/* ──────────────────────────────────────────────
   Demo 08 — Como a IA Aprende (Backprop)
   ────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #21262d;
  --text: #e6edf3;
  --muted: #6e7681;
  --accent: #58a6ff;
  --green: #56d364;
  --red: #f85149;
  --orange: #ffa657;
  --yellow: #e3b341;
  --purple: #d2a8ff;
  --header-h: 54px;
  --nav-h: 68px;
}

/* ── Layout global ── */
body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* ── Header ── */
#header {
  height: var(--header-h);
  flex-shrink: 0;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  gap: 16px;
  z-index: 10;
}

#header-left {
  display: flex;
  align-items: center;
  gap: 12px;
  overflow: hidden;
}

#back-btn {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.8rem;
  white-space: nowrap;
  transition: color 0.15s;
}
#back-btn:hover { color: var(--text); }

#header-title {
  font-weight: 700;
  font-size: 0.95rem;
  white-space: nowrap;
}

#header-badge {
  font-size: 0.72rem;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#step-box {
  display: flex;
  align-items: baseline;
  gap: 3px;
  flex-shrink: 0;
}

#step-label {
  font-size: 0.65rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-right: 2px;
}
#step-val {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
}
#step-total {
  font-size: 0.8rem;
  color: var(--muted);
}

/* ── Main ── */
#main {
  flex: 1;
  display: flex;
  overflow: hidden;
}

/* ── Painel de texto ── */
#text-panel {
  width: 340px;
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
}

#step-tag {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  transition: color 0.3s;
}

#step-title {
  font-size: 1.25rem;
  font-weight: 800;
  line-height: 1.25;
  color: #fff;
}

#step-desc {
  font-size: 0.9rem;
  line-height: 1.65;
  color: #b1bac4;
}

/* caixa de destaque (valor numérico etc.) */
#highlight-box {
  background: rgba(88,166,255,0.08);
  border: 1px solid rgba(88,166,255,0.25);
  border-radius: 10px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
#highlight-box.green {
  background: rgba(86,211,100,0.08);
  border-color: rgba(86,211,100,0.3);
}
#highlight-box.red {
  background: rgba(248,81,73,0.08);
  border-color: rgba(248,81,73,0.3);
}
#highlight-box.orange {
  background: rgba(255,166,87,0.08);
  border-color: rgba(255,166,87,0.3);
}
#highlight-box.hidden { display: none; }

#highlight-label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
}
#highlight-value {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
}

/* caixa de fórmula (KaTeX) */
#formula-box {
  background: #0d1117;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
}
#formula-box.hidden { display: none; }
#formula-rendered {
  color: var(--yellow);
  font-size: 0.95rem;
  line-height: 1.9;
  overflow-x: auto;
}
#formula-rendered .katex { font-size: 1em; }
#formula-rendered .katex-display { margin: 6px 0; }

/* Glossário de símbolos — abaixo da fórmula */
#formula-terms {
  background: rgba(88,166,255,0.04);
  border: 1px solid rgba(88,166,255,0.12);
  border-radius: 8px;
  padding: 12px 14px;
}
#formula-terms.hidden { display: none; }
.terms-header {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 9px;
}
.term-row {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 3px 0;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}
.term-row:last-child { border-bottom: none; }
.term-sym {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--yellow);
  min-width: 76px;
  flex-shrink: 0;
  font-family: 'Courier New', monospace;
  line-height: 1.4;
}
.term-def {
  font-size: 0.78rem;
  color: #8b949e;
  line-height: 1.45;
}

/* Bloco avançado — detalhes colapsáveis */
#advanced-box {
  background: rgba(210,168,255,0.05);
  border: 1px solid rgba(210,168,255,0.2);
  border-radius: 10px;
  padding: 0;
  overflow: hidden;
}
#advanced-box.hidden { display: none; }
#advanced-box summary {
  cursor: pointer;
  padding: 10px 14px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--purple);
  user-select: none;
  list-style: none;
}
#advanced-box summary::-webkit-details-marker { display: none; }
#advanced-box[open] summary { border-bottom: 1px solid rgba(210,168,255,0.15); }
#advanced-rendered {
  padding: 12px 14px;
  font-size: 0.82rem;
  line-height: 1.8;
  color: #c9b1e8;
  overflow-x: auto;
}
#advanced-rendered .katex { font-size: 0.92em; }
#advanced-rendered .katex-display { margin: 4px 0; }

/* ── Canvas section ── */
#canvas-section {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

#nn-canvas {
  display: block;
  max-width: 100%;
  max-height: 100%;
}

/* ── Legenda ── */
#legend {
  position: absolute;
  bottom: 16px;
  right: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: rgba(22,27,34,0.88);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 0.72rem;
  color: var(--muted);
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.line-sample {
  width: 24px;
  height: 3px;
  border-radius: 2px;
  flex-shrink: 0;
}
.line-sample.fwd { background: #58a6ff; }
.line-sample.bwd { background: #f85149; }

/* ── Navegação ── */
#nav {
  height: var(--nav-h);
  flex-shrink: 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  gap: 16px;
}

#nav button {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 10px 24px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, opacity 0.15s;
  white-space: nowrap;
}
#nav button:hover:not(:disabled) {
  background: #21262d;
  border-color: var(--accent);
}
#nav button:disabled {
  opacity: 0.3;
  cursor: default;
}

#btn-next {
  background: var(--accent);
  border-color: var(--accent);
  color: #0d1117;
}
#btn-next:hover:not(:disabled) {
  background: #79b8ff;
  border-color: #79b8ff;
}
#btn-next:disabled {
  background: var(--surface);
  border-color: var(--border);
  color: var(--muted);
}

/* Barra de progresso (bolinhas) */
#progress-track {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  justify-content: center;
}

.prog-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--border);
  transition: background 0.25s, transform 0.25s;
  cursor: pointer;
}
.prog-dot.visited { background: rgba(88,166,255,0.4); }
.prog-dot.active  { background: var(--accent); transform: scale(1.4); }
.prog-dot.phase-separator {
  width: 1px;
  height: 16px;
  border-radius: 1px;
  background: var(--border);
  cursor: default;
}

/* ── Dica teclado ── */
#keyboard-hint {
  position: fixed;
  bottom: calc(var(--nav-h) + 8px);
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  color: var(--muted);
  pointer-events: none;
  white-space: nowrap;
  opacity: 0.6;
}

kbd {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 0.68rem;
  font-family: inherit;
}

/* ── Transição de passo ── */
#text-panel { transition: opacity 0.25s; }
#text-panel.fading { opacity: 0; }

/* ── Responsive ── */
@media (max-width: 720px) {
  #main { flex-direction: column; }
  #text-panel {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 14px 16px;
    max-height: 190px;
  }
  #header-badge { display: none; }
  #legend { display: none; }
  #advanced-box { display: none !important; }
}