@import url('https://fonts.googleapis.com/css2?family=Boogaloo&family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── DESIGN TOKENS ─────────────────────────────────────────────────── */
:root {
  /* ── Pastel light theme (default) ── */
  --bg:            #FAF7FF;
  --surface:       #FFFFFF;
  --card:          #FDFBFF;
  --card-hover:    #F0EAFF;
  --border:        #E8DCFF;
  --border-bright: #D0B4FF;
  --accent:        #7C3AED;
  --accent-dim:    #EDE9FE;
  --accent-glow:   rgba(124,58,237,0.18);
  --purple:        #A855F7;
  --purple-dim:    #F3E8FF;
  --amber:         #D97706;
  --amber-dim:     #FEF3C7;
  --success:       #059669;
  --success-dim:   #D1FAE5;
  --danger:        #DC2626;
  --danger-dim:    #FEE2E2;
  --warning:       #EA580C;
  --warning-dim:   #FFEDD5;
  --text:          #1E1B4B;
  --text-muted:    #64748B;
  --text-dim:      #C4B5FD;
  --font-display:  'Boogaloo', cursive;
  --font-body:     'DM Sans', sans-serif;
  --font-mono:     'JetBrains Mono', monospace;
  --radius:        18px;
  --radius-sm:     12px;
  --radius-pill:   999px;
  --shadow:        0 4px 20px rgba(124,58,237,0.10), 0 1px 4px rgba(0,0,0,0.05);
  --shadow-sm:     0 2px 8px rgba(124,58,237,0.07);
  --shadow-glow:   0 0 20px rgba(124,58,237,0.22);
  --transition:    180ms ease;
  /* Zone/gradient surfaces */
  --zone-bg:       linear-gradient(135deg, #EDE9FE, #F3E8FF);
  --xp-card-bg:    linear-gradient(135deg, #EDE9FE 0%, #F3E8FF 100%);
  --sidebar-bg:    linear-gradient(180deg, #F5F0FF 0%, #EDE9FE 100%);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:          #0D0A1F;
    --surface:     #16103A;
    --card:        #1E1850;
    --card-hover:  #27206A;
    --border:      #372D80;
    --border-bright:#4E419A;
    --accent:      #A78BFA;
    --accent-dim:  rgba(167,139,250,0.14);
    --accent-glow: rgba(167,139,250,0.28);
    --purple:      #C4B5FD;
    --purple-dim:  rgba(196,181,253,0.12);
    --amber:       #FCD34D;
    --amber-dim:   rgba(252,211,77,0.12);
    --success:     #34D399;
    --success-dim: rgba(52,211,153,0.12);
    --danger:      #F87171;
    --danger-dim:  rgba(248,113,113,0.12);
    --warning:     #FB923C;
    --warning-dim: rgba(251,146,60,0.12);
    --text:        #EDE9FE;
    --text-muted:  #9F8DD0;
    --text-dim:    #3D3169;
    --shadow:      0 4px 24px rgba(0,0,0,0.55);
    --shadow-sm:   0 2px 10px rgba(0,0,0,0.38);
    --shadow-glow: 0 0 20px rgba(167,139,250,0.28);
    --zone-bg:     linear-gradient(135deg, #1E1850, #27206A);
    --xp-card-bg:  linear-gradient(135deg, #1A1545 0%, #22195A 100%);
    --sidebar-bg:  linear-gradient(180deg, #110D2A 0%, #0D0A1F 100%);
  }
}

/* ── RESET ──────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { height: 100%; height: 100dvh; font-size: 16px; }
body {
  height: 100%; height: 100dvh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}
button { cursor: pointer; font-family: inherit; border: none; background: none; }
input[type=range] { cursor: pointer; }

/* ── APP WRAPPER ────────────────────────────────────────────────────── */
#app {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Mobile: constrain to phone width */
#main-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  max-width: 540px;
  width: 100%;
  margin: 0 auto;
}

#screens-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

/* Sidebar hidden on mobile */
.sidebar { display: none; }

/* ── INSTALL BANNER ─────────────────────────────────────────────────── */
#install-banner {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  background: var(--accent-dim);
  border-bottom: 1px solid var(--accent-glow);
  font-size: 0.82rem;
  color: var(--accent);
  flex-shrink: 0;
}
#install-banner.visible { display: flex; }
#btn-install {
  margin-left: auto;
  background: var(--accent);
  color: #FFFFFF;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.8rem;
  font-weight: 600;
}
#btn-dismiss {
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 2px 6px;
}

/* ── SCREENS ────────────────────────────────────────────────────────── */
.screen {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  display: none;
  flex-direction: column;
  padding-bottom: 80px;
}
.screen.active { display: flex; }
.screen-inner {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 0 16px;
}
/* scrollbar */
.screen::-webkit-scrollbar { width: 4px; }
.screen::-webkit-scrollbar-track { background: transparent; }
.screen::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

/* ── BOTTOM NAV ─────────────────────────────────────────────────────── */
.nav-bottom {
  position: relative;
  flex-shrink: 0;
  height: 64px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: stretch;
  z-index: 100;
}
.nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  color: var(--text-muted);
  font-size: 0.68rem;
  font-weight: 500;
  transition: color var(--transition);
  padding-bottom: env(safe-area-inset-bottom, 0);
}
.nav-item.active { color: var(--accent); }
.nav-item svg { width: 22px; height: 22px; }

/* ── SHARED COMPONENTS ──────────────────────────────────────────────── */
.btn-primary {
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  width: 100%;
  transition: transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 4px 20px rgba(124,58,237,0.22);
  letter-spacing: 0.3px;
}
.btn-primary:active { transform: scale(0.97); }
.btn-primary:disabled { opacity: 0.45; pointer-events: none; }

.btn-outline {
  border: 2px solid var(--border-bright);
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.92rem;
  padding: 11px 22px;
  border-radius: var(--radius-pill);
  transition: border-color var(--transition), color var(--transition);
}
.btn-outline:hover, .btn-outline:active { border-color: var(--accent); color: var(--accent); }

.back-btn {
  color: var(--text-muted);
  font-size: 0.88rem;
  padding: 8px 4px;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: color var(--transition);
}
.back-btn:hover, .back-btn:active { color: var(--accent); }

.section-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin: 20px 0 12px;
}

/* ── HOME SCREEN ────────────────────────────────────────────────────── */
.home-inner { padding-bottom: 16px; }

.home-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0 12px;
}
.home-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.home-logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
}
.home-app-name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: var(--text);
  line-height: 1.1;
}
.home-app-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}
.home-streak {
  display: flex;
  align-items: center;
  gap: 5px;
  background: var(--card);
  border: 1px solid var(--border);
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--warning);
}

/* XP card */
.xp-card {
  background: var(--xp-card-bg);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 4px;
  position: relative;
  overflow: hidden;
}
.xp-card::before {
  content: '';
  position: absolute;
  top: -30px; right: -30px;
  width: 120px; height: 120px;
  background: radial-gradient(circle, rgba(124,58,237,0.12) 0%, transparent 70%);
  pointer-events: none;
}
.xp-level-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 10px;
}
.xp-level-label {
  font-family: var(--font-display);
  font-size: 1.2rem;
  color: var(--accent);
}
.xp-amount {
  font-size: 0.82rem;
  color: var(--text-muted);
}
.xp-bar {
  height: 10px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.xp-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #C4B5FD);
  border-radius: var(--radius-pill);
  transition: width 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 0 10px rgba(124,58,237,0.4);
}
.xp-next {
  font-size: 0.74rem;
  color: var(--text-dim);
  margin-top: 6px;
  text-align: right;
}

/* Topic grid */
.topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  padding-bottom: 8px;
}

.topic-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 14px 14px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
  cursor: pointer;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  position: relative;
  overflow: hidden;
  min-height: 130px;
}
.topic-card:not(.locked):hover,
.topic-card:not(.locked):active {
  transform: translateY(-2px);
  border-color: var(--tc, var(--accent));
  box-shadow: 0 6px 24px rgba(0,0,0,0.4), 0 0 0 1px var(--tc, var(--accent));
}
.topic-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--tc, var(--accent));
  opacity: 0;
  transition: opacity var(--transition);
}
.topic-card:not(.locked):hover::before { opacity: 1; }
.topic-card.locked {
  opacity: 0.45;
  cursor: default;
  border-style: dashed;
}
.topic-card-emoji {
  font-size: 2.2rem;
  line-height: 1;
  filter: drop-shadow(0 0 8px rgba(124,58,237,0.4));
}
.topic-card.locked .topic-card-emoji { filter: none; }
.topic-card-name {
  font-family: var(--font-display);
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.2;
}
.topic-card.locked .topic-card-name { color: var(--text-muted); }
.topic-card-stars {
  font-size: 0.85rem;
  letter-spacing: 1px;
}
.topic-card-bar {
  width: 80%;
  height: 4px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.topic-card-bar-fill {
  height: 100%;
  background: var(--tc, var(--accent));
  border-radius: var(--radius-pill);
  transition: width 0.6s ease;
}
.topic-card-lock-label {
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.3px;
}

/* ── HUB SCREEN ─────────────────────────────────────────────────────── */
.hub-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0 8px;
}
.hub-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 16px 20px;
  text-align: center;
  background: linear-gradient(180deg, var(--card) 0%, transparent 100%);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}
.hub-hero::before {
  content: '';
  position: absolute;
  top: -40px; left: 50%; transform: translateX(-50%);
  width: 200px; height: 200px;
  background: radial-gradient(circle, rgba(124,58,237,0.07) 0%, transparent 70%);
}
.hub-emoji {
  font-size: 3.5rem;
  line-height: 1;
  margin-bottom: 12px;
  filter: drop-shadow(0 0 16px rgba(124,58,237,0.5));
}
.hub-title {
  font-family: var(--font-display);
  font-size: 1.7rem;
  color: var(--text);
  margin-bottom: 6px;
}
.hub-metaphor {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
  max-width: 280px;
  line-height: 1.4;
}
.hub-modes {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.mode-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  display: flex;
  align-items: center;
  gap: 14px;
  text-align: left;
  transition: border-color var(--transition), transform var(--transition);
  width: 100%;
}
.mode-card:hover, .mode-card:active {
  border-color: var(--accent);
  transform: translateX(3px);
}
.mode-card.done { border-color: var(--success); }
.mode-icon { font-size: 1.7rem; flex-shrink: 0; }
.mode-label {
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--text);
}
.mode-detail {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 2px;
}
.mode-xp {
  margin-left: auto;
  background: var(--accent-dim);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  flex-shrink: 0;
}
.mode-card.done .mode-xp { background: var(--success-dim); color: var(--success); }

/* ── STUDY SCREEN ───────────────────────────────────────────────────── */
.study-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 12px;
  flex-shrink: 0;
}
.study-dots {
  display: flex;
  gap: 6px;
  align-items: center;
}
.study-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--border);
  transition: background var(--transition), transform var(--transition);
}
.study-dot.active {
  background: var(--accent);
  transform: scale(1.3);
  box-shadow: 0 0 8px var(--accent);
}
.study-dot.done { background: var(--success); }
.study-badge {
  font-size: 0.78rem;
  color: var(--text-muted);
  background: var(--card);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border);
}

.study-page-content {
  flex: 1;
  animation: fadeSlide 0.3s ease;
}
@keyframes fadeSlide {
  from { opacity: 0; transform: translateX(18px); }
  to   { opacity: 1; transform: translateX(0); }
}
.study-page-content.slide-back {
  animation: fadeSlideBack 0.3s ease;
}
@keyframes fadeSlideBack {
  from { opacity: 0; transform: translateX(-18px); }
  to   { opacity: 1; transform: translateX(0); }
}

.study-nav {
  display: flex;
  gap: 10px;
  padding: 16px 0 8px;
  flex-shrink: 0;
}
.study-nav > * { flex: 1; }

/* Study content components */
.study-heading {
  font-family: var(--font-display);
  font-size: 1.55rem;
  color: var(--text);
  line-height: 1.2;
  margin: 18px 0 14px;
}
.study-sub {
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--accent);
  margin: 18px 0 8px;
}
.study-p {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.65;
  margin-bottom: 12px;
}
.study-fact {
  background: var(--accent-dim);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 16px;
  margin: 14px 0;
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.5;
}
.study-fact strong { color: var(--accent); }
.study-warn {
  background: var(--warning-dim);
  border-left: 3px solid var(--warning);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 16px;
  margin: 14px 0;
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.5;
}

.concept-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 12px 0;
}
.concept-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.concept-icon { font-size: 1.5rem; flex-shrink: 0; }
.concept-body {}
.concept-title {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--text);
  margin-bottom: 3px;
}
.concept-desc { font-size: 0.86rem; color: var(--text-muted); line-height: 1.5; }

.algo-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 12px 0;
}
.algo-card {
  background: var(--card);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  border: 1px solid var(--border);
}
.algo-name {
  font-family: var(--font-display);
  font-size: 1rem;
  margin-bottom: 4px;
}
.algo-desc { font-size: 0.85rem; color: var(--text-muted); }
.algo-example {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  background: rgba(124,58,237,0.06);
  padding: 4px 8px;
  border-radius: 6px;
}

.realworld-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 12px 0;
}
.realworld-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.realworld-name { font-family: var(--font-display); font-size: 0.95rem; }
.realworld-tag {
  font-size: 0.72rem;
  background: var(--purple-dim);
  color: var(--purple);
  padding: 2px 10px;
  border-radius: var(--radius-pill);
}

/* Interactive demo */
.study-demo {
  background: var(--card);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 16px;
  margin: 14px 0;
}
.demo-label {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--accent);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.demo-server-box {
  background: var(--surface);
  border-radius: var(--radius-sm);
  padding: 14px;
  text-align: center;
  border: 1px solid var(--border);
  transition: border-color 0.3s, box-shadow 0.3s;
  margin-bottom: 14px;
}
.demo-server-box.stress { border-color: var(--warning); box-shadow: 0 0 12px var(--warning-dim); }
.demo-server-box.critical { border-color: var(--danger); box-shadow: 0 0 16px var(--danger-dim); animation: shake 0.4s ease; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  25%      { transform: translateX(-4px); }
  75%      { transform: translateX(4px); }
}
.demo-server-icon { font-size: 2rem; margin-bottom: 6px; }
.demo-server-name { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 10px; }
.demo-load-bar {
  height: 12px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
  margin-bottom: 8px;
}
.demo-load-fill {
  height: 100%;
  width: 25%;
  background: var(--success);
  border-radius: var(--radius-pill);
  transition: width 0.2s ease, background 0.3s ease;
}
.demo-load-label { font-size: 0.85rem; color: var(--text); }
.demo-slider-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.demo-slider {
  flex: 1;
  height: 6px;
  accent-color: var(--accent);
}
.demo-slider-val {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent);
  min-width: 28px;
  text-align: right;
}

/* LB distribution animation */
.lb-anim {
  padding: 12px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin: 14px 0;
}
.lb-node {
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 0.85rem;
  padding: 8px 20px;
  border-radius: var(--radius-pill);
  text-align: center;
  box-shadow: 0 0 20px rgba(124,58,237,0.4);
}
.lb-arrows {
  display: flex;
  justify-content: center;
  gap: 24px;
  color: var(--accent);
  font-size: 1.3rem;
  animation: pulse 1.6s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: 0.4; } 50% { opacity: 1; } }
.lb-servers {
  display: flex;
  gap: 10px;
}
.lb-server {
  background: var(--card);
  border: 1px solid var(--purple);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.8rem;
  text-align: center;
  color: var(--purple);
  font-family: var(--font-display);
  box-shadow: 0 0 12px rgba(139,92,246,0.2);
}

/* ── QUIZ SCREEN ────────────────────────────────────────────────────── */
.quiz-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 0 12px;
  flex-shrink: 0;
}
.quiz-progress-bar {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.quiz-progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: var(--radius-pill);
  transition: width 0.4s ease;
}
.quiz-counter {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

.quiz-type-badge {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  align-self: flex-start;
  margin-bottom: 10px;
}

.quiz-question {
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--text);
  line-height: 1.35;
  margin-bottom: 20px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 18px;
}
.quiz-option {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  text-align: left;
  font-size: 0.95rem;
  color: var(--text);
  transition: border-color var(--transition), background var(--transition);
  line-height: 1.4;
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
}
.quiz-option:hover { border-color: var(--accent); background: var(--accent-dim); }
.quiz-option.selected { border-color: var(--accent); background: var(--accent-dim); color: var(--accent); }
.quiz-option.correct  { border-color: var(--success); background: var(--success-dim); color: var(--success); }
.quiz-option.wrong    { border-color: var(--danger); background: var(--danger-dim); color: var(--danger); }
.quiz-option.revealed { border-color: var(--success); background: var(--success-dim); color: var(--success); }
.quiz-option.disabled { pointer-events: none; opacity: 0.6; }

.opt-marker {
  width: 24px; height: 24px;
  border-radius: 50%;
  border: 2px solid currentColor;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.7rem;
  flex-shrink: 0;
  font-weight: 700;
  transition: background var(--transition);
}
.quiz-option.selected .opt-marker,
.quiz-option.correct .opt-marker,
.quiz-option.wrong .opt-marker,
.quiz-option.revealed .opt-marker {
  background: currentColor;
  color: white;
}

/* Select-all checkbox style */
.quiz-checkbox {
  width: 22px; height: 22px;
  border-radius: 6px;
  border: 2px solid currentColor;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8rem;
  flex-shrink: 0;
  transition: background var(--transition);
}
.quiz-option.selected .quiz-checkbox { background: currentColor; color: #FFFFFF; }

/* Ordering */
.ord-slots-zone {
  background: var(--surface);
  border: 2px dashed var(--border-bright);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin-bottom: 14px;
  min-height: 80px;
}
.ord-slots-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}
.ord-slots { display: flex; flex-direction: column; gap: 6px; }
.ord-slot {
  background: var(--border);
  border-radius: 8px;
  min-height: 42px;
  display: flex;
  align-items: center;
  padding: 6px 10px;
  cursor: pointer;
  transition: background var(--transition);
}
.ord-slot.empty { background: rgba(255,255,255,0.03); border: 1px dashed var(--border); }
.ord-slot-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-right: 8px;
  flex-shrink: 0;
}
.ord-chip-placed {
  font-size: 0.88rem;
  color: var(--text);
  flex: 1;
}
.ord-slot:hover .ord-chip-placed { color: var(--danger); }
.ord-slot.correct-slot { background: var(--success-dim); border: 1px solid var(--success); }
.ord-slot.wrong-slot   { background: var(--danger-dim);  border: 1px solid var(--danger); }

.ord-bank-zone {
  margin-bottom: 14px;
}
.ord-bank-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.ord-bank { display: flex; flex-wrap: wrap; gap: 8px; }
.ord-bank-chip {
  background: var(--card);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 0.88rem;
  color: var(--text);
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}
.ord-bank-chip:hover, .ord-bank-chip:active {
  border-color: var(--accent);
  background: var(--accent-dim);
  color: var(--accent);
  transform: scale(1.03);
}

/* Quiz feedback */
.quiz-feedback {
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  margin: 12px 0;
  font-size: 0.9rem;
  line-height: 1.5;
  animation: feedbackIn 0.25s ease;
}
@keyframes feedbackIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.quiz-feedback.correct { background: var(--success-dim); border: 1px solid var(--success); color: var(--success); }
.quiz-feedback.wrong   { background: var(--danger-dim);  border: 1px solid var(--danger);  color: var(--danger); }
.quiz-feedback-title   { font-family: var(--font-display); font-size: 1.05rem; margin-bottom: 4px; }
.quiz-feedback-body    { color: var(--text); opacity: 0.85; }

/* Quiz results */
.quiz-results {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 30px 0 20px;
  text-align: center;
  gap: 16px;
  flex: 1;
}
.results-emoji { font-size: 4rem; animation: bounceIn 0.5s cubic-bezier(0.34, 1.56, 0.64, 1); }
@keyframes bounceIn { from { opacity:0; transform:scale(0.3); } to { opacity:1; transform:scale(1); } }
.results-title { font-family: var(--font-display); font-size: 1.8rem; color: var(--text); }
.results-stars { font-size: 2rem; letter-spacing: 4px; }
.results-score { font-size: 0.95rem; color: var(--text-muted); }
.results-xp {
  background: var(--accent-dim);
  border: 1px solid var(--accent);
  border-radius: var(--radius-pill);
  padding: 8px 24px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--accent);
}
.results-actions { display: flex; flex-direction: column; gap: 10px; width: 100%; margin-top: 8px; }

/* ── GAME SCREEN ────────────────────────────────────────────────────── */
.game-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 0 0 8px;
}
.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 10px;
  flex-shrink: 0;
}
.game-stat {
  display: flex;
  align-items: center;
  gap: 5px;
  background: var(--card);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}
.game-stat.timer { color: var(--warning); }
.game-stat.score { color: var(--accent); }
.game-stat.best  { color: var(--text-muted); }
.game-stat.timer.urgent { color: var(--danger); animation: timerPulse 0.8s ease infinite; }
@keyframes timerPulse { 0%,100% { opacity:1; } 50% { opacity:0.5; } }

.game-packet-zone {
  flex-shrink: 0;
  background: var(--zone-bg);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
  margin-bottom: 14px;
  min-height: 110px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  position: relative;
  overflow: hidden;
}
.game-packet-zone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 10px,
    rgba(124,58,237,0.02) 10px,
    rgba(124,58,237,0.02) 11px
  );
}
.packet-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
}
.packet-bubble {
  background: var(--accent-dim);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--accent);
  box-shadow: var(--shadow-sm);
  animation: packetIn 0.3s cubic-bezier(0.34,1.56,0.64,1);
}
@keyframes packetIn { from { opacity:0; transform:scale(0.7) translateY(-10px); } to { opacity:1; transform:scale(1) translateY(0); } }
.packet-instruction {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.game-servers {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
  flex-shrink: 0;
}
.game-server {
  flex: 1;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 8px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), transform var(--transition);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.game-server:hover, .game-server:active {
  border-color: var(--tc, var(--accent));
  transform: translateY(-2px);
}
.game-server.overloaded { border-color: var(--danger); animation: shake 0.4s ease; }
.game-server.crashed    { opacity: 0.45; pointer-events: none; filter: grayscale(1); }
.server-emoji  { font-size: 1.4rem; }
.server-name   { font-family: var(--font-display); font-size: 0.85rem; color: var(--text); }
.server-lb {
  height: 8px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.server-lb-fill {
  height: 100%;
  border-radius: var(--radius-pill);
  background: var(--success);
  transition: width 0.4s ease, background 0.3s;
}
.server-pct {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
}
.server-route-btn {
  background: var(--tc, var(--accent));
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 0.82rem;
  padding: 6px 4px;
  border-radius: 8px;
  font-weight: 700;
  transition: opacity var(--transition);
}
.game-server:hover .server-route-btn { opacity: 0.85; }

.game-tip {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  padding: 6px;
  font-style: italic;
}

/* Game start / end overlay */
.game-start {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 16px;
  padding: 20px;
}
.game-title {
  font-family: var(--font-display);
  font-size: 1.9rem;
  color: var(--text);
}
.game-subtitle { font-size: 0.9rem; color: var(--text-muted); max-width: 280px; line-height: 1.5; }
.game-how {
  background: var(--card);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  text-align: left;
  width: 100%;
  max-width: 340px;
}
.game-how-title { font-family: var(--font-display); font-size: 1rem; color: var(--accent); margin-bottom: 8px; }
.game-how-item {
  display: flex;
  gap: 8px;
  font-size: 0.87rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  line-height: 1.4;
}

/* XP Toast */
.xp-toast {
  position: fixed;
  top: 20%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 1.3rem;
  padding: 10px 28px;
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-glow);
  z-index: 9999;
  pointer-events: none;
  animation: toastPop 1.8s ease forwards;
}
@keyframes toastPop {
  0%   { opacity:0; transform:translateX(-50%) scale(0.6) translateY(20px); }
  20%  { opacity:1; transform:translateX(-50%) scale(1.05) translateY(0); }
  80%  { opacity:1; transform:translateX(-50%) scale(1) translateY(0); }
  100% { opacity:0; transform:translateX(-50%) scale(0.9) translateY(-20px); }
}

/* ── UTILITIES ──────────────────────────────────────────────────────── */
.mt-8  { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.text-center { text-align: center; }
.flex-center { display:flex; align-items:center; justify-content:center; }
code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  background: rgba(124,58,237,0.08);
  color: var(--accent);
  padding: 1px 6px;
  border-radius: 4px;
}

/* ── SCALE WARS GAME ────────────────────────────────────────────────── */
.sw-health-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}
.sw-health-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.73rem;
  color: var(--text-muted);
}
.sw-health-bar {
  height: 10px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.sw-health-fill {
  height: 100%;
  background: var(--success);
  border-radius: var(--radius-pill);
  transition: width 0.5s ease, background 0.3s;
}
.sw-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 0 10px;
  flex-shrink: 0;
}
.sw-scenario-card {
  background: var(--zone-bg);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 20px 16px 16px;
  margin-bottom: 14px;
  text-align: center;
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}
.sw-scenario-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(139,92,246,0.02) 10px, rgba(139,92,246,0.02) 11px);
}
.sw-scenario-num {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
  margin-bottom: 10px;
}
.sw-scenario-text {
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--text);
  line-height: 1.45;
  position: relative;
}
.sw-timer-track {
  height: 3px;
  background: var(--border);
  border-radius: var(--radius-pill);
  overflow: hidden;
  margin-top: 12px;
  position: relative;
}
.sw-timer-fill {
  height: 100%;
  border-radius: var(--radius-pill);
  background: var(--accent);
  transition: width 1s linear, background 0.3s;
}
.sw-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
  flex-shrink: 0;
}
.sw-option {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}
.sw-option:hover:not(:disabled), .sw-option:active:not(:disabled) {
  border-color: var(--purple);
  background: var(--purple-dim);
  transform: translateY(-2px);
}
.sw-option.correct  { border-color: var(--success); background: var(--success-dim); }
.sw-option.wrong    { border-color: var(--danger);  background: var(--danger-dim);  opacity: 0.65; }
.sw-option:disabled { pointer-events: none; }
.sw-opt-icon  { font-size: 1.8rem; }
.sw-opt-label { font-family: var(--font-display); font-size: 0.95rem; color: var(--text); }
.sw-opt-desc  { font-size: 0.76rem; color: var(--text-muted); line-height: 1.3; }
.sw-explanation {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-size: 0.87rem;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: 12px;
  flex-shrink: 0;
}
.sw-explanation strong { color: var(--accent); }

/* ── SERVICE ROUTER GAME ────────────────────────────────────────────── */
.sr-stats {
  display: flex;
  gap: 8px;
  align-items: center;
  padding: 12px 0 8px;
  flex-shrink: 0;
}
.sr-stat {
  background: var(--card);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.84rem;
}
.sr-stat.timer { color: var(--warning); }
.sr-stat.score { color: var(--accent);  }
.sr-stat.streak { color: var(--success); }
.sr-stat.urgent { color: var(--danger); animation: timerPulse 0.8s ease infinite; }
.sr-request-zone {
  background: var(--zone-bg);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 18px 16px;
  text-align: center;
  margin-bottom: 14px;
  min-height: 100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-shrink: 0;
}
.sr-request-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
}
.sr-request-bubble {
  background: var(--purple-dim);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--purple);
  box-shadow: var(--shadow-sm);
  animation: packetIn 0.3s cubic-bezier(0.34,1.56,0.64,1);
}
.sr-instruction {
  font-size: 0.8rem;
  color: var(--text-muted);
}
.service-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
  margin-bottom: 10px;
  flex-shrink: 0;
}
.service-btn {
  background: var(--card);
  border: 2px solid var(--sc, var(--border));
  border-radius: var(--radius-sm);
  padding: 12px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), border-color var(--transition);
}
.service-btn:hover:not(:disabled), .service-btn:active:not(:disabled) {
  transform: scale(1.06);
  background: color-mix(in srgb, var(--sc, var(--accent)) 15%, transparent);
}
.service-btn.correct-svc { background: var(--success-dim); border-color: var(--success) !important; animation: correctFlash 0.4s ease; }
.service-btn.wrong-svc   { background: var(--danger-dim);  border-color: var(--danger)  !important; animation: shake 0.3s ease; }
.service-btn:disabled    { pointer-events: none; opacity: 0.5; }
@keyframes correctFlash  { 0%,100% { transform:scale(1); } 50% { transform:scale(1.1); } }
.service-emoji { font-size: 1.5rem; }
.service-name  { font-family: var(--font-display); font-size: 0.8rem; color: var(--text); }
.sr-tip {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
  font-style: italic;
  padding: 4px;
}

/* ── CACHE DASH GAME ────────────────────────────────────────────────── */
.cd-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
  flex-shrink: 0;
}
.cd-option {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}
.cd-option:hover:not(:disabled), .cd-option:active:not(:disabled) {
  transform: translateY(-2px);
}
.cd-option.cache-btn:hover:not(:disabled), .cd-option.cache-btn:active:not(:disabled) {
  border-color: var(--warning);
  background: var(--warning-dim);
}
.cd-option.db-btn:hover:not(:disabled), .cd-option.db-btn:active:not(:disabled) {
  border-color: var(--success);
  background: var(--success-dim);
}
.cd-option.correct  { border-color: var(--success); background: var(--success-dim); }
.cd-option.wrong    { border-color: var(--danger);  background: var(--danger-dim);  opacity: 0.65; }
.cd-option:disabled { pointer-events: none; }
.cd-opt-icon   { font-size: 1.9rem; }
.cd-opt-label  { font-family: var(--font-display); font-size: 1rem; color: var(--text); }
.cd-opt-speed  { font-size: 0.74rem; color: var(--text-muted); }
.cd-why {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.86rem;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: 10px;
  flex-shrink: 0;
  animation: feedbackIn 0.25s ease;
}
.cd-request-text {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  white-space: pre-line;
  text-align: center;
  line-height: 1.6;
}

/* ── QUEUE MASTER GAME ──────────────────────────────────────────────── */
.qm-queue-zone {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 12px;
  flex-shrink: 0;
}
.qm-queue-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-dim);
  margin-bottom: 8px;
}
.qm-queue-items {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.qm-job-chip {
  background: var(--surface);
  border: 1px solid var(--border-bright);
  border-radius: 8px;
  padding: 5px 10px;
  font-size: 0.78rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}
.qm-job-chip.current {
  border-color: var(--warning);
  color: var(--warning);
  background: var(--warning-dim);
  font-weight: 600;
  transform: scale(1.05);
}
.qm-job-chip .job-size-badge {
  background: var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 0.68rem;
  color: var(--text-dim);
}
.qm-workers {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
  flex-shrink: 0;
}
.qm-worker {
  flex: 1;
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 8px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), transform var(--transition);
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.qm-worker:hover:not(.busy-full), .qm-worker:active:not(.busy-full) {
  border-color: var(--tc, var(--accent));
  transform: translateY(-2px);
}
.qm-worker.busy-full { opacity: 0.5; pointer-events: none; border-color: var(--danger); }
.qm-worker-name   { font-family: var(--font-display); font-size: 0.85rem; color: var(--text); }
.qm-worker-lb     { height: 8px; background: var(--border); border-radius: var(--radius-pill); overflow: hidden; }
.qm-worker-lb-fill { height: 100%; border-radius: var(--radius-pill); background: var(--success); transition: width 0.4s ease, background 0.3s; }
.qm-worker-load   { font-family: var(--font-mono); font-size: 0.72rem; color: var(--text-muted); }
.qm-worker-btn    { background: var(--tc, var(--accent)); color: #FFFFFF; font-family: var(--font-display); font-size: 0.78rem; padding: 5px 4px; border-radius: 7px; font-weight: 700; }
.qm-tip { font-size: 0.8rem; color: var(--text-muted); text-align: center; font-style: italic; }

/* ── CDN LOCATOR GAME ───────────────────────────────────────────────── */
.cdn-request-zone {
  background: var(--zone-bg);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 18px 16px;
  text-align: center;
  margin-bottom: 14px;
  min-height: 90px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-shrink: 0;
}
.cdn-user-bubble {
  background: #EFF6FF;
  border: 1px solid #93C5FD;
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-family: var(--font-display);
  font-size: 1rem;
  color: #1D4ED8;
  box-shadow: var(--shadow-sm);
  animation: packetIn 0.3s cubic-bezier(0.34,1.56,0.64,1);
}
.cdn-edge-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 10px;
  flex-shrink: 0;
}
.cdn-edge-btn {
  background: var(--card);
  border: 2px solid var(--sc, var(--border));
  border-radius: var(--radius-sm);
  padding: 14px 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}
.cdn-edge-btn:hover:not(:disabled), .cdn-edge-btn:active:not(:disabled) {
  transform: scale(1.04);
  background: color-mix(in srgb, var(--sc, var(--accent)) 15%, transparent);
}
.cdn-edge-btn.correct-cdn { background: var(--success-dim); border-color: var(--success) !important; animation: correctFlash 0.4s ease; }
.cdn-edge-btn.wrong-cdn   { background: var(--danger-dim);  border-color: var(--danger)  !important; animation: shake 0.3s ease; }
.cdn-edge-btn:disabled    { pointer-events: none; opacity: 0.5; }
.cdn-edge-emoji  { font-size: 1.6rem; }
.cdn-edge-name   { font-family: var(--font-display); font-size: 0.88rem; color: var(--text); }
.cdn-edge-region { font-size: 0.72rem; color: var(--text-muted); }
.cdn-why {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.86rem;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: 10px;
  flex-shrink: 0;
  animation: feedbackIn 0.25s ease;
}

/* ══════════════════════════════════════════════════════════════════════
   DESKTOP LAYOUT  ≥ 768 px
══════════════════════════════════════════════════════════════════════ */
@media (min-width: 768px) {
  /* ── Root layout ─────────────────────────────────────────────────── */
  body { overflow: hidden; }

  #install-banner { max-width: none; }

  #main-wrap {
    flex-direction: row;
    max-width: none;
    margin: 0;
    height: 100%;
  }

  #screens-wrap {
    flex: 1;
    min-width: 0;
  }

  /* ── Hide mobile bottom nav ───────────────────────────────────────── */
  .nav-bottom { display: none !important; }

  /* ── Screen padding: no bottom padding needed (no nav bar) ──────── */
  .screen { padding-bottom: 0; }

  /* ── Content max-width: keep reading lines comfortable ──────────── */
  .screen-inner {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 32px;
  }

  /* ── SIDEBAR ─────────────────────────────────────────────────────── */
  .sidebar {
    display: flex;
    flex-direction: column;
    width: 268px;
    flex-shrink: 0;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    overflow-x: hidden;
    height: 100%;
  }
  .sidebar::-webkit-scrollbar { width: 4px; }
  .sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

  /* Sidebar header */
  .sb-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 22px 18px 16px;
    cursor: pointer;
    transition: opacity var(--transition);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
  }
  .sb-header:hover { opacity: 0.85; }
  .sb-logo {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    filter: drop-shadow(0 0 8px rgba(124,58,237,0.45));
    flex-shrink: 0;
  }
  .sb-app-name {
    font-family: var(--font-display);
    font-size: 1.15rem;
    color: var(--text);
    line-height: 1.1;
  }
  .sb-app-sub {
    font-size: 0.68rem;
    color: var(--text-muted);
    letter-spacing: 0.4px;
    margin-top: 1px;
  }

  /* Sidebar user card */
  .sb-user {
    padding: 14px 18px 12px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
  }
  .sb-user-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 8px;
  }
  .sb-level-pill {
    background: var(--accent-dim);
    color: var(--accent);
    font-family: var(--font-display);
    font-size: 0.72rem;
    padding: 2px 10px;
    border-radius: var(--radius-pill);
    border: 1px solid rgba(124,58,237,0.25);
    flex-shrink: 0;
  }
  .sb-rank {
    font-size: 0.78rem;
    color: var(--text-muted);
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .sb-streak {
    font-size: 0.78rem;
    color: var(--warning);
    flex-shrink: 0;
  }
  .sb-xp-bar {
    height: 5px;
    background: var(--border);
    border-radius: var(--radius-pill);
    overflow: hidden;
    margin-bottom: 4px;
  }
  .sb-xp-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), #C4B5FD);
    border-radius: var(--radius-pill);
    box-shadow: 0 0 6px rgba(124,58,237,0.4);
  }
  .sb-xp-label {
    font-size: 0.68rem;
    color: var(--text-dim);
    text-align: right;
  }

  /* Sidebar section */
  .sb-section-label {
    padding: 14px 18px 6px;
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-dim);
    flex-shrink: 0;
  }

  /* Sidebar topic list */
  .sb-topics {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 2px 10px 10px;
    gap: 1px;
  }
  .sb-topic {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 10px;
    border-radius: 10px;
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    transition: background var(--transition), color var(--transition), transform var(--transition);
    color: var(--text-muted);
    border-left: 2px solid transparent;
  }
  .sb-topic:hover { background: var(--card); color: var(--text); transform: translateX(2px); }
  .sb-topic.sb-active {
    background: var(--accent-dim);
    color: var(--accent);
    border-left-color: var(--accent);
  }
  .sb-topic.sb-locked { opacity: 0.38; cursor: default; pointer-events: none; }
  .sb-topic-emoji { font-size: 1.1rem; flex-shrink: 0; }
  .sb-topic-name  { font-size: 0.85rem; flex: 1; font-weight: 500; line-height: 1.2; }
  .sb-topic-stars { font-size: 0.72rem; flex-shrink: 0; letter-spacing: 1px; }

  .sb-divider {
    height: 1px;
    background: var(--border);
    margin: 6px 10px;
    flex-shrink: 0;
  }

  /* Sidebar footer */
  .sb-footer {
    padding: 12px 18px;
    border-top: 1px solid var(--border);
    flex-shrink: 0;
    font-size: 0.68rem;
    color: var(--text-dim);
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  /* ── HOME SCREEN — desktop enhancements ─────────────────────────── */
  .home-inner { padding-top: 0; }

  .desktop-welcome {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 28px 0 20px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 20px;
  }
  .desktop-welcome-text h2 {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--text);
    margin-bottom: 6px;
  }
  .desktop-welcome-text p {
    font-size: 0.95rem;
    color: var(--text-muted);
    max-width: 420px;
    line-height: 1.5;
  }
  .desktop-welcome-stats {
    display: flex;
    gap: 12px;
    flex-shrink: 0;
  }
  .desktop-stat-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 18px;
    text-align: center;
    min-width: 90px;
  }
  .desktop-stat-val {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--accent);
    line-height: 1;
  }
  .desktop-stat-label {
    font-size: 0.68rem;
    color: var(--text-muted);
    margin-top: 3px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
  }

  /* Hide the mobile header/XP card on desktop (sidebar handles it) */
  .home-header { display: none; }
  .xp-card     { display: none; }

  /* 3-column topic grid on desktop */
  .topic-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
  }
  .topic-card { min-height: 150px; padding: 20px 16px 16px; }
  .topic-card-emoji { font-size: 2.4rem; }
  .topic-card-name  { font-size: 1rem; }

  /* ── HUB SCREEN — desktop enhancements ──────────────────────────── */
  .hub-header { padding: 24px 0 16px; }

  .hub-hero {
    flex-direction: row;
    text-align: left;
    align-items: center;
    gap: 24px;
    padding: 24px 28px;
  }
  .hub-emoji { font-size: 3rem; margin-bottom: 0; flex-shrink: 0; }
  .hub-title { font-size: 2rem; }
  .hub-metaphor { max-width: none; }

  /* Mode cards in a row */
  .hub-modes { flex-direction: row; gap: 12px; }
  .mode-card {
    flex: 1;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 8px;
    padding: 20px 14px;
  }
  .mode-icon { font-size: 2rem; }
  .mode-xp   { margin-left: 0; margin-top: 6px; }

  /* ── STUDY SCREEN — desktop enhancements ────────────────────────── */
  .study-heading { font-size: 1.75rem; }
  .study-p       { font-size: 1rem; line-height: 1.7; }

  .algo-grid    { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .concept-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }

  /* ── QUIZ — desktop enhancements ────────────────────────────────── */
  .quiz-question { font-size: 1.4rem; }
  .quiz-option   { padding: 16px 20px; font-size: 1rem; }

  .ord-bank { gap: 10px; }
  .ord-bank-chip { padding: 10px 18px; font-size: 0.92rem; }

  /* ── GAME — desktop enhancements ────────────────────────────────── */
  .game-wrapper  { max-width: 680px; margin: 0 auto; width: 100%; }
  .game-servers  { gap: 12px; }
  .game-server   { padding: 14px 12px; }
  .sw-options    { gap: 12px; }
  .sw-option     { padding: 20px 14px; }
  .service-grid  { gap: 10px; }
  .service-btn   { padding: 16px 10px; }
  .cdn-edge-grid { gap: 10px; }
  .cdn-edge-btn  { padding: 18px 12px; }
  .qm-workers    { gap: 12px; }
  .cd-options    { gap: 12px; }
}