@import url('https://fonts.googleapis.com/css2?family=Baloo+2:wght@500;600;700;800&family=Karla:ital,wght@0,400;0,500;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500;700&family=Silkscreen:wght@400;700&display=swap');

/* ── DESIGN TOKENS ──────────────────────────────────────────────────── */
:root,
[data-theme="dark"] {
  --bg:            #14112C;
  --bg-grid:       rgba(237,234,255,0.05);
  --surface:       #1F1B42;
  --surface-raised:#2A2456;
  --border:        rgba(237,234,255,0.10);
  --border-bright: rgba(237,234,255,0.22);
  --text:          #EDEAFF;
  --text-dim:      #A79FD1;
  --text-faint:    #6F6797;

  --brick:         #FF7A45;
  --brick-dim:     rgba(255,122,69,0.14);
  --signal:        #39FF88;
  --signal-dim:    rgba(57,255,136,0.14);
  --alarm:         #FF3D6E;
  --alarm-dim:     rgba(255,61,110,0.14);
  --query:         #8C7CFF;
  --query-dim:     rgba(140,124,255,0.16);

  --shadow:        0 8px 28px rgba(0,0,0,0.45);
  --shadow-sm:     0 2px 10px rgba(0,0,0,0.35);
  --glow-signal:   0 0 0 1px rgba(57,255,136,0.5), 0 0 20px rgba(57,255,136,0.35);
  --glow-alarm:    0 0 0 1px rgba(255,61,110,0.5), 0 0 20px rgba(255,61,110,0.35);
  --glow-brick:    0 0 0 1px rgba(255,122,69,0.5), 0 0 20px rgba(255,122,69,0.3);
}

[data-theme="light"] {
  --bg:            #EAEEF6;
  --bg-grid:       rgba(23,20,51,0.06);
  --surface:       #FFFFFF;
  --surface-raised:#F5F7FB;
  --border:        rgba(23,20,51,0.10);
  --border-bright: rgba(23,20,51,0.20);
  --text:          #171433;
  --text-dim:      #57517E;
  --text-faint:    #8A84AD;

  --brick:         #B94717;
  --brick-dim:     rgba(185,71,23,0.10);
  --signal:        #0B7A41;
  --signal-dim:    rgba(11,122,65,0.10);
  --alarm:         #D01B52;
  --alarm-dim:     rgba(208,27,82,0.10);
  --query:         #5B45E0;
  --query-dim:     rgba(91,69,224,0.10);

  --shadow:        0 8px 24px rgba(23,20,51,0.12);
  --shadow-sm:     0 2px 8px rgba(23,20,51,0.08);
  --glow-signal:   0 0 0 1px rgba(14,159,85,0.4), 0 0 14px rgba(14,159,85,0.22);
  --glow-alarm:    0 0 0 1px rgba(217,28,86,0.4), 0 0 14px rgba(217,28,86,0.22);
  --glow-brick:    0 0 0 1px rgba(217,83,27,0.4), 0 0 14px rgba(217,83,27,0.18);
}

:root {
  --font-display: 'Baloo 2', sans-serif;
  --font-pixel:   'Silkscreen', monospace;
  --font-body:    'Karla', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;

  --radius:       16px;
  --radius-sm:    10px;
  --radius-pill:  999px;
  --transition:   160ms ease;
}

/* ── 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:
    linear-gradient(var(--bg-grid) 1px, transparent 1px) 0 0 / 28px 28px,
    linear-gradient(90deg, var(--bg-grid) 1px, transparent 1px) 0 0 / 28px 28px,
    var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
  transition: background-color var(--transition), color var(--transition);
}
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 700; line-height: 1.15; letter-spacing: 0.01em; }
button { cursor: pointer; font-family: inherit; border: none; background: none; color: inherit; }
a { color: inherit; text-decoration: none; }
code, pre, .mono { font-family: var(--font-mono); }
::selection { background: var(--query); color: #fff; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 999;
  background: var(--surface); color: var(--text);
  padding: 10px 16px; border-radius: var(--radius-sm);
  border: 2px solid var(--brick);
}
.skip-link:focus { left: 12px; top: 12px; }

:focus-visible {
  outline: 3px solid var(--query);
  outline-offset: 2px;
  border-radius: 4px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

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

#topbar {
  flex-shrink: 0;
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
#topbar .brand { display: flex; align-items: center; gap: 8px; cursor: pointer; }
#topbar .brand img { width: 28px; height: 28px; }
#topbar .brand-name { font-family: var(--font-pixel); font-size: 0.9rem; color: var(--brick); }
#topbar .spacer { flex: 1; }

.theme-toggle {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-pill);
  background: var(--surface-raised);
  border: 1px solid var(--border);
  font-size: 1.1rem;
  transition: border-color var(--transition), transform var(--transition);
}
.theme-toggle:hover { border-color: var(--border-bright); transform: translateY(-1px); }

#main-wrap {
  flex: 1; display: flex; overflow: hidden; min-height: 0;
}

/* ── SIDEBAR (desktop) ──────────────────────────────────────────────── */
.sidebar { display: none; }

/* ── SCREENS ────────────────────────────────────────────────────────── */
#screens-wrap { flex: 1; display: flex; flex-direction: column; overflow: hidden; min-height: 0; }
.screen {
  flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch;
  padding: 20px 16px 96px;
}
.screen::-webkit-scrollbar { width: 8px; }
.screen::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 4px; }

/* ── BOTTOM NAV (mobile) ───────────────────────────────────────────── */
.nav-bottom {
  flex-shrink: 0;
  display: flex;
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 6px 4px calc(6px + env(safe-area-inset-bottom));
}
.nav-item {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; gap: 3px;
  padding: 6px 4px;
  border-radius: var(--radius-sm);
  font-size: 0.68rem;
  color: var(--text-faint);
  transition: color var(--transition), background var(--transition);
}
.nav-item .nav-icon { font-size: 1.25rem; }
.nav-item.active { color: var(--brick); background: var(--brick-dim); }

/* ── TYPOGRAPHY UTILITIES ──────────────────────────────────────────── */
.eyebrow {
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--text-faint);
}
.page-title { font-size: 1.6rem; margin: 4px 0 6px; }
.page-sub { color: var(--text-dim); font-size: 0.92rem; margin-bottom: 18px; }

/* ── BUTTONS ────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font-display); font-weight: 700; font-size: 0.95rem;
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--brick); color: #14112C; box-shadow: var(--shadow-sm); }
.btn-primary:hover { box-shadow: var(--glow-brick); }
.btn-ghost { background: var(--surface-raised); color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--border-bright); }
.btn-success { background: var(--signal); color: #0A2015; }
.btn-success:hover { box-shadow: var(--glow-signal); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; box-shadow: none; }

/* ── CARDS ──────────────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow-sm);
}

.module-card {
  display: flex; align-items: center; gap: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 10px;
  transition: border-color var(--transition), transform var(--transition);
}
.module-card:hover { border-color: var(--border-bright); transform: translateX(2px); }
.module-card .icon-block {
  width: 46px; height: 46px; flex-shrink: 0;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem;
  background: var(--surface-raised);
}
.module-card .body { flex: 1; min-width: 0; }
.module-card .title { font-family: var(--font-display); font-weight: 600; font-size: 1rem; }
.module-card .desc { font-size: 0.8rem; color: var(--text-dim); margin-top: 2px; }
.module-card .progress-track {
  height: 5px; border-radius: var(--radius-pill);
  background: var(--border); overflow: hidden; margin-top: 8px;
}
.module-card .progress-fill { height: 100%; background: var(--signal); border-radius: var(--radius-pill); }
.module-card.locked { opacity: 0.5; }
.module-card.locked .icon-block { filter: grayscale(1); }

/* ── BADGES / PILLS ─────────────────────────────────────────────────── */
.pill {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.75rem; font-weight: 600;
  background: var(--surface-raised);
  border: 1px solid var(--border);
}
.pill-signal { background: var(--signal-dim); color: var(--signal); border-color: transparent; }
.pill-alarm  { background: var(--alarm-dim); color: var(--alarm); border-color: transparent; }
.pill-query  { background: var(--query-dim); color: var(--query); border-color: transparent; }

.pixel-stat {
  font-family: var(--font-pixel);
  color: var(--brick);
  font-size: 0.85rem;
}

/* ── NEON FEEDBACK STATES (correct / incorrect query) ─────────────── */
.flash-correct {
  border-color: var(--signal) !important;
  box-shadow: var(--glow-signal) !important;
}
.flash-incorrect {
  border-color: var(--alarm) !important;
  box-shadow: var(--glow-alarm) !important;
  animation: shake 320ms ease;
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

/* ── SKYLINE PROGRESS STRIP (signature element) ────────────────────── */
.skyline {
  display: flex; align-items: flex-end; flex-wrap: wrap;
  gap: 14px 10px;
  padding: 20px 14px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}
.skyline-building {
  flex-shrink: 0;
  width: 34px;
  display: flex; flex-direction: column; align-items: center;
  gap: 4px;
}
.skyline-tower {
  width: 100%;
  border-radius: 3px 3px 0 0;
  background: var(--surface-raised);
  border: 1px solid var(--border-bright);
  border-bottom: none;
  display: flex; flex-direction: column; align-items: center;
  gap: 4px;
  padding-top: 6px;
}
.skyline-tower[data-band="beginner"] { height: 56px; }
.skyline-tower[data-band="intermediate"] { height: 92px; }
.skyline-tower[data-band="advanced"] { height: 128px; }
.skyline-window {
  width: 6px; height: 6px;
  background: var(--border-bright);
  border-radius: 1px;
}
.skyline-window.lit {
  background: var(--signal);
  box-shadow: 0 0 6px var(--signal);
}
.skyline-building.mastered .skyline-tower { border-color: var(--signal); }
.skyline-label {
  font-size: 0.55rem; color: var(--text-faint); white-space: nowrap;
  font-family: var(--font-mono);
}

/* ── INSTALL BANNER ─────────────────────────────────────────────────── */
#install-banner {
  display: none; align-items: center; gap: 10px;
  padding: 10px 16px;
  background: var(--query-dim);
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem; color: var(--query);
  flex-shrink: 0;
}
#install-banner.visible { display: flex; }
#btn-install {
  margin-left: auto; background: var(--query); color: #fff;
  padding: 5px 14px; border-radius: var(--radius-pill);
  font-size: 0.78rem; font-weight: 700; font-family: var(--font-display);
}
#btn-dismiss { color: var(--text-faint); font-size: 0.9rem; padding: 2px 6px; }

/* ── BAND HEADINGS (module list grouping) ──────────────────────────── */
.band-heading {
  display: flex; align-items: baseline; gap: 10px;
  margin: 26px 0 12px;
}
.band-heading:first-child { margin-top: 0; }
.band-heading .band-title { font-size: 1.05rem; }
.band-heading .band-sub { font-size: 0.75rem; color: var(--text-faint); font-family: var(--font-mono); }

/* ── STAT ROW (XP / streak / uptime, home screen) ──────────────────── */
.stat-row { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 20px; }
.stat-chip {
  flex: 1; min-width: 110px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
}
.stat-chip .stat-value { font-family: var(--font-pixel); font-size: 1.1rem; color: var(--brick); }
.stat-chip .stat-label { font-size: 0.68rem; color: var(--text-faint); font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.05em; margin-top: 2px; }

/* ── LESSON LIST (inside a module) ─────────────────────────────────── */
.lesson-row {
  display: flex; align-items: center; gap: 12px;
  padding: 13px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  margin-bottom: 8px;
  transition: border-color var(--transition);
}
.lesson-row:hover { border-color: var(--border-bright); }
.lesson-row .lesson-check {
  width: 22px; height: 22px; flex-shrink: 0;
  border-radius: var(--radius-pill);
  border: 2px solid var(--border-bright);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.7rem;
}
.lesson-row.done .lesson-check { background: var(--signal); border-color: var(--signal); color: #0A2015; }
.lesson-row .lesson-title { flex: 1; font-size: 0.9rem; }

/* ── STUDY READER ───────────────────────────────────────────────────── */
.study-metaphor {
  font-size: 1rem;
  padding: 14px 16px;
  border-left: 3px solid var(--brick);
  background: var(--brick-dim);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 14px;
}
.study-breakdown { font-size: 0.92rem; color: var(--text-dim); margin-bottom: 14px; }
.study-breakdown code { background: var(--surface-raised); padding: 1px 5px; border-radius: 4px; font-size: 0.85em; color: var(--query); }
.code-block {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  overflow-x: auto;
  white-space: pre;
  color: var(--signal);
  margin-bottom: 18px;
}

/* ── EMPTY / COMING SOON STATE ──────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-dim);
}
.empty-state .empty-icon { font-size: 2.2rem; margin-bottom: 10px; }

/* ── BADGE GRID ─────────────────────────────────────────────────────── */
.badge-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(90px, 1fr)); gap: 10px; }
.badge-tile {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  padding: 12px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  text-align: center;
}
.badge-tile.locked { opacity: 0.35; }
.badge-tile .badge-icon { font-size: 1.6rem; }
.badge-tile .badge-title { font-size: 0.68rem; color: var(--text-dim); }

/* ── JOIN TYPE DIAGRAM (Joining Tables lesson) ─────────────────────── */
.join-diagram {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
  margin: 16px 0;
}
.join-type-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  padding: 12px;
  text-align: center;
}
.jd-row { display: flex; align-items: center; gap: 4px; margin-bottom: 8px; }
.jd-box {
  flex: 1; height: 32px;
  border-radius: 6px;
  border: 2px solid var(--border-bright);
  background: transparent;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-size: 0.6rem; color: var(--text-faint);
  overflow: hidden; white-space: nowrap;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.jd-mid { font-size: 0.9rem; color: var(--text-faint); flex-shrink: 0; }
.jd-name { font-family: var(--font-display); font-weight: 700; font-size: 0.85rem; }
.jd-desc { font-size: 0.7rem; color: var(--text-dim); margin-top: 2px; }

.jd-inner .jd-mid { color: var(--signal); font-weight: 700; }
.jd-left-join .jd-box.jd-left { background: var(--signal); border-color: var(--signal); color: #0A2015; }
.jd-left-join .jd-mid { color: var(--signal); }
.jd-right-join .jd-box.jd-right { background: var(--signal); border-color: var(--signal); color: #0A2015; }
.jd-right-join .jd-mid { color: var(--signal); }
.jd-full .jd-box { background: var(--signal); border-color: var(--signal); color: #0A2015; }
.jd-full .jd-mid { color: var(--signal); }

/* ── QUIZ ENGINE ────────────────────────────────────────────────────── */
.quiz-progress { display: flex; gap: 4px; margin-bottom: 18px; }
.quiz-progress-seg { flex: 1; height: 5px; border-radius: var(--radius-pill); background: var(--border); }
.quiz-progress-seg.done { background: var(--signal); }
.quiz-progress-seg.current { background: var(--query); }

.quiz-question { font-family: var(--font-display); font-size: 1.1rem; margin-bottom: 16px; line-height: 1.35; }
.quiz-options { display: flex; flex-direction: column; gap: 8px; margin-bottom: 18px; }
.quiz-option {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--border);
  background: var(--surface);
  font-size: 0.9rem;
  text-align: left;
  transition: border-color var(--transition), background var(--transition);
}
.quiz-option:hover:not(:disabled) { border-color: var(--border-bright); }
.quiz-option .opt-marker {
  width: 20px; height: 20px; flex-shrink: 0;
  border-radius: var(--radius-pill);
  border: 2px solid var(--border-bright);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem;
}
.quiz-option[data-shape="square"] .opt-marker { border-radius: 4px; }
.quiz-option.picked .opt-marker { background: var(--query); border-color: var(--query); color: #fff; }
.quiz-option.correct { border-color: var(--signal); background: var(--signal-dim); }
.quiz-option.correct .opt-marker { background: var(--signal); border-color: var(--signal); color: #0A2015; }
.quiz-option.incorrect { border-color: var(--alarm); background: var(--alarm-dim); }
.quiz-option.incorrect .opt-marker { background: var(--alarm); border-color: var(--alarm); color: #fff; }
.quiz-option:disabled { cursor: default; }

.quiz-feedback {
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  margin-bottom: 16px;
}
.quiz-feedback.is-correct { background: var(--signal-dim); color: var(--signal); }
.quiz-feedback.is-incorrect { background: var(--alarm-dim); color: var(--alarm); }

/* Ordering blocks */
.order-slots { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
.order-slot {
  min-height: 42px;
  border: 2px dashed var(--border-bright);
  border-radius: var(--radius-sm);
  display: flex; align-items: center;
  padding: 0 12px;
  font-family: var(--font-mono); font-size: 0.8rem;
  color: var(--text-faint);
}
.order-slot.filled { border-style: solid; border-color: var(--query); background: var(--query-dim); color: var(--text); cursor: pointer; }
.order-bank { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.order-block {
  font-family: var(--font-mono); font-size: 0.8rem;
  padding: 9px 14px;
  border-radius: var(--radius-sm);
  background: var(--surface-raised);
  border: 1px solid var(--border-bright);
  transition: transform var(--transition), opacity var(--transition);
}
.order-block:hover { transform: translateY(-2px); }
.order-block.used { opacity: 0.3; pointer-events: none; }

/* ── JOIN FACTORY GAME ──────────────────────────────────────────────── */
.jf-board {
  position: relative;
  display: flex; justify-content: space-between; gap: 20px;
  padding: 18px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  margin-bottom: 16px;
  min-height: 220px;
}
.jf-col { flex: 1; display: flex; flex-direction: column; gap: 10px; max-width: 220px; }
.jf-col-right { align-items: flex-end; }
.jf-table-label { font-family: var(--font-display); font-weight: 700; font-size: 0.85rem; text-align: center; margin-bottom: 4px; }
.jf-notch {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--border-bright);
  background: var(--surface-raised);
  font-family: var(--font-mono); font-size: 0.76rem;
  text-align: left;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}
.jf-notch:hover:not(:disabled) { transform: scale(1.03); }
.jf-notch.selected { border-color: var(--query); background: var(--query-dim); }
.jf-notch.connected { border-color: var(--signal); background: var(--signal-dim); }
.jf-notch:disabled { opacity: 0.5; }
.jf-round-banner {
  text-align: center; padding: 10px; margin-bottom: 14px;
  font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-faint);
}

/* Conveyor belt — activates when the round's key pair is correctly matched */
.jf-conveyor {
  position: relative;
  height: 14px;
  border-radius: var(--radius-pill);
  background: var(--surface-raised);
  border: 1px solid var(--border);
  margin: 4px 0 18px;
  overflow: hidden;
}
.jf-conveyor.active { border-color: var(--signal); background: var(--signal-dim); }
.jf-conveyor .jf-packet {
  position: absolute; top: 2px; left: -14px;
  width: 10px; height: 10px; border-radius: 2px;
  background: var(--signal); box-shadow: 0 0 8px var(--signal);
  animation: jf-packet-move 1.1s linear infinite;
}
.jf-conveyor .jf-packet:nth-child(2) { animation-delay: 0.37s; }
.jf-conveyor .jf-packet:nth-child(3) { animation-delay: 0.74s; }
@keyframes jf-packet-move { to { left: 100%; } }

/* ── INDEX SPEED RUNNER GAME ───────────────────────────────────────── */
.isr-scenario { margin-bottom: 16px; }
.isr-track {
  display: flex; flex-direction: column; gap: 12px;
  padding: 16px;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 16px 0;
}
.isr-lane {
  position: relative;
  height: 38px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
}
.isr-lane-label {
  position: absolute; left: 10px; top: 50%; transform: translateY(-50%);
  font-family: var(--font-mono); font-size: 0.65rem; color: var(--text-faint);
  z-index: 2;
}
.isr-flag {
  position: absolute; top: 50%; transform: translate(-50%, -50%);
  font-size: 1rem; z-index: 1; opacity: 0.7;
}
.isr-racer {
  position: absolute; top: 50%; left: var(--start, 3%);
  transform: translate(-50%, -50%);
  font-size: 1.4rem; z-index: 3;
}
.isr-racer.isr-run-rocket { animation: isr-move var(--duration, 0.8s) cubic-bezier(.16,.85,.24,1) both; }
.isr-racer.isr-run-slug { animation: isr-move var(--duration, 3s) steps(16) both; }
@keyframes isr-move { from { left: var(--start, 3%); } to { left: var(--target, 3%); } }

/* ── DESKTOP LAYOUT (768px+) ───────────────────────────────────────── */
@media (min-width: 768px) {
  #topbar { display: none; }
  .nav-bottom { display: none; }

  .sidebar {
    display: flex; flex-direction: column;
    width: 260px; flex-shrink: 0;
    background: var(--surface);
    border-right: 1px solid var(--border);
    padding: 20px 16px;
    overflow-y: auto;
  }
  .sidebar .brand { display: flex; align-items: center; gap: 10px; cursor: pointer; margin-bottom: 22px; }
  .sidebar .brand img { width: 32px; height: 32px; }
  .sidebar .brand-name { font-family: var(--font-pixel); font-size: 1rem; color: var(--brick); }
  .sidebar .brand-sub { font-family: var(--font-mono); font-size: 0.7rem; color: var(--text-faint); }

  .sidebar-section-label {
    font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.08em;
    text-transform: uppercase; color: var(--text-faint);
    margin: 18px 0 8px;
  }
  .sidebar-link {
    display: flex; align-items: center; gap: 10px;
    padding: 9px 10px; border-radius: var(--radius-sm);
    font-size: 0.88rem; color: var(--text-dim);
    transition: background var(--transition), color var(--transition);
  }
  .sidebar-link:hover { background: var(--surface-raised); color: var(--text); }
  .sidebar-link.active { background: var(--brick-dim); color: var(--brick); font-weight: 700; }

  .sidebar-footer {
    margin-top: auto; padding-top: 14px; border-top: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
    font-size: 0.72rem; color: var(--text-faint);
  }

  #screens-wrap { max-width: 880px; margin: 0 auto; width: 100%; }
  .screen { padding: 32px 32px 48px; }
}