/* ============================================================
   TuxLab — styl "system log", nie "neon hacker template".
   Paleta celowo ograniczona:
     --green  = funkcjonalny kolor podstawowy (postęp, sukces, linki)
     --red    = błędy / niepowodzenia
     --amber  = podpowiedzi / ostrzeżenia
     --violet = RZADKI akcent — wyłącznie testy końcowe, ukończenie
                całego kursu i sekwencja startowa. Rzadkość = ranga.
   Kontrasty dobrane pod WCAG 2.1 AA (min. 4.5:1 dla tekstu).
   ============================================================ */

:root {
  --bg-0: #0a0d12;
  --bg-1: #0f131a;
  --bg-2: #141920;
  --bg-3: #1a212b;
  --border: #262f3d;
  --border-soft: #1e2530;

  --text-hi: #eaeef4;
  --text-mid: #a9b4c4;
  --text-dim: #6c7789;

  --green: #4ade80;
  --green-dim: #2f8f5b;
  --turquoise: #2dd4bf;
  --test-gradient: linear-gradient(90deg, var(--turquoise), var(--green));
  --red: #f0625f;
  --amber: #e3b341;
  --violet: #b18cf5;
  --violet-dim: #7c5cc4;

  --radius-s: 4px;
  --radius-m: 8px;
  --radius-l: 12px;

  --font-mono: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Inter", Arial, sans-serif;

  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background: var(--bg-0);
  color: var(--text-hi);
  font-family: var(--font-sans);
  line-height: 1.5;
}

/* Delikatna tekstura skanlinii zamiast kolorowego glow — subtelny artefakt CRT,
   a nie dekoracja. Prawie niewidoczna, celowo. */
body {
  background-image:
    repeating-linear-gradient(0deg, rgba(255,255,255,0.012) 0px, rgba(255,255,255,0.012) 1px, transparent 1px, transparent 3px);
  background-attachment: fixed;
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

a { color: var(--green); }

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

#skip-link {
  position: absolute; left: -999px; top: 0; z-index: 500;
  background: var(--green); color: #04140f; padding: 10px 16px; border-radius: 0 0 8px 0;
  font-weight: 600;
}
#skip-link:focus { left: 0; }

#app { max-width: 880px; margin: 0 auto; padding: 24px 18px 80px; }

code, pre, .mono { font-family: var(--font-mono); }

/* ---------- Nagłówki w stylu pliku konfiguracyjnego ---------- */
.section-title {
  font-family: var(--font-mono); font-size: 0.82rem; font-weight: 600;
  color: var(--text-dim); text-transform: lowercase; letter-spacing: 0.02em;
  margin: 32px 0 12px; padding-bottom: 8px; border-bottom: 1px dashed var(--border-soft);
  display: flex; align-items: center; gap: 8px;
}
.section-title::before { content: '#'; color: var(--green); font-weight: 700; }

/* ---------- Boot sequence (jednorazowa, przy pierwszym wejściu) ---------- */
#boot-overlay {
  position: fixed; inset: 0; z-index: 1000; background: var(--bg-0);
  display: flex; align-items: center; justify-content: center; padding: 24px;
  cursor: pointer;
}
#boot-overlay[hidden] { display: none; }
.boot-log {
  font-family: var(--font-mono); font-size: 0.92rem; color: var(--text-mid);
  max-width: 460px; width: 100%;
}
.boot-log .line { opacity: 0; white-space: pre-wrap; margin: 0 0 4px; animation: bootLineIn 0.25s ease forwards; }
.boot-log .ok { color: var(--green); font-weight: 700; }
.boot-log .tag-violet { color: var(--violet); font-weight: 700; }
.boot-log .welcome { color: var(--text-hi); font-size: 1.1rem; margin-top: 14px; }
.boot-skip { color: var(--text-dim); font-size: 0.76rem; margin-top: 18px; }
@keyframes bootLineIn { from { opacity: 0; transform: translateY(2px); } to { opacity: 1; transform: translateY(0); } }

/* ---------- Hero / home ---------- */
.hero { padding: 12px 0 28px; }
.eyebrow {
  font-family: var(--font-mono); color: var(--green); font-size: 0.85rem; margin: 0 0 6px;
  letter-spacing: 0.01em;
}
.hero-title {
  font-family: var(--font-mono); font-size: clamp(1.8rem, 6vw, 2.6rem); margin: 0 0 10px;
  line-height: 1.1; font-weight: 700; letter-spacing: -0.01em;
}
.accent-violet { color: var(--violet); }
.hero-sub { color: var(--text-mid); max-width: 60ch; margin: 0 0 20px; }

.hero-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 16px; }
.stat-box {
  background: var(--bg-2); border: 1px solid var(--border-soft); border-radius: var(--radius-m);
  padding: 12px 10px; text-align: center;
}
.stat-num { display: block; font-family: var(--font-mono); font-size: 1.2rem; color: var(--text-hi); font-weight: 700; }
.stat-label { display: block; font-size: 0.7rem; color: var(--text-dim); margin-top: 2px; font-family: var(--font-mono); }

.progress-track {
  height: 8px; background: var(--bg-2); border: 1px solid var(--border-soft);
  border-radius: 999px; overflow: hidden;
}
.progress-fill {
  height: 100%; background: var(--test-gradient);
  border-radius: 999px; transition: width 0.5s ease;
}

/* ============================================================
   ŚCIEŻKA KATEGORII — "attack chain": pionowa oś + węzły na
   przemian lewo/prawo, zamiast płaskiej listy kart.
   Struktura pozostaje semantyczną listą (<ol><li><button>) —
   wygląd ścieżki to czysto wizualna nakładka (aria-hidden).
   ============================================================ */
.chain-wrap { position: relative; margin: 0; padding: 4px 0; }
.chain-spine {
  position: absolute; left: 50%; top: 0; bottom: 0; width: 2px; transform: translateX(-50%);
  background: linear-gradient(to bottom,
    var(--green) 0%, var(--green) var(--fill-pct, 0%),
    var(--border) var(--fill-pct, 0%), var(--border) 100%);
  z-index: 0;
}
.chain-list { list-style: none; margin: 0; padding: 0; position: relative; z-index: 1; }
.chain-item { display: flex; margin-bottom: 14px; }
.chain-item:nth-child(odd) { justify-content: flex-start; }
.chain-item:nth-child(even) { justify-content: flex-end; }

.chain-node-btn {
  width: calc(50% - 26px); display: flex; align-items: center; gap: 12px; text-align: left;
  background: var(--bg-2); border: 1px solid var(--border-soft); border-radius: var(--radius-m);
  padding: 12px; color: inherit; font: inherit; cursor: pointer; position: relative;
  transition: border-color 0.15s ease, transform 0.15s ease, background 0.15s ease;
}
.chain-item:nth-child(even) .chain-node-btn { flex-direction: row-reverse; text-align: right; }
.chain-node-btn:hover { border-color: var(--green); transform: translateY(-1px); background: var(--bg-3); }
.chain-item.is-complete .chain-node-btn { border-color: var(--green-dim); }

/* Łącznik od węzła do centralnej osi */
.chain-node-btn::after {
  content: ''; position: absolute; top: 50%; width: 20px; height: 2px; background: var(--border-soft);
}
.chain-item:nth-child(odd) .chain-node-btn::after { right: -20px; }
.chain-item:nth-child(even) .chain-node-btn::after { left: -20px; }
.chain-item.is-complete .chain-node-btn::after { background: var(--green-dim); }

.node-badge {
  flex-shrink: 0; width: 46px; height: 46px; border-radius: 50%; position: relative;
  background: conic-gradient(var(--green) calc(var(--pct, 0) * 1%), var(--border-soft) 0);
  display: flex; align-items: center; justify-content: center;
}
.node-badge::before {
  content: ''; position: absolute; inset: 3px; border-radius: 50%; background: var(--bg-2);
}
.node-badge-glyph {
  position: relative; z-index: 1; font-family: var(--font-mono); font-size: 0.78rem;
  color: var(--text-mid); font-weight: 700; letter-spacing: -0.02em;
}
.chain-item.is-complete .node-badge-glyph { color: var(--green); }

.node-info { flex: 1; min-width: 0; }
.node-filename { display: block; font-family: var(--font-mono); font-size: 0.72rem; color: var(--text-dim); }
.node-title { font-weight: 600; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.chain-item:nth-child(even) .node-title { justify-content: flex-end; }
.node-subtitle { display: block; color: var(--text-dim); font-size: 0.8rem; margin-top: 1px; }
.node-progress { display: flex; gap: 4px; margin-top: 6px; }
.chain-item:nth-child(even) .node-progress { justify-content: flex-end; }
.mini-pip {
  font-family: var(--font-mono); font-size: 0.62rem; padding: 1px 5px; border-radius: 3px;
  background: var(--bg-1); color: var(--text-dim); border: 1px solid var(--border-soft);
}
.mini-pip.on { color: #04140f; background: var(--green); border-color: var(--green); font-weight: 700; }

.badge {
  font-size: 0.66rem; font-weight: 700; padding: 1px 6px; border-radius: 3px;
  background: rgba(74,222,128,0.13); color: var(--green); border: 1px solid var(--green-dim);
  font-family: var(--font-mono);
}
.badge-violet {
  background: rgba(177,140,245,0.13); color: var(--violet); border-color: var(--violet-dim);
}

/* ---------- Testy końcowe (jedyne miejsce z fioletem — celowo) ---------- */
.finals-hint { color: var(--text-dim); font-size: 0.86rem; margin: -4px 0 14px; font-family: var(--font-mono); }
.finals-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.final-card, .quiz-cta {
  display: flex; flex-direction: column; align-items: flex-start; gap: 4px;
  background: var(--bg-2); border: 1px solid var(--violet-dim); border-radius: var(--radius-m);
  padding: 16px; cursor: pointer; color: inherit; font: inherit; text-align: left;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.final-card:hover:not(:disabled) { border-color: var(--violet); transform: translateY(-1px); box-shadow: 0 0 0 1px var(--violet-dim); }
.final-card:disabled { opacity: 0.45; cursor: not-allowed; border-color: var(--border-soft); }
.final-card.is-complete { border-color: var(--violet); background: rgba(177,140,245,0.06); }
.final-icon { font-family: var(--font-mono); font-size: 1.1rem; color: var(--violet); }
.final-title { font-weight: 600; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.final-sub { color: var(--text-dim); font-size: 0.8rem; }

/* .quiz-cta reutilizuje kartę, ale w kolorze funkcjonalnym (zielonym), nie fioletowym */
.quiz-cta { border-color: var(--border-soft); }
.quiz-cta:hover { border-color: var(--green); transform: translateY(-1px); }
.quiz-cta.is-complete { border-color: var(--green-dim); background: rgba(74,222,128,0.05); }
.quiz-cta .final-icon { color: var(--text-mid); }
.quiz-cta.is-complete .final-icon { color: var(--green); }

.app-footer { margin-top: 40px; text-align: center; }
.link-btn {
  background: none; border: none; color: var(--text-dim); text-decoration: underline;
  cursor: pointer; font-size: 0.85rem; font-family: inherit; padding: 6px;
}
.link-btn:hover { color: var(--green); }

/* ---------- Widok lekcji ---------- */
.breadcrumb { margin-bottom: 18px; }
.cat-header { display: flex; align-items: center; gap: 14px; margin-bottom: 4px; }
.cat-icon-lg {
  font-family: var(--font-mono); font-size: 1.5rem; color: var(--text-mid); flex-shrink: 0;
  width: 48px; height: 48px; display: flex; align-items: center; justify-content: center;
  background: var(--bg-2); border: 1px solid var(--border-soft); border-radius: var(--radius-m);
}
.cat-header h1 { margin: 0; font-size: 1.4rem; }
.cat-filename { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-dim); }

.lesson-counter { color: var(--text-dim); font-size: 0.85rem; margin: 6px 0 16px; font-family: var(--font-mono); }

.lesson-list { list-style: none; margin: 0 0 32px; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.lesson-card {
  background: var(--bg-2); border: 1px solid var(--border-soft); border-radius: var(--radius-m);
  padding: 14px 16px;
}
.lesson-card.is-done { border-color: var(--green-dim); }
.lesson-card-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-bottom: 10px; }
.lesson-cmd {
  font-size: 1rem; color: var(--text-hi); background: var(--bg-0);
  padding: 4px 10px; border-radius: var(--radius-s); border: 1px solid var(--border-soft);
  word-break: break-word;
}
.check-btn {
  flex-shrink: 0; width: 28px; height: 28px; border-radius: 50%;
  border: 1px solid var(--border); background: var(--bg-1); color: var(--green);
  cursor: pointer; font-weight: 700; display: flex; align-items: center; justify-content: center;
  transition: transform 0.15s ease, border-color 0.15s ease; font-family: var(--font-mono); font-size: 0.85rem;
}
.check-btn[aria-pressed="true"] { border-color: var(--green); background: rgba(74,222,128,0.12); }
.check-btn:active { transform: scale(0.9); }

.lesson-en, .lesson-pl { margin: 4px 0; font-size: 0.92rem; }
.tag {
  font-family: var(--font-mono); font-size: 0.64rem; font-weight: 700; color: var(--bg-0);
  background: var(--text-dim); padding: 1px 6px; border-radius: 3px; margin-right: 6px;
}
.lesson-desc { color: var(--text-mid); font-size: 0.9rem; margin: 8px 0; }
.lesson-example {
  background: var(--bg-0); border: 1px solid var(--border-soft); border-radius: var(--radius-s);
  padding: 10px 12px; overflow-x: auto; margin: 8px 0 0; font-size: 0.86rem; color: var(--green);
  position: relative;
}
.lesson-example::before { content: '$ '; color: var(--text-dim); }

.cat-quiz-cta { margin-top: 20px; }
.quiz-cta-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }

/* ---------- Quiz ---------- */
.quiz-header { margin-bottom: 18px; }
.quiz-header h1 { font-size: 1.2rem; margin: 0 0 6px; font-family: var(--font-mono); font-weight: 700; }
.quiz-progress-text { color: var(--text-dim); font-size: 0.85rem; margin: 0 0 10px; font-family: var(--font-mono); }

.quiz-card {
  background: var(--bg-2); border: 1px solid var(--border-soft); border-radius: var(--radius-l);
  padding: 20px;
}
.quiz-source { color: var(--text-dim); font-size: 0.76rem; font-family: var(--font-mono); margin: 0 0 8px; }
.quiz-source::before { content: '# '; }
.quiz-question { font-size: 1.08rem; font-weight: 600; margin: 0 0 18px; }

.mcq-options { border: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.mcq-option {
  display: flex; align-items: center; gap: 12px; text-align: left;
  background: var(--bg-1); border: 1px solid var(--border-soft); border-radius: var(--radius-m);
  padding: 12px 14px; color: inherit; font: inherit; cursor: pointer; font-family: var(--font-mono);
  font-size: 0.9rem; transition: border-color 0.15s ease, background 0.15s ease;
}
.mcq-option:hover:not(:disabled) { border-color: var(--green); background: var(--bg-3); }
.mcq-option:disabled { cursor: default; }
.mcq-letter {
  width: 24px; height: 24px; border-radius: 3px; background: var(--bg-0); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.74rem; flex-shrink: 0;
  color: var(--text-mid);
}
.mcq-option.is-correct { border-color: var(--green); background: rgba(74,222,128,0.1); }
.mcq-option.is-correct .mcq-letter { background: var(--green); color: #04140f; border-color: var(--green); }
.mcq-option.is-wrong { border-color: var(--red); background: rgba(240,98,95,0.08); }
.mcq-option.is-wrong .mcq-letter { background: var(--red); color: #200; border-color: var(--red); }

.type-form { display: flex; flex-direction: column; gap: 8px; }
.type-label { font-size: 0.85rem; color: var(--text-mid); font-family: var(--font-mono); }
.type-input {
  font-family: var(--font-mono); font-size: 1rem; background: var(--bg-0); color: var(--text-hi);
  border: 1px solid var(--border); border-radius: var(--radius-s); padding: 12px 14px;
}
.type-input:focus { border-color: var(--green); }
.type-hint { color: var(--amber); font-size: 0.82rem; min-height: 1.2em; margin: 0; font-family: var(--font-mono); }
.type-input.shake { animation: shake 0.4s ease; border-color: var(--red); }
@keyframes shake {
  10%, 90% { transform: translateX(-2px); } 20%, 80% { transform: translateX(3px); }
  30%, 50%, 70% { transform: translateX(-5px); } 40%, 60% { transform: translateX(5px); }
}

.quiz-feedback {
  margin-top: 16px; padding: 10px 14px; border-radius: var(--radius-m); font-size: 0.9rem;
  min-height: 0; font-family: var(--font-mono);
}
.quiz-feedback:empty { display: none; }
.fb-correct { background: rgba(74,222,128,0.08); border: 1px solid var(--green-dim); color: var(--text-hi); }
.fb-wrong { background: rgba(240,98,95,0.06); border: 1px solid var(--red); color: var(--text-hi); }
.fb-wrong code { color: var(--text-hi); font-weight: 700; }
.log-tag { font-weight: 700; margin-right: 6px; }
.log-tag-ok { color: var(--green); }
.log-tag-fail { color: var(--red); }
.retry-note { color: var(--amber); font-size: 0.85rem; display: block; margin-top: 4px; }
.quiz-feedback .exp-text { font-family: var(--font-sans); color: var(--text-mid); display: block; margin-top: 4px; }

.next-btn-wrap { margin-top: 16px; display: flex; justify-content: flex-end; }

.btn-primary, .btn-secondary {
  font: inherit; padding: 11px 20px; border-radius: var(--radius-m); cursor: pointer;
  font-weight: 600; border: 1px solid transparent; font-family: var(--font-mono); font-size: 0.9rem;
}
.btn-small { padding: 7px 14px; font-size: 0.82rem; flex-shrink: 0; }
.btn-primary { background: var(--test-gradient); color: #04140f; }
.btn-primary:hover { filter: brightness(1.1); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-secondary { background: var(--bg-1); color: var(--text-hi); border-color: var(--border); }
.btn-secondary:hover { border-color: var(--green); }
.btn-violet { background: var(--violet); color: #17102b; }
.btn-violet:hover { filter: brightness(1.1); }

/* ---------- Baner instalacji PWA ---------- */
#install-banner-root:empty, #install-banner:empty { display: none; }
.install-banner {
  display: flex; align-items: center; justify-content: center; gap: 14px; flex-wrap: wrap;
  background: var(--bg-2); border-bottom: 1px solid var(--border-soft);
  padding: 10px 18px; font-size: 0.86rem; color: var(--text-mid); font-family: var(--font-mono);
}
.install-banner-actions { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }

.pulse-success { animation: pulseSuccess 0.5s ease; }
@keyframes pulseSuccess { 0% { box-shadow: 0 0 0 0 rgba(74,222,128,0.5);} 100% { box-shadow: 0 0 0 14px rgba(74,222,128,0);} }

/* ---------- Ekran wyniku — blok logu systemowego, nie emoji ---------- */
.result-screen { padding: 40px 16px; }
.result-log {
  max-width: 420px; margin: 0 auto; background: var(--bg-0); border: 1px solid var(--border-soft);
  border-radius: var(--radius-m); padding: 18px 20px; font-family: var(--font-mono); font-size: 0.9rem;
}
.result-log .line { margin: 0 0 6px; color: var(--text-mid); }
.result-log .line:last-child { margin-bottom: 0; }
.result-pass .result-log .headline { color: var(--green); font-size: 1.05rem; font-weight: 700; }
.result-fail .result-log .headline { color: var(--red); font-size: 1.05rem; font-weight: 700; }
.result-score-val { color: var(--text-hi); font-weight: 700; }
.result-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-top: 20px; }

/* ---------- Toast ---------- */
#toast-root { position: fixed; inset: 0; pointer-events: none; z-index: 300; overflow: hidden; }
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translate(-50%, 20px);
  background: var(--bg-2); border: 1px solid var(--border); color: var(--text-hi);
  padding: 9px 16px; border-radius: var(--radius-m); font-size: 0.85rem; font-family: var(--font-mono);
  opacity: 0; transition: opacity 0.25s ease, transform 0.25s ease; pointer-events: none;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast-error { border-color: var(--red); }

/* ---------- Flash logu sukcesu (zastępuje konfetti) ---------- */
#success-flash-root {
  position: fixed; top: 14px; left: 50%; transform: translateX(-50%); z-index: 400;
  pointer-events: none; text-align: center;
}
.success-flash-line {
  font-family: var(--font-mono); font-size: 0.86rem; color: var(--green);
  background: var(--bg-2); border: 1px solid var(--green-dim); border-radius: var(--radius-s);
  padding: 6px 12px; margin-bottom: 6px; opacity: 0;
  animation: flashIn 0.3s ease forwards, flashOut 0.3s ease 1.5s forwards;
}
@keyframes flashIn { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: translateY(0); } }
@keyframes flashOut { from { opacity: 1; } to { opacity: 0; } }

/* ---------- Responsywność ---------- */
@media (max-width: 640px) {
  .chain-spine { left: 22px; }
  .chain-item:nth-child(odd), .chain-item:nth-child(even) { justify-content: flex-start; }
  .chain-node-btn, .chain-item:nth-child(even) .chain-node-btn {
    width: calc(100% - 46px); margin-left: 46px; flex-direction: row; text-align: left;
  }
  .chain-item:nth-child(even) .node-title, .chain-item:nth-child(even) .node-progress { justify-content: flex-start; }
  .chain-node-btn::after, .chain-item:nth-child(even) .chain-node-btn::after {
    left: -46px; width: 24px; right: auto;
  }
}
@media (max-width: 560px) {
  .hero-stats { grid-template-columns: 1fr 1fr 1fr; }
  .finals-grid, .quiz-cta-grid { grid-template-columns: 1fr; }
  .install-banner { flex-direction: column; align-items: flex-start; }
}

/* ---------- prefers-reduced-motion ---------- */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

/* ---------- Wysoki kontrast / focus ---------- */
@media (forced-colors: active) {
  .progress-fill, .mini-pip.on, .chain-spine, .node-badge { forced-color-adjust: none; }
}