/* CSIT654 v3 LMS sample — Network Security & Cryptography */
:root {
  --navy: #0b172a;
  --navy-2: #132337;
  --blue: #2563eb;
  --blue-soft: #dbeafe;
  --cyan: #06b6d4;
  --cyan-soft: #cffafe;
  --green: #16a34a;
  --green-soft: #dcfce7;
  --amber: #f59e0b;
  --red: #dc2626;
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --shadow: 0 10px 30px rgba(11, 23, 42, 0.08);
  --radius: 16px;
  --font: "Segoe UI", system-ui, -apple-system, sans-serif;
  --display: "Segoe UI Semibold", "Segoe UI", system-ui, sans-serif;
  --m1: #2563eb;
  --m2: #7c3aed;
  --m3: #16a34a;
  --m4: #06b6d4;
  --m5: #f59e0b;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
[hidden] { display: none !important; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1200px 500px at 10% -10%, rgba(37, 99, 235, 0.12), transparent 60%),
    radial-gradient(900px 400px at 100% 0%, rgba(6, 182, 212, 0.10), transparent 55%),
    var(--bg);
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
button, .btn {
  font: inherit;
  cursor: pointer;
  border: 0;
  border-radius: 999px;
  padding: 0.7rem 1.15rem;
  background: var(--blue);
  color: #fff;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
button:hover, .btn:hover { transform: translateY(-1px); box-shadow: 0 8px 18px rgba(37, 99, 235, 0.25); }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line);
}
.btn-cyan { background: var(--cyan); color: var(--navy); }
.btn-soft { background: var(--blue-soft); color: var(--blue); }

.app-shell {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
}
@media (max-width: 960px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .sidebar.open { display: block; position: fixed; inset: 0; z-index: 40; }
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1.25rem;
  background: rgba(255,255,255,0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--navy), var(--blue));
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 0.85rem;
}
.top-actions { display: flex; align-items: center; gap: 0.6rem; }
.search {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: 0.55rem 0.95rem;
  min-width: 180px;
  color: var(--muted);
}

.sidebar {
  background: var(--navy);
  color: #dbe7f7;
  padding: 1.25rem 1rem 2rem;
}
.sidebar h2 {
  margin: 0 0 0.35rem;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #8ea3c0;
}
.sidebar .course-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1.25rem;
  line-height: 1.3;
}
.nav-section { margin-bottom: 1.25rem; }
.nav-item {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.55rem 0.7rem;
  border-radius: 10px;
  color: #c6d4e8;
  margin-bottom: 0.2rem;
  font-size: 0.92rem;
}
.nav-item:hover { background: rgba(255,255,255,0.06); color: #fff; }
.nav-item.active { background: rgba(37, 99, 235, 0.35); color: #fff; }
.nav-item .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #4b6280;
  flex: 0 0 auto;
}
.nav-item.done .dot { background: var(--green); }
.nav-item.current .dot { background: var(--cyan); box-shadow: 0 0 0 3px rgba(6,182,212,0.25); }

.main { min-width: 0; }
.content { padding: 1.5rem clamp(1rem, 3vw, 2.25rem) 3rem; max-width: 1100px; }

.crumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
  color: var(--muted);
  font-size: 0.88rem;
  margin-bottom: 1rem;
}
.crumb a:hover { color: var(--blue); }
.crumb .sep { opacity: 0.5; }

.hero {
  background: linear-gradient(135deg, var(--navy) 0%, #163258 55%, #1d4ed8 120%);
  color: #fff;
  border-radius: calc(var(--radius) + 4px);
  padding: clamp(1.4rem, 3vw, 2.2rem);
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  right: -40px;
  top: -40px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(6,182,212,0.35), transparent 70%);
}
.hero h1 {
  margin: 0 0 0.4rem;
  font-size: clamp(1.6rem, 3vw, 2.35rem);
  letter-spacing: -0.03em;
  max-width: 16ch;
  position: relative;
  z-index: 1;
}
.hero p {
  margin: 0;
  max-width: 46ch;
  color: #c7d7ef;
  position: relative;
  z-index: 1;
}

.progress-wrap { margin-top: 1.25rem; position: relative; z-index: 1; max-width: 420px; }
.progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.86rem;
  margin-bottom: 0.4rem;
  color: #d7e4f8;
}
.progress-track {
  height: 10px;
  border-radius: 999px;
  background: rgba(255,255,255,0.15);
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  width: 42%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--cyan), #60a5fa);
}

.continue-card {
  margin-top: 1.15rem;
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: 14px;
  padding: 0.85rem 1rem;
  position: relative;
  z-index: 1;
}
.continue-card strong { display: block; font-size: 0.95rem; }
.continue-card span { color: #b8cae4; font-size: 0.82rem; }

.grid-5 {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.9rem;
  margin-top: 1.5rem;
}
@media (max-width: 1100px) { .grid-5 { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 700px) { .grid-5 { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .grid-5 { grid-template-columns: 1fr; } }

.module-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1rem 1.05rem;
  box-shadow: 0 1px 0 rgba(15,23,42,0.02);
  transition: border-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
  min-height: 168px;
  display: flex;
  flex-direction: column;
}
.module-card:hover {
  transform: translateY(-2px);
  border-color: #bfdbfe;
  box-shadow: var(--shadow);
}
.module-card .num {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}
.module-card h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
  letter-spacing: -0.02em;
  line-height: 1.25;
}
.module-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.4;
  flex: 1;
}
.module-card .meta {
  margin-top: 0.8rem;
  font-size: 0.78rem;
  color: var(--muted);
}

.section-title {
  margin: 2rem 0 0.85rem;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}
.subtle { color: var(--muted); margin: 0 0 1rem; max-width: 60ch; }

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.15rem 1.2rem;
}
.outcomes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 0.55rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.outcomes li {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem 0.8rem;
  font-size: 0.9rem;
}
.outcomes li::before {
  content: "→ ";
  color: var(--blue);
  font-weight: 700;
}

.concept-map {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.85rem;
  margin-top: 1rem;
}
@media (max-width: 800px) { .concept-map { grid-template-columns: 1fr; } }
.map-col {
  background: var(--bg);
  border: 1px dashed #cbd5e1;
  border-radius: 14px;
  padding: 0.9rem;
}
.map-col h4 {
  margin: 0 0 0.65rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.map-node {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.55rem 0.7rem;
  margin-bottom: 0.4rem;
  font-size: 0.88rem;
}
.map-node.parent {
  background: var(--navy);
  color: #fff;
  border-color: transparent;
  font-weight: 600;
}
.map-node.child { margin-left: 0.65rem; }
.map-node a:hover { color: var(--blue); }

.mode-tabs {
  display: inline-flex;
  gap: 0.35rem;
  background: #eef2f7;
  padding: 0.3rem;
  border-radius: 999px;
  margin: 0.5rem 0 1.1rem;
}
.mode-tabs button {
  background: transparent;
  color: var(--muted);
  box-shadow: none;
  padding: 0.45rem 0.9rem;
}
.mode-tabs button.active {
  background: #fff;
  color: var(--text);
  box-shadow: 0 1px 4px rgba(15,23,42,0.08);
}

.block {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  margin-bottom: 0.9rem;
}
.block h3 {
  margin: 0 0 0.55rem;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.block p { margin: 0; line-height: 1.55; }

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}
@media (max-width: 700px) { .compare-grid { grid-template-columns: 1fr; } }
.compare-side {
  border-radius: 14px;
  padding: 0.9rem 1rem;
  border: 1px solid var(--line);
}
.compare-side.passive { background: #eff6ff; border-color: #bfdbfe; }
.compare-side.active { background: #fff7ed; border-color: #fed7aa; }
.compare-side h4 { margin: 0 0 0.5rem; }
.compare-side ul { margin: 0; padding-left: 1.1rem; color: var(--muted); }
.compare-side li { margin-bottom: 0.35rem; }

.example {
  background: linear-gradient(180deg, #ecfeff, #fff);
  border-color: #a5f3fc;
}
.remember {
  background: linear-gradient(180deg, #f0fdf4, #fff);
  border-color: #bbf7d0;
}
.remember ul { margin: 0.35rem 0 0; padding-left: 1.1rem; }

.diagram {
  display: grid;
  gap: 0.45rem;
  justify-items: center;
  padding: 0.5rem 0;
}
.diagram .box {
  min-width: 180px;
  text-align: center;
  background: var(--navy);
  color: #fff;
  border-radius: 12px;
  padding: 0.65rem 1rem;
  font-weight: 600;
}
.diagram .box.key { background: var(--cyan); color: var(--navy); }
.diagram .arrow { color: var(--muted); font-size: 1.1rem; }
.diagram-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0.35rem;
  margin-top: 0.35rem;
}
.diagram-table td {
  text-align: center;
  vertical-align: middle;
  padding: 0.45rem 0.55rem;
  border-radius: 10px;
  font-size: 0.88rem;
  line-height: 1.35;
  color: var(--text);
  background: #f8fafc;
  border: 1px solid var(--line);
}
.diagram-table td.flow {
  background: transparent;
  border: 0;
  color: var(--muted);
  font-weight: 600;
  padding: 0.15rem;
}
.diagram-caption {
  margin: 0 0 0.35rem;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}
.feedback-wrong-detail {
  margin-top: 0.55rem;
  padding: 0.65rem 0.75rem;
  border-radius: 12px;
  background: #fff7ed;
  border: 1px solid #fed7aa;
  font-size: 0.92rem;
  line-height: 1.45;
}
.feedback-wrong-detail .answer-line { margin: 0 0 0.35rem; }
.topic-select {
  margin: 0.5rem 0 0.75rem;
  max-width: 28rem;
}
.topic-select select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.45rem 0.65rem;
  background: #fff;
  color: var(--text);
  font: inherit;
}

.quick-check .q {
  border-top: 1px solid var(--line);
  padding: 0.85rem 0 0.2rem;
}
.quick-check .q:first-child { border-top: 0; padding-top: 0; }
.opts { display: grid; gap: 0.4rem; margin-top: 0.55rem; }
.opt {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.6rem 0.8rem;
  background: #fff;
  text-align: left;
  color: var(--text);
  box-shadow: none;
}
.opt.correct { border-color: #86efac; background: var(--green-soft); }
.opt.wrong { border-color: #fca5a5; background: #fef2f2; }

.footer-nav {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.chip-row { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0.6rem 0; }
.chip {
  background: var(--blue-soft);
  color: var(--blue);
  border-radius: 999px;
  padding: 0.28rem 0.65rem;
  font-size: 0.78rem;
  font-weight: 600;
}

.mode-panel { display: none; }
.mode-panel.show { display: block; animation: fade 0.25s ease; }
@keyframes fade {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: none; }
}

.sample-banner {
  background: #fff7ed;
  border: 1px solid #fed7aa;
  color: #9a3412;
  border-radius: 12px;
  padding: 0.7rem 0.9rem;
  font-size: 0.88rem;
  margin-bottom: 1rem;
}

.brand-sub { font-size: 0.75rem; color: var(--muted); font-weight: 500; }
.chip-lmr { background: #ffedd5; color: #c2410c; }
.lmr-badge {
  display: inline-block;
  margin-left: 0.35rem;
  padding: 0.1rem 0.4rem;
  border-radius: 999px;
  background: #fb923c;
  color: #fff;
  font-size: 0.65rem;
  font-weight: 700;
  vertical-align: middle;
}
.map-group { margin-bottom: 1rem; }
.map-group-title {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.map-nodes { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.map-nodes .node {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.5rem 0.75rem;
  font-size: 0.86rem;
}
.map-nodes .node:hover { border-color: #93c5fd; }
.map-nodes .node.seen { border-color: #93c5fd; background: #eff6ff; }
.map-nodes .node.done { border-color: #86efac; background: #f0fdf4; }

.topic-list { display: grid; gap: 0.35rem; }
.topic-row {
  display: grid;
  grid-template-columns: 2rem 1fr auto;
  gap: 0.75rem;
  align-items: center;
  padding: 0.65rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}
.topic-row:hover { border-color: #93c5fd; }
.topic-row .idx { color: var(--muted); font-weight: 700; font-size: 0.85rem; }
.topic-row .t-status { color: var(--muted); font-size: 0.8rem; }

.flash-list { display: grid; gap: 0.45rem; }
.flash-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.55rem 0.8rem;
  background: #fff;
}
.flash-card summary { cursor: pointer; font-weight: 600; }
.flash-card p { margin: 0.55rem 0 0; color: var(--muted); }

.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}
.q {
  border-top: 1px solid var(--line);
  padding: 0.85rem 0 0.2rem;
  margin-bottom: 0.5rem;
}
.q:first-child { border-top: 0; padding-top: 0; }
.explain { margin-top: 0.55rem; color: var(--muted); font-size: 0.9rem; }
.chip-btn {
  background: #fff;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.35rem 0.75rem;
  font-size: 0.82rem;
  box-shadow: none;
}
.chip-btn.active { background: var(--blue-soft); color: var(--blue); border-color: #93c5fd; }
.block ul { margin: 0.35rem 0 0; padding-left: 1.15rem; }
.block li { margin-bottom: 0.35rem; line-height: 1.45; }

.chip-pdf {
  background: #ecfeff;
  color: #0e7490;
  text-decoration: none;
}
.chip-pdf:hover { filter: brightness(0.97); }
.pdf-link {
  color: var(--blue);
  font-weight: 600;
  text-decoration: none;
}
.pdf-link:hover { text-decoration: underline; }
.pdf-banner {
  margin: 0 0 0.9rem;
  padding: 0.7rem 0.9rem;
  border-radius: 12px;
  background: #ecfeff;
  border: 1px solid #a5f3fc;
  font-size: 0.92rem;
}
.pdf-banner a { color: #0e7490; font-weight: 700; }

/* —— Practice (browse + sessions) —— */
.practice-page { max-width: 820px; }
.mode-pick {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  margin: 1.25rem 0 1.5rem;
}
@media (max-width: 720px) { .mode-pick { grid-template-columns: 1fr; } }
.mode-card {
  text-align: left;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.15rem 1.2rem;
  box-shadow: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-height: 160px;
}
.mode-card:hover {
  border-color: #93c5fd;
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}
.mode-card.featured {
  background: linear-gradient(160deg, #eff6ff, #fff 55%);
  border-color: #bfdbfe;
}
.mode-card .mode-num {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--blue);
}
.mode-card h2 {
  margin: 0;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}
.mode-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
  flex: 1;
}
.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.55rem;
}
@media (max-width: 560px) { .stat-strip { grid-template-columns: 1fr 1fr; } }
.stat-strip > div {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem 0.85rem;
}
.stat-strip span {
  display: block;
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.stat-strip strong {
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.practice-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem 0.85rem;
  margin-bottom: 0.85rem;
}
.toolbar-title {
  margin: 0;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  flex: 1;
}
.toolbar-actions { display: flex; gap: 0.45rem; flex-wrap: wrap; }
.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1.15rem;
  color: var(--muted);
  font-size: 0.88rem;
  margin: 0 0 1rem;
}
.meta-row strong { color: var(--text); }

.q-card { margin-bottom: 0.85rem; }
.q-card-head {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.45rem;
}
.q-stem {
  margin: 0 0 0.65rem;
  line-height: 1.5;
  font-size: 1.02rem;
}
.q-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.55rem;
  margin-top: 0.75rem;
  padding-top: 0.65rem;
  border-top: 1px solid var(--line);
}
.concept-link {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--blue);
}
.concept-link:hover { text-decoration: underline; }
.pill {
  display: inline-block;
  border-radius: 999px;
  padding: 0.15rem 0.55rem;
  font-size: 0.72rem;
  font-weight: 700;
}
.pill.ok { background: var(--green-soft); color: #166534; }
.pill.warn { background: #ffedd5; color: #9a3412; }

.session-card { min-height: 220px; }
.sess-progress {
  height: 8px;
  border-radius: 999px;
  background: #e2e8f0;
  overflow: hidden;
  margin: 0.65rem 0 1rem;
}
.sess-progress > i {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--blue));
  border-radius: inherit;
}
.feedback {
  margin-top: 0.75rem;
  padding: 0.7rem 0.85rem;
  border-radius: 12px;
  background: var(--green-soft);
  border: 1px solid #bbf7d0;
  font-size: 0.92rem;
  line-height: 1.45;
}
.feedback.bad {
  background: #fef2f2;
  border-color: #fecaca;
}
.session-footer { margin-top: 1rem; }

/* —— Home redesign —— */
.home-wide { max-width: 1100px; }
.hero-wide h1 { max-width: none; }
.hero-wide p { max-width: 52ch; }
.progress-wide { max-width: 520px; }
.top-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.85rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--muted);
}
.top-nav a:hover, .top-nav a.here { color: var(--blue); }
.sync-pill {
  background: #f1f5f9;
  color: var(--navy);
  border: 1px solid var(--line);
  box-shadow: none;
  font-size: 0.85rem;
  padding: 0.45rem 0.85rem;
}
.sync-drawer {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem 0.5rem;
}
.path-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
}
@media (max-width: 900px) { .path-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .path-grid { grid-template-columns: 1fr; } }
.path-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.05rem;
  min-height: 140px;
  transition: border-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}
.path-card:hover {
  transform: translateY(-2px);
  border-color: #bfdbfe;
  box-shadow: var(--shadow);
}
.path-card .num {
  width: 36px; height: 36px; border-radius: 10px;
  display: grid; place-items: center; color: #fff; font-weight: 700; font-size: 0.85rem;
  margin-bottom: 0.65rem;
}
.path-card h3 { margin: 0 0 0.35rem; font-size: 0.95rem; letter-spacing: 0.04em; }
.path-card p { margin: 0; color: var(--muted); font-size: 0.86rem; line-height: 1.4; }
.quick-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  margin-bottom: 2rem;
}
@media (max-width: 900px) { .quick-row { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .quick-row { grid-template-columns: 1fr; } }
.quick-card {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0.9rem 1rem;
}
.quick-card strong { display: block; margin-bottom: 0.25rem; }
.quick-card span { color: var(--muted); font-size: 0.88rem; }
.quick-card:hover { border-color: #93c5fd; }

/* —— Real concept map —— */
.cmap-panel { background: linear-gradient(180deg, #f8fafc, #fff); }
.cmap-story { color: var(--muted); margin: 0 0 1rem; max-width: 70ch; line-height: 1.5; }
.cmap-root {
  display: inline-block;
  background: var(--navy);
  color: #fff;
  font-weight: 700;
  border-radius: 12px;
  padding: 0.55rem 0.9rem;
}
.cmap-flow { color: var(--muted); font-size: 1.1rem; margin: 0.35rem 0; text-align: center; max-width: 100%; }
.cmap-branch {
  border: 1px dashed #cbd5e1;
  border-radius: 14px;
  padding: 0.85rem;
  margin-bottom: 0.35rem;
  background: #fff;
}
.cmap-branch-head {
  display: flex; flex-wrap: wrap; gap: 0.35rem 0.75rem; align-items: baseline;
  margin-bottom: 0.65rem;
}
.cmap-branch-head span { color: var(--muted); font-size: 0.85rem; }
.cmap-nodes { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.cmap-node {
  display: flex; flex-direction: column; gap: 0.15rem;
  min-width: 140px; max-width: 220px;
  background: #f8fafc; border: 1px solid var(--line); border-radius: 12px;
  padding: 0.55rem 0.7rem; font-size: 0.88rem;
}
.cmap-node strong { font-size: 0.9rem; }
.cmap-node span { color: var(--muted); font-size: 0.78rem; }
.cmap-node:hover { border-color: #93c5fd; background: #eff6ff; }
.cmap-node.done { border-color: #86efac; background: #f0fdf4; }
.cmap-node.seen { border-color: #93c5fd; background: #eff6ff; }
.cmap-node.current { border-color: var(--cyan); box-shadow: 0 0 0 2px rgba(6,182,212,0.2); }

/* —— Sidebar marks —— */
.nav-group { margin-bottom: 0.85rem; }
.nav-group-label {
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em;
  color: #8ea3c0; margin: 0.35rem 0.7rem 0.35rem;
}
.nav-item .mark {
  width: 1.1rem; flex: 0 0 auto; text-align: center;
  font-size: 0.85rem; color: #8ea3c0;
}
.nav-item.done .mark { color: #4ade80; }
.nav-item.current .mark { color: var(--cyan); }
.nav-item.seen .mark { color: #93c5fd; }
.nav-item .dot { display: none; }

/* —— Where am I / source / confusion / flash —— */
.where-ami {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.35rem;
  margin: 0 0 0.75rem; font-size: 0.86rem; color: var(--muted);
}
.where-label {
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.06em;
  margin-right: 0.35rem; color: #94a3b8;
}
.where-step.here { color: var(--text); font-weight: 700; }
.where-sep { opacity: 0.45; }
.source-details {
  margin: 0 0 1rem; font-size: 0.88rem; color: var(--muted);
}
.source-details summary { cursor: pointer; font-weight: 600; color: var(--muted); }
.source-details p { margin: 0.4rem 0 0; }
.confusion {
  background: linear-gradient(180deg, #fff7ed, #fff);
  border-color: #fed7aa;
}
.confusion h3 { color: #9a3412; }

.flash-stage { margin-top: 0.5rem; }
.flash-face {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 1.15rem 1.2rem;
  background: #fff;
  min-height: 180px;
}
.flash-q {
  margin: 0.75rem 0 1rem;
  font-size: 1.15rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  line-height: 1.4;
}
.flash-a {
  margin: 0 0 1rem;
  padding: 0.75rem 0.85rem;
  background: #f8fafc;
  border-radius: 12px;
  color: var(--muted);
  line-height: 1.5;
}
.flash-actions, .flash-nav {
  display: flex; flex-wrap: wrap; gap: 0.45rem; margin-top: 0.65rem;
}

.practice-progress-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
  margin: 1rem 0 1.5rem;
}
.pp-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 700px) { .pp-grid { grid-template-columns: 1fr; } }
.pp-grid span {
  display: block; font-size: 0.75rem; color: var(--muted);
  text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.25rem;
}
.pp-grid strong { font-size: 1.2rem; }
.pp-grid .progress-track { margin-top: 0.45rem; background: #e2e8f0; }