-secondary);
  color: #4A3300;
  font-size: .62rem; font-weight: 800; text-transform: uppercase;
  padding: .12rem .5rem; border-radius: var(--radius-pill);
}

/* ---- try it yourself editor ---- */
.s21code-tryit {
  border: 1px solid var(--s21-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.s21code-tryit-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .5rem;
  flex-wrap: wrap;
  background: var(--s21-bg);
  padding: .6rem 1rem;
  font-weight: 700;
  font-size: .88rem;
  border-bottom: 1px solid var(--s21-border);
}
.btn-sm-s21 { padding: .35rem .75rem; font-size: .78rem; }

.s21code-tryit-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 260px;
}
@media (max-width: 767px) {
  .s21code-tryit-body { grid-template-columns: 1fr; }
}

#s21code-editor {
  width: 100%;
  height: 100%;
  min-height: 260px;
  border: none;
  border-right: 1px solid var(--s21-border);
  background: #0F1712;
  color: #EDEFEC;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: .84rem;
  line-height: 1.55;
  padding: 1rem;
  resize: vertical;
  tab-size: 2;
}
#s21code-editor:focus { outline: none; }
@media (max-width: 767px) {
  #s21code-editor { border-right: none; border-bottom: 1px solid var(--s21-border); }
}

#s21code-frame {
  width: 100%;
  min-height: 260px;
  border: none;
  background: #fff;
}

.s21code-output {
  margin: 0;
  padding: 1rem;
  min-height: 260px;
  background: #0F1712;
  color: #7CE3A6;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: .84rem;
  line-height: 1.6;
  white-space: pre-wrap;
  overflow-y: auto;
}

.s21code-crumb i { color: var(--s21-primary); }

.s21code-pager {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.25rem;
}
.s21code-pager-btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: var(--s21-primary);
  color: #fff;
  border: none;
  padding: .6rem 1.1rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: .85rem;
  cursor: pointer;
  transition: background .18s var(--ease), transform .18s var(--ease);
  max-width: 260px;
}
.s21code-pager-btn span,
.s21code-pager-btn { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.s21code-pager-btn:hover { background: var(--s21-primary-dark); transform: translateY(-2px); }

/* ---- collapse toggle ---- */
.s21code-collapsed .s21code-collapsible { display: none; }

/* ==========================================================================
   Standalone Smart21Code page (smart21code.html) — a fuller, more "real
   tutorial site" look: a sticky green category bar under the site header,
   a flat full-height sidebar, and a wider two-column reading layout.
   ========================================================================== */
body.s21code-page main { background: var(--s21-white); }

.s21code-masthead {
  background: linear-gradient(135deg, var(--s21-primary) 0%, var(--s21-primary-dark) 100%);
  color: #fff;
  padding: 2.4rem 0 4.4rem;
}
.s21code-masthead .badge-pill { background: rgba(255,255,255,.16); color: #fff; }
.s21code-masthead h1 { font-family: var(--font-display); font-weight: 800; }
.s21code-masthead p { color: rgba(255,255,255,.85); max-width: 620px; }
.s21code-masthead .breadcrumb a { color: rgba(255,255,255,.75); }
.s21code-masthead .breadcrumb-item.active { color: #fff; }

/* sticky green category bar, W3Schools-style */
.s21code-topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--s21-primary-dark);
  margin-top: -2.6rem;
  box-shadow: 0 4px 14px rgba(0,0,0,.18);
}
.s21code-topbar .s21code-lang-tabs {
  margin-bottom: 0;
  gap: 0;
  flex-wrap: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}
.s21code-topbar .s21code-lang-tabs::-webkit-scrollbar { display: none; }
.s21code-topbar .s21code-lang-tab {
  --lang-color: #fff;
  border: none;
  border-radius: 0;
  background: transparent;
  color: rgba(255,255,255,.78);
  padding: .95rem 1.15rem;
  flex: 0 0 auto;
}
.s21code-topbar .s21code-lang-tab i { color: inherit; }
.s21code-topbar .s21code-lang-tab:hover { background: rgba(255,255,255,.08); color: #fff; transform: none; }
.s21code-topbar .s21code-lang-tab.active {
  background: var(--s21-primary);
  color: #fff;
  box-shadow: inset 0 -3px 0 var(--s21-secondary);
}

.s21code-page-body {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 0;
  align-items: start;
  border: 1px solid var(--s21-border);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  overflow: hidden;
  background: var(--s21-white);
}
@media (max-width: 991px) {
  .s21code-page-body { grid-template-columns: 1fr; }
}

.s21code-page-body .s21code-sidebar {
  background: var(--s21-bg);
  border: none;
  border-right: 1px solid var(--s21-border);
  border-radius: 0;
  position: sticky;
  top: 56px;
  max-height: calc(100vh - 56px);
}
@media (max-width: 991px) {
  .s21code-page-body .s21code-sidebar { position: static; max-height: none; border-right: none; border-bottom: 1px solid var(--s21-border); }
}
.s21code-page-body .s21code-topic-link.active {
  border-left: 4px solid var(--s21-secondary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.s21code-page-body .s21code-lesson {
  border: none;
  border-radius: 0;
  padding: 2rem clamp(1rem, 4vw, 3rem);
}

.s21code-side-panel {
  background: var(--s21-bg);
  border: 1px solid var(--s21-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}
.s21code-side-panel h6 { font-weight: 800; }
.s21code-side-panel ul { list-style: none; padding: 0; margin: 0; }
.s21code-side-panel li { padding: .4rem 0; border-bottom: 1px dashed var(--s21-border); font-size: .88rem; }
.s21code-side-panel li:last-child { border-bottom: none; }
.s21code-side-panel li a { color: var(--s21-text); font-weight: 600; }
.s21code-side-panel li a:hover { color: var(--s21-primary); }