:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --surface1: #ffffff;
  --surface2: #f1f5f9;
  --surface3: #e8eef5;
  --border: #e2e8f0;
  --border2: #cbd5e1;
  --text: #0f172a;
  --muted: #64748b;
  --accent-main: #2563eb;
  --accent-sel: #059669;
  --accent2: #db2777;
  --accent3: #0d9488;
  --accent4: #d97706;
  --accent-orange: #ea580c;
  --accent-py: #3776ab;
  --rejected: #dc2626;
  --code-bg: #f8fafc;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: 'Plus Jakarta Sans', system-ui, sans-serif;
  overflow-x: hidden;
  line-height: 1.55;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(37, 99, 235, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.035) 1px, transparent 1px);
  background-size: 36px 36px;
  pointer-events: none;
  z-index: 0;
}
.top-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(15, 23, 42, 0.03);
}
.top-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  color: var(--text);
}
.top-title span { color: var(--accent-py); }
.page { position: relative; z-index: 1; }
header {
  padding: 32px 40px 24px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #ffffff 0%, #eef6ff 55%, transparent 100%);
}
.tag-row { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 14px; }
.tag {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 20px;
  font-weight: 700;
}
.tag-blue { color: #1d4ed8; border: 1px solid #bfdbfe; background: #eff6ff; }
.tag-sel { color: #047857; border: 1px solid #a7f3d0; background: #ecfdf5; }
.tag-orange { color: #c2410c; border: 1px solid #fed7aa; background: #fff7ed; }
.tag-py { color: #1e40af; border: 1px solid #bfdbfe; background: #dbeafe; }
h1 { font-size: clamp(22px, 4vw, 34px); line-height: 1.15; margin-bottom: 8px; letter-spacing: -0.4px; color: #0f172a; }
.subtitle { font-size: 14px; color: var(--muted); max-width: 760px; line-height: 1.75; }
.container { max-width: 1100px; margin: 0 auto; padding: 24px 24px 56px; }
.realworld-box {
  background: #fff7ed;
  border: 1px solid #fed7aa;
  border-radius: 14px;
  padding: 22px 26px;
  margin-bottom: 18px;
  border-left: 4px solid var(--accent-orange);
  box-shadow: var(--shadow);
}
.realworld-box h2 { font-size: 15px; margin-bottom: 10px; color: #c2410c; }
.realworld-box p { color: #57534e; font-size: 14px; line-height: 1.75; }
.theory-box {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 26px;
  margin-bottom: 18px;
  border-left: 4px solid var(--accent3);
  box-shadow: var(--shadow);
}
.theory-box h2 { font-size: 15px; margin-bottom: 12px; color: #0f172a; }
.theory-box p { color: #334155; font-size: 14px; line-height: 1.75; }
.theory-points { list-style: none; }
.theory-points li { margin-bottom: 10px; line-height: 1.65; color: #475569; font-size: 14px; }
.theory-points li strong { color: #b45309; }
.learn-path, .checkpoint, .why-box, .try-box {
  border-radius: 14px;
  padding: 18px 22px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.learn-path {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-left: 4px solid var(--accent-main);
}
.learn-path h2 { font-size: 14px; color: #1d4ed8; margin-bottom: 10px; }
.learn-path ol { margin: 0; padding-left: 18px; color: #334155; font-size: 13px; line-height: 1.7; }
.checkpoint {
  background: #ecfdf5;
  border: 1px solid #a7f3d0;
  border-left: 4px solid var(--accent-sel);
}
.checkpoint h2 { font-size: 14px; color: #047857; margin-bottom: 8px; }
.checkpoint ul { margin: 0; padding-left: 18px; color: #334155; font-size: 13px; line-height: 1.7; }
.why-box {
  background: #faf5ff;
  border: 1px solid #e9d5ff;
  border-left: 4px solid #9333ea;
}
.why-box h2 { font-size: 14px; color: #7e22ce; margin-bottom: 8px; }
.why-box p { margin: 0; color: #4c1d95; font-size: 13px; line-height: 1.7; }
.try-box {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-left: 4px solid var(--accent4);
}
.try-box h2 { font-size: 14px; color: #b45309; margin-bottom: 8px; }
.try-box p { margin: 0; color: #78350f; font-size: 13px; line-height: 1.7; }
.main-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  background: #f8fafc;
}
.card-header h3 { font-size: 13px; font-weight: 700; color: #0f172a; }
.dot { width: 8px; height: 8px; border-radius: 50%; }
.viz-stage {
  padding: 24px 20px;
  background: #ffffff;
  min-height: 220px;
}
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  padding: 16px 20px;
  background: #f8fafc;
  border-top: 1px solid var(--border);
}
.btn {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid var(--border2);
  background: #ffffff;
  color: #475569;
  cursor: pointer;
  transition: all 0.15s;
  font-weight: 600;
}
.btn:hover { border-color: var(--accent-main); color: var(--accent-main); background: #eff6ff; }
.btn-primary {
  border-color: #93c5fd;
  color: #1e40af;
  background: linear-gradient(90deg, #dbeafe, #ecfdf5);
}
.step-label { font-size: 12px; color: var(--muted); font-family: 'IBM Plex Mono', monospace; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-bottom: 18px; }
.code-block {
  padding: 18px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  line-height: 1.8;
  overflow-x: auto;
  background: var(--code-bg);
  color: #0f172a;
  border-top: 1px solid var(--border);
}
.code-line { display: flex; gap: 10px; padding: 2px 4px; border-radius: 4px; }
.code-line.hl { background: #fef3c7; }
.i1 { padding-left: 16px; }
.ln { color: #94a3b8; min-width: 20px; user-select: none; font-size: 11px; }
.kw { color: #be185d; font-weight: 600; }
.fn { color: #1d4ed8; }
.cm { color: #64748b; font-style: italic; }
.str { color: #0369a1; }
.vr { color: #047857; }
.op { color: #b45309; }
.num { color: #0f766e; }
.section-hdr {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: #334155;
  margin: 22px 0 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
}
.section-hdr::after {
  content: '';
  flex: 1;
  height: 2px;
  background: linear-gradient(90deg, var(--border2) 0%, transparent 100%);
}
.flow-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px;
}
.flow-node {
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--border2);
  background: #f8fafc;
  font-size: 12px;
  font-weight: 600;
  text-align: center;
  min-width: 88px;
  transition: all 0.25s;
  color: #334155;
}
.flow-node.active {
  border-color: #f59e0b;
  color: #b45309;
  background: #fffbeb;
  box-shadow: 0 8px 20px rgba(245, 158, 11, 0.18);
  transform: translateY(-2px);
}
.flow-arrow { color: #94a3b8; font-size: 18px; }
.output-console {
  margin-top: 14px;
  padding: 14px 16px;
  border-radius: 10px;
  background: #f8fafc;
  border: 1px solid var(--border2);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  color: #047857;
  min-height: 52px;
  white-space: pre-wrap;
}
.scene-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: center;
}
.scene-visual {
  padding: 20px;
  border-radius: 12px;
  border: 1px dashed #93c5fd;
  background: #eff6ff;
  text-align: center;
}
.scene-emoji { font-size: 48px; margin-bottom: 10px; }
.scene-caption { font-size: 12px; color: var(--muted); line-height: 1.5; }
.decision-tree {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 16px;
}
.tree-node {
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid var(--border2);
  background: #f8fafc;
  font-size: 12px;
  font-weight: 600;
  color: #334155;
}
.tree-node.diamond {
  border-color: #f59e0b;
  color: #b45309;
  background: #fffbeb;
}
.tree-node.result-yes { border-color: #10b981; color: #047857; background: #ecfdf5; }
.tree-node.result-no { border-color: #f87171; color: #b91c1c; background: #fef2f2; }
.tree-branch {
  display: flex;
  gap: 40px;
  justify-content: center;
  width: 100%;
}
.thermo {
  width: 48px;
  height: 200px;
  margin: 0 auto;
  border: 2px solid var(--border2);
  border-radius: 24px;
  position: relative;
  overflow: hidden;
  background: #f1f5f9;
}
.thermo-fill {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(0deg, #ef4444, #fbbf24, #22c55e);
  transition: height 0.4s ease;
}
.grade-bar {
  height: 28px;
  border-radius: 8px;
  background: #e2e8f0;
  overflow: hidden;
  display: flex;
  margin: 12px 0;
}
.grade-seg {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: 800;
  color: rgba(0,0,0,0.55);
  opacity: 0.45;
  transition: opacity 0.25s, transform 0.25s;
}
.grade-seg.active { opacity: 1; transform: scaleY(1.08); color: #fff; text-shadow: 0 1px 2px rgba(0,0,0,0.35); }
.g-f { background: #ef4444; }
.g-d { background: #f97316; }
.g-c { background: #eab308; }
.g-b { background: #84cc16; }
.g-a { background: #22c55e; }
.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
  max-width: 280px;
  margin: 0 auto;
}
.cal-cell {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  font-size: 11px;
  border-radius: 6px;
  border: 1px solid var(--border2);
  background: #ffffff;
  color: #334155;
}
.cal-cell.leap { border-color: #10b981; background: #ecfdf5; color: #047857; font-weight: 800; }
.cal-cell.dim { opacity: 0.35; }
.info-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border2);
  background: #ffffff;
  color: var(--muted);
  margin-top: 10px;
}
.info-pill b { color: #b45309; }
.use-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}
.use-card {
  padding: 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #ffffff;
  text-align: center;
  transition: all 0.2s;
  cursor: pointer;
  box-shadow: var(--shadow);
}
.use-card:hover, .use-card.active {
  border-color: #93c5fd;
  background: #eff6ff;
}
.use-card .icon { font-size: 28px; margin-bottom: 8px; }
.use-card strong { display: block; font-size: 12px; margin-bottom: 4px; color: #0f172a; }
.use-card span { font-size: 11px; color: var(--muted); line-height: 1.4; }
.var-locker {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 12px;
}
.var-slot {
  padding: 14px;
  border-radius: 12px;
  border: 2px solid var(--border);
  background: #ffffff;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
}
.var-slot:hover, .var-slot.active {
  border-color: #60a5fa;
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.12);
  background: #f8fbff;
}
.var-slot .label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: #b45309;
  margin-bottom: 6px;
}
.var-slot .value {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 18px;
  font-weight: 600;
  color: #0f172a;
}
.var-slot .type-tag {
  display: inline-block;
  margin-top: 8px;
  font-size: 10px;
  padding: 3px 8px;
  border-radius: 999px;
  font-weight: 800;
}
.type-int { color: #1d4ed8; background: #dbeafe; border: 1px solid #93c5fd; }
.type-float { color: #b45309; background: #fef3c7; border: 1px solid #fcd34d; }
.type-str { color: #be185d; background: #fce7f3; border: 1px solid #f9a8d4; }
.type-bool { color: #047857; background: #d1fae5; border: 1px solid #6ee7b7; }
.math-viz {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 20px;
}
.math-box {
  min-width: 72px;
  padding: 16px 20px;
  border-radius: 12px;
  border: 1px solid var(--border2);
  background: #ffffff;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 22px;
  font-weight: 700;
  text-align: center;
  color: #0f172a;
  box-shadow: var(--shadow);
}
.math-op { font-size: 24px; color: #d97706; }
.loop-track {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  padding: 16px;
  min-height: 80px;
}
.loop-chip {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  border: 1px solid var(--border2);
  background: #ffffff;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 14px;
  font-weight: 700;
  color: #64748b;
  opacity: 0.45;
  transform: scale(0.92);
  transition: all 0.25s;
}
.loop-chip.done { opacity: 1; border-color: #10b981; color: #047857; background: #ecfdf5; transform: scale(1); }
.loop-chip.current {
  opacity: 1;
  border-color: #f59e0b;
  color: #b45309;
  background: #fffbeb;
  box-shadow: 0 0 14px rgba(245, 158, 11, 0.25);
  transform: scale(1.08);
}
.accumulator {
  text-align: center;
  padding: 16px;
  border-radius: 12px;
  border: 1px dashed #5eead4;
  background: #f0fdfa;
  margin-top: 12px;
}
.accumulator strong {
  display: block;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 28px;
  color: #0f766e;
  margin-top: 6px;
}
.mode-toggle {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
}
.mode-toggle .btn.active {
  border-color: #6ee7b7;
  color: #047857;
  background: #ecfdf5;
}
.name-parts {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 16px;
}
.name-chip {
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #ffffff;
  font-weight: 600;
  color: #0f172a;
  box-shadow: var(--shadow);
}
.name-chip.plus { border: none; background: none; color: #d97706; font-size: 20px; box-shadow: none; }
.name-result {
  width: 100%;
  margin-top: 12px;
  padding: 14px;
  text-align: center;
  border-radius: 10px;
  background: #eff6ff;
  border: 1px solid #93c5fd;
  font-size: 18px;
  font-weight: 700;
  color: #1e40af;
}
.gate-viz {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 16px;
}
.gate {
  width: 100%;
  max-width: 280px;
  padding: 16px;
  border-radius: 12px;
  border: 2px solid #fca5a5;
  background: #fef2f2;
  text-align: center;
  transition: all 0.3s;
  color: #991b1b;
}
.gate.open {
  border-color: #34d399;
  background: #ecfdf5;
  color: #065f46;
}
.times-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
  padding: 12px;
}
.times-cell {
  min-width: 40px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid var(--border2);
  background: #ffffff;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  text-align: center;
  color: #64748b;
  opacity: 0.45;
  transition: all 0.2s;
}
.times-cell.lit {
  opacity: 1;
  border-color: #60a5fa;
  color: #1d4ed8;
  background: #eff6ff;
}
@media (max-width: 860px) {
  .grid-2, .scene-card, .use-grid, .var-locker { grid-template-columns: 1fr; }
  header { padding: 24px 18px 20px; }
  .container { padding: 18px 14px 36px; }
}

/* ── Diagrams + topic quiz (AI-workshop style) ── */
.py-diagram {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 18px;
  margin: 14px 0 18px;
  overflow-x: auto;
}
.py-diagram h2 {
  font-size: 15px;
  margin: 0 0 12px;
  color: #0f172a;
}
.py-diagram svg {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
}
.py-quiz {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  margin: 22px 0 8px;
}
.py-quiz-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 14px;
}
.py-quiz-head h2 {
  margin: 0;
  font-size: 18px;
  color: #0f172a;
}
.py-quiz-head .pill {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #1d4ed8;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 999px;
  padding: 4px 10px;
}
.py-quiz-q {
  border: 1px solid var(--border2);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 12px;
  background: #f8fafc;
}
.py-quiz-q p {
  margin: 0 0 10px;
  color: #0f172a;
  font-weight: 600;
  font-size: 14px;
}
.py-quiz-opts {
  display: grid;
  gap: 8px;
}
.py-quiz-opts label {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border2);
  background: #ffffff;
  cursor: pointer;
  color: #334155;
  font-size: 13px;
  line-height: 1.45;
}
.py-quiz-opts label:hover { border-color: #93c5fd; background: #f8fbff; }
.py-quiz-opts label.selected { border-color: #2563eb; background: #eff6ff; }
.py-quiz-opts label.correct { border-color: #059669; background: #ecfdf5; color: #065f46; }
.py-quiz-opts label.wrong { border-color: #dc2626; background: #fef2f2; color: #991b1b; }
.py-quiz-feedback {
  margin-top: 8px;
  font-size: 13px;
  min-height: 1.2em;
  color: #64748b;
}
.py-quiz-feedback.ok { color: #065f46; }
.py-quiz-feedback.bad { color: #991b1b; }
.py-quiz-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-top: 8px;
}
.py-quiz-score {
  margin-left: auto;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  color: #1e293b;
  font-weight: 600;
}

/* KODIN PY DIAGRAM */
.kodin-diagram {
  margin: 12px 0 22px;
  padding: 16px 16px 12px;
  background: linear-gradient(180deg, #f8fafc 0%, #ffffff 72%);
  border: 1px solid var(--border, #e2e8f0);
  border-radius: 16px;
}
.kodin-diagram .kd-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--accent-main, #2563eb);
  margin-bottom: 4px;
}
.kodin-diagram .kd-sub {
  color: var(--muted, #64748b);
  font-size: 0.9rem;
  margin-bottom: 12px;
}
.kd-flow {
  display: flex; flex-wrap: wrap; gap: 6px 6px;
  align-items: stretch; justify-content: center;
}
.kd-box {
  min-width: 104px; max-width: 190px; flex: 1 1 104px;
  background: #fff; border: 2px solid var(--border, #e2e8f0); border-radius: 12px;
  padding: 10px 8px; text-align: center; font-size: 13px; line-height: 1.35;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.04);
}
.kd-box strong { display: block; font-size: 14px; margin-bottom: 2px; }
.kd-box span { display: block; color: var(--muted, #64748b); font-size: 12px; }
.kd-box.blue { border-color: #2563eb; background: #eff6ff; }
.kd-box.teal { border-color: #0d9488; background: #f0fdfa; }
.kd-box.amber { border-color: #d97706; background: #fffbeb; }
.kd-box.pink { border-color: #db2777; background: #fdf2f8; }
.kd-box.green { border-color: #059669; background: #ecfdf5; }
.kd-box.slate { border-color: #94a3b8; background: #f8fafc; }
.kd-arrow {
  display: flex; align-items: center; justify-content: center;
  color: #2563eb; font-weight: 800; font-size: 18px; min-width: 18px;
}
.kd-note {
  text-align: center; color: var(--muted, #64748b); font-size: 12px; margin-top: 10px;
}
/* /KODIN PY DIAGRAM */