:root {
  --bg: #030305;
  --surface: #0a0b10;
  --surface-2: #10121a;
  --border: rgba(255, 255, 255, 0.08);
  --border-soft: rgba(255, 255, 255, 0.15);
  --text: #f8f8f2;
  --text-muted: #8f98ad;
  --comment: #6272a4;
  --accent: #bd93f9;
  --accent-2: #ff79c6;
  --ok: #50fa7b;
  --partial: #ffb86c;
  --error: #ff5555;
  --radius: 16px;
  --radius-sm: 11px;
  --font-mono: 'JetBrains Mono', ui-monospace, 'Cascadia Code', Consolas, Menlo, monospace;
  --font-display: var(--font-mono);
  --font-body: 'Inter', system-ui, sans-serif;
  /* syntax colours (Dracula) */
  --tk-kw: #ff79c6;
  --tk-str: #f1fa8c;
  --tk-num: #bd93f9;
  --tk-fn: #50fa7b;
  --tk-bi: #8be9fd;
  --tk-cls: #8be9fd;
  --tk-const: #bd93f9;
  --tk-op: #ff79c6;
  --tk-com: #6272a4;
  --tk-interp: #ffb86c;
  color-scheme: dark;
  /* show == != <= -> exactly as typed (no ligatures): this deck teaches '=' vs '==' */
  font-variant-ligatures: none;
  font-feature-settings: 'liga' 0, 'calt' 0;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  overscroll-behavior-y: none;
}

/* ---- black editor atmosphere: soft neon glows + a faint code watermark ---- */
.aurora-bg { position: fixed; inset: 0; z-index: 0; overflow: hidden; background: var(--bg); }
.aurora-blob { position: absolute; border-radius: 50%; filter: blur(95px); will-change: transform; }
.blob-1 {
  width: 56vh; height: 56vh; top: -22%; left: -18%;
  background: radial-gradient(circle, #bd93f9 0%, transparent 70%);
  opacity: 0.2;
  animation: drift1 34s ease-in-out infinite alternate;
}
.blob-2 {
  width: 46vh; height: 46vh; top: 36%; right: -26%;
  background: radial-gradient(circle, #ff79c6 0%, transparent 70%);
  opacity: 0.13;
  animation: drift2 40s ease-in-out infinite alternate;
}
.blob-3 {
  width: 44vh; height: 44vh; bottom: -24%; left: 2%;
  background: radial-gradient(circle, #50fa7b 0%, transparent 70%);
  opacity: 0.1;
  animation: drift3 46s ease-in-out infinite alternate;
}
@keyframes drift1 { from { transform: translate(0,0); } to { transform: translate(8%,10%); } }
@keyframes drift2 { from { transform: translate(0,0); } to { transform: translate(-10%,8%); } }
@keyframes drift3 { from { transform: translate(0,0); } to { transform: translate(6%,-8%); } }

.code-bg {
  position: absolute; inset: 0; width: 100%; height: 100%;
  font-family: 'JetBrains Mono', Consolas, monospace; font-size: 9.5px;
  opacity: 0.15; pointer-events: none;
}

.grain {
  position: absolute; inset: -10%; opacity: 0.03; mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='140' height='140'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

#app {
  position: relative; z-index: 1;
  display: flex; flex-direction: column;
  height: 100dvh; height: 100vh;
  max-width: 560px; margin: 0 auto;
}

.view-container {
  flex: 1; overflow-y: auto;
  padding: 30px 18px calc(116px + env(safe-area-inset-bottom, 0px));
  -webkit-overflow-scrolling: touch;
}

.view-header { margin-bottom: 22px; }
.view-title { font-family: var(--font-mono); font-size: 25px; font-weight: 700; letter-spacing: -0.02em; }
.title-py { font-size: 36px; line-height: 1.1; letter-spacing: -0.03em; }
.title-py .prompt { color: var(--ok); margin-right: 2px; }
.title-py .title-word {
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-2) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.cursor {
  display: inline-block; width: 0.55em; height: 1.05em; margin-left: 6px; vertical-align: -0.14em;
  background: var(--ok); box-shadow: 0 0 14px rgba(80,250,123,0.6);
}
.view-subtitle { font-family: var(--font-mono); font-size: 12px; color: var(--comment); margin-top: 8px; line-height: 1.5; }

.section-title {
  font-family: var(--font-mono); font-size: 12.5px; font-weight: 500;
  color: var(--comment); margin: 30px 0 14px;
}
.section-title::before { content: '# '; }

.packet-card, .flash-card, .summary-card, .global-stat-card, .stat-packet-row {
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.04), 0 14px 34px -22px rgba(0,0,0,0.9);
}

@keyframes riseIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.packet-card, .flash-card, .summary-card { animation: riseIn 0.4s cubic-bezier(.2,.7,.3,1) both; }

.sub-chip, .btn-packet-all, .btn-packet-errors, .btn-packet-partial, .btn-packet-review, .tier-chip, .nav-btn, .assess-btn, .btn-primary, .packet-card, .quick-start-btn {
  transition: transform 0.12s ease, background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.sub-chip:active, .btn-packet-all:active, .btn-packet-errors:active, .btn-packet-partial:active, .btn-packet-review:active, .tier-chip:active, .nav-btn:active, .assess-btn:active, .btn-primary:active, .quick-start-btn:active {
  transform: scale(0.96);
}

/* ---- quick start ---- */
.quick-start-card {
  display: flex; align-items: center; gap: 14px;
  border-radius: 18px;
  padding: 18px 18px 18px 20px;
  margin-bottom: 14px;
  background: linear-gradient(135deg, rgba(189,147,249,0.14), rgba(255,121,198,0.07) 60%, rgba(10,11,16,0.9));
  border: 1px solid rgba(189,147,249,0.35);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.06), 0 0 38px -16px rgba(189,147,249,0.6);
  animation: riseIn 0.4s cubic-bezier(.2,.7,.3,1) both;
}
.quick-start-icon { font-size: 28px; }
.quick-start-info { flex: 1; min-width: 0; }
.quick-start-label { font-family: var(--font-mono); font-weight: 700; font-size: 14.5px; }
.quick-start-sub { font-size: 12px; color: var(--text-muted); margin-top: 3px; }
.quick-start-btn {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0a0a10; border: none; border-radius: var(--radius-sm);
  padding: 12px 16px; font-size: 12.5px; font-weight: 700; font-family: var(--font-mono);
  cursor: pointer; white-space: nowrap; flex-shrink: 0;
  box-shadow: 0 8px 22px -8px rgba(189,147,249,0.8);
}

/* ---- error summary ---- */
.error-summary {
  font-family: var(--font-mono); font-size: 12px; color: var(--error); font-weight: 500;
  padding: 4px 4px 14px;
}
.error-summary.ok { color: var(--ok); }

/* ---- packets: each section is a ".py file" with its own colour ---- */
.packet-list { display: flex; flex-direction: column; gap: 12px; }
.packet-card { border-radius: var(--radius); padding: 15px 16px 16px; border-left: 3px solid var(--cat, var(--accent)); }
.packet-header { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 11px; gap: 10px; }
.packet-title { font-family: var(--font-mono); font-weight: 700; font-size: 14.5px; min-width: 0; }
.packet-file { margin-left: 9px; font-size: 10.5px; font-weight: 400; color: var(--comment); }
.packet-dot {
  display: inline-block; width: 8px; height: 8px; border-radius: 50%;
  margin-right: 9px; vertical-align: 1px;
  background: var(--cat, var(--accent)); box-shadow: 0 0 10px var(--cat, var(--accent));
}
.packet-count { font-family: var(--font-mono); font-size: 12px; color: var(--text-muted); white-space: nowrap; }
.packet-count .num { color: var(--cat, var(--ok)); font-weight: 700; }

.mini-bar { display: flex; height: 6px; border-radius: 99px; overflow: hidden; background: rgba(255,255,255,0.07); }
.mini-bar-seg { height: 100%; }
.seg-ok { background: var(--ok); }
.seg-partial { background: var(--partial); }
.seg-error { background: var(--error); }
.seg-new { background: transparent; }

.packet-actions { margin-top: 14px; display: flex; flex-direction: column; gap: 10px; }
.btn-packet-all {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0a0a10; border: none; border-radius: var(--radius-sm);
  padding: 11px; font-size: 12.5px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
  box-shadow: 0 8px 22px -12px rgba(189,147,249,0.9);
}
.sub-chip-row { display: flex; gap: 8px; flex-wrap: wrap; }
.sub-chip {
  flex: 1; min-width: 40px; background: var(--surface-2); border: 1px solid var(--border);
  color: var(--text-muted); border-radius: var(--radius-sm); padding: 9px 4px;
  font-size: 12px; font-weight: 700; cursor: pointer; font-family: var(--font-mono);
}
.btn-packet-errors {
  background: rgba(255,85,85,0.12); border: 1px solid rgba(255,85,85,0.42);
  color: var(--error); border-radius: var(--radius-sm); padding: 10px;
  font-size: 12px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}
.btn-packet-partial {
  background: color-mix(in srgb, var(--partial) 14%, transparent);
  border: 1px solid color-mix(in srgb, var(--partial) 45%, transparent);
  color: var(--partial); border-radius: var(--radius-sm); padding: 10px;
  font-size: 12px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}
.btn-packet-review {
  background: var(--surface-2); border: 1px solid var(--border-soft);
  color: var(--text); border-radius: var(--radius-sm); padding: 10px;
  font-size: 12px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}
.tier-chip-row { display: flex; gap: 8px; flex-wrap: wrap; }
.tier-chip {
  background: color-mix(in srgb, var(--ok) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--ok) 40%, transparent);
  color: var(--ok); border-radius: var(--radius-sm); padding: 8px 11px;
  font-size: 11.5px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}

/* ---- session ---- */
.bottom-nav.hidden { display: none; }
.session-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 14px; gap: 10px;
}
.session-exit {
  background: var(--surface); border: 1px solid var(--border); color: var(--text);
  border-radius: 99px; padding: 8px 14px; font-size: 12px; font-weight: 600; cursor: pointer;
  font-family: var(--font-mono); white-space: nowrap;
}
.back-btn { margin-bottom: 18px; }
.session-progress-label {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--comment);
  flex: 1; min-width: 0; text-align: center; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.session-count { font-family: var(--font-mono); font-size: 13px; font-weight: 700; color: var(--text); white-space: nowrap; }
.session-count-total { color: var(--text-muted); font-weight: 400; }

.progress-bar-track { height: 4px; background: rgba(255,255,255,0.07); border-radius: 99px; margin-bottom: 20px; overflow: hidden; }
.progress-bar-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.3s ease; box-shadow: 0 0 12px rgba(189,147,249,0.8); }

/* the card is an editor window: traffic-light dots + a "<section>.py" tab */
.flash-card {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  min-height: 320px;
  display: flex; flex-direction: column;
  background: #06070a;
  border: 1px solid color-mix(in srgb, var(--cat, var(--accent)) 38%, rgba(255,255,255,0.08));
  box-shadow: 0 0 0 1px rgba(0,0,0,0.7), 0 26px 60px -28px color-mix(in srgb, var(--cat, var(--accent)) 60%, transparent), 0 0 46px -22px var(--cat, var(--accent));
}
.flash-card.tappable { cursor: pointer; }
.card-chrome {
  display: flex; align-items: center; gap: 14px;
  padding: 11px 14px; background: #0d0f15; border-bottom: 1px solid var(--border);
}
.chrome-dots { display: inline-flex; gap: 6px; }
.chrome-dots i { display: block; width: 10px; height: 10px; border-radius: 50%; }
.chrome-dots i:nth-child(1) { background: #ff5f57; }
.chrome-dots i:nth-child(2) { background: #febc2e; }
.chrome-dots i:nth-child(3) { background: #28c840; }
.chrome-file {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--text-muted);
  display: inline-flex; align-items: center; gap: 7px;
}
.file-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--cat, var(--accent)); box-shadow: 0 0 8px var(--cat, var(--accent)); }
.card-body { padding: 24px 20px 24px; flex: 1; text-align: left; }
.q-text {
  font-family: var(--font-mono); font-size: 16.5px; font-weight: 700; line-height: 1.6;
  overflow-wrap: anywhere;
}
.prompt { color: var(--ok); font-weight: 700; }
.reveal-stack { width: 100%; margin-top: 24px; display: flex; flex-direction: column; gap: 14px; }
.reveal-row {
  border-top: 1px dashed rgba(255,255,255,0.14);
  padding-top: 16px;
  animation: riseIn 0.3s ease both;
}
.reveal-label { font-family: var(--font-mono); font-size: 12px; color: var(--comment); margin-bottom: 9px; }
.a-text {
  font-size: 15.5px; line-height: 1.75; color: #e9e9f0; overflow-wrap: anywhere;
}

/* inline code + syntax colours */
code.code {
  font-family: var(--font-mono); font-size: 0.86em; font-weight: 500;
  padding: 2px 7px; border-radius: 6px;
  background: #13151d; border: 1px solid rgba(255,255,255,0.09);
  color: var(--text); white-space: pre-wrap; overflow-wrap: anywhere;
}
.q-text code.code { font-weight: 600; }
.tk-kw { color: var(--tk-kw); }
.tk-str { color: var(--tk-str); }
.tk-num { color: var(--tk-num); }
.tk-fn { color: var(--tk-fn); }
.tk-bi { color: var(--tk-bi); }
.tk-cls { color: var(--tk-cls); }
.tk-const { color: var(--tk-const); }
.tk-op { color: var(--tk-op); }
.tk-com { color: var(--tk-com); font-style: italic; }
.tk-interp { color: var(--tk-interp); }

.session-footer { margin-top: 22px; }
.session-tap-hint { text-align: center; font-family: var(--font-mono); font-size: 12px; color: var(--comment); }
.assess-row { display: flex; gap: 10px; }
.assess-btn {
  flex: 1; border: none; border-radius: var(--radius-sm); padding: 15px 8px;
  font-size: 13.5px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}
.assess-wrong { background: rgba(255,85,85,0.13); color: var(--error); border: 1px solid rgba(255,85,85,0.45); }
.assess-correct { background: rgba(80,250,123,0.12); color: var(--ok); border: 1px solid rgba(80,250,123,0.42); }

.summary-card { border-radius: 18px; padding: 32px 22px; text-align: center; border-top: 1px solid rgba(189,147,249,0.4); }
.summary-pct {
  font-family: var(--font-mono); font-size: 48px; font-weight: 700;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.summary-sub { font-family: var(--font-mono); font-size: 12.5px; color: var(--text-muted); margin: 8px 0 22px; }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0a0a10; border: none; border-radius: var(--radius-sm);
  padding: 13px; font-size: 13.5px; font-weight: 700; font-family: var(--font-mono); cursor: pointer;
}
.btn-full { width: 100%; }

/* ---- stats ---- */
.global-stat-grid { display: flex; gap: 10px; }
.global-stat-card { flex: 1; border-radius: var(--radius); padding: 16px 6px; text-align: center; }
.global-stat-num { font-family: var(--font-mono); font-size: 25px; font-weight: 700; }
.global-stat-label { font-family: var(--font-mono); font-size: 10.5px; color: var(--text-muted); margin-top: 3px; }

.stat-packet-list { display: flex; flex-direction: column; gap: 10px; }
.stat-packet-row { border-radius: var(--radius-sm); padding: 14px; border-left: 3px solid var(--cat, var(--border)); }
.stat-packet-label { font-family: var(--font-mono); font-weight: 700; font-size: 13px; margin-bottom: 9px; }
.stat-packet-nums { font-family: var(--font-mono); font-size: 10.5px; color: var(--text-muted); margin-top: 9px; }

.btn-reset {
  display: block; width: 100%; margin-top: 30px;
  background: transparent; border: 1px solid var(--border);
  color: var(--text-muted); border-radius: var(--radius-sm);
  padding: 12px; font-size: 12px; font-weight: 600; font-family: var(--font-mono);
  cursor: pointer; transition: border-color 0.15s ease, color 0.15s ease;
}
.btn-reset:active { border-color: var(--error); color: var(--error); }

/* ---- floating bottom nav (status-bar vibe) ---- */
.bottom-nav {
  position: absolute; bottom: calc(16px + env(safe-area-inset-bottom, 0px)); left: 16px; right: 16px;
  display: flex; background: rgba(6, 7, 10, 0.92); border: 1px solid var(--border-soft);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-radius: 18px; padding: 7px;
  box-shadow: 0 16px 40px -12px rgba(0,0,0,0.9), 0 0 30px -20px var(--accent);
}
.nav-btn {
  flex: 1; background: none; border: none; color: var(--text-muted);
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 8px 2px; cursor: pointer; border-radius: 13px; font-family: var(--font-mono);
}
.nav-btn.active { color: var(--accent); background: linear-gradient(135deg, rgba(189,147,249,0.18), rgba(255,121,198,0.08)); }
.nav-icon { font-size: 19px; }
.nav-label { font-size: 9.5px; font-weight: 600; }