:root {
  --bg: #0f0520;
  --bg2: #17082e;
  --card: #1c0d38;
  --border: #3a1f6a;
  --purple: #d4b8f5;
  --purple-dim: #9b80c4;
  --blue: #90c0ff;
  --green: #90e090;
  --yellow: #f5e090;
  --red: #ffb0b0;
  --orange: #ffcc88;
  --text: #e0d4f8;
  --text-dim: #b8a8d8;
  --code-bg: #0d0220;
  --code-border: #2a1060;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, sans-serif;
  font-size: 14px;
  line-height: 1.7;
  padding-bottom: 60px;
}

header {
  background: linear-gradient(135deg, #21093d, #0d0420);
  border-bottom: 2px solid var(--border);
  padding: 36px 40px 28px;
  text-align: center;
}

header h1 {
  font-size: 22px;
  color: var(--purple);
  font-weight: 800;
  margin-bottom: 6px;
}

header p { color: var(--purple-dim); font-size: 13px; }

header .back-link {
  display: inline-block;
  margin-top: 12px;
  color: var(--blue);
  font-size: 12px;
  text-decoration: none;
}

header .back-link:hover { text-decoration: underline; }

.bloco-nav {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-top: 18px;
  flex-wrap: wrap;
}

.bloco-nav a {
  padding: 5px 16px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
}

.nav-b1 { background: #2a1060; color: #c4a6f0; border: 1px solid #5030a0; }
.nav-b2 { background: #102040; color: #a6c8f0; border: 1px solid #204080; }
.nav-b3 { background: #102810; color: #a6e0a6; border: 1px solid #205020; }

.bloco-title {
  padding: 14px 40px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .8px;
  text-transform: uppercase;
  border-top: 3px solid;
  border-bottom: 1px solid;
  margin-top: 40px;
}

.bloco-title.b1 { background: #1a0840; border-color: #7c3aed; color: #c4a6f0; border-bottom-color: #3a1f6a; }
.bloco-title.b2 { background: #071428; border-color: #2563eb; color: #a6c8f0; border-bottom-color: #1a3a6a; }
.bloco-title.b3 { background: #071407; border-color: #16a34a; color: #a6e0a6; border-bottom-color: #1a4a1a; }

.card {
  margin: 20px 40px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 22px;
  background: #21093d;
  border-bottom: 1px solid var(--border);
}

.enc-num {
  background: #4a2090;
  color: #e0ccff;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 15px;
  flex-shrink: 0;
}

.card-header h2 { font-size: 16px; font-weight: 700; color: var(--purple); }
.card-header p  { font-size: 11.5px; color: var(--purple-dim); margin-top: 2px; }

.section { padding: 18px 22px; border-bottom: 1px solid var(--code-border); }
.section:last-child { border-bottom: none; }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .7px;
  padding: 3px 10px;
  border-radius: 10px;
  margin-bottom: 10px;
}

.lbl-meta   { background: #2a1000; color: #ffcc88; border: 1px solid #6a3000; }
.lbl-serve  { background: #1a1040; color: #b090f0; border: 1px solid #3a2080; }
.lbl-quando { background: #0d1f3a; color: #90b8f0; border: 1px solid #1a4080; }
.lbl-python { background: #0d200d; color: #80d080; border: 1px solid #1a4020; }
.lbl-ref    { background: #2a1a00; color: #f0c060; border: 1px solid #6a4000; }

.section p  { color: var(--text-dim); font-size: 13px; margin-bottom: 8px; }
.section p:last-child { margin-bottom: 0; }
.section ul { color: var(--text-dim); font-size: 13px; padding-left: 18px; }
.section ul li { margin-bottom: 5px; }

.metaphor {
  background: linear-gradient(135deg, #1a0a00, #2a1400);
  border: 1px solid #6a3800;
  border-left: 4px solid #f0a030;
  border-radius: 8px;
  padding: 14px 16px;
  margin-bottom: 12px;
  font-size: 13px;
  color: #e8c88a;
  line-height: 1.6;
}

.metaphor strong { color: var(--orange); }
.metaphor-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .6px;
  color: #f0a030;
  margin-bottom: 6px;
  display: block;
}

.tip {
  background: #1a1030;
  border-left: 3px solid #7c3aed;
  border-radius: 0 6px 6px 0;
  padding: 10px 14px;
  margin-top: 10px;
  font-size: 12.5px;
  color: #c0b0e0;
}

.tip strong { color: var(--yellow); }

.ref-list { list-style: none; padding: 0; }
.ref-list li {
  font-size: 12px;
  color: #b0a0c8;
  padding: 5px 0;
  border-bottom: 1px solid #2a1a45;
  line-height: 1.5;
}
.ref-list li:last-child { border-bottom: none; }
.ref-list li span.ref-tag {
  display: inline-block;
  background: #2a1800;
  color: #f0c060;
  font-size: 10px;
  font-weight: 700;
  padding: 1px 7px;
  border-radius: 8px;
  margin-right: 8px;
  white-space: nowrap;
}
.ref-list li em { color: #d4b8a0; font-style: italic; }

/* Python runner */
.python-runner {
  margin-top: 6px;
  border: 1px solid var(--code-border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--code-bg);
}

.python-runner .toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: #1a0d35;
  border-bottom: 1px solid var(--code-border);
  font-size: 11px;
  color: var(--purple-dim);
}

.python-runner .run-btn {
  background: #2a1060;
  color: #d4b8f5;
  border: 1px solid #5030a0;
  border-radius: 6px;
  padding: 4px 14px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
}

.python-runner .run-btn:hover { background: #3a1880; }
.python-runner .run-btn:disabled { opacity: 0.5; cursor: wait; }

.python-runner textarea.code-input {
  width: 100%;
  min-height: 200px;
  padding: 16px;
  background: var(--code-bg);
  color: #c3e88d;
  border: none;
  resize: vertical;
  font-family: 'Consolas', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 12.5px;
  line-height: 1.55;
  tab-size: 4;
}

.python-runner .code-output {
  display: none;
  padding: 12px 16px;
  border-top: 1px solid var(--code-border);
  font-family: 'Consolas', 'Fira Code', monospace;
  font-size: 12px;
  color: #80cbc4;
  white-space: pre-wrap;
  max-height: 400px;
  overflow-y: auto;
}

.python-runner .code-output.visible { display: block; }
.python-runner .code-output.error { color: #ffb0b0; }
.python-runner .code-output img { max-width: 100%; margin-top: 8px; border-radius: 4px; }

.py-loading {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 12px;
  color: var(--purple);
  z-index: 1000;
  display: none;
}

.py-loading.visible { display: block; }

footer.page-footer {
  text-align: center;
  padding: 40px 20px 20px;
  color: var(--purple-dim);
  font-size: 12px;
}

footer.page-footer a { color: var(--blue); }

@media (max-width: 700px) {
  .card { margin: 12px 10px; }
  header { padding: 24px 16px 18px; }
  .bloco-title { padding: 12px 16px; }
}