/* ============================================================
   PHP OOP MASTERY — style.css
   Design: IDE-terminal aesthetic, dark bg, syntax-color accents
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;600;700&family=Inter:wght@300;400;500;600&display=swap');

/* ── TOKENS ─────────────────────────────────────────────── */
:root {
  --bg:          #0d1117;
  --surface:     #161b22;
  --surface-2:   #1f2937;
  --border:      #30363d;
  --border-glow: #58a6ff44;

  --php-blue:    #58a6ff;   /* variables / keywords   */
  --php-purple:  #c084fc;   /* class names            */
  --php-green:   #3fb950;   /* strings / success      */
  --php-orange:  #f97316;   /* functions / accents    */
  --php-yellow:  #e3b341;   /* constants              */
  --php-red:     #f85149;   /* errors / emphasis      */

  --text:        #e6edf3;
  --text-muted:  #8b949e;
  --text-dim:    #484f58;

  --radius:      8px;
  --radius-lg:   14px;
  --font-mono:   'JetBrains Mono', 'Fira Code', monospace;
  --font-ui:     'Inter', system-ui, sans-serif;

  --glow-blue:   0 0 20px #58a6ff33, 0 0 40px #58a6ff18;
  --glow-purple: 0 0 20px #c084fc33, 0 0 40px #c084fc18;
}

/* ── RESET ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
}
a { color: var(--php-blue); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* ── SCROLLBAR ───────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ── TOPBAR ──────────────────────────────────────────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.topbar-brand {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--php-purple);
  white-space: nowrap;
}
.topbar-brand span { color: var(--php-blue); }
.topbar-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.topbar-nav a {
  font-size: 0.8rem;
  color: var(--text-muted);
  padding: 4px 10px;
  border-radius: var(--radius);
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}
.topbar-nav a:hover,
.topbar-nav a.active {
  background: var(--surface-2);
  color: var(--text);
  text-decoration: none;
}
.topbar-nav a.active { color: var(--php-blue); }

/* ── PROGRESS BAR (global, top of page) ─────────────────── */
#global-progress {
  position: fixed;
  top: 56px;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--php-purple), var(--php-blue));
  width: 0%;
  z-index: 99;
  transition: width 0.4s ease;
  box-shadow: var(--glow-blue);
}

/* ── HERO ────────────────────────────────────────────────── */
.hero {
  padding: 6rem 2rem 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, #c084fc18 0%, transparent 70%),
    radial-gradient(ellipse 40% 30% at 80% 100%, #58a6ff12 0%, transparent 60%);
  pointer-events: none;
}
.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--php-green);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}
.hero-eyebrow::before { content: '// '; opacity: 0.5; }
.hero h1 {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5vw, 3.75rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}
.hero h1 .kw  { color: var(--php-blue); }
.hero h1 .cls { color: var(--php-purple); }
.hero h1 .fn  { color: var(--php-orange); }
.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.8;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}
.stat-item { text-align: center; }
.stat-number {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--php-purple);
  display: block;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--php-purple);
  color: #fff;
  padding: 0.75rem 2rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s, box-shadow 0.15s;
  cursor: pointer;
  border: none;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-purple);
  text-decoration: none;
  color: #fff;
}

/* ── SECTION SHELL ───────────────────────────────────────── */
.section { padding: 4rem 2rem; }
.section + .section { padding-top: 0; }
.container { max-width: 1100px; margin: 0 auto; }
.section-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--php-orange);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  margin-bottom: 0.75rem;
}
.section-title {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  margin-bottom: 1rem;
}
.section-title .accent { color: var(--php-purple); }
.section-body {
  color: var(--text-muted);
  max-width: 680px;
  margin-bottom: 3rem;
}

/* ── OVERALL PROGRESS TRACKER (signature element) ───────── */
.progress-tracker {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 4rem;
  position: relative;
  overflow: hidden;
}
.progress-tracker::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--php-purple), var(--php-blue), transparent);
}
.tracker-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.tracker-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
}
.tracker-pct {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--php-purple);
  line-height: 1;
}
.tracker-pct-label { font-size: 0.75rem; color: var(--text-muted); }
.tracker-bar-bg {
  height: 6px;
  background: var(--surface-2);
  border-radius: 3px;
  margin-bottom: 2rem;
  overflow: hidden;
}
.tracker-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--php-purple), var(--php-blue));
  border-radius: 3px;
  transition: width 0.6s cubic-bezier(.4,0,.2,1);
  box-shadow: var(--glow-blue);
}
.tracker-sessions {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 6px;
}
.tracker-dot {
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--surface-2);
  border: 2px solid var(--border);
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s, transform 0.15s, box-shadow 0.2s;
  position: relative;
}
.tracker-dot:hover { transform: scale(1.2); }
.tracker-dot.done {
  background: var(--php-green);
  border-color: var(--php-green);
  box-shadow: 0 0 8px #3fb95066;
}
.tracker-dot.active {
  background: var(--php-purple);
  border-color: var(--php-purple);
  box-shadow: 0 0 10px #c084fc66;
  animation: pulse-dot 2s ease-in-out infinite;
}
@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 10px #c084fc66; }
  50%       { box-shadow: 0 0 18px #c084fcaa; }
}
.tracker-dot[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 0.7rem;
  font-family: var(--font-mono);
  white-space: nowrap;
  padding: 4px 8px;
  border-radius: 4px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.15s;
  z-index: 10;
}
.tracker-dot:hover[data-tooltip]::after { opacity: 1; }

/* ── SESSION CARDS ───────────────────────────────────────── */
.sessions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}
.session-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.session-card:hover {
  border-color: var(--php-purple);
  transform: translateY(-3px);
  box-shadow: var(--glow-purple);
  text-decoration: none;
}
.session-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  opacity: 0;
  transition: opacity 0.2s;
}
.session-card:hover::before { opacity: 1; }
.card-accent-blue::before   { background: var(--php-blue); }
.card-accent-purple::before { background: var(--php-purple); }
.card-accent-green::before  { background: var(--php-green); }
.card-accent-orange::before { background: var(--php-orange); }
.card-accent-yellow::before { background: var(--php-yellow); }

.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.5rem;
}
.card-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  background: var(--surface-2);
  padding: 2px 8px;
  border-radius: 4px;
  white-space: nowrap;
}
.card-badge {
  font-size: 0.68rem;
  font-family: var(--font-mono);
  padding: 2px 8px;
  border-radius: 4px;
  white-space: nowrap;
}
.badge-done     { background: #3fb95022; color: var(--php-green); border: 1px solid #3fb95044; }
.badge-active   { background: #c084fc22; color: var(--php-purple); border: 1px solid #c084fc44; }
.badge-locked   { background: var(--surface-2); color: var(--text-dim); border: 1px solid var(--border); }

.card-title {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}
.card-topics {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.card-topics li {
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-left: 1.1rem;
  position: relative;
}
.card-topics li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--php-orange);
  font-size: 0.65rem;
  top: 3px;
}
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}
.card-duration { display: flex; align-items: center; gap: 0.4rem; }
.card-duration::before { content: '⏱'; font-size: 0.85rem; }
.card-cta {
  color: var(--php-blue);
  font-size: 0.78rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap 0.15s;
}
.session-card:hover .card-cta { gap: 0.6rem; }

/* ── HOW IT WORKS ────────────────────────────────────────── */
.how-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.5rem;
}
.how-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}
.how-icon {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
}
.how-item h3 {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}
.how-item p { font-size: 0.85rem; color: var(--text-muted); }

/* ── RESOURCES BOX ───────────────────────────────────────── */
.resources-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem 2.5rem;
  position: relative;
  overflow: hidden;
}
.resources-box::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, #58a6ff0a 0%, transparent 70%);
  pointer-events: none;
}
.resources-box-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--php-yellow);
  margin-bottom: 1rem;
}
.resources-box-label::before { content: '📚 '; }
.resources-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.resource-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.2s;
}
.resource-item:hover { border-color: var(--php-blue); }
.resource-rank {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--php-yellow);
  min-width: 28px;
  line-height: 1;
  margin-top: 2px;
}
.resource-info h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}
.resource-info h4 a { color: var(--text); }
.resource-info h4 a:hover { color: var(--php-blue); }
.resource-info p { font-size: 0.8rem; color: var(--text-muted); }
.resource-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  background: var(--php-blue);
  color: var(--bg);
  padding: 1px 7px;
  border-radius: 4px;
  margin-left: 0.5rem;
  font-weight: 600;
  vertical-align: middle;
}

/* ── SESSION PAGE SPECIFICS ──────────────────────────────── */
.session-hero {
  padding: 4rem 2rem 3rem;
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}
.session-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 50% at 0% 50%, #c084fc0d 0%, transparent 60%);
  pointer-events: none;
}
.session-breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}
.session-breadcrumb a { color: var(--text-muted); }
.session-breadcrumb a:hover { color: var(--php-blue); }
.session-breadcrumb span { color: var(--text-dim); margin: 0 0.4rem; }
.session-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--php-orange);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 0.75rem;
}
.session-h1 {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}
.session-meta {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 3px 10px;
  border-radius: 20px;
}

/* ── CONTENT LAYOUT ──────────────────────────────────────── */
.session-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 2rem;
  padding: 3rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
  align-items: start;
}
.session-main { min-width: 0; }
.session-sidebar { position: sticky; top: 72px; }

/* content blocks */
.content-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
}
.content-block h2 {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
  color: var(--php-blue);
}
.content-block h3 {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--php-purple);
  margin: 1.5rem 0 0.75rem;
}
.content-block p { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 1rem; }
.content-block ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 1rem;
}
.content-block ul li {
  font-size: 0.88rem;
  color: var(--text-muted);
  padding-left: 1.2rem;
  position: relative;
}
.content-block ul li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--php-blue);
  font-size: 0.78rem;
}

/* code block */
.code-block {
  background: #0a0e14;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 1.25rem 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
}
.code-block-header {
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
  padding: 0.5rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.code-lang {
  font-size: 0.7rem;
  color: var(--php-orange);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.code-copy {
  font-size: 0.7rem;
  color: var(--text-dim);
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-mono);
  transition: color 0.15s;
}
.code-copy:hover { color: var(--php-blue); }
.code-block pre {
  padding: 1.25rem;
  overflow-x: auto;
  margin: 0;
}
/* Syntax highlighting via classes */
.kw  { color: var(--php-blue); }
.cls { color: var(--php-purple); }
.fn  { color: var(--php-orange); }
.str { color: var(--php-green); }
.cmt { color: var(--text-dim); font-style: italic; }
.num { color: var(--php-yellow); }
.var { color: #79c0ff; }

/* ── SIDEBAR WIDGETS ─────────────────────────────────────── */
.sidebar-widget {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 1rem;
}
.sidebar-widget-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

/* timer widget */
.timer-display {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--php-blue);
  text-align: center;
  margin: 0.75rem 0;
  letter-spacing: 0.05em;
}
.timer-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 1rem;
}
.timer-controls {
  display: flex;
  gap: 0.5rem;
}
.timer-btn {
  flex: 1;
  padding: 0.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.timer-btn:hover { background: var(--border); }
.timer-btn.primary { background: var(--php-purple); border-color: var(--php-purple); color: #fff; }
.timer-btn.primary:hover { background: #a855f7; }
.timer-progress-bar {
  height: 3px;
  background: var(--surface-2);
  border-radius: 2px;
  margin-top: 0.75rem;
  overflow: hidden;
}
.timer-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--php-blue), var(--php-purple));
  border-radius: 2px;
  transition: width 1s linear;
}

/* checklist */
.checklist { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.checklist-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 6px;
  padding: 4px;
  transition: background 0.1s;
}
.checklist-item:hover { background: var(--surface-2); }
.checklist-item input[type="checkbox"] {
  accent-color: var(--php-green);
  width: 14px;
  height: 14px;
  cursor: pointer;
  flex-shrink: 0;
}
.checklist-item.checked { color: var(--text-dim); text-decoration: line-through; }

/* session nav */
.session-nav-btns {
  display: flex;
  gap: 0.5rem;
}
.nav-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.6rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  text-decoration: none;
  text-align: center;
}
.nav-btn:hover { background: var(--border); color: var(--text); text-decoration: none; }
.nav-btn.nav-next { border-color: var(--php-purple); color: var(--php-purple); }
.nav-btn.nav-next:hover { background: #c084fc1a; }

/* ── REVIEW SECTION ──────────────────────────────────────── */
.review-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 3px solid var(--php-yellow);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
}
.review-block h2 {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--php-yellow);
  margin-bottom: 1.25rem;
}
.review-block h2::before { content: '⏱ '; }
.quiz-question {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1rem;
}
.quiz-question p {
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}
.quiz-options { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.quiz-option {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px 8px;
  border-radius: 6px;
  border: 1px solid transparent;
  transition: background 0.15s, border-color 0.15s;
}
.quiz-option:hover { background: var(--border); }
.quiz-option input { accent-color: var(--php-purple); }
.quiz-option.correct { background: #3fb95015; border-color: #3fb95055; color: var(--php-green); }
.quiz-option.wrong   { background: #f8514915; border-color: #f8514955; color: var(--php-red); }
.quiz-submit {
  display: flex;
  justify-content: flex-end;
  margin-top: 0.75rem;
}
.btn-check {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.btn-check:hover { background: var(--border); }

/* ── FOOTER ──────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}
footer a { color: var(--text-dim); }
footer a:hover { color: var(--php-blue); }

/* ── UTILITIES ───────────────────────────────────────────── */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.text-green  { color: var(--php-green); }
.text-blue   { color: var(--php-blue); }
.text-purple { color: var(--php-purple); }
.text-orange { color: var(--php-orange); }
.text-yellow { color: var(--php-yellow); }
.mono { font-family: var(--font-mono); }
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 800px) {
  .session-layout {
    grid-template-columns: 1fr;
    padding: 1.5rem 1rem;
  }
  .session-sidebar { position: static; }
  .topbar-nav { display: none; }
  .tracker-sessions { grid-template-columns: repeat(5, 1fr); }
  .hero { padding: 4rem 1rem 3rem; }
  .hero-stats { gap: 1.5rem; }
  .sessions-grid { grid-template-columns: 1fr; }
}
@media (max-width: 500px) {
  .topbar { padding: 0 1rem; }
  .section { padding: 3rem 1rem; }
}

/* ── REDUCED MOTION ──────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}