/* === SDK Learning Workspace — Base Styles === */

:root {
  --bg: #fafaf8;
  --text: #1a1a1a;
  --text-muted: #6b6b6b;
  --accent: #2563eb;
  --accent-light: #dbeafe;
  --border: #e5e5e0;
  --card-bg: #ffffff;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #d97706;
  --radius: 6px;
}

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

body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

h1 { font-size: 2rem; font-weight: 700; margin-bottom: 0.5rem; letter-spacing: -0.02em; }
h2 { font-size: 1.35rem; font-weight: 600; margin: 2rem 0 0.75rem; letter-spacing: -0.01em; }
h3 { font-size: 1.05rem; font-weight: 600; margin: 1.5rem 0 0.5rem; color: var(--text-muted); }

p { margin-bottom: 1rem; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

strong { font-weight: 600; }

code {
  font-family: "Cascadia Code", "Fira Code", Consolas, monospace;
  font-size: 0.9em;
  background: var(--accent-light);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

pre {
  background: #1e1e2e;
  color: #cdd6f4;
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1rem 0;
  font-size: 0.88rem;
  line-height: 1.6;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
}

/* === Cards === */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin: 1rem 0;
}

/* === Buttons === */
.btn {
  display: inline-block;
  padding: 0.5rem 1.25rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 0.95rem;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.15s;
}
.btn:hover { background: #1d4ed8; }
.btn:active { background: #1e40af; }

/* === Quiz === */
.quiz { margin: 1.5rem 0; }
.quiz-question { font-weight: 600; margin-bottom: 0.75rem; }
.quiz-options { list-style: none; }
.quiz-options li { margin-bottom: 0.4rem; }
.quiz-options button {
  width: 100%; text-align: left;
  padding: 0.6rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card-bg);
  cursor: pointer;
  font-size: 0.95rem;
  transition: background 0.1s, border-color 0.1s;
  font-family: inherit;
}
.quiz-options button:hover { background: var(--accent-light); border-color: var(--accent); }
.quiz-options button.correct { background: #dcfce7; border-color: var(--success); }
.quiz-options button.wrong { background: #fef2f2; border-color: var(--danger); }
.quiz-options button:disabled { cursor: default; opacity: 0.85; }
.quiz-feedback { margin-top: 0.75rem; font-size: 0.92rem; min-height: 1.5em; }
.quiz-feedback.correct-fb { color: var(--success); }
.quiz-feedback.wrong-fb { color: var(--danger); }

/* === Analogy box === */
.analogy {
  background: linear-gradient(135deg, #fef9c3 0%, #fef3c7 100%);
  border-left: 3px solid var(--warning);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 1.25rem 0;
  font-size: 0.95rem;
}

/* === Definition callout === */
.definition {
  background: var(--accent-light);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 1.25rem 0;
}

/* === Comparison table === */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.92rem;
}
.compare-table th {
  text-align: left;
  font-weight: 600;
  padding: 0.5rem 0.75rem;
  border-bottom: 2px solid var(--border);
  background: var(--card-bg);
}
.compare-table td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.compare-table tr:hover td { background: #fafaf8; }

/* === Footer nav === */
.lesson-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.88rem;
  color: var(--text-muted);
}
.lesson-footer p { margin-bottom: 0.5rem; }

/* === Tag === */
.tag {
  display: inline-block;
  font-size: 0.78rem;
  padding: 0.15em 0.55em;
  border-radius: 99px;
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 500;
  margin-right: 0.3rem;
}

/* === Section divider === */
.section-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.6rem; height: 1.6rem;
  background: var(--accent);
  color: #fff;
  border-radius: 99px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-right: 0.5rem;
  vertical-align: middle;
}

/* === Sidebar Navigation === */
.sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: 210px;
  height: 100vh;
  background: var(--card-bg);
  border-right: 1px solid var(--border);
  padding: 1.5rem 0.9rem;
  overflow-y: auto;
  z-index: 100;
  font-size: 0.82rem;
}
.sidebar-header {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.6rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
}
.sidebar-header a { color: var(--text); text-decoration: none; }
.sidebar-section { margin-bottom: 1rem; }
.sidebar-section-title {
  font-weight: 600;
  font-size: 0.72rem;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
  letter-spacing: 0.04em;
}
.sidebar-links { list-style: none; margin: 0; padding: 0; }
.sidebar-links li { margin-bottom: 0.2rem; }
.sidebar-links a {
  display: block;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius);
  color: var(--text-muted);
  text-decoration: none;
  transition: background 0.1s, color 0.1s;
  font-size: 0.82rem;
}
.sidebar-links a:hover { background: var(--accent-light); color: var(--accent); }
.sidebar-links a.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}
.sidebar-divider {
  height: 1px;
  background: var(--border);
  margin: 0.6rem 0;
}

@media (max-width: 1100px) {
  .sidebar { display: none; }
}

@media print {
  body { max-width: 100%; padding: 1rem; font-size: 11pt; }
  .btn, .quiz button, .sidebar { display: none; }
}